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Vol. 32, No. 1, 2001

Volume 32, Number 1, 2001

Historical Changes in the Abundance and Distribution of the American
Avocet at the Northern Limit of Its Winter Range Mark A. Colwell,

Tamar Danufsky, Ryan L. Mathis, and Stanley W. Harris 1

Report of the California Bird Records Committee: 1998 Records

Richard A. Erickson and Robert A. Hamilton 13

Arizona Bird Committee Report: 1996-1999 Records

Gary H. Rosenberg 50

Recolonization of the Flicker and Other Notes from Isla Guadalupe,
Mexico Paul R. Sweet, George F. Barrowclough, John T, Klicka,
Liliana Montahez-Godoy, and Patricia Escalante- Pliego 71

NOTES

Orange Bishops Breeding in Phoenix, Arizona Thomas A. Gatz . . 81

Breeding-Season Home Ranges of Spotted Owls in the San
Bernardino Mountains, California Guthrie S. Zimmerman,

William S. LaHaye, and R. J. Gutierrez 83

First Report of the Gray Heron in the United States

Kenneth M. Burton and Sean D. Smith 88

Cloacal Inspection or Pecking in Allen's Hummingbird

Janet L. Leonard 91

Book Reviews Steve N. G. Howell, Robert A, Hamilton 93

Featured Photo Steve N. G. Howell 97

Cover photo by © Brian E. Small of Los Angeles, California: Nutting’s
Flycatcher { Myiarchus nuttingi), Mason Regional Park, Irvine, California,
January, 2001. If accepted, this will be the first record of Nutting’s
Flycatcher for the State of California.

Western Birds solicits papers that are both useful to and understandable by amateur field
ornithologists and also contribute significantly to scientific literature. The journal welcomes
contributions from both professionals and amateurs. Appropriate topics include
distribution, migration, status, identification, geographic variation, conservation, behavior,
ecology, population dynamics, habitat requirements, the effects of pollution, and
techniques for censusing, sound recording, and photographing birds in the field. Papers
of general interest will be considered regardless of their geographic origin, but particularly
desired are reports of studies done in or bearing on the Rocky Mountain and Pacific states
and provinces, including Alaska and Hawaii, western Texas, northwestern Mexico, and the
northeastern Pacific Ocean.

Send manuscripts to Kathy Molina, Section of Ornithology, Natural
History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA
90007. For matter of style consult the Suggestions to Contributors to Western Birds
(8 pages available at no cost from the editor) and the Council of Biology Editors Style
Manual (available for $24 from the Council of Biology Editors, Inc., 9650 Rockville
Pike, Bethesda, MD 20814).

Reprints can be ordered at author’s expense from the Editor when proof is returned or
earlier.

Good photographs of rare and unusual birds, unaccompanied by an article but
with caption including species, date, locality and other pertinent
information, are wanted for publication in Western Birds. Submit photos and
captions to Photo Editor. Also needed are black and white pen and
ink drawings of western birds. Please send these, with captions, to
Graphics Manager.

WESTERN BIRDS

Volume 32, Number 1, 2001

HISTORICAL CHANGES IN THE ABUNDANCE AND
DISTRIBUTION OF THE AMERICAN AVOCET AT
THE NORTHERN LIMIT OF ITS WINTER RANGE

MARK A. COLWELL, TAMAR DANUFSKY, RYAN L. MATHIS, and STANLEY
W. HARRIS, Department of Wildlife, Humboldt State University, Areata, California
95521

ABSTRACT: Humboldt Bay, California, is the northern limit of the winter
distribution of the American Avocet (Recurvirostra americana ) on the Pacific coast.
After the first record in 1935, avocets were uncommon (17 observations) until the
early 1960s, when a wintering population of <100 birds became established in North
(Areata) Bay. Numbers increased to approximately 1000 by the early 1990s but have
since declined to approximately 500. From 1968 to 1985, avocets consistently used
intertidal habitats and oxidation ponds in the northeast quarter of Areata Bay.
Beginning in the mid-1990s they expanded their use of Areata Bay and into South
Bay. During February and March 1998 and February 2000, up to 32 occasionally fed
in flooded pastures adjacent to the bay; only two avocets had been observed there in
the previous 40 years. At low tide, avocets aggregated in intertidal habitats of Areata
Bay and South Bay. We hypothesize that they increased because of a rangewide
population increase and that in Humboldt Bay they concentrate where small particle
size of sediments makes for better feeding habitat. Altered habitat quality, especially
during wet years (late 1990s), may have changed avocet distribution in Humboldt Bay.

Understanding changes in the abundance and distribution of a species is
a central theme of animal ecology, and research at the limits of an
organism’s range can provide valuable insight into factors limiting a species’
distribution, especially when conducted over a long period. The American
Avocet ( Recurvirostra americana) winters in intertidal and freshwater
habitats along the Atlantic, Gulf, and Pacific coasts of North America
(Robinson et al. 1997). Along the Pacific coast, Humboldt Bay, California
represents the northern extreme of the species’ winter range (Evans and
Harris 1994, Robinson et al. 1997); there are no winter records from the
Pacific Northwest (Paulson 1993). Evans and Harris (1994) showed that
avocets were a recent addition to the wintering avifauna of the northern
California coast, first recorded in 1935. Beginning in the 1960s, a growing
population of wintering avocets concentrated in the northeast quarter of

Western Birds 32:1-12, 2001

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

Humboldt Bay {Evans and Harris 1994). Since 1989, we have collected
information on avocet abundance and distribution at Humboldt Bay and
have noticed changes in the patterns reported by Evans and Harris (1994).
Here, we summarize changes in avocet distribution and abundance on
Humboldt Bay and discuss possible reasons for these changes.

STUDY AREA

Humboldt Bay (40° 46' N, 124° 14' W) is the largest bay between San
Francisco Bay, California, 370 km south, and Coos Bay, Oregon, 335 km
north (Barnhart et al. 1992). Costa (1982) characterized the bay as a tidal
coastal lagoon with limited freshwater input. The bay consists of three
sections, each of which is at the end of a different tributary. The largest
section, Areata Bay, receives fresh water from Jacoby and Freshwater creeks.
Broad intertidal habitats of Areata Bay consist of sediments varying from
clayey silts of intertidal flats to sandy substrates lining main channels. Much of
the lower intertidal reaches of the center of Areata Bay supports eelgrass
[Zostera marina), but the extent of this habitat has been reduced by oyster
culture (Barnhart et al. 1992). Oxidation ponds of the Areata marsh and
sewage-treatment facility lie on the northeast shore of Areata Bay. A narrow
shipping channel connects Areata Bay to Entrance Bay. The channel and
Entrance Bay are dredged to provide access to ships, hence most intertidal
habitats have steep banks and coarse substrates. The Elk River empties into
the main channel and provides some intertidal flats, which are partially
covered by eelgrass. South Bay consists of extensive intertidal habitats and
substrates varying from sand to clayey silt. Large relatively pristine eelgrass
beds cover much of the lower intertidal reaches of South Bay. Salmon Creek
enters the southeast corner of South Bay through Humboldt Bay National
Wildlife Refuge (HBNWR). Since 1850, people have converted much of the
bay’s salt marsh and intertidal habitats to agricultural lands, especially pasture.
Barnhart et al. (1992) described Humboldt Bay in detail.

METHODS

Our examination of avocet population size and distribution relies on
several independent sources of data collected over the last 50 years. The
quality of this information varies with the different objectives of researchers
and unequal sampling effort.

Field notes. Harris has kept regular field notes on bird distribution and
abundance around Humboldt Bay since 1959. From these notes, we
collated maximum annual estimates and locations of avocets.

Christmas Bird Counts. Two CBC circles cover virtually all intertidal
habitats of Humboldt Bay and abut at the harbor entrance. The Centerville
CBC, conducted for 41 years, covers all of South Bay. Harris has coordi-
nated this count and collated data since 1973. To the north, the Areata
CBC, conducted since 1984, covers all of Areata Bay and the main channel
leading to the bay entrance. Because we were able to identify most locations
at which observers recorded avocets, CBC data offer an important historical
perspective on the species’ use of the bay.

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

Graduate theses. Two graduate theses provided data on avocet distribu-
tions. In 1968 and 1969, Gerstenberg (1972) surveyed all shorebirds at nine
locations on Humboldt Bay. Evans (1988) summarized avocet distribution
baywide during three winters (1982-83 through 1984-85); he made 76
surveys at 1 1 sites within Areata Bay and 42 surveys from 1 1 locations in
South Bay. Since each used different survey methods and collated data
differently, we summarized their information as follows. Using Gerstenberg’s
(1972) maximum winter count of avocets at each of his survey locations, we
summed all avocet observations at the nine locations and calculated the
proportion at each site (yielding a proportional abundance). Evans (1988)
summarized his results as the average monthly high- and low-tide count at
each location. We used the maximum average winter (October-February)
count for each location to represent use of a site. Next, we calculated the
proportion of these summed maximum counts for each location.

Baywide shorebird surveys. From 1989 to 1994 and again in 1998,
Colwell coordinated multiple observers who surveyed Humboldt Bay simul-
taneously to estimate seasonal use by shorebirds (Colwell 1994). Surveys
were shore-based counts of intertidal habitats of the bay, adjacent pastures
and freshwater sloughs, and ocean beaches fronting the bay. The survey
protocol entailed four sequential half-hour scans (Altmann 1974) during
which observers estimated the number of shorebirds using an area. The start
of each half-hour scan was synchronized among observers to reduce the
likelihood that birds moving between areas would be counted by more than
one observer. We surveyed shorebirds during rising tides so that foraging
birds were pushed by the advancing tide toward shore, improving observers’
estimates of abundance (Colwell and Cooper 1993). Observers conducted
surveys from prominent observation points around the bay to maximize
observation area and minimize overlap between adjacent observers (further
details in Colwell and Cooper 1993, Colwell 1994).

During the five years of surveys, sampling effort varied greatly with weather
and the number of observers (Colwell 1994); many locations were not
surveyed every year, although some sites received regular coverage, often by
the same observers. Consequently, we selected the single maximum count of
avocets at each site from 10 winter survey dates (November and February,
1989-1994). We summed these maximum counts and calculated the propor-
tional abundance of observations at each location. In this form, data were
corrected for possible changes in avocet population size at Humboldt Bay. We
summarized 1998 survey data separately by the same method.

Winter 1 998-1 999 surveys. At 19 locations around the bay, we used a
protocol similar to that of the shorebird surveys to esitmate winter (Novem-
ber 1998-January 1999) shorebird numbers. Unlike baywide surveys (see
above), which took place during flood tides, we did these surveys during ebb
tides, when intertidal flats were exposed. Areas surveyed varied from 3.5 to
52.1 ha; we based their boundaries on edges of channels, salt marsh, and
other prominent habitat features. We summarized these data as the maxi-
mum count of four surveys at each site and present data as the proportion at
each location of total avocet observations (Danufsky 2000).

Low-tide avocet mapping. At five tides <0.33 m (January, February, and
October 1999; January and February 2000), we mapped avocets on high-

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

resolution images of the bay, overlaid by a UTM-based grid system. Observ-
ers mapped avocets from the same shoreline observation points used in the
baywide surveys (see above) and from boats moving through the bay’s main
channels. We marked the location of avocets on images by means of
topographic features like channels, islands, and saltmarsh points and we
recorded the number of avocets observed within each 500-m grid. We
standardized data by calculating the number of avocets in a grid cell within
five observation periods (January and February 1999 and 2000, October
1999). For cells including intertidal habitats exposed at low tide, we
calculated the average number of avocets per grid cell and variance. We
compared observed avocet distributions to a random model by using the
index of dispersion (/, variance-to-mean ratio; Krebs 1989). If avocets were
randomly distributed among grid cells, this ratio equaled one; if they were
aggregated it was greater than one; if they were evenly distributed it was less
than one. We compared each survey’s / value to a random distribution by
means of a two-tailed t test.

RESULTS

Population estimates. Over 40 years, avocet numbers have varied signifi-
cantly (Kruskal-Wallis test, % 2 = 36.4, P = 0.00002) among the five-year
intervals (Figure 1). Beginning in the 1950s, a small population established
itself at Humboldt Bay. Numbers nearly doubled over the next two decades.

1600 n

1400

1200

Ifl

S 600
©
z ;

400

200

0 1 —
1955

S
*

1960 1965

1970

1975 1980 1985 1990 1995

Figure 1 . Estimates (maximum counts) of American Avocets wintering at Humboldt
Bay, California, from 1955 to 1999, based onfield notes (1955-1967; 1970-1981;
1995-1997), graduate theses (1968-1969; 1982-1985), shorebird surveys (1989-
1994; 1998) and baywide mapping of avocet distributions (1999-2000).

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

Tabic 1 Estimates of the Number and Spatial Distribution of Nonbreeding
American Avocets at Humboldt Bay, California, Based on Bay-wide Map-

ping During Diurnal Low Tides

30-31
Jan 1999

27-28
Feb 1999

23 Oct
1999

29-30
Jan 2000

13 Feb
2000

Number of avocets

543

343

182

475

479

Mean (per grid celi)

1.65

1.04

0.55

1.44

1.45

Variance (per grid cell)

62.33

21.97

17.43

90.89

70.97

Dispersion index

37.9

21.1

31.6

63.1

48.9

t value

758.1

261.6

217.2

1118.1

869.0

<0.01

Observed low tide (m)

-0.31,-0.51

-0.02,-0.10

0.10

0.55, 0.49

0.63

Time of low tide

1712, 1748

1618, 1724

1642

1300, 1424

1212

By the early 1990s, estimates ranged from 850 to 1200 birds, after which
numbers declined during the late 1990s. During January/February low-tide
mapping in 1998-1999 and 1999-2000, we estimated an average of 460
± 84 (range 343-543) avocets on Humboldt Bay (Table 1).

Historical distributions in Humboldt Bay. Avocets occurred on 20% of
Centerville CBCs over the count’s 41-year history; 98% of the 372 avocets
occurred between 1994 and 1999 (Table 2). Except for records of no more
than four individuals in 1969, 1975, and 1978, avocets first appeared on
the Centerville CBC in 1994, when 39 were in the Eel River lowlands. In
1995 none were reported; in 1996, when inclement weather compromised
survey efforts, eight were at HBNWR adjacent to South Bay. From 1997 to
1999, 98 to 99% of avocets occurred on HBNWR; no more than four were
reported in the Eel River lowlands.

Avocets occurred on all 16 Areata CBCs (Table 2). Total numbers varied
greatly (mean 763 ± 379); high numbers reported from 1993 to 1995 almost

Table 2 Averages and Ranges of American Avocet Numbers
on the Centerville and Areata Christmas Bird Counts by Five-
Year Periods

5- Year Interval

Centerville CBC

Areata CBC

1955-1959

0°

1960-1964

—

1965-1969

0.2 (0-1)

—

1970-1974

—

1975-1979

1 (0-4)

—

1980-1984

839°

1985-1989

590 (500-800)

1990-1994

8 (0-39)

825 (564-1806)

1995-1999

65 (0-165)

665 (382-1176)

“One estimate only; CBC began the last year of this interval.

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

Pacific

Ocean

Mudflat

Areata

68/6982/8389/94 98 98/99

10 12 Kilometers

Figure 2. A 30-year history of changes in the proportional abundance of American
Avocets around Areata Bay, California, based on field notes, graduate theses,
shorebird surveys, and recent research. Data are from shore-based surveys and do not
include the center of Areata Bay.

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

certainly represent summed counts from different observers. A decline in
avocet observations in Areata Bay paralleled the increase in South Bay.

Over the past three decades, the spatial distribution of avocets in intertidal
habitats of Humboldt Bay has changed (Figure 2). During the late 1960s
(Gerstenberg 1972) and mid-1980s (Evans 1988), avocets used the north
and east parts of Areata Bay nearly exclusively. During the early 1990s,
baywide surveys revealed a similar pattern, but a few avocets (6.1%)
occurred on the south and west shores of Areata Bay; only six occurred
outside Areata Bay in the southwest corner of South Bay (1992 and 1993).
During January and February 1998, avocet use of the north and east sectors
of Areata Bay declined, whereas use of south and west areas increased
sharply. From November 1998 to January 1999, avocets were more evenly
distributed around Areata Bay than they were 10-30 years earlier. On
numerous occasions during January and February 1998, S. Manion and
Mathis observed 5-32 avocets feeding at low tide in flooded pastures north
and west of Areata Bay. On 16 February 2000, Colwell observed 15 avocets
feeding in flooded fields of HBNWR.

Avocet densities during winter 1999 and 2000. From the total number
of birds in each grid cell, we determined that avocets were concentrated
(Table 1) along channels and on intertidal flats of Areata Bay and in the
southeast corner of South Bay (Figure 3).

DISCUSSION

The number of nonbreeding avocets at Humboldt Bay clearly has varied
greatly over the past 50 years. Although Grinnell and Miller (1944) listed no
coastal records for the avocet north of Marin County (Novato), they omitted
two specimens collected at Humboldt Bay 17 and 18 August 1935
(Humboldt State University; Davis 1939). From 1945 through 1958, 17
avocets occurred on Humboldt Bay on six occasions. Beginning in 1959,
their numbers increased steadily from 75 (1959) to 800-1400 (1980s-90s).
A similar increase occurred in the Point Reyes region, another important
wintering area on California’s north coast (G. W. Page pers. comm.,
Shuford et al. 1989). More recently, the number of avocets wintering at
Humboldt Bay appears to have declined by 50% to approximately 500.

Virtually all early records of avocets were concentrated in the northeast
quarter of Areata Bay. Nelson (1989) surveyed waterbirds in South Bay from
July 1987 to June 1988 and listed avocets as seen irregularly, with numbers
insufficient to warrant analysis. CBC data corroborate the early differences
between Areata Bay and South Bay. Beginning in the 1990s, avocets
expanded to the south and west shores of Areata Bay. CBC data show that
in 1994 a small number of avocets began to feed on intertidal flats in the
southeast corner of South Bay; at high tide they roosted in freshwater
habitats of HBNWR. Most recently, during the winters of 1998 and 2000,
avocets fed in flooded pastures adjacent to Areata Bay, which had rarely
been observed previously (Harris unpubl. data).

Establishment and growth of the Humboldt Bay population. At least
two explanations, not mutually exclusive, exist for the establishment and
increase in numbers of avocets at Humboldt Bay: (1) the avocet’s breeding

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

Figure 3. Low-tide distribution of wintering American Avocets in intertidal habitats of
Humboldt Bay during winter mapping surveys (see Table 1). Numbers represent the
total number of avocets observed in each grid cell (500 x 500 m).

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

population has increased in the region supplying winter visitors to Humboldt
Bay; (2) nonbreeding habitat has changed, allowing avocets to expand their
range into formerly unoccupied areas. On the basis of the Breeding Bird
Survey, Robbins et al. (1986) reported that from 1965 to 1979 the
population of the American Avocets increased significantly. This increase
coincided with the major period of growth in the Humboldt Bay avocet
population. Breeding Bird Survey data for 1966 to 1996 suggest that the
population increased at >0.25% per year in Oregon, California, and
Nevada, all breeding locales for color-marked birds observed at Humboldt
Bay (Robinson and Oring 1996, Plissner et al. 1999).

Evaluating the habitat hypothesis is difficult. Specimens show that
nonbreeding avocets visited Humboldt Bay occasionally earlier in the 20th
century (and probably before that). In the late 1950s local numbers began to
increase. Evans and Harris (1994) speculated that construction of sewage-
oxidation ponds in the northeast corner of Areata Bay in 1957 offered
important habitat that was previously unavailable. Their habitat-limitation
argument was based on spatial and temporal coincidence and seems
plausible — numbers increased dramatically after the ponds’ construction,
and avocets occurred only in their vicinity. From 1980s data, Evans and
Harris (1994) described an ‘avocet home range’’ (868 ha) in the north-east
corner of Areata Bay where avocets occurred predictably; they recorded
only 30 observations of avocets outside this home range during 1142 hours
observation.

The habitat-limitation hypothesis posits that, prior to the construction of
oxidation ponds, Humboldt Bay lacked one or more habitat requirements
(e.g., food, water, sanctuary from predators) necessary to support wintering
avocets (Evans and Harris 1994). Evans (1988) reported that avocets used
these oxidation ponds to feed on cladocerans ( Daphnia magna), especially
during October and November; most other times, however, avocets fed on
nearby intertidal flats exposed during low tide. In addition to food, oxidation
ponds may provide an important source of fresh water for avocets occupy-
ing saltwater habitats (Evans and Harris 1994). Evans and Harris (1994)
discounted the importance of fresh water because avocets breed in hypersa-
line environments and have a well-developed salt gland (Mahoney and Jehl
1985). In hypersaline habitats, however, avocets concentrate in areas of
fresh water (L. W. Oring pers. comm.). This suggests that although avocets
possess the physiological adaptation to tolerate these habitats, they pay an
energetic cost in doing so, possibly influencing their distribution.

Avocet distributions within Humboldt Bay and along the Pacific coast.
An extension of the habitat-limitation hypothesis posits that the absence of
avocets from some areas of Humboldt Bay stemmed from an absence of
essential habitat requirements. A partial explanation for the patchy distribu-
tion of avocets within the bay (Figure 3) may be related to the distribution of
intertidal sediment types — avocets occurred in areas characterized by fine
(silty-clay) sediments and were absent from areas with coarse (sandy)
sediments (Thompson 1971). Danufsky (2000) found support for this
hypothesis in an inverse relationship between avocet occurrence and sub-
strate particle size. The aggregated baywide distribution of avocets probably
stems from a relationship between substrate composition, prey availability,

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

and the manner in which avocets feed. At Humboldt Bay, most avocets feed
with a single scything maneuver (Evans and Harris 1994), a tactile foraging
method of sweeping the bill through the upper film of sediment (Hamilton
1975). Sediment type influences habitat use by avocets. For example,
Quammen (1982) experimentally manipulated substrates at Newport Bay,
California, and found that avocets moved more quickly through and scythed
less (pecked more) where sand was added to a mud substrate. We hypoth-
esize that avocet distributions are related to their scything for prey in fine
substrates, which vary in their distribution in Humboldt Bay.

If substrate particle size influences distributions of foraging avocets, then
historical changes in avocet distribution in Humboldt Bay suggest that this
habitat characteristic changed abruptly in the 1990s. In the mid-1990s,
avocets began using areas of the bay that they rarely used during the period
of population expansion (1960-1995). We speculate that wet years (1995-
1999), coupled with logging of Humboldt Bay’s watershed, increased the
amount of fine sediments in the bay, altering avocet foraging habitat.
Interestingly, the February 1998 observations of avocets feeding in flooded
pastures adjacent to Areata Bay coincided with the strongest (wettest) El
Nino on record.

Furthermore, we speculate that, in part, the northern limit of the avocet ’s
winter range on the Pacific coast also may be related to the preference for
feeding in fine sediments (Robinson et al. 1997). Specifically, the broad flats
and fine sediments of Humboldt Bay are uncommon at bays along the
Oregon and Washington coast. At least 17 major estuaries occur on the
Oregon coast; Washington has five such estuaries. Fifteen of the estuaries in
Oregon (e.g., Nestucca, Nehalem, and Rogue) are steep-banked with sandy
substrates. Grays Harbor and Willapa Bay, Washington, and perhaps Coos
Bay and Tillamook Bay, Oregon, offer broad intertidal flats and fine
substrates of the type apparently favored by avocets. During migration,
avocets occur occasionally on the Oregon-Washington coast. Paulson
(1993) reported two avocets at Coos Bay on 12 December 1980, but they
were not observed after that date. In summary, the combination of Humboldt
Bay’s fine sediments, abundant prey (e.g., crustaceans, oligochaetes, poly-
chaetes) linked to these substrates (Robinson et al. 1997), and moderate
climate provide conditions sufficient to support avocets. These conditions
are generally absent farther north on the Pacific coast.

CONSERVATION IMPLICATIONS

During January and February 1998 and February 2000, avocets fed in
flooded pastures adjacent to Humboldt Bay. In this area, avocets had been
observed in pastures rarely — Gerstenberg (1972) reported two in pastures
during September 1969. Pastures commonly flood each winter following
heavy rain. These observations strongly suggest that during winter 1998
food availability in intertidal habitats was reduced because of habitat changes.

In 1997-1998, winter use of flooded pastures coincided with two noteworthy
environmental events. First, on 7 November 1997, an oil spill (-5000 gallons Bunker
C fuel) occurred in Humboldt Bay, and oil contaminated intertidal flats throughout the
west and southwest portions of Areata Bay, the main channel, and limited areas of

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

South Bay. As yet, the effect of this oil on avocets remains undetermined, but oil may
have killed some proportion of the avocets’ invertebrate prey, forcing the birds to feed
in pastures. Second, the record rainfall generated by El Nino of winter 1998-1999,
coupled with soil exposed by timber harvesting, may have increased the amount of
sediments deposited on flats during winter storms. We speculate that during winter
1998 these factors reduced invertebrate populations and habitat, forcing avocets to
seek food in alternative foraging habitats.

The hypothesis that avocets and their prey were influenced by heavy
sedimentation in the bay is bolstered by similar observations for another bay-
dependent species with a very different feeding ecology, the Black Brant
(Branta bernicla nigricans). During winter, and more so during spring
migration, thousands of Brant stage at Humboldt Bay where they feed
nearly exclusively on eelgrass. During winter and spring 1998, Brant fed
extensively in pastures adjacent to Areata Bay and South Bay. This pattern
was observed only once before, during winter 1953, another El Nino year.
During winter 1998-1999, K. Kovacs (pers. comm) and Mathis commented
independently on the poor quality of eelgrass and its covering by sediment.

Historical accounts of avocets and recent studies seeking to estimate their
population and distribution within Humboldt Bay establish the foundation for
long-term monitoring of avocets. Moreover, features of the American Avocet
make it an ideal subject for monitoring changes in population size, distribu-
tion, and habitat use at Humboldt Bay and elsewhere. Its conspicuous pied
plumage, large size, and loose flocking tendencies make it easy to identify,
observe, and count. Its use of fine sediment in intertidal habitats and
dependence on prey taken from surface sediments render it a strong
candidate as an indicator species for habitat change, which may influence
other coastal waterbirds. We urge researchers at other locations to monitor
avocets and expand our understanding of the relationships between avocet
population size, distribution, and changes in the habitats in which they forage.

ACKNOWLEDGMENTS

For assistance, we thank the many individuals listed by Colwell (1994) and B.
Acord, S. Bartz, K. Bentler, J. Bettaso, B. Brown, B. Condon, L. Connolly, N. Cull,
K. Dhillon, E. Elias, C. Erickson, B. Frey, M. Gabriel, R. Green, P. Herrera, J.
Liebezeit, L. Leeman, T. Leeman, M. Marriot, J. Mayer, S. McAllister, J. Moore, K.
Nelson, M. Ortwerth, N. Pappani, J. Reilly, D. Ruthrauff, J. Saunders, L. Shannon,
and J. Verschuyl. R. LeValley, N. War nock, and an anonymous reviewer improved the
manuscript. We greatly appreciate the efforts of G. Eberly, D. Lee, and E. McCoy,
who safely piloted us through channels of the bay. Partial support for our research
came from a grant from the Oiled Wildlife Care Network, California Dept, of Fish and
Game (Eureka office), and Humboldt State University.

LITERATURE CITED

Altmann, J. 1974. Observational study of behavior: Sampling methods. Behaviour
49: 227-267.

Barnhart, R. A., Boyd, M. J., and Pequegnat, J. E. 1992. The ecology of Humboldt
Bay, California: An estuarine profile. U.S. Fish & Wildlife Serv. Biol. Rep. 1.

Colwell, M. A. 1994. Shorebirds of Humboldt Bay, California: Abundance estimates
and conservation implications. W. Birds 25:137-145.

CHANGES IN THE ABUNDANCE AND DISTRIBUTION OF THE AVOCET

Colwell, M. A., and Cooper, R. J. 1993. Estimates of coastal shorebird abundance:
The importance of multiple counts. J. Field Ornithol, 64:293-301.

Danufsky, T. 2000. Winter shorebird communities of Humboldt Bay: Species diver-
sity, distributions, and habitat characteristics. M.S. thesis, Humboldt State
University, Areata, CA.

Davis, J. M. 1939. More shorebirds from Humboldt Bay region. Condor 41:124.

Evans, T. J. 1988. Habitat use and behavioral ecology of American Avocets
(Recurui rostra americana ) wintering at Humboldt Bay, California. M.S. thesis,
Humboldt State University, Areata, CA.

Evans, T. J., and Harris, S. W. 1994. Status and habitat use by American Avocets
wintering at Humboldt Bay, California. Condor 96:178-189.

Gerstenberg, R H. 1972. A study of shorebirds in Humboldt Bay, California — 1968-
1969. M.S. thesis, Humboldt State University, Areata, CA.

Grinneli, J., and Miller, A. H. 1944. The distribution of the birds of California. Pac.
Coast Avifauna 27.

Hamilton, R. B. 1975. Comparative behavior of the American Avocet and the Black-
necked Stilt (Recurvirostridae). Ornithol. Monogr. 17.

Krebs, C. J. 1989. Ecological Methodology. Harper Collins, New York.

Mahoney, S. A., and Jehl, J. R., Jr. 1985. Adaptations of migratory shorebirds to
highly saline and alkaline lakes: Wilson’s Phalarope and American Avocet.
Condor 87: 520-527.

Nelson, E. T. 1989. The composition, distribution, and seasonal abundance of
waterbirds using South Humboldt Bay, California, July 1987-June 1988. M.S.
thesis, Humboldt State University, Areata, CA.

Paulson, D. R. 1993. Shorebirds of the Pacific Northwest. Univ. of Wash. Press,
Seattle.

Plissner, J. H., Haig, S. M., and Oring, L. W. 1999. Within- and between-year
dispersal of American Avocets among multiple western Great Basin wetlands.
Wilson Bull. 111:314-320.

Quammen, M. L. 1982. Influence of subtle substrate differences on feeding by
shorebirds on intertidal mudflats. Mar. Biol. 71:339-343.

Robbins, C. S., Bystrak, D., and Geissler, P. H. 1986. The Breeding Bird Survey: Its
first fifteen years, 1965-1979. U. S. Fish & Wildlife Service Resource Publ. 157.

Robinson, J. A., and Oring, L. W. 1996. Long-distance movements by American
Avocets and Black-necked Stilts. J. Field Ornithol. 67:307-320.

Robinson, J. A., Oring, L. W., Skorupa, J P, and Boettcher, R. 1997. American
Avocet (Recurui rostra americana ), in The Birds of North America (A. Poole and
F. Gill, eds.), no, 275. Acad. Nat. Sci., Philadelphia.

Shuford, W. D., Page, G. W., Evens, J. G., and Stenzel, L. E. 1989. Seasonal
abundance of waterbirds at Point Reyes: A coastal California perspective. W.
Birds 20:137-265.

Thompson, R. W. 1971. Recent sediments of Humboldt Bay, Eureka, California, final
report. Petrol. Res. Fund PRF 789-G2.

Accepted 2 September 2000

REPORT OF THE CALIFORNIA BIRD
RECORDS COMMITTEE: 1998 RECORDS

RICHARD A. ERICKSON, LSA Associates, One Park Plaza, Suite 500, Irvine,
California 92614

ROBERT A. HAMILTON, 34 Rivo Alto Canal, Long Beach, California 90803

ABSTRACT: The California Bird Records Committee assessed 269 records of 92
species in 1998, accepting 195 of them. New to California were the Bulwer’s Petrel
( Bulweria buhverii), photographed on Monterey Bay, Monterey Co., the Bristle-
thighed Curlew ( Numenius tahitiensis), photographed and videotaped at Crescent
City, Del Norte Co., and Pt. Reyes, Marin Co., the American Woodcock ( Scolopax
minor), photographed at Iron Mountain Pumping Plant, San Bernardino Co., the
Iceland Gull ( Larus gloucoides), photographed at Bodega Harbor, Sonoma Co., and
Otay, San Diego Co., the Bridled Tern ( Sterna anaethetus), sketched and described
at Bolsa Chica, Orange Co., and the Olive-backed Pipit (Anihus hodgsoni ), photo-
graphed at Southeast Farallon Island, San Francisco Co. The Harris’s Hawk
(j Parabuteo unicinctus ) is no longer considered extirpated from California. With these
additions, California’s bird list stands at 613 species, eight of which are nonnative.

This 24th report of the California Bird Records Committee (hereafter the
CBRC or the Committee) details the evaluation of 269 records of 92
species. Although most records pertain to birds found in 1998, the period
covered by this report spans the 25 years from 1974 to 1999. Accepted
were 195 records involving 73 species. The acceptance rate of 72.5% was
typical for the last decade but below the overall Committee average
(Rottenborn and Morlan 2000). Sixty-three records were not accepted
because of insufficient documentation or descriptions were inconsistent with
known identification criteria. Six additional records were not accepted
because of questions concerning the bird’s natural occurrence or establish-
ment of introduced populations. Counties best represented by accepted
records were Monterey (14 records), Kern (13), Orange (13), San Diego
(13), Marin (11), San Francisco (11), and Riverside (10). Records were
accepted from 20 other counties.

Highlights of this report include the addition of six species new to the
California list: Bulwer’s Petrel ( Bulweria bulwerii), Bristle-thighed Curlew
( Numenius tahitiensis), American Woodcock ( Scolopax minor), Iceland
Gull ( Larus glaucoides), Bridled Tern ( Sterna anaethetus), and Olive-
backed Pipit (An thus hodgsoni). Potential first state records not accepted
include the Lesser White-fronted Goose (Anser erythropus), Barnacle
Goose ( Branta leucopsis), Falcated Duck ( Anas falcata), Ross’s Gull
(. Rhodostethia rosea), and McKay’s Bunting ( Plectrophenax hyperboreus).
Also reported here is the Committee’s decision to readmit the Harris’s Hawk
( Parabuteo unicinctus) to the list of extant species in California. With these
additions, California’s list stands at 613 species, of which eight are non-
native and two have been extirpated in historical times. Potential first state
records of the Shy Albatross (Thalassarche cauta), Glossy Ibis ( Plegadis
falcinellus), Northern Bobwhite ( Colinus uirginianus), Slaty-backed Gull
{ Larus schistisagus ), Eastern Bluebird ( Sialia sialis), and Gray Silky-fly-

Western Birds 32:13-49, 2001

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

catcher ( Ptilogonys cinereus) are currently being considered.

Other highlights include accepted records of the Wedge-tailed Shearwater
{Puffinus pacificus), Neotropic Cormorant { Phalacrocorax brasilianus ),
Whooper Swan ( Cygnus cygnus), Common Pochard (Aythya ferina),
Gyrfalcon ( Falco rusticolis), Mongolian (Charadrius mongolicus) and
Wilson’s (C, wilsonia ) plovers, Sooty Tern ( Sterna fuscata), Long-billed
Murrelet ( Brachyramphus perdix), Ruby-throated Hummingbird
( Archilochus colubris), Veery (Catharus fuscescens), and Field Sparrow
{Spizella pusilla). Also accepted were California’s first spring Sulphur-
bellied Flycatcher ( Myiodynastes luteiventris) and the first CBRC-reviewed
Blue-headed Vireos { Vireo solitarius). The Committee’s decision not to
accept a long-standing record of the Red-necked Stint ( Calidris ruficollis ;
the state’s only purported specimen record) is reported. Species recorded in
especially high numbers in 1998 included the Short-tailed Albatross
( Phoebastria albatrus; 3 records), Lesser Black-backed Gull (Larus fuscus;
10), Eastern Wood-Pewee ( Contopus virens; 5), Dusky-capped Flycatcher
( Myiarchus tuberculifer; 8), Philadelphia Vireo ( Vireo philadelphicus; 8),
Yellow-green Vireo ( Vireo flauouiridis; 8), Gray Catbird { Dumetella
carolinensis; 16), Painted Bunting ( Passerina ciris; 7), and Common
Grackle (Quisca/us quiscula ; 5).

The list of species reviewed by the CBRC is posted at the Western Field
Ornithologists’ web site (http://www,wfo-cbrc.org). This site also includes
the entire California state list, the Committee’s bylaws, a reporting form for
direct e-mail submission of records to the CBRC, the addresses of current
Committee members, a photo gallery of recent submissions including
several birds published in this report, a list of relevant publications by CBRC
members, and other information about the CBRC, WFO, and Western
Birds.

All records reviewed by the CBRC (including copies of descriptions,
photographs, videotapes, audio recordings and Committee comments) are
archived at the Western Foundation of Vertebrate Zoology, 439 Calle San
Pablo, Camarillo, California 93012, and are available for public review. The
CBRC solicits and encourages observers to submit documentation for all
species on the review list, as well as species unrecorded in California.
Documentation should be sent to Guy McCaskie, CBRC Secretary, P O.
Box 275, Imperial Beach, CA 91933-0275 (e-mail: guymcc@pacbell.net).

Committee News. The Committee’s voting membership after the 6
January 2001 annual meeting consisted of Jon L. Dunn, Richard A.
Erickson (chairman), Kimball L. Garrett (vice chairman), Robert A. Hamilton,
Bert McKee, Joseph Morlan, Michael A. Patten, Peter Pyle, Scott B. Terrill,
and John C. Wilson. Guy McCaskie will serve as non-voting secretary.
Recent Committee members who also voted on many of the records in this
report include Matthew T. Heindel, Steve N. G. Howell, Alvaro Jaramillo,
Guy McCaskie, Michael M. Rogers (outgoing secretary), Stephen C.
Rottenborn, Mike San Miguel, and Daniel S. Singer.

At its 15 January 2000 meeting the Committee decided to publish its
Annotated List of the Birds of California — for the first time including
nesting annotations created by the Committee — in California Fish and

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Game, to remove the Gray Catbird ( Dumetella carolirtensis ) and the
species pair of the White/Black-backed Wagtails ( Motacilla albaAugens)
from the CBRC review list, the latter to conform with all other species pairs/
groups where records must be attributed to a single species, to place the
Harris’s Hawk ( Parabuteo unici rictus) on the review list but to review
records in five-year increments (see species account below), and to review
records of the Iceland Gull ( Larus glaucoides) in one-year increments (see
species account below). Also, see Miscellaneous Decisions below.

Format and Abbreviations. As in other recent CBRC reports, records are
generally listed geographically, from north to south, and/or chronologically
by first date of occurrence. Included with each record is the location, county
abbreviation (see below), and date span. The date span usually follows that
published in North American Birds (formerly American Birds or Field
Notes ) but, if the CBRC accepts a date span that differs from a published
source, the differing dates are italicized. Initials of the observer(s) responsible
for finding and/or identifying the bird(s) — if known and if they have supplied
supportive documentation — are followed by a semicolon, then the initials, in
alphabetized order by surname, of additional observers submitting support-
ive documentation, then the CBRC record number consisting of the year of
observation and chronological number assigned by the secretary. All records
are sight records unless otherwise indicated: a dagger (+) indicates the
observer supplied a supportive photograph, (t) videotape, (§) a voice
recording, and (#) a specimen record, followed by the acronym (see below)
of the institution housing the specimen and its catalog number.

An asterisk (*) prior to a species’ name indicates that the species is no
longer on the CBRC review list. The first number in parentheses after the
species’ name is the number of records accepted by the CBRC through this
report; the second is the number of new records accepted in this report
(because this number excludes records thought to pertain to returning
individuals, it may be zero). Two asterisks (**) after the species’ total indicate
that the number of accepted records refers only to a restricted review period
or includes records accepted for statistical purposes only; see Roberson
(1986) for more information.

When individual birds return to a location after a lengthy or seasonal
absence, each occurrence is reviewed under a separate record number, and
Committee members indicate whether or not they believe the bird is the
same as one accepted previously. Such decisions follow the opinion of the
majority of members and, if a bird is considered a returning individual, the
total number of records remains unchanged.

Although the CBRC does not formally review the age, sex, or subspecies
of each bird, information on these subjects is often provided during the
review process (and in some cases a strong or unanimous consensus is
achieved). We report much of this information.

The CBRC uses standard abbreviations for California counties; those used
in this report are ALA, Alameda; BUT, Butte; CC, Contra Costa; DN, Del
Norte; F1UM, Humboldt; IMP, Imperial; INY, Inyo; KER, Kern; LAS,
Lassen; LA, Los Angeles; MRN, Marin; MEN, Mendocino; MNO, Mono;
MTV, Monterey; ORA, Orange; PLA, Placer; RIV, Riverside; SAC, Sacra-

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

mento; SBE, San Bernardino; SD, San Diego; SF, San Francisco; SJ, San
Joaquin; SLO, San Luis Obispo; SM, San Mateo; SBA, Santa Barbara;
SCL, Santa Clara; SCZ, Santa Cruz; SIS, Siskiyou; SON, Sonoma; TRI,
Trinity; VEN, Ventura; YUB, Yuba. A full list of county abbreviations is
available on the WFO-CBRC web site. Other abbreviations used: I., island;
L,, lake; Mt, mountain; n. miles, nautical miles; N.W.R., national wildlife
refuge; Pt., point; R., river; W.M.A., wildlife management area.

Museum collections housing specimens cited in this report, allowing
access to Committee members for research, or otherwise cited are the
California Academy of Sciences, San Francisco (CAS), Natural History
Museum of Los Angeles County, Los Angeles (LACM), Pacific Grove
Museum of Natural History (PGMNH), San Bernardino County Museum,
Redlands (SBCM), San Diego Natural History Museum (SDNHM), Santa
Barbara Museum of Natural History (SBMNH), and the Museum of Verte-
brate Zoology, University of California, Berkeley (MVZ).

RECORDS ACCEPTED

YELLOW-BILLED LOON Gauia adamsii (65, 1). A first-winter bird was at Field’s
Landing, HUM, 18 Jan 1998 (MHM; 1998-023). An alternate-plumaged adult off
Otter Pt., Pacific Grove, MTY, 24 Nov 1998-19 Mar 1999 (DR; 1999-059) returned
for its sixth winter, as summarized by Rottenborn and Morlan (2000).

SHORT-TAILED ALBATROSS Phoehastria albatrus (7**, 3). The long-predicted
increase in records of this endangered species in California waters may be underway.
Immatures about 20 miles W of Bodega Head, SON, 28 Aug 1998 (GLf, DnWNf;
BDP, DGS; 1998-148), 15 n. miles W of Pt. Reyes (38° 03' N, 123° 21' W), MRN,
26 Oct 1998 (BMcKf; ADeM, SWe ; 1998-179), and 3 n. miles WNW of Pt. Pinos
(36° 40'N, 122° 00'W), MTY, 21 Dec 1998 (SNGH, ADeM; RJA, SFB, RLBf, JEG,
GGr, PKe, DLShf, MS, RLTf; 1998-231) were considered separate individuals by the
Committee and provided the first accepted records since 1987, On the basis of
photographs, Pyle considered the first two birds “somewhat worn whereas the third
was immaculate (also per SNGH description),” leading him to conclude that the first
two birds were >1 year old and the third was in its first year (ca. 6 months old). This
also explains the pale eye crescents apparent on the first two birds but not the third,
the first sign of adult plumage (H. Hasegawa pers. comm, to Pyle). A photograph of
the third bird appeared in N. Am. Birds 53:203 and on the cover of Western Birds
vol. 31, no. 1 (2000).

BULWER’S PETREL Bulweria bulwerii (1, 1). One seen well by a boatload of
observers on Monterey Bay, MTY, 26 July 1998 (JD, BMcKt; AB, GBf, JEG, JMof,
DLSh, RLTf, DWf; 1998-119) represented the first well-documented record for
North America — preceding a bird off North Carolina (LeGrand et al. 1999) by only
days. Therefore the record was forwarded to the American Birding Association’s
Checklist Committee for its review. The similar Jouanin’s Petrel (B. fallax) has been
recorded as close as Hawaii (Clapp 1971) but is stockier (thicker winged, larger
headed, and larger billed) and typically has proportionally shorter outer rectrices. The
Committee’s unanimous acceptance of the record on a single circulation is a
testament to the exceptional package of documentation compiled by veteran trip
organizer Debra L. Shearwater. Photographs appeared in Field Notes 52:498 and
519.

WEDGE-TAILED SHEARWATER Puffinus pacificus (3, 1). A dark-morph indi-
vidual was on Monterey Bay, MTY, 10-21 Oct 1998 (EWGf, TMcG; BBf, RLBff,

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

DCf, ADeMt, PGf, JEG, AKf, GMcC, BMcKf, DR+, MMRt, DMS, DLSh, WDS,
JSf, RLTf; 1998-162). Another exceptionally complete set of documentation (cf.
Bulwer’s Petrel) made the decision of Committee members easy. The previous
California records were from Monterey Bay, MTY, 31 Aug 1986 (Stallcup et al.
1988, Bevier 1990) and the Salton Sea, RIV, 31 Jul 1988 (McCaskie and Webster
1990, Pyle and McCaskie 1992). A photograph of the 1998 bird appeared on the
cover of N. Am. Birds vol. 53, no. 1 (1999).

MANX SHEARWATER Puffinuspuffinus (43, 6). A record of one seen from shore
at Pigeon Pt., SM, 5 May 1996 (GD, NL; 1996-077A) received the requisite number
of accept votes only on its fourth and final circulation. Five accepted records in 1998
represented only half of the previous year’s record total (Rottenborn and Morlan
2000): Cordell Bank. MRN, 11 Jul (MI; 1999-144), three on Monterey Bay, SCZ, 8
Aug (MI, BMcK; 1998-021; BMcKf, MI; 1998-022; MI; 1999-134), and one at SE
Farallon I , SF, 3 Oct (WR; 1999-032). One additional record from 1998 is still under
Committee review.

MASKED BOOBY Sula dactylatra (11, 1). The recent surge in records of this
species continued with an adult at Aho Nuevo L, SM, 19 Jun-6 Aug 1998 (MF, MM,
CAM, JM, JDP, RWR, MMR, SCR, DGS, FT; 1998-098). The bird was clearly a
Masked Booby in the now limited sense that excludes the Nazca Booby (S. grand),
newly recognized as a species (Pitman and Jehl 1998, Roberson 1998, AOU 2000).
Field Notes 52:499 refers to a videotape that the CBRC has not seen.

BLUE-FOOTED BOOBY Sula nebouxii (80**, 0). A subadult near Obsidian Butte,
IMP, 19-28 Feb 1998 (JEP, DSP; RJN; 1998-111) was considered probably the
same individual as one seen at Salton City, IMP, 29 Nov 1997 (Rottenborn and
Morlan 2000).

BROWN BOOBY Sula leucogaster (58, 7). Four records in 1998 were uncompli-
cated, but records of three birds found earlier were not. The former were an immature
at San Simeon State Beach, SLO, 19 Jan 1998 (TME, KH; 1998-054; what may
have been the same bird was reported at Morro Bay, SLO, 20-22 Dec 1997 — N.
Am. Birds 52:256), an adult at Morro Rock, SLO, 5 Jul 1998 (MG; 1998-122), an
adult male at Pt. Reyes, MRN, 7 Jun 1998 (KB, GGa, KCK, LMLf, JM, RSf; 1998-
088), and a second-year male at SE Farallon L, SF, 12-24 Oct 1998 (WR, PPf;
1999-007). The Pt. Reyes bird was the northernmost ever recorded in California; one
was in northwestern Washington 18 Oct-9 Nov 1997 (Field Notes 52:114-115).

Most interesting of the other three records was an immature seen from a boat 12
n. miles SSW of Santa Barbara, SBA, 31 Aug 1996 (BS; DG, KAH, AH, DKf, CAM,
MMR; 1996-1 17A; Figure 1). The record received 80% acceptance in its first round
of circulation as a Red-footed Booby (S. sula; 1996-117) before failing acceptance by
the same margin. It was then resubmitted as a Brown Booby (1996-1 17 A) and gained
a unanimous decision on its second round. Descriptions of the bird’s foot color varied,
so observers were not of one mind concerning the bird’s identity. The Committee’s
initial reliance on reported reddish feet (also suggested by photographs) eventually
gave way to a full consideration of other characters (i.e., underwing pattern, dark
brown coloration, bill color and bill/head shape, heavier structure, uniform color of
central rectrices) and a realization that apparent foot color can be influenced greatly
by lighting.

An immature 15 miles SE of East Pt., Santa Rosa L, SBA, 30 Sep 1997 (BDf; 1998-
069) was supported by a single color photograph and was accepted (unanimously) only
after its third circulation (a second bird reported without documentation was not
accepted). This may have been the same bird seen between Santa Rosa I. and Santa Cruz
I., SBA, 19 Oct 1997 (Rottenborn and Morlan 2000). Another immature at Newport
Beach, ORA, 7 Dec 1997-7 Feb 1998 (LRH; GMcC, JEP, DGS; 1997-211) was

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

initially identified as a Red-footed Booby. Only after circulating the record three times did
the Committee consider the entire date span to pertain to the same bird.

NEOTROPIC CORMORANT Phalacrocorax brasilianus (10, 2). Adults were
near Obsidian Butte, Salton Sea, IMP, 28 Apr-12 Jul 1998 (KZKf; GMcC, MAPf,
SCR, DGS; 1998-079) and 3 miles S of Mecca, Salton Sea, RIV, 14 Jun-16 Jul 1998
(MAPf; GMcC; 1998-097).

TRICOLORED HERON Egretta tricolor (26**, 1). Returning adults were at the
Tijuana R. estuary, SD, 25 Jul 1998-12 Feb 1999 (GMcC; 1998-112; same as

1997- 184, Rottenborn and Morlan 2000) and Bolsa Chica, ORA, 31 Oct 1998-7
May 1999 (RF, MTH, PKnf, VL, JM, MMRt, SS; 1998-200; same as 1997-167 and

1998- 004, Rottenborn and Morlan 2000). Another adult was 4 miles S of Mecca,
Salton Sea, RIV, 31 Jan-7 Mar 1998 (MAP; KLGf, CAM, GMcC; 1998-048).

REDDISH EGRET Egretta rufescens (78, 3). An immature around Johnson Rd.
and Colfax St. at the N end of the Salton Sea, RIV, 11 Jul -1 Aug 1998 (RC, GMcC,
MJSM, DGS; 1998-101) was considered the same as an immature at Obsidian Butte,
Salton Sea, IMP, 2-8 Aug 1998 (GMcC; MJSM; 1998-114). On the coast, an adult
was at Seal Beach N.W.R., ORA, 17 Apr 1998 (JF; 1998-071), and an immature was
at the Tijuana R. estuary, SD, 29 Aug- 4 Oct 1998 (GMcC; 1998-121).

YELLOW-CROWNED NIGHT-HERON Nyctanassa uiolacea (18, 0). The adult
that has been reported at La Jolla, SD, for nearly 20 years (Rottenborn and Morlan
2000) was seen again 30 Apr-26 May 1998 (DGS; 1998-083).

EMPEROR GOOSE Chen canagica (63, 1). One was on the Garcia R. Flats, MEN,
28 Dec 1996-24 Feb 1997 (ERH; MGt, MMRt, PMS; 1997-091). Two birds were
initially reported with marginal written documentation, but photographs received
subsequently documented the presence of only one .

TRUMPETER SWAN Cygnus buccinator (24, 2). Adults were 7.5 miles NNE of
Marysville, YUB, 3 Feb 1994 (TM, BEWt; 1998-077) and on Rindge Tract, SJ, 17
Dec 1995 (WH; 1998-215). A second adult accompanying the latter bird, also
reported as a Trumpeter Swan, was not accepted.

WHOOPER SWAN Cygnus cygnus (5, 1). An adult at Lower Klamath N.W.R.,
SIS, 28 Jan 1998 (TCB; 1998-026) was in the same area as ones seen in 1991-92
and 1994 (McCaskie and San Miguel 1999) and may have been the same individual.
Patten (2000) summarized recurring doubts concerning the provenance of Whooper
Swans in North America.

GARGANEY Anas querquedula (21, 1). One at the Salinas sewer ponds, MTY, 25
Apr-4 May 1998 (CHo; DR, SCR, JSf; 1998-084) fit the pattern of males in spring
established by most records of this species (Spear et al. 1988) and was the first to be
found in Monterey County.

COMMON POCHARD Aythya ferina (2, 1). Two males photographed at Bolsa
Chica, ORA, 26 Dec 1994 (PK; 1995-082; Figure 2) made California’s second
record, following a male at Silver Lake, SBE, during falls and winters between
February 1989 and November 1992 (Patten 1993). The current record struggled
through four rounds because the birds were identified from photographs well after the
sighting, and the prints that accompanied the record through three rounds were
inadequate for some members to rule out hybrids. Communication between Commit-
tee members and the photographer and inspection of the original slides led to
eventual acceptance by a 9-1 plurality.

KING EIDER Somateria spectabilis (34, 1). Record 1998-014 involved a female
seen at Laguna Beach, ORA, 23 Dec 1995 (JEP) and at Huntington Beach, ORA, 28
Dec 1995 (DSP).

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

MISSISSIPPI KITE Ictinia mississippiensis (27, 1). A first-summer bird at Furnace
Creek Ranch, Death Valley, INY, 6-7 Jun 1998 (SCR, MJM, MMRf, MJSM, SBT;
KSG, MSM; 1998-087) was at the site of more records than anywhere else in
California but was the first in the state since 1994 (Howell and Pyle 1997).

HARRIS’S HAWK Parabuteo unicinctus (4**, 4). Following the appearance of a
number of Harris’s Hawks in southwestern California in 1994, the Committee
packaged several records together under number 1996-080 so it could reconsider its
designation of the California population as extirpated. After a single circulation, we
decided to consider the individual reports separately to avoid the possibility of different
members accepting different records and no single record achieving acceptance on its
own. After three more circulations, four records had been accepted: up to eight at
Borrego Valley, SD, 15 Apr 1994-22 Sep 1996 (RT; AME, RAE, PJ, PEL, CAM,
GMcC, MAPf, DRf; 1996-080A; Figure 3), up to five (including two that constructed
a nest) at Boulevard, SD, 1 Jun 1994-31 Oct 1995 (PEL, ADS; 1996-080B), one in
the Coachella Valley, RIV, 31 Dec 1994-29 Jan 1995 (SJM; MAP; 1996-080D), and
up to five at George AFB, SBE, 2-21 Jan 1995 (EACf, CAM, MAP, MSM; 1996-
080E). Thus the Committee no longer considers the species extirpated from Califor-
nia. Four more records from the same period are still under review.

At its January 2000 meeting the Committee decided to review subsequent records
only once every five years. Patten and Erickson (2000), using primarily CBRC data,
summarized the reappearance of this species in California and northern Baja
California, emphasizing the cyclic nature of this species’ occurrence in those areas
over the past 150 years. Erickson et al. (in press) reported additional recent records for
northern Baja California.

*ZONE-TAILED HAWK Buteo albonotatus (54, 3). An adult was in Mission Viejo,
ORA, 18 Oct 1975 (SJG; 1999-178), an adult was near Lake Henshaw, SD, 13 Jun
1998 (PU; 1999-039), a returning adult (cf. Rottenborn and Morlan 2000) was at
Goleta, SBA, 21 Oct 1998-24 Mar 1999 (FE; SS; 1998-206), and two adults were at
San Diego Wild Animal Park, San Pasqual, SD, 19 Nov 1998-15 Mar 1999 (GMcC,
JM; 1999-024), one judged to be a returning bird (cf. Rottenborn and Morlan 2000).

GYRFALCON Falco rusticolus (8, 1). A gray-morph juvenile at Tule Lake N.W.R.,
SIS, 24 Nov 1998 (RE; 1999-058) was the fifth to be recorded in the California
portion of the Klamath Basin.

YELLOW RAIL Coturnicops noueboracensis (70, 2). Females were found in
weakened condition in Manhattan Beach, LA, 20 Oct 1998 (#LACM 110747; 1999-
097) and Santee, SD, 16 Dec 1998 (#SDNHM 50186; 1998-232). There were only
four previous accepted records for southern California, three in the period 1896-
1917.

In comments, Patten noted the light weight of both specimens (perhaps merely a
result of their poor condition) and questioned how the similar Swinhoe’s Rail (C.
exqui situs) of east Asia was eliminated from consideration. Although the chance of
Swinhoe’s Rail reaching California is remote and these specimens do match other
Yellow Rail specimens, specimens for comparison with Swinhoe’s Rail are not
available at either museum. This question seems relevant to other California speci-
mens as well, so an eventual review of all records may be in order.

MONGOLIAN PLOVER Charadrius mongolicus (8, 2). Juveniles were at Bodega
Harbor, SON, 2-3 Sep 1996 (DnWNf; KB, LML, BDP; 1996-118) and the Eel River
Wildlife Area, HUM, 2-3 Oct 1998 (SNGH, SWe; WB, AJ, JSM, GMcC, JM, MSM;
1998-150). Previous California records, all coastal from Marin County through
Ventura County, span the period 12 July to 25 September.

WILSON’S PLOVER Charadrius wilsonia (8, 1). An adult male was at Coronado,
SD, 27 Apr-1 May 1998 (NBB, BFf, PAG, RL, JOZ; 1998-072); reports of it as late

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Figure 1. Immature Brown Booby, Sula leucogaster, 12 nautical miles south-
southwest of Santa Barbara, Santa Barbara County, 31 Aug 1996 (1996-1 17A). This
individual was originally identified as a Red-footed Booby, S. sula, and was nearly
accepted as such. Note the seemingly red feet but also apparent whitish mottling on
the underwing coverts and the bill’s shape (relatively thick with flat forehead and
culmen) and color (bluish gray with no hint of pinkish).

Photo by David Koeppel

Figure 2. Male Common Pochard, Aythya ferina, one of two at Bolsa Chica, Orange
County, 26 Dec 1994 (PK; 1995-082) that represent the second record for California.

Photo by Peter Knapp

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Figure 3. Adult Harris’s Hawk, Parabuteo uriicinctus, in Borrego Springs, San
Diego County, 13 Jan 1995 (1996-080A), one of up to eight there beginning in April
1994. On the basis of this record and three others, the species is no longer considered
extirpated in California.

Photo by Don Roberson

as 2 May were not accepted. Surprisingly, of six California records in the latter half of
the 20th century, only one other was south of Ventura County.

AMERICAN OYSTERCATCHER Haematopus paUiatus (16, 1). An adult was at
San Nicolas L, VEN, 28 Jun-3 Sep 1998 (RAH; 1998-117); nine of California’s
accepted records are from the Channel Islands.

BRISTLE-THIGHED CURLEW Numenius tahitiensis (2, 2). California’s first
accepted records, of one at Battery Pt., Crescent City, DN, 14-16 May 1998 (ADBf;
BED, GEf, GMcC, JM, DvWN, DRt; 1998-075) and one at Kehoe Beach, Pt. Reyes,
MRN, 16-25 May 1998 (LMLf ; KB, LC, MF, BG, SCH, SNGHf, KCK, MJM, JSM,
JLM, JM, BDP, MAP, RWR, JR, MMR, SCR, TR, MSMt, DGS, RSt; 1998-076),
were part of a larger phenomenon involving 13-17 birds from Washington through
central California and discussed in detail by Patterson (1998) and Mlodinow et al.
(1999). Photographs of the accepted birds were published by Patterson (1998), in
Field Notes 52:384, and on the cover of Western Birds vol. 30, no. 3 (1999). Two
other records were not accepted (see below).

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

f . J*

aii

Figure 4. Adult Iceland Gull, Larus glaucoides, at Bodega Harbor, Sonoma County,
13 Jan 1985 (1985-007), the first accepted record for California.

Photo by Albert Ghiorso

BAR-TAILED GOD WIT Limosa lopponica (23, 2). An adult was at Ravenswood
Open Space Preserve. SM, 12-29 Sep 1998 (RST; AME, MF, DGS; 1998-138), and
a juvenile was at the confluence of Alviso and Coyote sloughs. SCL/ALA, 2 Oct 1998
(SCR; 1998-204).

AMERICAN WOODCOCK Scolopax minor (1. 1). One was at Iron Mt. Pumping
Plant, SBE, 3-9 Nov 1998 (MAP, GMcC; RF. KSG. JM, DRt: 1998-177). Patten et
al. (1999) provided details of this record, California's first.

LITTLE GULL Larus minutus (72, 4). An adult was at Mystic L., near Lakeview,
RIV, 15 Nov 1998-27 Mar 1999 (MAPt: DSC, RF, RL. CAM, GMcC, JM; 1998-
181). An adult or bird in second alternate plumaqe at Alviso, SCL, 28 Apr-2 May
1998 (SCR; MWE, MF, NL, MJM, RWR; 1998-070) was followed by one in first
alternate plumage there 8-17 May 1998 (SCR; NL, JM; 1998-078). One in first
alternate plumage at Lower Klamath N.W.R.. SIS, 14-16 Jun 1998 (ADB, RE; 1998-
140) was at a less traditional time and place.

BLACK-HEADED GULL Larus ridibundus (20, 0). An adult at Santa Barbara,
SBA, 17 Nov-24 Dec 1997 (DSW; 1997-204} returned for its sixth winter at the
same location.

ICELAND GULL Larus glaucoides (2, 2). After nearly 15 years of intermittent
review (cf. Heindel and Garrett 1995, Rottenborn and Morlan 2000) and the formal
input of at least 12 outside consultants from throughout North America and Europe
(E. A. T. Blom, Davis Finch, Roger Foxall, Daniel D. Gibson, Michel Gosselin, Peter
J. Grant, Raymond Henson, Ted Hoogendoorn, Dennis Paulson, J. V. Remsen, Jr.,
Stuart Tingley, Thede Tobish), this species was finally added to the state list at the
January 2000 meeting, on the basis of two records: an adult at Bodega Harbor, SON,
30 Dec 1984-18 Jan 1985 (KFC, DDeS; JRAt, LCB, RAE, AGf, RLeBt, GMcC,

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

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Figure 5. First-winter Lesser Black-backed Gull, Lorus fuscus, at Obsidian Butte,
Salton Sea, Imperial County, 25 Jan 1998 (1998-042), the first record of this
plumage in California.

Sketch by Michael A. Patten

JM, DnWNt, JOlt, BDP, DGSt, RSt, SWif; 1985-007; Figure 4) and a juvenile at
the Otay dump, SD, 17-25 Jan 1986 (REWt; LRBt, JLDf, JML, MJL, GMcC, DR,
ASt; 1986-015). Perhaps not surprisingly, both of these birds were at the pale end of
the spectrum (i.e., more like nominate glaucoides than the expected Kumlien’s Gull,
L. g. kumlieni, of North America); birds closer in appearance to kumlieni (and thus
pale Thayer’s Gulls, L. thayeri, as well) have not fared well in the CBRC review
process (see Rottenborn and Morlan 2000 and Records Not Accepted below).

Many Committee members expressed skepticism of the current taxonomic treat-
ment of the Iceland/Thayer’s Gull complex in America (AOU 1973, 1983, 1998) —
indeed, that skepticism was largely responsible for the temporary suspension of
CBRC review of these records — but all eventually agreed that such taxonomic
considerations are beyond the scope of the CBRC and that the treatment here
matches better what has been done with extralimital records elsewhere in North

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

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Figure 6. Adult Bridled Tern, Sterna anaethetus, at Bolsa Chica, Orange County, 17
Jul 1998 (1998-105), the first accepted record for California.

Sketch by Marshall Iliff

America. Because of the complex taxonomy and identification of this species, records
will be handled differently than for other species; records will not begin circulation as
received but will be held until the next annual meeting, when they may or may not
undergo an expedited review. Rottenborn and Morlan (2000) addressed the
Committee’s latest dealings with these birds.

LESSER BLACK-BACKED GULL Larus fuscus (17, 8). California is not immune
from the population expansion of this species in North America, as ten individuals
were seen in 1998: a returning adult at Alviso, SCL, 11 Oct 1997-23 Jan 1998
(MJM; MWE, MF, JM, RWR; 1997-150) and again in the Alviso area, SCL/ALA, 21
Oct-8 Dec 1998 (SCR; MMRt; 1998-203), a second-winter bird at L. Cunningham,
San Jose, SCL, 31 Oct 1997-31 Mar 1998 (SCRf, MMRt; MF, MTH, NL, MJM,
GMcC, JM, RWR, DRf, RMSf, MSi; 1997-1 78), returning in its third winter 20 Dec
1998-14 Mar 1999 (SCR; MJM, MMRf; 1999-001), an adult at L. Cunningham,
San Jose, SCL, 8 Jan 1998 (BMcK; 1998-003), a returning adult at Doheny State
Beach, ORA, 8 Oct 1997-4 Mar 1998 (JDWf; TC, MTHf, MF, GMcC; 1997-156)
and again 4 Nov 1998-10 Mar 1999 (LMLf, JM, DSP; 1998-201) with a second
adult there 30 Nov-7 Dec 1998 (DSP; MTH; 1998-207), an adult at the Whitewater
R. delta, Salton Sea, RIV, 14 Feb-8 Mar 1998 (MAP; CAM, GMcC; 1998-049), an
adult at Salton Sea State Recreation Area, RIV, 21 Jan-7 Mar 1998 (DSP; TC, KLGt,
MTH, RL, CAM, GMcC, KM, MAP; 1998-025), an adult at Obsidian Butte, Salton
Sea, IMP, 19 Jan 1998 (GMcC, PEL; 1998-039), a first-winter bird at Obsidian Butte,
IMP, 24 Jan-8 Mar 1998 (MAP; KLG, MTHf, CAM, GMcC; 1998-042; Figure 5),
and an adult at the Brawley landfill, IMP, 30 Dec 1998-1 Feb 1999 (SJT; 1999-048),
considered probably different from one at the same locality 22-27 Jan 1996
(McCaskie and San Miguel 1999). A photograph of the first San Jose bird was
published in Field Notes 52:253.

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Figure 7. Possible Blue-headed Vireo, Vireo solitarius, on San Nicolas Island,
Ventura County, 20 Oct 1998 (1998-216), The extensively white-edged outer
rectrices, blackish tertials with thick whitish edges, brilliant white throat, bluish head,
and seemingly sharp demarcation between throat and auricular support identification
as Blue-headed, but using known identification criteria most members could not rule
out a bright Cassin’s Vireo.

Photo by Sandra G. Harvill

Several CBRC members expressed the concern that not all California birds may be
of European/eastern North American origin (i,e., L. /. graellsii ) and that certain
Asian taxa (e.g., heuglini, taymirensis) may be involved as well. In the end, the
AOU’s (1998) regarding all of these taxa as subspecies of the Lesser Black-backed
Gull rendered such concerns outside the scope of CBRC review. In the future, if the
AOU defines a less inclusive Lesser Black-backed Gull, some or all of these records
may be reconsidered.

BRIDLED TERN Sterna anaethetus (1, 1). An adult at Bolsa Chica, ORA, 17 Jul
1998 (MI; KSG, JEP; 1998-105; Figure 6) represents the first accepted record for the
state; another record from Bolsa Chica 12 Jun 1993 (Erickson and Terrill 1996) has
been resubmitted in light of the 1998 sighting. The Bridled Tern becomes one of five
species on the state list supported by only sight records.

After some initial confusion concerning potential differences between the west
Mexican S. a. nelsoni and the Caribbean S. a. recognita/melanoptera (i.e., the bird
had a pale collar and white on at least the two outer rectrices), the record was accepted
unanimously on the second circulation. Ridgway (1919) said only that nelsoni is
“similar to S. a. recognita but averaging larger, with relatively longer or more slender
bill, and under parts of body tinged with pale gray. ” The tail pattern also eliminates the
only other similar species, the Gray-backed Tern (S. lunata) of the central Pacific.

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

SOOTY TERN Sterna fuscata (6, 0). A returning adult (cf. Rottenborn and Morlan
2000) was at Bolsa Chica, ORA, 12-19 Apr 1998 (PEL; 1998-080).

LONG-BILLED MURRELET Brachyramphus perdix (3, 1). Birds in “basic”
plumage (first alternate?) at Pt. Saint George, DN, 21 Jul 1998 (ADB; 1998-1 18A),
29 Jul 1998 (ADB; 1 998-1 18B), and 22-23 Aug 1998 (BED; 1998-118) were
judged to be the same individual, contra N. Am. Birds 53:101. Rottenborn and
Morlan (2000) reported the first accepted records of this species and summarized
other records that remain unreviewed by the CBRC, including several specimens.

RUDDY GROUND-DOVE Columbina talpacoti (69, 3). An immature male was
found dead 22 km N of Blythe, RIV, 26 Nov 1992 (#LACM 107326; SC; KLG, MAP;
1994-72), an immature male was at Furnace Creek Ranch, Death Valley, I NY, 7 Oct
1998 (JHef; TH; 1998-212), and a male was at Independence, INY, 2 Nov 1998
(RAHu; 1998-213). Patten took the Blythe specimen to Moore Laboratory of
Zoology at Occidental College, there confirming its identity as C.t. eluta of western
Mexico (the subspecies believed to account for all California records). Acceptance of
the last bird was not unanimous, as Morlan felt that the description failed to rule out
a Plain-breasted Ground-Dove (C. minuta), a southern species that seems very
unlikely to reach California as a natural vagrant (its status in captivity is unknown). The
larger size and black axillars of talpacoti are distinctive, as are purple markings on the
wing coverts of minuta,

GROOVE-BILLED ANI Crotophaga sulcirostris (11, 1). One at Desert Center,
RIV, 4 Oct 1998 (MAP, BDS; 1998-155) provided the seventh fall record from the
interior, conforming to the predominant pattern developing in California.

BROAD-BILLED HUMMINGBIRD Cynanthus latirostris (54, 2). Lone females
presumably wintering were at San Elijo Lagoon, SD, 5-8 Jan 1998 (MBS; MMR;

1998- 027) and Goleta, SBA, 28 Nov 1998-28 Feb 1999 (RAH; GMcC, DR, SCR;

1999- 062).

RUBY-THROATED HUMMINGBIRD Archilochus colubris (4, 1). An immature
female captured at SE Farallon L, SF, 25 Aug 1998 (PPf; SD, DH, MHf; 1999-008)
fit the species’ incipient pattern of early fall vagrancy to California (the previous two
fall records, also from this location, were on 21-22 Aug 1985 and 7 Sep 1994).
Howell and Pyle (1997) discussed its separation from other small hummers, particu-
larly the Black-chinned (A. alexandri ); Pyle (1997) authored the definitive treatment
for this species in the hand (as all accepted California records have been).

GREATER PEWEE Contopus pertinax (32, 1). An individual that wintered at
Brock Research Center, IMP, 24 Dec 1998-27 Feb 1999 (MAPt; RF, KSG, KZKt,
CAM, GMcC, JM, MMRt, MJSM, DMS; 1999-043) was identified as an adult
because of its fresh, truncate rectrices and unworn tertials (the Greater Pewee is
unique among North American Contopus in retaining the juvenal flight feathers
during the first prebasic molt; Pyle 1997). A color photograph of this bird was
published in N. Am. Birds 53:221.

EASTERN WOOD-PEWEE Contopus virens (9, 5). A virtual invasion of this
eastern flycatcher in spring/summer 1998 more than doubled the state’s accepted
records, with individuals found at Bodega Head, SON, 3 Jun 1998 (ANW; PCo§,
BDP; 1998-115). Pt. Reyes, MRN, 22 Jun 1998 (JM; TBf; 1998-004), Mono L.
County Park, MNO, 4-8 Jul 1998 (SH|, RSt; MWE§, DL, DP§, JiP, DRt, AW; 1998-
103), Galileo Hill Park, KER, 10 Jun 1998 (MTH; 1998-120), and South Fork
Wildlife Area, KER, 27 Jun-9 Jul 1998 (SAL; MTH, MAP; 1998-102). With
vocalizations critical to distinguishing this species from the Western Wood-Pewee (C.
sordidulus), audio tape nicely supported the Bodega and Mono Lake records (photos
of the latter bird supported the record but were not definitive). A photo of the Pt.

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Reyes bird showed a relatively pale breast and entirely yellow-orange lower mandible,
marks highly suggestive of the species claimed, but probably more important to this
record’s acceptance was an hour the finder spent listening to and describing the bird’s
somewhat variable clearly whistled songs mixed with frequent call notes, none of
which were like those of its western counterpart. The Galileo bird, a first for Kern
County, gave only frequent “chip” call-notes with an occasional “Dusky-capped
Flycatcher-like peeeeeah” (described as the typical Eastern Wood-Pewee song minus
the final syllable). These vocalizations, combined with the bird’s appearance (the lower
mandible was “all orange-yellow” and its “very crisp” plumage featured a “white
throat, faint vest, and fairly light undertail coverts”) and the observer’s skill and
experience levels, were considered adequate for CBRC endorsement. The bird at
South Fork Wildlife Area was observed and heard singing by several observers.

YELLOW-BELLIED FLYCATCHER Empidonax flaviventris (12, 1). A silent
immature at California City, KER, 7 Sep 1998 (MTH; RC, MSM, MJSM, JCWt;

1998- 124) was the fifth for Kern County, which now claims nearly half the state’s
records. All California records but one (Carpinteria, SBA, 16-17 Oct 1987 ; Pyle and
McCaskie 1992) are for September. Although sight records of this species are still
somewhat contentious within the Committee because of the high potential for
confusion with the Western Flycatcher complex ( E , difficilis/occidentalis) and the
Acadian Flycatcher (E. uirescens ), this record received unanimous endorsement
during the first round of voting. Photographs of this bird were not definitive, but they
supported prolonged close observations by several experienced observers, and
submission of the photos was considered important by at least one member. The
spacing of the primaries on this bird was not inspected (cf. DeSante et al. 1985,
Heindel and Pyle 1999), but independent review of museum specimens by Howell (in
litt.) and Patten (in litt.) suggests that this feature’s utility may be limited because of
overlap in the pattern of primary spacing of the Yellow-bellied and Western
flycatchers.

DUSKY-CAPPED FLYCATCHER Myiarchus tuherculifer (52, 7). Acceptance of
one at Bolinas, MRN, 12 Jan-21 Mar 1998 (KH; PP; 1998-002) and one inland at
Finney L„ IMP, 12 Jan-28 Mar 1998 (BDCW; KLGt, GMcC, MAP; 1998-051)
yields a seasonal total of eight for 1997-98. In 1998-99, a returning bird was at
Santa Cruz, SCZ, 19 Dec 1998 (SG; 1999-027, same as 1998-062), and new
individuals were at Bodega Bay, SON, 22-27 Dec 1998 (BDP; JEPa, DnWN; 1999-
005), nearby at Bodega Dunes Campground, SON, 23 Dec 1998-16 Jan 1999
(DnWNf; BDP, JEPa; 1999-006), Los Osos, SLO, 12-19 Dec 1998 (TME; KH ;

1999- 096), Ventura 28 Dec 1998-2 Jan 1999 (WW; DDesJt; 1999-029), and Long
Beach, LA, 27 Dec 1998-28 Mar 1999 (KSG; RF, MJSM, MSMf, JM; 1999-016).
Records of this southern flycatcher follow an upward trend and scatter fairly evenly
northward along the coast to Sonoma County, with outliers farther north and in the
interior. San Diego County claims only three records, suggesting that this corner of
the state may lie southwest of the vector followed by most vagrants to California. All
accepted records are thought to pertain to late fall migrants or, particularly, overwin-
tering birds.

GREAT CRESTED FLYCATCHER Myiarchus crinitus (42, 2). Individuals were at
Twenty-nine Palms, SBE, 12 Sep 1998 (BiD, EACf; 1998-221) and in Manhattan
Beach, LA, 18 Oct 1998 (KLf; KSG, TEW; 1998-208). The former record was the
state’s third earliest and only the fifth inland. Despite being underexposed, photo-
graphs helped this report gain unanimous acceptance since they showed important
field marks, particularly pale edging to the inner tertials that appears thicker basally
than expected on a Brown-crested Flycatcher (M. tyranrtulus ■ Heindel and Patten
1996, Pyle 1997).

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

SULPHUR-BELLIED FLYCATCHER Myiodynastes luteiventris (13, 1).
California’s first spring record, at Gazos Creek, SM, 14 Jun 1998 (RST; BMcKt,
AME; 1998-106), was the first of its kind for San Mateo County and the fourth for
northern California. Photographs were inadequate to eliminate the similar Streaked
Flycatcher (M. maculatus), but all three observers described the Sulphur-bellied’s
distinctively thick blackish malar streak. Those with the best views also noted blackish
streaks on a whitish background from the throat to the lower breast and flanks,
unstreaked belly, undertail coverts washed with yellow, lack of yellow in the face, and
only a very limited amount of pale on the lower mandible (cf . Howell and Webb 1995,
Pyle 1997). A report of this bird continuing on 15 Jun 1998 received no CBRC
support, as members were not convinced that the description ruled out a female
Black-headed Grosbeak (Pheucticus melonocephalus).

THICK-BILLED KINGBIRD Tyrannus crassirostris (14, 1). One at Pomona, LA,
14 Oct 1998-1 Mar 1999 (MJSM; 1998-175) returned for its seventh winter at this
location, while an immature at Half Moon Bay, SM, 19 Dec 1998-7 Mar 1999
(AWK; GEC, MD, MWEt, RF, NL, LML f, MMa, JM, CL, DvWN, MMRf; 1998-233)
was a first for San Mateo County and one of the northernmost records for this species.
The age of the latter bird was inferred from the rufous edgings to the rectrices and
wing coverts, fresh tertials, and bright yellow underparts (cf. Pyle 1997).

WHITE -EYED VIREO Vireo griseus (38, 2). A singing male at Butano Creek, SM,
18 Jun 1998 (DLSu; 1999-026) furnished a county first, while another at Pt. Saint
George, DN, 27 Jun 1998 (ADB; 1998-141) was well north of the state’s previous
northernmost records (in Marin County). Approximately 75% of accepted records are
from spring (8 May to late June).

YELLOW-THROATED VIREO Vireo flavifrons (69, 2), One at Pt. Reyes, MRN,
13 Jun 1998 (AME; 1998-108) was in spring, season of approximately 70% of
California’s records. The state’s third in winter was at Westminster, ORA, 29 Dec
1998-15 Feb 1999 (KSG, SSo, RF, JM, GMcC, MTH, DR; 1999-018).

BLUE-HEADED VIREO Vireo sohtarius (5**, 5). This recently recognized species
was added to the review list in 1998 (records from 1997 and later), with the following
records being the first to gain formal CBRC acceptance: likely immature female on SE
Farallon I., SF, 1 Oct 1998 (PP; 1999-011), immature (likely male) banded on SE
Farallon I., SF, 1 1 Oct 1998 (WR, PPt; 1999-012), immature male banded at the Big
Sur R. mouth, MTY, 28 Sep 1998 (JBot; 1999-057), one at Arroyo Grande Creek,
SLO, 14 Oct 1998 (BS; 1998-157), and a wintering bird in Orange, ORA, 31 Oct
1998-16 Jan 1999 (DRW; 1999-095). At least some pre-1997 records will undergo
a form of review, and anyone who has observed this species in the state in any year
is urged to submit contemporaneous documentation to the Committee.

Blue-headed Vireos are difficult to separate from bright Cassin’s Vireos (V cassinii)
under field conditions (Heindel 1996, Pyle 1997), and evaluation of many records is
troublesome, even with a fairly detailed description and/or photographs (see Fig-
ure 7). Accepted birds were described as possessing or photographed exhibiting (1) an
immaculate white throat sharply demarcated from the auriculars (no blending at the
border), (2) white center of breast and belly, (3) blue or blue-gray head contrasting with
a green back (some with greenish napes), and (4) lemon-washed flanks (often very
bright). One bird in hand was reported to have outer rectrices with pale outer edges
approximately 1 mm thick. Until identification criteria are better delineated, the
Committee requests unusually detailed and precise descriptions of suspected Blue-
headed Vireos.

‘PHILADELPHIA VIREO Vireo philadelphicus (116, 8). Individuals found within
the typical autumn window of occurrence (mid September to late October) were at
Fairhaven, HUM, 2 Oct 1998 (BED, DRi; RF, JM, MMR, GMcC, MSM; 1998-152),

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Pt. Reyes, MRN, 30 Sep 1998 (PU; JFH, DGS; 1998-189), El Granada, SM, 4 Oct
1998 (RST; 1999-046), Big Sur R. mouth, MTY, 27 Oct 1998 (JBo; 1999-056;
banded immature), Los Angeles R. near Glendale, LA, 26 Sep-11 Oct 1998 (KLG;
1999-037), and Huntington Beach, ORA, 12-22 Oct 1998 (KSG, MSM; 1998-
199). One at Bodega Head, SON, 5-10 Sep 1998 (DnWN; KCK, BDP, DGS; 1998-
134) arrived a day later than the state’s earliest fall record. A singing male at the
Parker Creek Diversion Dam, MNO, 21 Jun 1998 (ES; DMaf, DP§, JiP; 1998-104)
furnished California’s eleventh in spring, with Mono County accounting for six of
these records (the previous five occurred at Oasis). Although photographs of this bird
appear to be diagnostic, and the record was accepted unanimously, a recorded song
included phrases that some members considered similar to those of a Warbling Vireo
(V gilvus ) and thus seemingly atypical for a Philadelphia Vireo.

YELLOW-GREEN VIREO Vireo flavouiridis (63, 8). This vireo’s impressive
showing in fall 1998 matches the previous seasonal high set in fall 1988; as in that
year, seven occurred along the coast. Individuals were at Fort Funston, SF, 30 Sep-4
Oct 1998 (LC, MWE, MJM, JM; 1998-151), Lighthouse Field State Beach, SCZ, 15
Oct 1998 (SG; 1998-220), Oso Flaco L., SLO, 28 Sep 1998 (BS; 1998-145),
Oxnard Plain, VEN 13-16 Sep 1998 (GMcC, MSM; 1998-139), Oxnard Plain, VEN,
26 Sep-4 Oct 1998 (SJT; JLD; 1998-229), Oxnard Plain, VEN, 29-30 Sep 1998
(MSM; JLD; DSP; 1998-154), and Pt. Loma, SD, 17 Oct 1998 (GMcC; GLR; 1998-
165). Few of these birds were aged specifically, but none was thought to be an adult.
An immature at Galileo Hill Park, KER, 6 Oct 1998 (MTH; 1998-219) provided the
second record for Kern County and only the state’s fourth inland.

VEERY Catharus juscescens (10, 1). An immature banded at the Big Sur R.
mouth, MTY, 21 Sep 1998 (JBof; 1998-174) made the state’s seventh fall record.
This bird’s appearance was consistent with C. /. salicicola.

GRAY-CHEEKED THRUSH Catharus minimus (20, 1). An immature at Galileo
Hill Park, KER, 9 Oct 1998 (MTH; DSP, JCW; 1998-184; Figure 8) was the second
identified inland in California, the first having been at the same park 14-18 Sep 1989
(Patten and Erickson 1994).

WOOD THRUSH Hylocichla mustelina (14, 1). An immature at California City,
KER, 11-13 Oct 1998 (KSG, MTH, GMcC, MAP, MJSM, SBTt, JCW ; 1998-160)
was a first for Kern County and the state’s fifth Wood Thrush inland.

*GRAY CATBIRD Dumetella carolinensis (101, 16). After a single spring record
in 1998 — of a one-year-old bird banded near the Carmel R. mouth, MTY, 20 Jun
1998 (KN; 1998-109) — Gray Catbirds arrived in bulk in fall 1998; the final tally of 15
records eclipsed the previous high seasonal total of seven from fall 1991 . Remarkably,
seven of these were inland, including four in Kern County (just one previous fall
occurrence there). Individuals were at Chico, BUT, 7-8 Oct 1998 (RW; HO, JOs,
RER, MSk: 1998-167), Bodega Head, SON, 22 Sep-8 Oct 1998 (DnWN; DGS;
1998-188), Pt. Reyes, MRN, 22-23 Sep 1998 (KB, JFH, DGS; 1998-156), SE
Farallon I., SF, 31 Oct 1998 (WR; ISt; 1999-033; immature; Figure 9), Tunitas
Creek, SM, 23 Oct 1998 (AW; 1998-168), near Ano Nuevo State Reserve, SM, found
dead 30 Dec 1998, likely wintering (BMcKf; #LACM 111151; 1999-070), Galileo
Hill Park, KER, 14 Oct 1998 (KSG; 1999-034), near Cantil, KER, 23 Oct 1998
(MTH; 1998-21 8), California City, KER, 18 Oct-31 Dec 1998 (JHu; MTH, MAPf,
DMS, GMcC, MSM, MJSM, JCWf; 1998-171; adult), California City, KER, 20 Oct-
16 Nov 1998 (JHu; MTH, GMcC, MSM; 1998-180; immature), Iron Mt. Pumping
Plant, SBE, 24 Oct 1998 (MAP; BiD; 1998-169; immature), Horsethief Springs,
Kingston Range, SBE, 6 Oct 1998 (BiD; 1998-122), McGrath State Beach, VEN, 19
Sep 1998 (NF; 1999-040), San Nicolas L, VEN, 1 1-17 Oct 1998 (RAH; WW; 1999-
045; banded), and San Diego, SD, 27-28 Oct 1998 (GLR; GMcC; 1998-170). The

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

»j-«k ) («w a WU~,»

4 T- V

&ft^-cAetlcf0{ s TV*i4
? (Jcf r*

H*tf t &r*t C+ y Ca.

Figure 8. Gray-cheeked Thrush, Catharus minimus, at Galileo Hill Park, Kern
County, 9 Oct 1998 (1998-184). Key features include dominance of cool gray tones
to the upperparts, brownish-black spotting on white underparts, whitish border to the
lower auriculars, and incomplete whitish eye-ring.

Sketch by John C. Wilson

number of accepted records indicates that the Gray Catbird is a rare, regular
component of California’s avifauna, and records after 1999 will not be reviewed.

WHITE/BLACK-BACKED WAGTAIL Motacilla ctlba/lugens (5, 3). In 1993,
Howell and David Sibley were asked independently to review five vexing northern
California records (1988-290, 1989-130, 1989-210, 1990-189, 1990-200); we
thank them for their effort and advice, provided both in letters to the Committee and
via publication of Sibley and Howell (1998), which included their updated opinions on
all California records. The three records discussed here (among the five reviewed by
Howell and Sibley) were originally considered by the CBRC in the early 1990s, then
re-reviewed following publication of Sibley and Howell’s enlightening paper. Unfortu-
nately, members were still unable to reach consensus on the age and sex of these
birds, a step critical to identifying them to species (Pyle 1997). For two of these
records, pitfalls inherent in the identification process were compounded by differing
opinions regarding the likelihood that each pertained to a single bird that wintered in
the same general area for four consecutive years. Finally, given that these wagtails are
known to interbreed, at least occasionally (e.g., Kishchinski and Lobkov 1979,
Badyaev et al. 1996), the potential for hybridization naturally affected members’
opinions (although Sibley and Howell suspected that “fewer than 5%” of the 216
wagtail specimens they inspected might have been hybrids). Though records such as
these frustrate the field ornithologist (and bird records committees), they are instruc-
tive reminders that the natural world does not always conform neatly to our organizing

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Figure 9. Gray Catbird, Dumetella carolinensis, on Southeast Farallon Island, San
Francisco County, 31 Oct 1998 (1999-033), one of a record 16 accepted records in
1998. The four inner greater coverts have been replaced and thus contrast with the
duller outer greater coverts and primary coverts, a “molt limit” not shown by fall
adults. Note also the lackluster remiges, typical of immatures.

Photo by Ivan Samuels

schemes and that some birds may simply not be identifiable to species, even by skilled
observers studying them at close range.

An early fall vagrant at the Eel River Wildlife Area, HUM, 1-3 Sep 1994 (NL,
DEQt, DSa; 1994-133A) was submitted as a White Wagtail and received four
“accept" votes, along with six votes for acceptance at the species-pair level. Upon its
1998 re-submission the voting results after two rounds were identical to the original
results (four votes for the White Wagtail, six votes for the species pair). Most members
were nearly convinced that the bird was, in fact, an adult White Wagtail, but some
were troubled that a well-regarded observer (one of many who observed this bird
without submitting documentation) verbally reported having observed dark scapular
lines not visible in two distant photographs. Sibley and Howell (1998) identified this
individual only to the species-pair level.

A widely seen and closely studied bird at Moss Landing, MTY, 21 Dec 1990-21
Jan 1991 (DEG; JLD, SNGH, GMcC, PEL, RJO’Bt, MAP, DRt, DAS, SWe; 1990-
200A; photograph in Am. Birds 45:317) was generally thought to be an adult female
White or immature Black-backed Wagtail. The record was twice submitted as a
“White/Black-backed Wagtail,” receiving unanimous support to the species-pair level
each time. After the first review (as 1990-200), Morlan accepted it as a Black-backed,
while Roberson and Pyle accepted it as a White that had wintered in the general area
the preceding three years (Moss Landing, MTY, 23 Dec 1988-21 Jan 1989 [1988-
290j; Sunset State Beach, SCZ, 3-11 Dec 1989 [1989-210]; Pajaro R. mouth/
Sunset State Beach SCZ/MTY 7 Nov-3 Dec 1990 [1989-210)). In the second review
(as 1990-200A), Pyle’s opinion remained unchanged, while the remaining votes went

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

to the species pair (Roberson was then off the Committee). Lars Svensson kindly
reviewed a photograph of this bird but was unable to state anything conclusive
regarding the appearance of birds of the subspecies ocularis of NE Siberia and NW
Alaska (i.e., those known to reach California). Sibley and Howell (1998) identified this
bird only to the species-pair level, opining that it was probably an adult female White
Wagtail, although probably not the same individual involved in previous records from
the general vicinity (because the appearance changed too rapidly from that ascribed to
1990-189A, discussed in the following paragraph; S. Howell pers. comm.).

One at the Pajaro R. mouth/Sunset State Beach, MTY/SCZ, 7 Nov-3 Dec 1990
(BMe; JSM, JMS; 1990-189A) was seen by fewer observers and supported by much
sparser details than were the preceding two records. It was first submitted as a White
Wagtail and received three “accept” votes (all members accepting the species pair). In
1993, commenting at the CBRC’s request, Sibley (in litt.) regarded the descriptions of
this bird as “just too little to go on,” while noting that they suggested an immature
White Wagtail; Howell (in litt.) simply considered the documentation insufficient to
support a species-level identification. Sibley and Howell (1998) erroneously published
this record as an immature White Wagtail (S. Howell in litt.). Upon its resubmission in
1998, four members accepted it as a White Wagtail, with all members accepting the
species pair. Among those accepting, Jaramillo, McCaskie, and Pyle reckoned it was
likely a returning bird; Rottenborn, following Sibley and Howell (1998), considered it
more likely an immature.

OLIVE-BACKED PIPIT Anthus hodgsoni (1, 1). A first-fall bird observed and
banded at SE Farallon I., SF, 26-29 Sep 1998 (RB, PC, WR; DMaf, PPf; 1999-010)
marked the debut of this distinctive Old World species in California. This individual
belonged the “expected” subspecies yunnanensis of northern Eurasia, which has
accounted for all vagrant Olive-backed Pipits of known race in the New World.
Capitolo et al. (2000) presented a full account of this record, including photographs
and a summary of the North American records.

SPRAGUE’S PIPIT Anthus spragueii (27, 1). Imperial County’s second record,
comprising at least 12 wintering near Calipatria, IMP, 10 Jan-21 Feb 1998 (KLG,
MTH, PEL, RL, CAM, GMcC, TRC, MAP; 1998-040), exceeded the largest flocks
previously recorded in California (flocks of up to five near Needles, 2-27 Nov 1986,
Langham 1991, and near Lancaster, LA, 22 Nov 1981-7 Mar 1982, Binford 1985).
The birds were in a field of cut Bermuda Grass ( Cynodon dactylon) near the
intersection of Sinclair Road and Highway 111.

BLUE-WINGED WARBLER Vermivora pinus (26, 1). An immature male at
Birchim Canyon, NW of Bishop, 1NY, 6 Sep 1998 (DP, JiP; JHe, TH; 1998-214) was
the second recorded in Inyo County. This eastern warbler’s pattern of vagrancy is
atypical in that inland records account for most of the state total (61%); perhaps even
more unusual, 58% of the fall records are away from the coast.

GOLDEN-WINGED WARBLER Vermivora chrysoptera (60, 1). A male at SE
Farallon I., SF, 29-30 Sep 1998 (IS; RB, PP, WR; 1999-013) was the island’s third
fall record and seventh overall.

YELLOW-THROATED WARBLER Dendroica dominica (85, 3). One at the
Carmel R mouth, MTY, 9 Sep 1998 (DR; 1998-142) was judged to be of the more
regularly occurring subspecies albilora, while an immature male at San Nicolas I.,
VEN, 7-14 Sep 1998 (RAH; SGH; 1998-193) with some yellow in the lores was not
ascribed a race (some albilora can show this). A bird presumed to be wintering was in
Eureka, HUM, 14 Jan 1998 (MHM; 1998-022).

GRACE’S WARBLER Dendroica graciae (34, 1). The state’s northernmost coastal
record was at Jacks' Peak Regional Park, MTY, 12 Dec 1998-3 Feb 1999 (RFT; JA,
DPH, CH, DR, MMR; 1999-004).

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

PINE WARBLER Dendroica pinus (56, 1). A male that wintered at El Dorado Park,
Long Beach, LA, 25 Nov 1998-10 Apr 1999 (KSG, CAM, MSM, MJSM, JM, SSo ;
1998-202) began singing by the end of its stay. This bird was judged to be probably
different from 1997-193, a likely immature male that wintered in a different part of
this large park in 1997-98. Although this species winters in the state with some
regularity, no individual is believed to have returned for a second year. One reported
in Fountain Valley, ORA, 17-18 Nov 1998 (N. Am. Birds 53:106) was not submitted
for review.

WORM-EATING WARBLER Helmitheros uermiuorus (84, 1). One at San Pedro,
LA, 23 Nov-14 Dec 1996 (DMH; KLG; 1997-025) required three circulations
because a submitted photograph was not identifiable and the only submitted descrip-
tion covered just the bird’s call notes and behaviors, plus a sketch depicting the
undertail coverts. Additional documentation was eventually submitted and the record
was accepted unanimously, but other widely seen birds routinely fare poorly in CBRC
review for similar reasons (cf. the account for this species under Records Not
Accepted). One reported at Moss Landing, MTY, 16 Nov 1998 ( N . Am. Birds
53:102) was not submitted for review.

MOURNING WARBLER Oporornis Philadelphia (106, 3). Accepted were an
immature male banded at SE Farallon L, SF, 15-16 Sep 1998 (PP; WR|; 1999-014),
an immature at Chorro Creek, Morro Bay, SLO, 20 Sep 1997 (JSR; WB- 1998-038),
and an immature banded at San Nicolas I., VEN, 12-13 Sep 1998 (RAH; 1998-136).
The first two birds were described as showing the distinctly yellow throats typical of
this species, while the last had a throat described in the hand as being “pale gray with
pale yellow tips; the yellow coloration was quite muted and would have been difficult
to discern in the field.” While members were somewhat concerned with this descrip-
tion, all distinctive measurements, appearances, and the call were consistent with a
Mourning Warbler and eliminated congeners. In-hand photographs of this interesting
bird were, unfortunately, destroyed by the developer.

RED-FACED WARBLER Cardellina rubrifrorts (11, 1). One photographed at
Bishop, INY, 20-21 May 1998 (BT; NBB, KSG, JHet, TH, DP, JiP; 1998-085)
constituted the state’s eighth spring record, all but one at inland locales. This bird’s
relatively dull plumage suggested perhaps a one-year-old female, but Pyle (1997)
urged caution in assessing age and sex in this species.

SCARLET TANAGER Piranga oliuacea. (99, 5). A female was photographed at
Pt. Reyes, MRN, 1 Jun 1998 (RS; GGrt; 1998-096). A male observed there on 30
Sep 1998 (RS; JFH, DGS, SCH, PU; 1998-158) was described by all viewers as
having entirely black remiges and wing coverts, indicating an adult (it was termed a
“young male” in N. Am. Birds 53:102). Additional fall males were at Galileo Hill
Park, KER, 1 Oct 1998 (DSP; 1998-183), Chatsworth, LA, 27 Oct 1998 (JWSt;

1998- 190; immature), and Huntington Beach, ORA, 31 Oct-1 Nov 1998 (KSG;

1999- 113; immature).

CASSIN’S SPARROW Aimophila cassinii. (40, 1). A male was voice-recorded as
it sang and skylarked in the North Domenegoni Hills, RIV, 26 May 1995 (KFC§;
1999-198). Whereas the species’ diagnostic primary song was captured on tape,
several members noted that a second song (presumed to be from the same bird)
sounded atypical for a Cassin’s Sparrow. Spring vagrants in May and June account for
most California records.

FIELD SPARROW Spizella pusilla (6, 1). Kern County’s first was photographed at
Inyokern, KER, 1-4 Nov 1998 (SStf; MTH; 1998-205). Like previous California
Field Sparrows’, this bird’s appearance was consistent with the pale western subspe-
cies arenacea.

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

SNOW BUNTING Plectrophenax nivalis (64, 2). One was at Areata Marsh,
HUM, 28 Oct 1998 (PL; 1999-055), and a female was photographed on SE Farallon
I., SF, 1 Nov 1998 (PPt; 1999-035). Each fit the predominant pattern of late fall
records from the northern coast.

PAINTED BUNTING Passerina ciris (65, 7). First-fall birds on the Shasta R. NE of
Grenada, SIS, 19 Sep 1998 (RE; 1999-036) and at Pt. Reyes, MRN, 29 Sep 1998
(GE; JMR; 1998-172) were county firsts. Other immatures were at Furnace Creek
Ranch, Death Valley, INY, 24 Sep^lO Oct 1997 (RJN; JHe, TH, GMcC, MAP;
1997-146, 1997-146A) and 21 Sep 1998 (GMcC; MSM; 1998-144), at Ridgecrest,
KER, 24-27 Sep 1998 (LSu ; 1998-210), and near Cantil, KER, 6-7 Sep 1998
(MTH; 1998-217). These records fit the predominant pattern of Painted Bunting
records in California, of immatures occurring from late August through mid October.

An adult male at Twentynine Palms, SBE, 8 Oct 1998 (BiD; 1998-223) was
accepted 8-2 as a natural vagrant in the first round on the strength of its relatively
remote desert location and appropriate date. While the Committee shares a general
uneasiness that released/escaped birds may account for a considerable proportion of
the state’s adult male Painted Bunting records (see this species’ account under
Records Not Accepted, Natural Occurrence Questionable), this vote demonstrates
that those concerns can be overcome.

COMMON GRACKLE Quiscalus quiscula (44, 5). Records were of a weakened
male taken as a specimen from Rohnert Park, SON, 15 Nov 1997 (SEt; 1999-101;
^Sonoma State University 1985), a spring migrant photographed at Pt. Sur, MTY, 21
Apr 1998 (JBo; DRf; 1998-089), a male photographed and voice recorded at
Bishop, INY, 13 Sep 1998 (DPt§, JiP; 1998-211), a singing male videotaped in
Wildomar, RIV, 21 Jan-15 Feb 1998 (CHaf; TRC, GMcC, CAM, MAP; 1998-041),
and a singing male voice recorded at Twentynine Palms, SBE, 27 Mar-11 Apr 1998
(MF, MAP, DGS, JOZ§; 1998-061). Like the previous California records, all birds
identifiable to subspecies were of the expected Bronzed race versicolor. The Rohnert
Park and Pt. Sur birds were county firsts.

Through spring 1988, 15 of 22 accepted records were of apparent spring migrants
occurring between 12 April and 12 June. From fall 1988 through fall 1998, only four
of 22 accepted records fell within this spring window. During the latter period, 15
records pertained to apparent fall migrants. Inyo County claims a remarkable 18
records, more than triple the total for any other county.

RECORDS NOT ACCEPTED, identification not established

LEAST GREBE Tachybaptus dominicus. The description of a bird in Golden Gate
Park, SF, 22 Jan 1998 (1998-043) was insufficient to establish its identity.

STREAKED SHEARWATER Calonectris leucomelas. One reported on Monterey
Bay, MTY, 6 Dec 1998 (1999-003) received no support.

MANX SHEARWATER Puffin us puffinus. The documentation for a small black
and white shearwater S of Santa Cruz I., SBA, 20 Sep 1998 (1998-143) was
considered inadequate to support the record; the species remains unconfirmed in
California waters south of Morro Bay or north of Bodega Bay.

RED-TAILED TROPICBIRD Phaethon rubricauda. The report of one seen briefly
from shore off south Vandenberg Air Force Base, SBA, 10 September 1998 (1998-
038) received limited support through two circulations.

BLUE-FOOTED BOOBY Sula nebouxii. A bird reported at Battery East, SF, 26
Sep 1998 (1999-075) was not identified by all observers present. Several Committee
members accepted that a booby was seen, but all but one agreed with those observers
who considered the identification only probable.

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

LESSER WHITE-FRONTED GOOSE Anser erpthropus. The report of one at Tule
Lake N.W.R., SIS, 15 Mar 1998 (1998-057) received but a single vote to accept.

TRUMPETER SWAN Cpgnus buccinator. The Committee’s traditional tough
stand on this species continued, as evidenced by the following records not accepted:
adult near Lower Klamath N.W.R., SIS, 14 Feb 1998 (1998-194), adult at Ash Creek
W.M.A., LAS, 15 Feb 1998 (1998-195), adult at Cosumnes R. Preserve, SAC, 16
Nov 1998 (1998-227), one heard only N of Marysville, YUB, 16 Dec 1998 (1998-
228), and two adults and three imrnatures on Clair Engle L., TRI, 29 Dec 1998
(1999-023). Only the last record received any accept votes. We appreciate the efforts
of the Trumpeter Swan Society to compile reports of this species in California, but
records lacking adequate documentation will ultimately fail to receive the Committee’s
blessing.

FALCATED DUCK Anas falcata. The report of a male seen briefly at Gray Lodge
W.M.A., BUT, 15 Feb 1998 (1998-046) was interesting but received little support
from Committee members.

AMERICAN BLACK DUCK Anas rubripes. Votes on a record of a bird seen briefly
at Cosumnes R. Preserve, SAC, 14 Mar 1997 (1997-069) were initially split almost
evenly among “accepted," “not accepted — natural occurrence questionable,” and
“not accepted — identification not established.” Votes for the last option dominated in
the third and final circulation.

KING EIDER Somateria spectabilis. One at Pt. Reyes, MRN, 29 Jan-16 Feb
1997 (1997-061) received a split vote on its fourth and final circulation. Most
Committee members agreed that this bird (seen by many, including at least one CBRC
member) was probably identified correctly, but the documentation was considered
inadequate.

* ZONE-TAILED HAWK Buteo albonotatus. Individuals at Carlsbad, SD, 20 Nov
1997 (1998-031) and 4.2 miles SE of Onyx Summit, SBE, 30 Aug 1998 (1998-124)
were not documented to the Committee’s satisfaction.

YELLOW RAIL Coturnicops noveboracensis. One seen briefly, and only in flight,
at Fort Bragg, MEN, 5 Oct 1995 (1998-132) received majority acceptance initially
but only a minority on the second and final round.

GRAY-TAILED TATTLER Heteroscelus brevipes. A report of one at Bodega
Head, SON, 30 May 1998 (1998-093) received no support, whereas one heard, and
seen as a silhouette only, at Princeton Harbor, SM, 6 Jun 1998 (1998-164) received
three and two “accept” votes on two rounds. Another report from Pt. Reyes during
the same period is still under CBRC review.

BRISTLE-THIGHED CURLEW Numenius tahitiensis. Reports of two birds at
Kehoe Beach, Pt. Reyes, MRN, 6 May 1998 (1998-090) and one at Big Lagoon,
HUM, 9 May 1998 (1998-081) corresponded with the 1998 landfall (see accepted
records) but were not accepted by simple majorities on a single circulation. The Marin
birds were identified about ten days after the sighting, and the Humboldt bird was seen
only in flight.

RED-NECKED STINT Calidris ruficoilis. The identity of a male stint in presumed
first alternate plumage collected at the mouth of the Alamo R., Salton Sea, IMP, 17
Aug 1974 (#SDNHM 38887; GMcC, JBut; 1984-085) remains unresolved. The
record was published as a Red-necked Stint by McCaskie (1975), Roberson (1980),
Garrett and Dunn (1981), AOU (1983), Veit (1988), and Small (1994), but the CBRC
has never accepted it; since receiving a simple majority vote on its first circulation in
1985, the record never reached even a split vote on four subsequent rounds. All have
agreed that the bird was either a Red-necked or a Little Stint, but most have been

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

unwilling to go beyond that. In 1993, the specimen was sent to the National Museum
of Natural History where M. Ralph Browning and the late Claudia Wilds compared it
with approximately 100 specimens of Red-necked and Little stints but were unable to
identify it. Nevertheless, the record did receive three accept votes on its final circulation,
and many members believe the specimen may yet be identified. The Committee would
welcome the chance to review any significant reanalysis of the specimen.

LITTLE STINT Calidris minuta. A reported juvenile at Eureka, HUM, 16-21 Sep
1992 (1993-050, 1993-050A) received three to six “accept” votes during five
circulations (the review process was restarted following receipt of better photographs),
and most Committee members agreed that the bird may have been a Little Stint. In
contrast, a bird reported from Abbott’s Lagoon, Pt. Reyes, MRN, 9 Aug 1998 (1998-
125) received no support.

WHITE-RUMPED SANDPIPER Calidris fuscicollis. One reported from the Santa
Maria R. estuary, SBA, 6 Sep 1997 (1998-032) received but a single vote to accept
on its second circulation. The observers failed to note a white rump, and the plumage
described matched neither an adult or a (very early) juvenile.

JACK SNIPE Lymnocryptes minimus. A report from Kern N.W.R., KER, 31 Dec
1998 (1999-002) received no CBRC support.

ICELAND GULL Larus glaucoides. Records not accepted included an adult at
Areata, HUM, 6-23 Feb 1987 (1987-072), two juveniles at Alviso, SCL, 16-28 Jan
1998 (1998-091), a juvenile at Moss Landing, MTY, 15-20 Feb 1998 (1998-059),
a juvenile near Milpitas, SCL, 24 Feb 1998 (1998-107), and a second-winter bird at
Ano Nuevo Pt., SM, 27 Feb 1998 (1998-056). The first bird resembled a typical
Kumlien’s Gull (L. g. kumlieni ) but was not photographed and received only five or six
votes to accept on each of four circulations. The other records scored more poorly,
with only one to three votes to accept per record per circulation, except for six votes
for the Alviso birds in the initial round. Rottenborn and Morlan (2000) provided more
information on records of this species not accepted by the CBRC; Terrill et al. (1999)
discussed the situation in the San Jose area in more detail. Howell (2000; in votes)
emphasized another potential confounding factor in review of potential Iceland Gulls:
hybrid Glaucous-winged (L. glaucescens) x Herring (L. argentatus) Gulls.

ROSS’S GULL Rhodostethia rosea. An adult reported from Berkeley, ALA, 14
Jan 1998 (1998-100) was described with too little detail for a first state record.

RUDDY GROUND-DOVE Columbina talpacoti. Most members felt that a bird at
Twentynine Palms, SBE, 24 Oct 1998 (1998-225) was likely this species, but by the
third round of voting only four members considered the description adequate to
support the record. Several comments referenced the Plain-breasted Ground-Dove
(C. minuta), a situation discussed under Records Accepted.

RUBY-THROATED HUMMINGBIRD Archilochus colubris. A female reported at
Pt. Reyes, MRN, 26 Aug 1998 (1999-054) received no votes for acceptance after two
voting rounds. In light of cautionary treatment by Pyle (1997), and considering other
tantalizing encounters with Archilochus hummingbirds in the state that ultimately
proved to involve likely or definite Black-chinneds, most members indicated unwilling-
ness to accept sight records of this species without definitive observations of the
shapes of the primaries (cf. Howell and Webb 1995, National Geographic Society
1999, Sibley 2000). We urge observers claiming vagrant Ruby-throated Humming-
birds to obtain definitive photographs (including the primaries) and/or in-hand data.

GREATER PEWEE Contopus pertinax. Nine positive votes cast in the first round
for a bird photographed at SE Farallon I., SF, 1 June 1998 (1998-116) would
normally have constituted Committee endorsement of the state’s first spring record of

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

a Greater Pewee, but Heindel requested recirculation to further consider a fairly bold
breast pattern, relatively bold wing-bars, missing greater wing-coverts, and fresh
tertials contrasting with wings that otherwise looked worn to most members {Figure
10). Howell and Jaramillo, the members most familiar with the Greater Pewee and
potentially confusing tropical species, considered this record to be fairly straightfor-
ward; nonetheless, a majority voted not to accept in the third and fourth rounds,
believing that the bird looked atypical (at least in photographs) and was inadequately
supported by written details. Morlan and Patten opined that the bird may have been
an Eastern Wood-Pewee (C. virens), partly because of an unprecedented incursion of
that species to California in spring 1998. Given that the bird was seen at close range
over the course of a day by at least two observers {only one of whom submitted a
report), questions raised by the equivocal photographs might have been resolved by
recording more detailed observations of the bird’s appearance and size. Comments on
Figure 10 are welcome.

EASTERN WOOD-PEWEE Contopus virens. A single observer briefly described a
singing Eastern Wood-Pewee at Pt, Reyes, MRN, 1 Jun 1998 {1998-196). Though
the distinctive “pee-a-wee” song was mentioned, the rest of the description was too
superficial, with the problematic claim that the “head, upperparts, and tail were all
brown.” The record therefore received no Committee support, although it could be
revived with submission of corroborating information from others reported to have
seen this bird. Also from the same observer were reports of a vocalizing bird at
Greenhorn Summit, KER, 1 Aug 1998 (1998-197) and another bird at Pt, Reyes,
MRN, 24 Sep 1998 (1998-198). Lacking convincing detail, these reports received no
support.

ALDER FLYCATCHER Empidonax alnorum. A widely studied immature
Empidonax at Galileo Hill Park, KER, 7-11 October 1998 (1998-161; Figures 11
and 12) may well have been an Alder Flycatcher, but whereas the calls (most
commonly “a bunting-like pit” but with occasional “soft whits”) were atypical for
western Willow Flycatchers (E. traillii brewsteri, E. t. adastus, E. t. extimus), they
fell short of the more powerful “peep” or “beck” calls normally heard from Alder
Flycatchers. After examining slides of 1998-161 with a large number of specimens of
both the Willow and Alder at hand, Philip Unitt concluded that the western subspecies
of Willow Rycatcher were eliminated on the basis of tertial pattern and that the bird
was likely an Alder Rycatcher. Without specimens of first-fall eastern Willow Rycatch-
ers (£. t. traillii) for comparison, however (juveniles certainly identified as E. t. traillii
are almost lacking in collections), he was unwilling to state with certainty that the bird
was an Alder Flycatcher. The record was defeated 1-9 after two rounds of voting, with
most members opining that they would likely have voted differently if the bird had
sounded like a typical Alder Flycatcher. Two singing birds in spring comprise
California’s only accepted records.

BLUE-HEADED VIREO Vireo solitarius. Individuals were not accepted from
Mono L. County Park, MNO. 5 Sep 1995 (1999-128), Eureka, HUM, 19 Dec 1998
(1999-116), Pt. Reyes, MRN, 19 Sep 1998 (1998-187), LosOsos, SLO, 15-22 Sep
1998 (1999-071), San Nicolas I., VEN, 20 Oct 1998 (1998-216; Figure 7), and
Pilarcitos Creek, SM, 1 Nov 1998 (1999-047). As might be expected, reports of this
taxon have surged following the three-way split of the Solitary Vireo complex, but
identification of this vireo is more problematic than many observers seem to
appreciate, and the CBRC is unlikely to endorse records of incompletely or ambigu-
ously described birds. The field marks discussed under Accepted Records are particu-
larly important. Note also that most Blue-headed Vireos appear to pass through
California from late September through October and that reports from outside this
window may require exceptionally complete details for CBRC endorsement.

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Figure 10. Possible Greater Pewee, Corttopus pertinax, on Southeast Farallon
Island, San Francisco County, 1 June 1998 (1998-116). This bird’s crest and bill
appear more or less typical for a Greater Pewee, but most members considered the
whitish wing-bars and edging to the inner secondaries and tertials to be outside the
species’ typical range of variation.

Photo by Clyde Morris

‘PHILADELPHIA VIREO Vireo philadelphicus. Descriptions of a bird at Galileo
Hill Park, KER, 4 Oct 1998 (1998-153) failed to rule out the similar Warbling Vireo
and received no votes for acceptance.

YELLOW-GREEN VIREO Vireo flauouiridis. One reported at the Marin Head-
lands, MRN, 5 Oct 1996 (1997-049) fell a vote shy of acceptance after four voting
rounds, while one reported from Moss Beach, SM, 4 Oct 1998 (1998-226) received
only four votes to accept in the first round. In each case, members expressed concern
that a bright Red-eyed Vireo (V. oiivaceus) was not eliminated. Yellow-green Vireos
are most reliably identified by the extension of yellow tones from the shoulder to
behind the auriculars and by yellow edges to the remiges and rectrices (Terrill and
Terrill 1981, Erickson and Terrill 1996),

VEERY Cotharus fuscescens. Descriptions of a rusty Catharus thrush at the
Carmel River mouth, MTY, 21-22 Sep 1998 (1999-052) pointed toward this
species, but most members ultimately concurred that the observers’ views were too
brief to permit the bird’s confident identification.

BLUE-WINGED WARBLER Vermiuora pinus. One reported at Birchim Canyon,
NW of Bishop, INY, 22 May 1998 (1998-082) was seen rather briefly by a lone
observer and received only one “accept” vote during the first round. Apart from most
members’ unwillingness to accept uncorroborated records from the observer, the

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Figure 11. Alder/Willow Flycatcher, Empidonax alnorum/traillii at Galileo Hill
Park, Kern County, 11 Oct 1998 (1998-161). Alder-like features evident in this
photo include the whitish chin and throat, generally grayish underparts, prominent
wing bars, fairly obvious eye-ring, and relatively short bill.

Photo by Larry Sansone

description of the wings and back was atypical for a Blue-winged Warbler, and the bird
could not be refound by others later in the day.

PINE WARBLER Dendroica pinus. Reports of brightly colored individuals at
Arroyo de la Cruz, SLO, 25 Sep 1998 (1999-042) and Oceano, SLO, 1 Oct 1998
(1999-041) each garnered four votes of acceptance during the first round. Members
are generally skeptical of Pine Warblers reported in September and early October, and
the CBRC is presently re-reviewing the three accepted records from before 13
October. It appears that observers underestimate the variability of Blackpoll (D.
striata) and Bay-breasted (D. castanea) warblers, which can appear nearly plain
backed during their first fall. Observers should also be aware that a Pine Warbler’s tail
is no longer than that of a Blackpoll or Bay-breasted (Pyle 1997); thus, descriptions of
this feature should relate the undertail coverts to the tail tip. Early fall claims of the Pine
Warbler should be backed by impeccable details, preferably by multiple observers, or
by definitive photographs.

WORM-EATING WARBLER Helmitheros uermivorus. A report of one in Ventura,
VEN, 6-25 Jan 1997 (1997-085) ultimately foundered after four rounds, despite
having been seen by multiple observers during an extended stay. The only description

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

submitted for CBRC review pointed toward this rather distinctive warbler, but most
members were concerned by mention of “a few small brown streaks at the top of the
chest,” which this species would not show unless wet or otherwise mussed. This
debacle again demonstrates how CBRC review can be undermined when observers
assume that others will submit adequate supporting details. If additional details are
received, the record will be re-reviewed.

CONNECTICUT WARBLER Oporornis agilis. One reported at the Big Sur
Ornithology Lab, MTY, 13 Sep 1998 (1998-192) was supported by fairly extensive
notes that most members took as supporting the observer’s claim. Another person
present on the day of the sighting, however, submitted a note to the Committee
stating that the observer “considered the record tentative” on that day, and conveying
an “impression [from the observer] that the bird was seen very, very briefly (1-2
seconds) only.” In light of this testimony, the record garnered only four votes in the
first round.

MOURNING WARBLER Oporornis Philadelphia, The Committee withheld en-
dorsement of individuals claimed at Santa Barbara I., SBA, 31 May 1974 (1980-
021A; resubmitted after prior nonacceptance as a Connecticut Warbler), Ferndale,
HUM, 31 Aug 1996 (1997-048), Hansen Dam Park, Los Angeles, LA, 24 Sep 1996
(1997-026), Big Sur R. mouth, MTY, 19 Sep 1998 (1999-066), and Mt. Diablo State
Park, CC, 16 Oct 1998 (1999-064). Most members opined that the bird at the Big
Sur R. mouth was most likely a Common Yellowthroat ( Geothlypis trichas). The
revived report from Santa Barbara 1., which four members voted to accept, seemingly
suffered more from the baggage of prior submission (the observer having previously
argued for another species) than from weakness of the documentation, which
indicated an alternate-plumaged female Mourning Warbler. The remaining three
reports involved birds described as showing little or no yellow in the throat, which in
fall should indicate an adult female, which should account for a very small percentage
of vagrants; an aberrant bird or hybrid (the latter unproven; Pitocchelli 1993, Heindel
and Patten 1996); or the observer’s failure to detect pale yellow (cf. earlier discussion
of 1998-136). Though most members considered these reports to be likely correct,
observer inexperience and other factors ultimately turned the voting decisively against
them. For further information on identification of this species and congeners see Pyle
and Henderson (1990), Pyle (1997), and Dunn and Garrett (1997).

SCARLET TANAGER Piranga oliuacea. Members generally agreed that a male
was seen at Furnace Creek Ranch, Death Valley, INY, 10 Nov 1997 (1998-060), but
after four rounds three members remained unconvinced that the record was ad-
equately documented.

SMITH’S LONGSPUR Calcarius pictus. A report of one at Galileo Hill Park, KER,
10 Oct 1998 (1998-185) received no votes for acceptance, a few members suggest-
ing that the details better fit a Vesper Sparrow (Pooecetes gramineus). A report from
San Nicolas I., VEN, 18 Oct 1998 (1999-030) was thought to have greater potential
of being correct, but after two rounds this report also received no votes to accept
because the Vesper Sparrow and other longspurs were not convincingly ruled out.

McKAY’S BUNTING Plectrophenax hyper bo reus. A nearly white bird associating
with Dark-eyed Juncos ( Junco hyemalis) west of Orleans, HUM, 18 Sep 1998
(1998-147) was considered by the Committee to have almost certainly been a
partially albinistic Dark-eyed Junco.

VARIED BUNTING Passerina versicolor. An adult male reported at Lancaster,
LA, 21-23 Apr 1996 (1996-100) received no votes for acceptance after four rounds,
the tallies being evenly split between “identification not established” and “natural
occurrence questionable.” Although most members considered the identification to be

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

likely correct, several were concerned that one description likened the bird’s size to
that of a Lark Sparrow ( Chondestes grammicus ) and that the only other description
appeared to have been written several weeks after the sighting. Members’ standards
of acceptance are generally quite high for this species owing to its extreme rarity in
California (two accepted records to date) and to its potential for escape from captivity.
Hamilton (in press) has seen as many as 42 for sale in northwestern Baja California
(Rosarito, 5 July 2000). For such species, observations should be detailed enough to
detect signs of possible earlier captivity (e.g., atypical coloration in any feather tract,
broken remex tips, frayed rectrices, abnormally long claws, bill deformities), and the
description should indicate that such an inspection was conducted.

PAINTED BUNTING Passerina ciris. The description of one reported at San Elijo
Lagoon, SD, 20 Aug 1996 (1997-028) included relatively little detail, and the bill was
described as being “very small and black.” Since the Painted Bunting’s bill is relatively
large for a Passerina bunting and is typically dusky with a pinkish tinge, documenta-
tion of this record was considered deficient by all but one member after the third round
of voting.

COMMON GRACKLE Quiscalus quiscula. Brown-headed individuals reported at
the Honey Lake Wildlife Area, LAS, 11 May 1998 (1998-074) and at Panamint
Springs, INY, 17 Oct 1998 (1999-063) received almost no Committee support
because the descriptions did not match any post-juvenal plumage of the Common
Grackle. Members opined that the latter description better fit a small female Great-
tailed Grackle (Q. quiscula), with Patten suggesting the possibility of a small bird of the
subspecies nelson i in a flock of the substantially larger monsoni; these races have
colonized California rapidly in recent decades (Dinsmore and Dinsmore 1993, W.
Wehtje pers. comm.) and appear to be forming a “hybrid swarm” north and west of
the species’ historic range (Rea 1969, W. Wehtje pers. comm.). Another possibility
mentioned was a Great-tailed Grackle x Brewer’s Blackbird (Euphagus cyano-
cephalus), a hybrid combination believed to have occurred recently in Santa Maria,
SBA (unpubl. CBRC record 1999-122).

RECORDS NOT ACCEPTED, NATURAL OCCURRENCE
QUESTIONABLE (IDENTIFICATION ACCEPTED)

BROWN BOOBY Sula leucogaster. Another immature initially identified as a Red-
footed Booby (see accepted records above) was at a fishing pier on Pt. Loma, SD, 17
Nov 1997 (CTf ; AM|, SW; 1998-008). The bird was exceptionally tame (even for a
booby), in abnormal plumage (white feathers on the mid breast), entangled in fishing
line, and emaciated when taken into captivity that day. According to Meryl Faulkner,
an experienced wildlife rehabilitator specializing in seabirds, the condition of the feet,
bill, and feathers clearly indicated the bird had been in captivity for some time prior to
17 Nov 1997 (McCaskie, in comments). The fourth and final vote on the record was
five “accept” and five “not accept, natural occurrence questionable.”

BARNACLE GOOSE Branta leucopsis. One was at Granite Bay, PLA, at least 1
Jan-10 July 1998 (JAT; 1998-045). The record received no support as representing
a natural vagrant, from the observer or the Committee, but the archiving of records of
all long-distance migratory species is strongly encouraged.

PYRRHULOXIA Cardinalis sinuatus. Although occurring at an “expected” time
of year for natural strays of this species in California (May through July), a female at
Pt. Loma, SD, 10 Jun 1998 (REW; 1999-044) “appeared ragged” and was close
enough to the international border that six members considered it more likely an
escapee. Recent investigations (Hamilton in press) have yielded multiple sightings of

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Pyrrhuloxias (and many other wild-caught birds) at pet stores in northwestern Baja
California.

PAINTED BUNTING Passerina ciris. Records not endorsed by the Committee
include a spring adult male at Big Pine, INY, 9 Jun 1996 (JHe; 1996-105), a fall adult
male at Victorville, SBE, 12 Oct 1997 (BiD; 1997-165), and an adult male with an
adult female at Niland, IMP, 22-24 Dec 1998, with the female present to IS Jan
1999 (MSM; GMcC, MAP; 1999-017). Interestingly, the observer of the Victorville
bird also found the adult male at Twentynine Palms, SBE, 8 Oct 1998 (see accepted
records above). The former record failed to gain acceptance because Victorville is far
more urbanized than is Twentynine Palms (increasing, perhaps, the likelihood of
escape/release) and the underparts and rump of the Victorville bird were described as
being “salmon reddish” versus the Twentynine Palms bird’s “typical” shade of red.
The pair at Niland included the first green Painted Bunting detected wintering in
California (none of the seven prior reports of wintering adult males gained CBRC
endorsement). Nine members considered natural occurrence unlikely in this case
because the record involved a pair of adults and the likelihood that caged Painted
Buntings are kept and sold in fair numbers in the Mexicali region. The Big Pine bird,
which received seven votes for acceptance after four rounds, was well described by a
seasoned observer as showing normal bright coloration, and both the date and
location were perhaps ideal for a naturally occurring spring vagrant. It is, therefore,
not surprising that this record was highly controversial. We provide the following
condensation of Hamilton’s ongoing research into the Painted Bunting’s unusual
status in California to help clarify the Committee’s reasoning in this case.

Painted Buntings have, since 1962, established a pattern of fall vagrancy to
California consistent with that exhibited by other eastern landbirds, with 69 accepted
fall records between 17 August and 3 December. Green birds of unknown age
excluded, immatures account for 30 of 41 fall records (73%). With the exclusion of
eight fall records of adult males rejected by the Committee because of questionable
natural occurrence, the proportion of immatures rises to 91%. A share of first-year
birds in the range 73-91% matches expectations for naturally occurring vagrant
songbirds (e.g., Robbins et al. 1959, Ralph 1971, Gathreaux 1982, DeSante 1983).
During the remainder of the year, however, birds less than a year old account for just
one of 19 records (5%), with colorful males accounting for 17 of the 18 records of
adults (94%). Patterns of vagrancy such as these are, to our knowledge, unknown in
nature.

Painted Buntings are the single most abundant wild-caught species at bird markets
that we have monitored in Baja California, with a high count of 40 colorful males and
37 green birds at a Rosarito pet store 5 July 2000 (Hamilton in press). In addition,
birders note apparent escapees (colorful males with abnormal appearance) south of
the border with some regularity (Erickson et al. in press). Just as troubling, a colorful
male collected at the Sagehen Field Station, NEV, 17-18 Apr 1985 (1988-229) was
yellow below and scarred between the orbits, strong indications of prior captivity
(Hawthorne 1972). This record’s remote northeastern location and spring timing
might best be explained by a wild-caught escapee responding to migratory restless-
ness and attempting northward migration (alternate scenarios have not been articu-
lated).

A fundamental CBRC objective is to distinguish between natural patterns of
occurrence and those relating to captivity. Therefore, some members consider it best
to withhold CBRC endorsement of adult male Painted Buntings outside of fall
migration until it becomes clear that the preponderance of adult males in winter,
spring, and/or summer results from some unique natural phenomenon, not simply
wild-caught escapees adapting to their new surroundings in winter and yielding to
Zugunrhue in spring. Whereas winter and late summer records generally receive little

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Figure 12. Alder/Willow Flycatcher, Empidonax alnorum/traillii at Galileo Hill
Park, Kern County, 11 Oct 1998 (1998-161). The bold tertial edging and eye-ring
rule out western subspecies of the Willow Flycatcher, though not an eastern bird. The
appearance of a gray nape contrasting with tire greener back results from exposure of
the grayish bases of green-tipped nape feathers.

Photo by Larry Sansone

support, most members believe that Painted Buntings are likely to wander occasion-
ally to the eastern deserts in late spring/early summer Furthermore, colorful male
Painted Buntings may be more likely than females or nonbreeding green males to
“overshoot” their breeding grounds. Seemingly supporting this hypothesis are photos
in N, Am. Birds 53:343-344 of definitive alternate-plumaged males in Saskatchewan
1-13 May 1999 {underparts not clearly visible) and near Aztec, New Mexico, 28
April-2 May. Note, however, that an adult male photographed in northern Ontario
15 May 1998 (N. Am. Birds 52:406) had faded red underparts, suggesting diet
deficiencies and possible prior captivity. Because of such considerations, California’s
five spring/early summer records of colorful males in the eastern deserts are
particularly difficult to assess. Two accepted records from the 1980s (1986-262,
1987-138) are presently being reassessed, while two later records (1996-092, 1996-
105) are not accepted, and the fifth (2000-086) is circulating for the first time. All
members recognize the potential for each of these records to pertain to a naturally
occurring vagrant, but the lack of green birds causes a minority of members to
withhold endorsing them at this time.

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

With continued research and the accumulation of records, the Painted Bunting’s
natural patterns of vagrancy should become better established, perhaps prompting
reevaluation of certain records in light of more complete knowledge of the species’
natural history. In the meantime, we hope that increased understanding of the issues
will help replace current hostility over the fate of individual records with the positive
energy of a larger mystery to be solved. We strongly encourage the continued
submission of documentation of Painted Buntings, as these records are needed to
build a more complete picture of the species’ status and distribution in California. We
also welcome responses to this discussion.

RECORDS NOT ACCEPTED, Identification accepted but establishment
of introduced population questionable

TRUMPETER SWAN Cygnus buccinator. A neck-collared adult NW of Roseville,
PLA, 22-23 Dec 1998 (BEW; REM; 1998-230) was captured in northern Idaho,
released in southern Idaho in November 1996, and seen in various states and
provinces in the interim. McCaskie and San Miguel (1999) explained the CBRC’s
position on such records.

MISCELLANEOUS DECISIONS

The following decisions were made at the January 2000 meeting.

WHITE IBIS Eudocimus a I bus (2,0). Two records at the Salton Sea in the 1970s
are now considered as pertaining to the same individual. We infer an adult at the N end
of the sea, RIV, 10-24 Jul 1976 and at the S end of the sea, IMP, 5 Aug 1976 (1 976-
045) was the same as one at Unit 1, Salton Sea N.W.R., IMP, 25 Jun-14 Jul 1977
(1978-049). These records were originally reported by Luther et al. (1979, 1983).
The only other California record is of one collected in San Diego, SD, 15-20 Nov
1935 (Huey 1936, Dunn 1988).

GRAY SILKY-FLYCATCHER Ptilogonys cinereus. This species joined the Falcated
Duck (Anas falcata ), Crested Caracara ( Caracara cheriway), and Oriental Greenfinch
(i Carduelis sinica) on the Supplemental List of California birds (Patten and Erickson
1994) on the basis of these three records “not accepted, natural occurrence question-
able”: one photographed at Ventura, VEN, 9 Apr 1976 (1980-115, Binford 1985),
one at Pt. Loma, SD, 24 May 1993 (1993-115, McCaskie and San Miguel 1999),
and one photographed at Poway, SD, 10-12 Mar 1994 (1994-075, Howell and Pyle
1997). A more recent record from Orange County is still under review.

CORRIGENDA TO THE TWENTY-THIRD COMMITTEE REPORT
(Rottenborn and Morlan 2000)

The date of the accepted Wedge-rumped Storm-Petrel (1996-1 14) was not given.
This bird was recorded 31 July 1996.

CONTRIBUTORS

Mark Ackerman, R. J. Adams, John R. Arnold, Jonathan Ausubel, John Ayres
(JAy), Stephen F. Bailey, Alan Baldridge, Thomas C. Barber, Alan D. Barron, John
Barrow (JBa), Tony Battiste, Louis R. Bevier, Laurence C. Binford, Shauna Bingham,
Jim Booker (JBo), William Bouton, Bill Boyce, Ronald L. Branson, Greg Brinkley, N.
Bruce Broadbooks, Eric Brooks, Ryan Burnett, Kenneth Burton, John Butler, Kurt F.

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Campbell, Phil Capitolo, Eugene A. Cardiff, Kris K. Carter, George E. Chaniot, Jr.,
Ryan Chornock, Janis Christian, Sue Clark, Therese R. Clawson, Luke Cole, Daniel
S. Cooper, Don Cunningham, Jim Danzenbaker, Stephen J. Davies, Gary Deghi, A1
DeMartini, Bill Deppe, David F. DeSante, Don DesJardin, Bruce E. Deuel, Bruce
Dexter, Sandy Dierks, Vladimir Dinets, Matthew Dodder, Jon L. Dunn, Mark W.
Eaton, Demian A. Ebert, Thomas M. Edell, Alan M. Eisner, Ray Ekstrom, F, Emerson,
Richard A, Erickson, Sandy Etchell, Gil Ewing, Michael Feighner, George Finger,
Shawneen E. Finnegan, Robbie Fischer, John Fitch, Brian Foster, Nick Freeman,
Peter Gaede, Sylvia J. Gallagher, Gray Gallogly, Kimball L. Garrett, Douglas E.
George, Bruce Gerow (BGe), Steve Gerow, Albert Ghiorso, Karen S. Gilbert, Martin
Gilbert, Peter A. Ginsburg, Steven A. Glover, Dave Goodward, Ed Greaves, Eric W.
Greisen, Jennifer E, Green, Bill Grenfell, George Griffeth, Mary Gustafson, Charity
Hagan, Frank A. Hall, Robert A. Hamilton, Steve C. Hampton, Keith Hansen, Denise
Hardesty, Sandra G. Harvill, David P Haupt, Karen A. Havlena, Loren R. Hays, Scott
Hein, D. Mitchell Heindel, Jo Heindel, Matthew T, Heindel, Tom Heindel, Pablo
Herrera, Michelle Hester, Craig Hohenberger, James F. Holmes, Waldo Holt, Andrew
Howe, Steve N. G. Howell, Robert A. Hudson (RAHu), E. Rae Hudspeth, Joan
Humphrey, John E. Hunter, Marshall Iliff, Richard Irvin, Alvaro Jaramillo, Curtis
Johnson, H. Lee Jones, Paul Jorgensen, Robert J. Keiffer, Paul Keller, Alison Kent,
Peter Knapp, David Koeppel, Andrew W. Kratter, Kenneth Z. Kurland, Keith C.
Kwan, Debi Lamm, Jeri M. Langham, Kevin Larson, Stephen A. Laymon, Rick
LeBaudour, Paul E. Lehman, Gary S. Lester, Lauren P. Lester, Nick Lethaby, Ron
LeValley, Cindy Lieurance, Leslie M. Lieurance, Roger Linfield, Michael J.
Lippsmeyer, Paul Lohse, Guy Luneau, Rolf E. Mall, Michael J. Mammoser, Tim
Manolis (TM), Curtis A. Marantz, John S. Mariani, Dave Marquart (DMa), Bruce
Marshall (BMa), Doug Martin (DM), John Martin (JMa), Jennifer L. Matkin, Robert E.
Mauer, Jr. (REMa), Sean McAllister, Guy McCaskie, Todd McGrath, Bert McKee,
Patrick McNulty, Anthony Mercieca, Bob Merrill, Peter J. Metropulos, Mark Miller,
Kathy Molina, Joseph Morlan (JM), Clyde Morris, Michael H. Morris, Steve Morris,
Jim Mountjoy (JMo), Dan Murley (DMu), Stephen J. Myers, Dan W. Nelson, David W.
Nelson, Kristie Nelson, Richard J. Norton, Robert J. O’Brien, Jerry Oldenettel, Helen
Ost, John Ost, Debby Parker, Jim Parker, John E. Parmeter (JEPa), Benjamin D.
Parmeter, Michael A. Patten, Courtenay Peddle, Dharm S. Pellegrini, J.D. Phillips,
James E. Pike, Jeff Poklen, Gary W. Potter, Peter Pyle, David E. Quady, Kurt
Radamaker, Richard E. Redmond, Robert W. Reiling, David Rice (DRi), Will
Richardson, Jean M. Richmond, Janet Robbins, Don Roberson, Geoffrey L. Rogers,
Michael M. Rogers, Stephen C. Rottenborn, James S. Royer, Ruth A. Rudesill,
Tamiko Ruhlen, Edd Russel, Ron M. Saldino, Ivan Samuels, Michael J. San Miguel,
Mike San Miguel, Daan Sandee, Larry Sansone, Paul M. Saraceni, Brad Schram,
David M. Shaw, Douglas G. Shaw, Debra L. Shearwater, W. David Shuford, David A.
Sibley, Mary Simpson, Daniel S. Singer, Mike Skram, Arnold Small, Brenda D. Smith,
Reed V. Smith, Ron Smith (RSm), Jim Snowden (JSn), John Sorensen, Steve
Sosensky, Jean Marie Spoelman, Rich Stallcup, Susan Steele, Daniel M. Stoebel,
Mary Beth Stowe, Emilie Strauss, Jeffrey W. Streb, David L Suddjian, Robert
Sutherland (RSu), Mac Sutherlin, Lee Sutton, Ann D. Swart, Craig Taylor, Monte M.
Taylor, Richard L. Ternullo, Scott B. Terrill, Robert Theriault, Ronald S. Thorn,
Robert F. Tintle, Francis Toldi, Gerald L. Tolman, Bob Toth, John A. Trochet, Steve
J. Tucker, Philip Unitt, Sven Wahlberg (SvW), Stan Walens (SWa), Bruce E. Webb,
Sophie Webb, Dave Weber, Richard E. Webster, Walter Wehtje, Joel D. Weintraub,
Alan N. Wight, David S. Wilcove, Brian D.C. Williams, Douglas R. Willick, Rob Willis,
John C. Wilson, Steve Wilson, Adam Winer, Thomas E. Wurster, David G. Yee, James
O. Zimmer.

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

ACKNOWLEDGMENTS

This report would not have been possible without the 27 1 observers who submitted
reports to the Committee. Peter R. Bloom, Janet Linthicum, Eric Mellink, Kurt
Radamaker, Brian J. Walton, and Thomas E. Wurster provided input critical to CBRC
review of recent Harris’s Hawk records. M. Ralph Browning and the late Claudia
Wilds examined a stint specimen. Chris Corben offered insight on Mongolian Plover
identification. CBRC review of Iceland Gull records was assisted by Erik A. T. Blom,
Davis Finch, Roger Foxall, Daniel D. Gibson, Michel Gosselin, the late Peter J. Grant,
Raymond Henson, Ted Hoogendoorn, Dennis Paulson, J. V. Remsen, Jr., Stuart
Tingley, and Thede Tbbish. David A. Sibley advised on wagtail identification. Drafts of
this report were reviewed and improved by Kimball Garrett, Steve N. G. Howell,
Alvaro Jaramilio, Gary S. Lester, Michael Patten, Peter Pyle, Don Roberson, Michael
Rogers, and Mike San Miguel. Peg Stevens and Jon C. Fisher continued to archive the
committee’s materials at WFVZ. We extend our thanks to all.

LITERATURE CITED

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American Ornithologists’ Union. 2000. Forty-second supplement to the American
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Bevier, L. R. 1990. Eleventh report of the California Bird Records Committee. W.
Birds 21:145-176.

Binford, L. C. 1985. Seventh report of the California Bird Records Committee. W.
Birds 16:29-48.

Capitolo, P., Richardson, W., Burnett, R., and Pyle, P. 2000. First record of an Olive-
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Clapp, R. B. 1971. A specimen of Jouanin’s Petrel from Lisianski Island, northwest-
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DeSante, D. F. 1983. Annual variability in the abundance of migrant landbirds on
Southeast Farallon Island, California. Auk 100:826-852.

DeSante, D. F., Johnson, N. K., Le Valley, R., and Henderson, R. P. 1985. Occur-
rence and identification of the Yellow-bellied Flycatcher on Southeast Farallon
Island, California. W. Birds 16:153-160.

Dinsmore, J. J., and Dinsmore, S. J. 1993. Range expansion of the Great-tailed
Graclde in the 1900s. J. Iowa Acad. Sci. 100:54—59.

Dunn, J. L. 1988, Tenth report of the California Bird Records Committee. W. Birds
19:129-163.

Dunn, J. L., and Garrett, K. L. 1997. A Field Guide to Warblers of North America.
Houghton Mifflin, Boston.

Erickson, R. A., and Terrill, S. B. 1996. Nineteenth report of the California Bird
Records Committee: 1993 records. W. Birds 27:93-126.

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Erickson, R. A., Hamilton, R. A., and Howell, S, N. G. In press. New information on
migrant birds in northern and central portions of the Baja California Peninsula,
including species new to Mexico, in Birds of the Baja California Peninsula: Status,
Distribution, and Taxonomy (R. A. Erickson and S. N. G. Howell, eds.). Am.
Birding Assoc. Monogr. Field Ornithol.

Garrett, K., and Dunn, J. 1981. Birds of Southern California; Status and Distribution.
Los Angeles Audubon Soc., Los Angeles.

Gathreaux, S. A., Jr. 1982. Age-dependent orientation in migratory birds, in Avian
Navigation (F. Papi and H. G. Wallraff, eds.), pp. 68-74. Springer-Verlag, Berlin.

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Erickson and S. N. G. Howell, eds.). Am. Birding Assoc. Monogr. Field Ornithol.

Hawthorne, V. M. 1972. Painted Bunting record for northeastern California. Calif.
Birds 3:91-92.

Heindel, M, T. 1996. Field identification of the Solitary Vireo complex. Birding
28:458-471.

Heindel, M. T., and Garrett, K. L. 1995. Sixteenth annual report of the California
Bird Records Committee. W. Birds 26:1-33.

Heindel, M. T., and Patten, M. A. 1996. Eighteenth report of the California Bird
Records Committee: 1992 records. W. Birds 27:1-29.

Heindel, M., and Pyle, P. 1999. Identification of Yellow-bellied and “Western”
flycatchers. Birders’ J. 8:78-87.

Howell, S. N. G. 2000. Identification of Thayer’s-like gulls: The Herring x Glaucous-
winged gull problem. Birders’ J. 9:25-33.

Howell, S. N. G., and Pyle, P. 1997. Twentieth report of the California Bird Records
Committee: 1994 records. W. Birds 28:117-141.

Howell, S. N. G., and Webb, S. 1995. A Guide to the Birds of Mexico and Northern
Central America. Oxford Univ. Press, Oxford, England.

Huey, L. M. 1936. Noteworthy records from San Diego, California. Condor 38:121.

Kishchinski, A. A., and Lobkov. E. G. 1979. Spatial relationships between some bird
subspecies in the Beringiari forest-tundra (in Russian). Moskovskoe Obshchestvo
i Spytatelei Prirody. Otdel Biol. Biull. Novaia Seriia 5:11-23.

Langham, J. M. 1991. Twelfth report of the California Bird Records Committee. W.
Birds 22:97-130.

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Carolina coast. N. Am. Birds 53:113-115.

Luther, J. S., McCaskie, G., and Dunn, J. 1979. Third report of the California Bird
Records Committee. W. Birds 10:169-187.

Luther, J. S., McCaskie, G., and Dunn, J. 1983. Fifth report of the California Bird
Records Committee. W. Birds 14:1-16.

McCaskie, G. 1975. A Rufous-necked Sandpiper in southern California. W. Birds
6:111-113.

McCaskie, G., and San Miguel, M. 1999. Report of the California Bird Records
Committee: 1996 records, W. Birds 30:57-85.

McCaskie, G., and Webster, R. E. 1990. A second Wedge-tailed Shearwater in
California. W. Birds 21:139-140.

Mlodinow, S. G., Feldstein, S., and Tweit, B. 1999. The Bristle-thighed Curlew landfall

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of 1998: Climate factors and notes on identification. W. Birds 30:133-155.

National Geographic Society. 1999. Field Guide to the Birds of North America, 3rd
ed. Natl. Geogr. Soc., Washington, D.C.

Patten, M. A. 1993. First record of the Common Pochard in California. W. Birds
24:235-240.

Patten, M. A. 2000. Changing seasons: Winter season, December 1999 to February
2000. N. Am. Birds 54:146-148.

Patten, M. A., and Erickson, R. A. 1994. Fifteenth report of the California Bird
Records Committee. W. Birds 25:1-34.

Patten, M. A., and Erickson, R. A. 2000. Population fluctuations of the Harris’ Hawk
(Parabuteo unicinctus) and its reappearance in California. J. Raptor Research
34:187-195.

Patten, M. A,, McCaskie, G., and Morlan, J. 1999. First record of the American
Woodcock for California, with a summary of its status in western North America.
W. Birds 156-166.

Patterson, M. 1998. The great curlew fallout of 1998. Field Notes 52:150-155.

Pitman, R. L., and Jehl, J. R., Jr. 1998. Geographic variation and reassessment of
species limits in the “Masked” Boobies of the eastern Pacific Ocean. Wilson Bull.
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Bolinas, CA.

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fall. Birding 22:222-229.

Pyle, P., and McCaskie, G. 1992. Thirteenth report of the California Bird Records
Committee. W. Birds 23:97-132.

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73:243-246.

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Cassidix mexicanus nelsoni and Cossidix mexicanus monsoni in secondary
contact in central Arizona. M. S. thesis, Univ. of Ariz., Tucson.

Ridgway, R. 1919. The birds of North and Middle America, part VIII. U. S. Natl. Mus.
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15:23-25.

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CA.

Roberson, D. 1986. Ninth report of the California Bird Records Committee. W. Birds
17:49-77.

Roberson, D. 1998. Sulids unmasked: Which large booby reaches California? Field
Notes 52:276-297.

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Committee: 1997 records. W. Birds 31:1-37.

Sibley, D. A. 2000. The Sibley Guide to Birds. Knopf, New York.

Sibley, D. A., and Howell, S. N. G. 1998. Identification of White and Black-backed

REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 1998 RECORDS

Wagtails in basic plumage. W. Birds 29:180-198.

Small, A. 1994. California Birds: Their Status and Distribution. Ibis Publ., Vista, CA.

Spear, L. B., Lewis, M. J., Myers, M. T., and Pyle, R. L. 1988. The recent occurrence
of Garganey in North America and the Hawaiian Islands. Am. Birds 42:385-

Stallcup, R., Morlan, J., and Roberson, D. 1988. First record of the Wedge-tailed
Shearwater in California. W. Birds 19:61-68.

Terrill, S. B., and Terrill, L. S. 1981. On the field identification of Yellow-green, Red-
eyed, Philadelphia, and Warbling vireos. Continental Birdlife 2:144-149.

Terrill, S. B., Rottenborn, S. C., Singer, D. S., and Roberson, D. 1999. Winter
season: Middle Pacific coast region. N. Am. Birds 53:203-207.

Veit, R. R. 1988. Identification of the Salton Sea Rufous-necked Sandpiper. W. Birds
19:165-169.

392.

Accepted 1 1 November 2000

ARIZONA BIRD COMMITTEE REPORT:

1996-1999 RECORDS

GARY H. ROSENBERG, P. O. Box 91856, Tucson, Arizona 85752-1856

ABSTRACT: The Arizona Bird Committee assessed 218 records, accepting 138.
These included Arizona’s first records of the Leach’s ( Oceanodroma leucorhoa),
Black (O. melania), and Least (O. microsoma ) Storm-Petrels, Short-tailed Hawk
(Buteo brachyurus), Pacific Golden Plover ( Pluvialis fulua), Yellow-footed Gull
( Larus livens), and Carolina Wren ( Thryothorus ludovicianus), bringing the number
of bird species recorded in Arizona to 522.

This is the fourth report of the Arizona Bird Committee (hereafter ABC)
(see Speich and Parker 1973, Speich and Witzeman 1975, and Rosenberg
and Witzeman 1998, 1999). This report covers records mainly from the
period between 1996 and 1999 but also includes some from prior to 1996
previously not reported on by the ABC. A total of 218 reports submitted to
the ABC are addressed here, with 138 (63%) accepted. Seven species were
added to the Arizona list, Leach’s Storm-Petrel ( Oceanodroma leucorhoa),
Black Storm-Petrel ( Oceanodroma melania), Least Storm-Petrel
( Oceanodroma microsoma) (first physical documentation), Short-tailed
Hawk ( Buteo brachyurus), Pacific Golden-Plover ( Pluvialis fulua), Yellow-
footed Gull ( Larus livens), and Carolina Wren ( Thryothorus ludovicianus).
This brings the total number of species recorded in Arizona to 522, which
includes four species that have been accepted by the ABC but have not been
physically documented within the state: Leach’s Storm-Petrel, Swallow-
tailed Kite (Elanoides forficatus), Black Swift ( Cypseloides niger), and Blue-
headed Vireo ( Vireo so I i tar i us).

Other highlights reported on here include acceptance of Arizona’s second
Wandering Tattler ( Heteroscelus incanus), fifth Pomarine Jaeger
( Stercorarius pomainus), second Black-billed Cuckoo ( Coccyzus
erythropthalmus), third Eastern Wood-Pewee (Contopus virens), second
Nutting’s Flycatcher ( Myiarchus nuttingi), first breeding Winter Wren ( Tro-
glodytes troglodytes), third breeding Black-capped Gnatcatcher ( Polioptila
nigiceps ), first photographed Blue-winged Warblers ( Vermiuora pin us),
second and third photographed Prairie Warblers ( Dendroica discolor ), first
sound-recorded Fan-tailed Warbler ( Euthlypis lachrymosa ), first winter
Rufous-capped Warblers ( Basileuterus rufifrons), and third Field Sparrow
( Spizella pusilla).

The current Arizona Bird Committee (2000) consists of Chris D. Benesh,
Troy Corman, Roy M. Jones, David Krueper, Narca Moore-Craig, Gary H.
Rosenberg (secretary), Will Russell, and Mark M. Stevenson. Recent commit-
tee members who also voted on records in this report include Doug Danforth,
Kenn Kaufman, Chuck LaRue, G. Scott Mills, Dave Stejskal, and Carl Tomoff.
Janet Witzeman serves in a non-voting capacity as assistant secretary.

The list of species on the ABC’s review list can be found on its web page
(http://personal.riverusers.com/~ghrosenberg/GaryRosenbergHomePage.html).
Included on this web site as well are the ABC’s bylaws, a current list of
committee members, a brief history of the ABC, the past two reports by the

Western Birds 32:50-70, 2001

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

ABC (as published in Western Birds), a reporting form for electronic
submission of reports to the ABC, a selection of photographs of rarities from
Arizona, and a varying selection of photographs and discussions concerning
field-identification topics (e.g., the Black-capped Gnatcatcher). This site is a
work in progress.

The ABC encourages observers to submit documentation for species on
the review list, as well as new species for Arizona. All material should be sent
to Gary H. Rosenberg, ABC secretary, P. 0. Box 91856, Tucson, AZ
85752-1856 (e-mail ghrosenberg@theriver.com). The committee would
like to emphasize the importance of submitting sightings directly to the ABC
for review. The listing of reports, including those with written descriptions,
on local list-servers on the Internet may not make it to the ABC. Only those
reports submitted to the ABC, or to the regional editor for North American
Birds (who turns the material on review-list species over to the secretary of
the ABC), will be considered by the committee. The ABC thanks the many
observers from Arizona and around North America who have submitted
their documentation of sightings to the ABC.

Each record listed below includes a locality, county (abbreviation: see
below), date (span normally as published in Field Notes/North American
Birds), and initial observer if known. Additional observers who submitted
reports, photographs, and recordings are also listed. All records are sight
records unless noted otherwise with a symbol for a photograph, sound
recording, or specimen. It has not been customary for the ABC to review
individuals returning for multiple years, but these dates are normally included
within the accounts. The ABC emphasizes that the listing of reports under
Reports Not Accepted does not necessarily mean that the members of the
ABC “do not believe” the observer, simply that the documentation supplied
to the committee for evaluation was not detailed enough to substantiate the
sighting as a record.

The ABC’s abbreviations for counties in Arizona are APA, Apache; COS,
Cochise; COC, Coconino; GIL, Gila; GRA, Graham; GRE, Greenlee; LAP,
La Paz; MAR, Maricopa; MOH, Mohave; NAV, Navajo; PIM, Pima; PIN,
Pinal; SCR, Santa Cruz; YAV, Yavapai; YUM, Yuma. Other nonstandard
abbreviations commonly used within this report include *, specimen; B.T.A.,
Boyce Thompson Arboretum; L.C.R.V., lower Colorado River valley; N.I.R.,
Navajo Indian Reservation; N.M., national monument; N.W.R., national
wildlife refuge; ph., photograph; P.A.P., Pinal Air Park; P.R.D., Painted
Rock Dam; S.P.R., San Pedro River; S.T.P., sewage treatment plant; s.r.,
sound recording; UA, University of Arizona; v.t, video tape.

RECORDS ACCEPTED

RED-THROATED LOON Gauia stellata. A single individual was at L. Havasu City,
MOH, 25 Jan 1998 (TC). There have been about ten previous accepted records for
Arizona.

LEAST GREBE Tachyhaptus dominicus. A single individual was at a small pond in
E. Turkey Creek, Chiricahua Mts., COS, 1-2 Aug 1997 (ph. DF; see NAS Field Notes
52:101), and another was at Willcox, COS, 3 Nov 1998-10 Jan 1999 (DM; ph.
MMS). These represent the ninth and tenth state records.

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

LEACH’S STORM-PETREL Oceanodroma leucorhoa. Although no physical
documentation was obtained, excellent written details were submitted for at least one
individual seen during Tropical Storm Nora at L. Havasu City, MOH, 26 Sep 1997
(BH). This tropical storm brought unprecedented numbers of both Black and Least
Storm-Petrels to L. Havasu, L.C.R.V. This sighting represents one of the few inland
records of Leach's Storm-Petrel for the western U.S. (see Jones 1999).

BLACK STORM-PETREL Oceanodroma melania. After Tropical Storm Nora as
many as 40 were at L. Havasu City, MOH, 26 Sep 1997, with at least three
remaining there until 30 Sep 1997 (ph. TC, BGr, BH; Figure 1; see VJ. Birds
30:187). These represent the first records of this species from Arizona (see Jones
1999).

LEAST STORM-PETREL Oceanodroma microsoma . After Tropical Storm Nora
aproximately 200 were on L. Havasu, MOH, 26 Sep 1997, with several remaining
there until 30 Sep (ph. TC, BGr, BH, m.ob.; *UA; see W. Birds 30:188). The
photographs and two specimens provided the first physical documentation for this
species in Arizona; there were two previous accepted sight reports from the state
(Rosenberg et al. 1991). Similar storms have brought this species to the Salton Sea
previously (see Jones 1999, Kaufman 1977).

REDDISH EGRET Egretta rufescens. Accepted records are of one at P.R.D.,
MAR, 24 Aug 1997 (CBa), one at Avra Valley S.T.P., PIM, 17 Jul 1998 (ph. MMS),
and one at Gila Farms Pond, MAR, 10-11 Aug 1998 (ph. RMJ), bringing the total
number of accepted records for the state to nine.

WHITE IBIS Eudocimus albus. One was at Nogales S.T.P., SCR, 6 Jul-15 Sep
1999 (JSa; ph. MMS, GHR); there were five previous accepted records for Arizona.

Figure 1. These were some of the nearly 40 Black Storm-Petrels found on Lake
Havasu after Tropical Storm Nora 27 September 1998.

Photo by Bill Grossi

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

Figure 2. This Pacific Golden-Plover at the Western Sod Farm near Arizona City 8-
10 August 1998 provided a first Arizona record.

Photo by George Hentz

ROSEATE SPOONBILL Ajaia ajaja. Single individuals were at Gillespie Dam,
MAR, 19-22 Jul 1997 (SPe, MMS, DAI) and at Picacho Res., PIN, 25 Sep-4 Oct
1997 {DC; ph. MMS); these represent the fourth and fifth records since 1992.

ROSS’S GOOSE Chen rossii. A stunning blue-morph individual of this species at
Nogales, SCR, 28 Dec 1998 (MP, ph. MMS) represents the first sighting of this form
in Arizona.

BRANT Branta bernicla. Three at Cornville, YAV, 6 Apr 1998 (RR; ph. RR,
MMS), with one remaining until 19 Apr, represents the first report from Yavapai
County; there are fewer than ten records ever for Arizona, all of the subspecies
nigricans.

WHITE-WINGED SCOTER Melanitta fusca. Accepted records are of one at
Castle Rock Shores, L.C.R.V., LAP, 27 Dec 1985 (SGw), one in Tempe, MAR, 13-
31 Mar 1996 (RMJ), one at Ganado L., N.I.R., APA, 28 Nov 1997 (MMS, BHo,
GHR), and one at Green Valley, PIM, 3-6 Nov 1998 (RP, ph. MMS). This species is
now seen in Arizona nearly annually and has been removed as a review species
(Rosenberg and Witzeman 1998).

BLACK SCOTER Melanitta nigra. A single individual at Parker Dam, LAP, 1 Feb-
14 Apr 1996 (RMJ; ph. MMS) represents only a seventh record for Arizona.

RED-SHOULDERED HAWK Buteo lineatus. Accepted records are of one in s.w.
Phoenix, MAR, 17 Dec 1985 (RWi), one in Tucson, PIM, 20 Feb 1997 (RH), and one
in Scottsdale, MAR, 14 Apr 1998 (JB1). Although this species is reported in Arizona
nearly annually, very few are properly documented (see under Reports Not Accepted).
The ABC encourages observers to attempt to document all sightings of this species in
the state carefully, as many of the written descriptions of Red-shouldered Hawks

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

Figure 3. Arizona’s third Northern Jacana was at Arivaca Lake 19 October 1998.

Photo by Mark Stevenson

Figure 4. Arizona's first Yellow-footed Gull was at Wahweep Marina, Lake Powell, 23
April 1999.

Photo by Gary H. Rosenberg

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

Figure 5. Arizona’s second documented Nutting’s Flycatcher spent the winter of
1997-1998 at Patagonia Lake State Park.

Photo by Larry Sansorte

submitted to the committee for review fail to eliminate confusing species such as the
Broad-winged Hawk.

BROAD-WINGED HAWK Buteo platypterus. Accepted records are of one at
Kearns Canyon, N.I.R., NAV, 23 May 1992 (CL; ph. JBu), one at Cave Creek
Canyon, COS, 13 May 1994 (ph. BZ), one at Granite Creek near Prescott, YAV, 4
May 1997 (CT), and one at Comville, YAV, 9 Apr 1998 (TL, IT). As with Red-
shouldered Hawk, we receive reports of this species nearly annually, but many of
these fail to exclude similar species such as the Red-shouldered and Gray (B. nitidus)
hawks. We encourage observers to use care in identifying this species in Arizona.

SHORT-TAILED HAWK Buteo brachyurus. A dark-morph individual photo-
graphed on Miller Peak in the Huachuca Mts., COS, 31 July-4 Sep 1999 (ph, RH;
ph. GHR) established a first documented record for Arizona. A light-morph individual
seen earlier at the same location 26 July-4 Sep 1999 (RH) has been accepted as well,
given that the dark bird was photographed. There were three previous sight reports
from the state (see Rosenberg and Witzeman 1998), and these will now be re-
evaluated.

AMERICAN GOLDEN-PLOVER Pluvialis dominica. Reports of one at Western
Sod Farm near Arizona City, PIN, 27 Sep 1999 (RH, MMS; ph. MMS) and one in s.w.
Phoenix, MAR, 16 Oct 1999 (TC) were the only ones accepted. This species will

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

Figure 6. This male Black-capped Gnatcatcher was found nesting at Brown Canyon
22 April 1997.

Photo by Gary H. Rosenberg

remain a review species even though it is found annually because of the difficulty in
separating it from the very similar Pacific Golden-Plover.

PACIFIC GOLDEN-PLOVER Pluvial is fulva. A single individual at Western Sod
Farm near Arizona City, PIN, 6-12 Aug 1998 (RH; ph. GHe, MMS: s.r. RMJ; Figure
2) provided Arizona with its first record. This species is a regular fall visitor to the
California coast, with adults and one-year-old birds arriving during the first week of
August; therefore, one in Arizona at that season, while unprecedented, was not
unexpected. This sighting does represent one of the few noncoastal records of this
species.

NORTHERN JACANA Jacana spinosa. A stunning adult at Arivaca L., PIM, 15-
23 Oct 1998 (EB: ph. GHR, MMS; Figure 3) provided Arizona with its third accepted
record; the previous two records are both for June.

WANDERING TATTLER Heteroscelus incanus. A well-described individual at
Tucson S.T.P., PIM, 12 Sep 1991 (BL) was only the second for Arizona; the state’s
only previous tattler was found 18 Sep 1971 in Phoenix (see Witzeman 1997).

UPLAND SANDPIPER Bartramia longicauda. A single bird at Western Sod Farm
near Arizona City, PIN, 16 Aug 1999 (ph. RH) provided one of only a few accepted
Arizona records; interestingly, this species is regular as a fall migrant east of the
continental divide as close to Arizona as Las Cruces, New Mexico.

POMARINE JAEGER Stercorarius pomarinus. An adult was at Paloma Ranch
near Gila Bend, MAR, 8-12 Oct 1999 (ph. BGr, MMS; v.t. GHR). There were only
four previous Arizona records.

PARASITIC JAEGER Stercorarius parasiticus. One individual was on L. Havasu,
MOH, during Tropical Storm Nora 26 Sep 1997 (RMJ; see Jones 1999). There are

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

Figure 7. This Blue-winged Warbler was mist-netted along the San Pedro River near
Hereford 17 July 1999,

Photo by Lisa Walraven

Figure 8. Arizona’s second documented Prairie Warbler was at Wahweep, Lake
Powell, 30 November 1997.

Photo by Garj ; H. Rosenberg

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

fewer than ten previous sight reports from Arizona, many of which have not been
reviewed by the ABC (see Rosenberg and Witzeman 1998). Also, a jaeger of
undetermined species was at the Bill Williams arm of L. Havasu, LAP, 26 Nov 1999
(CBa); the description, while detailed enough to determine the bird to be a jaeger, was
not complete enough to establish the species.

LAUGHING GULL Larus atricilla. An adult was at Patagonia L., SCR, 13-15
Aug 1998 (GHR). There have been fewer than fifteen previous Arizona records.

MEW GULL Larus canus. Single individuals were at Lake Havasu City, MOH, 22
Feb 1998 (RH) and at Davis Dam, MOH, 29 Jan 1999 (JPi). Virtually all of the
previous Arizona records are from the Colorado River during winter.

YELLOW-FOOTED GLJLL Larus livens. A subadult bird at Wahweap, L Powell,
COC, 21-23 Apr 1999 (CL; ph. GHR, MMS; v.t. GHR; Figure 4; see N. Am. Birds
53:344) provided Arizona with its first record, although this species is regular at the
Salton Sea and at the northern end of the Gulf of California. This bird also
represented the first Utah record, and there is at least one record from Nevada (Lake
Mead).

GLAUCOUS GULL Larus hyperboreus. An immature at Fisher’s Landing along
the L.C.R.V. n. of Yuma, YUM, 28 Nov-29 Dec 1992 (JT) is only the third accepted
Glaucous Gull for Arizona.

Figure 9. Arizona’s first winter record of Rufous-capped Warbler was along the San
Pedro River near Hereford in December 1998,

Photo by Jim Burns

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

BLACK-LEGGED KITTIWAKE Risso tridactyla. Accepted records are of one at
Parker Dam, LAP, 11-19 Nov 1978 (BW) and of one adult at Willcox, COS, 15 Nov

1998 (JHa; ph. GHe). This species was more regular during the 1970s and 1980s;
there have been only five sightings in Arizona since 1990.

ARCTIC TERN Sterna paradisaea. A well-described immature from Many Farms
L,, APA, 19 Sep 1993 (CL) furnished only a fourth Arizona record.

BLACK-BILLED CUCKOO Coccyzus erythopthalmus. An individual photo-
graphed in Pinery Canyon, Chiricahua Mts., COS, 7 Oct 1984 (ph. RHi) represents
the first physically documented record for Arizona. The only other accepted record for
the state was from nearby Portal on 3 Oct 1984 (see Rosenberg and Witzeman 1998),
suggesting the possibility that both records involved the same individual.

GROOVE-BILLED ANI Crotophaga sulcirosrtis. Accepted records are of one at
Buckeye, MAR, 30 Jul 1985 (TC) and one at Lake Montezuma, COC, 24 Sep 1998
(DHo). This species is still casual in Arizona and remains on the review list.

BERYLLiNE HUMMINGBIRD Amazilia betyllina. Accepted records are of one in
Ramsey Canyon, COS, 29 May-13 Jun 1998 (CMa), another there 18-20 Jul 1999
(BCa), and one in Miller Canyon, COS, 5 Jul-early Aug 1999 (MMS). In recent years
this species appears to have become a regular summer visitor to feeders in the
Huachuca Mts. and likely breeds in canyons such as Ramsey and Miller in small
numbers. Observers need to be careful with the identification of the Berylline because
of the recent discovery of a hybrid Berylline x Magnificent Hummingbird in Arizona
(Heindel and Howell 2000).

PLAIN-CAPPED STARTHROAT Heliomaster constantii. One was in Madera
Canyon, SCR, 7 Jul-31 Aug 1997 (NC; ph. MMS). There have been about 20
sightings of this Mexican species in Arizona, ten of which have been reviewed by the
ABC. w

LUCIFER HUMMINGBIRD Calothorax lucifer. Accepted records away from the
Portal region are of one in French Joe Canyon, COS, 19 Jul 1997 (NCr) and a pair,
with a female sitting on a nest, in Chino Canyon, SCR, 13-20 Apr 1997 (NC,DNe;
ph. MMS, GHR), providing only a second nesting report from the state. The Lucifer
Hummingbird remains a review species for all reports away from the Portal area.

EARED TROGON Euptilotis neoxenus. Accepted records are of one along the
Black River, APA, 13 Jun 1992 (DF), one in Haunted Canyon, near Globe, PIN, 1
Jan-14 Mar 1996 (DPi, MMa), and one in Cave Creek Canyon, COS, 10-28 Nov

1999 (JBo; ph. JOl). The birds in Haunted Canyon and along the Black River were in
obscure canyons probably never birded before, making one wonder how many Eared
Trogons wander around Arizona without being found.

RED-HEADED WOODPECKER Melanerpes erythrocephalus. One at the P.A.P.
pecan grove, PIN, 25 Oct 1997-Apr 1998 (PS; ph. MMS) provided only a seventh
documented record from the state (Rosenberg and Witzeman 1998).

EASTERN WOOD-PEWEE Contopus virens. One singing individual in Madera
Canyon, SCR, 23 Jun-20 Aug 1998 (MMS, ph. MMS, s.r. GHR, RMJ) represents
only a third documented record for Arizona (see Rosenberg and Witzeman 1999).

LEAST FLYCATCHER Empidonax minimus. One well-described individual at
Arivaea L., PIM, 28 Nov 1996 (NCr) represents one of the few accepted reports of
this species for the state. Given the difficulty in distinguishing the Least from the Dusky
Flycatcher, the ABC still encourages observers to document all sightings of this species
physically.

NUTTING’S FLYCATCHER Myiarchus nuttingi. A well-documented individual at
Patagonia Lake State Park 14 Dec 1997-21 Mar 1998 (WR; ph. GHR, LSa, MMS, BZ;

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

s.r. GHR, RMJ; v.t. CDB; Figure 5; see cover N. Am. Birds 52, no. 2; 52:148)
represents only the second confirmed report of this species from the United States. The
only other documented occurrence was of an individual collected at Roosevelt Lake,
PIN, 8 Jan 1952 (Monson and Phillips 1981). The ABC has not reviewed one mist-
netted near Elgin, SCR, 1 5 Jul 1985, but photos published (Bowers and Dunning 1987)
suggest that the bird was likely a worn Ash-throated Flycatcher (M. cinerascens).
Observers are encouraged to attempt to document any report of this species in Arizona
with tape recordings of voice, which are useful for acceptance by the ABC, and not rely
solely on difficult-to-ascertain visual characters such as color of mouth lining.

WHITE-EYED VIREO Vireo griseus. The only accepted record was of one in
Portal, COS, 19 Aug 1998 (GHR); there were eleven previous records for Arizona.

BELL’S VIREO Vireo bellii. A report from the confluence of the Salt and Verde
rivers n.e. of Phoenix, MAR, 26 Dec 1993 (TC) represents one of the few accepted
winter sightings in the state.

PHILADELPHIA VIREO Vireo philadelphicus. Accepted records are of one in
French Joe Canyon, COS, 14 Apr 1996 (CCa) and one in s.w. Phoenix, MAR, 16
Oct 1999 (TC). The April report marks the earliest ever for spring in Arizona.

RED-EYED VIREO Vireo olivaceus. One at Kingfisher Pond along the upper San
Pedro R., COS, 16 May 1997 (DK) represents the only accepted record. This species
has certainly declined over the past 20 years, and, because of its similarity to the
Yellow-green Vireo (Terrill and Terrill 1981), it remains a review species.

YELLOW-GREEN VIREO Vireo flavoviridis. Two July reports accepted, of one at
Guadalupe Canyon, COS, 11 Jul 1988 (NMC; ph. MMS; s.r. CDB) and one at
Patagonia, SCR, 21-24 Jul 1999 (RH, JLD, MMS). Four of the five accepted Yellow-
green Vireos in Arizona were discovered in late June or July (Rosenberg and
Witzeman 1999).

BLUE JAY Cyanocitta cristata. One individual at River Mile 175 in the Grand
Canyon, COC, 7 May 1998 (CL; ph. NBr) was the sixth recorded in Arizona.

CAROLINA WREN Thryothorus ludovicianus. A singing individual at Cook’s
Lake along the San Pedro R. near Dudleyville, PIN, 18 Jun 1999-fall 2000 (TK, TC;
ph. TC, MMS; s.r. TC, GHR, CDB) provided Arizona with its first record. This species
has been expanding its range in Texas and New Mexico and was not unexpected.

WINTER WREN Troglodytes troglodytes. Although the Winter Wren is not a
review species, the committee did review the first summer reports from Arizona. One
individual was along the w. fork of Oak Creek Canyon, COC, 25 Jun 1994 (FBr) and
has been reported from there in subsequent years. Another individual was seen
carrying food (presumably to a nest) along Christopher Creek, COC, 21 Jul 1999
(KN, TC). The known breeding location nearest Arizona is northern California or
northern Idaho, but a singing male has been seen in the Jemez Mts. in northern New
Mexico in recent years (B. Howe pers. comm.).

BLACK-CAPPED GNATCATCHER Polioptila nigiceps. Accepted records are of
two pairs in Brown Canyon, PIM, 22 Apr 1997 (NC, RT; ph. GHR, MMS; s.r. GHR;
v.t. CDB; Figure 6), with at least one of the pairs attempting nesting and remaining
there until Jan 1998, one male at Patagonia, SCR, 25 May 1998 (DS, RT; s.r. DS),
one female in Chino Canyon, SCR, 23 Feb 1999 (RH), and a pair in California Gulch,
SCR, 23-31 Jul 1999 (RH; s.r. CDB; ph., s.r. DS). This species has been an irregular
breeder in Arizona, with the first record in the early 1970s (Phillips et al. 1973) and
the most recent in the late 1980s (possibly early 1990s). Extreme caution should be
exercised in identifying this species in Arizona because of apparent hybridization with
the Black-tailed Gnatcatcher ( P. melanura).

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

WOOD THRUSH Hglocichla mustelina. One was at Agua Caliente Park, Tucson,
PIM, 25-27 Oct 1997 (WLe, MMS). There are fewer than fifteen accepted records for
Arizona.

RUFOUS-BACKED ROBIN Turdus rufopal/iatus. One was in Guadalupe Can-
yon, COS, on the late dates of 3-4 Jun 1980 (CBr), one was at Kino Springs, SCR,
14 Dec 1986-1 Apr 1987 (RBa), one was well north in Prescott, YAV, 10 Dec 1988-
6 Jan 1989 (LF), one was along Sonoita Cr. below Patagonia L., SCR, 19 Dec 1992
(GH), one was netted along the San Pedro R. near Sierra Vista, COS, on the very late
date of 5 Jun 1996 (ph. DK), one wintered along the San Pedro R. near Hereford,
COS, 5 Dec 1998-2 Jan 1999 (JLe; v.r. CDB), two were at the B.T.A., PIN, 19-30
Jan 1998 (CT, m.ob.), and one was at the Arizona-Sonora Desert Museum, PIM, 4-
6 Nov 1999 (JKr; ph. MMS). This species is one of the more regular of the Mexican
strays to occur in Arizona; the June record is the first in summer for the state. The
Rufous-backed Robin is no longer a review species.

BOHEMIAN WAXWING Bombycilla garrulus. A large flock of at least 150
individuals in Flagstaff, COC, from early February into March {with one remaining to
10 Apr 1984) was photographed 15 Mar 1984 (ph. JCo, TC). To our knowledge, this
is the most recent sighting of this species in Arizona.

BLUE-WINGED WARBLER Vermivora pinus. Accepted records are of one in
Sycamore Canyon, SCR, 20 Dec 1998 (GSM), one along the Santa Cruz R. in
Tucson, PIM, 13-28 Mar 1999 (RGr; ph. RMJ, MMS; v.t. GHR; see N. Am. Birds
53:311), and one along the San Pedro R. near Hereford, COS, first seen 16 May
1999 (HKo) and later (probably the same individual) netted 17 Jul (ph. MSM; Figure
7). There were only five previous records for Arizona.

GOLDEN-WINGED WARBLER Vermivora chrysoptera. An accepted report of
one in Sabino Canyon, PIM, 15 Feb 1997 (CGo) provided one of the few winter
records for the state. Other accepted records are of one along the San Pedro R. near
Dudleyville, PIN, 18 Jun 1999 (TC) and one in Madera Canyon, SCR, 1-3 Nov 1999
(ph. MMS). This species is still considered casual in Arizona with about 20 records.

TENNESSEE WARBLER Vermivora peregrina. Records accepted by the commit-
tee are of one along the S.P.R. s. of Charleston, COS, 24 Sep 1986 (DK), one along
Granite Cr. near Prescott, YAV, 1 May 1997 (CT), and one in Cave Creek Canyon,
COS, 24-26 May 1997 (CHo). The Tennessee Warbler has now been removed from
the review list.

MAGNOLIA WARBLER Dendroica magnolia. Accepted records are of one at the
B.T.A., PIN, 29-30 Sep 1997 (RMJ) and one near Topock, MOH, 30 Nov 1997
(DWi). There are fewer than 25 records for the state.

CAPE MAY WARBLER Dendroica tigrina . Winter still appears to be the best
season to find this warbler in Arizona; records accepted are of one in Patagonia, SCR,
16 Dec 1984 (AMo), one at Fountain Hills, MAR, 22-24 Dec 1986 (RBr), and one
at the Forty-Niners Country Club in n.e. Tucson, PIM, 28 Nov-3 Dec 1998 (RH,
MMS). There are still fewer than 15 total records for Arizona.

BLACK-THROATED GREEN WARBLER Dendroica virens. The only report
submitted to the committee and accepted was of one at Portal, COS, 29 Oct 1993
(ph. DJa). This species was once thought of as regular in Arizona, but this record
represents only the second accepted record since 1990, with only a few reports not
submitted to the committee.

BLACKBURNIAN WARBLER Dendroica fusca. One accepted record of a male
from along the S.P.R. e. of Sierra Vista, COS, 27 May 1999 (DEd). There are still fewer
than 20 records for Arizona, about six of which have not been reviewed by the ABC.

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

YELLOW-THROATED WARBLER DencJroica dominica. One was at Reid Park in
Tucson, PIM, 31 Oct-7 Dec 1997 (CGr; ph. GHR, MMS), representing about a 20th
record for Arizona.

PINE WARBLER Dendroica pinus. Winter is certainly the best season to find this
warbler in the state; accepted reports were of one in Reid Park in Tucson, PIM, 26
Dec 1997-15 Feb 1998 (ph. MMS), one along the Santa Cruz R., PIM, 5-25 Jan

1998 (RBo; ph. RH), and one at Sweetwater Wetlands, Tucson, PIM, 23-26 Jan

1999 (TC; ph. MMS). There were only four previously accepted records for Arizona
(see Rosenberg and Witzeman 1999).

PRAIRIE WARBLER Dendroica discolor. Amazingly, one was photographed at
Wahweap, Lake Powell, COC, 30 Nov-1 Dec 1997 (ph. GHR, MMS; Figure 8), and
another individual was found and photographed by the same observer the next day, 1
Dec 1997, remaining until at least 11 Jan 1998, in Tucson, PIM (ph. MMS, GHR).
There was only one previous documented record for the state.

BAY-BREASTED WARBLER Dendroica castanea. The only accepted record is of
one in Horseshoe Canyon, Chiricahua Mts., COS, 7 Nov 1998 (NMC). There were
about 10 previously accepted records for Arizona.

BLACKPOLL WARBLER Dendroica striata. One accepted record of one at
Granite Reef Picnic Area along the Salt R. n.e. of Phoenix, MAR, 27 Oct 1991 (ph.
SGa). A large percentage of the Arizona reports have not been submitted to the ABC.

LOUISIANA WATERTHRUSH Seiurus motacilla. Accepted records are of one in
Cave Creek Canyon, COS, 27 Dec 1992 (CSa), one in Sycamore Canyon, SCR, late
Nov 1996-24 Jan 1997 (RH), one along the S.P.R. near Hereford, COS, 10 Sep
1998 (DK), one in Sycamore Canyon, SCR, 1 Feb 1999 (ph, MMS), and one along
Queen Creek near Superior, PIN, 7 Nov 1999 (MMS). It has been well demonstrated
that this species is a rare but regular winter visitor to rocky streams in s.e. Arizona. It
has been removed as a review species by the ABC, but sketch details are still requested
for inclusion of reports in N. Am. Birds.

KENTUCKY WARBLER Oporornis formosus. Accepted records are of one at
Kino Springs, SCR, 28 Oct 1978 (GHR), one in Flagstaff, COC, 1 1 May 1997 (FBr),
one in Scottsdale, MAR, 19 Nov 1997 (JB1), and one at the Roger Road Wastewater
facility, Tucson, PIM, 8-15 Oct 1998 (ph. MMS). This species has been removed as
a review species in Arizona, but sketch details are requested for inclusion of reports in
N. Am. Birds.

MOURNING WARBLER Oporornis Philadelphia. A well-described individual
from Navajo, NAV, 1 Oct 1988 (DS) made the only accepted record. There are only
five previously accepted records of the Mourning Warbler in Arizona, only one of
which has been documented with a photograph or specimen.

FAN-TAILED WARBLER Euthiypis lachrymosa. A singing male at Patagonia,
SCR, 21-27 May 1997 (JBo, WR, BPr; s.r. DS) provided Arizona with its sixth
record.

RUFOUS-CAPPED WARBLER Basileuterus rufifrons. Two winter reports were
accepted, of one along the S.P.R. near Hereford, COS, 4-30 Dec 1998 (MPr; ph
JBu, GHR; Figure 9) and one in lower Sycamore Canyon, SCR, 23 Dec 1998 (ph.
GHR, CDB). These represent the first winter records for Arizona and the ninth and
tenth records overall.

SCARLET TANAGER Piranga oliuacea. Reports of one breeding-plumaged male
at the Hassayampa River Preserve near Wickenburg, MAR, 26 Apr 1998 (EHo) and
one at Paloma, MAR, 25 Oct 1998 (RMJ) were the only ones accepted. There are

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

only 14 accepted records for the state, with an additional eiqht reports not submitted
to the ABC.

FLAME-COLORED TANAGER Piranga bidentata. Two accepted records of
females were of one in Miller Canyon, COS, 29 May 1997 (TC) and one nesting, and
apparently mated with a Western Tanager (P. ludoviciana), in Whitetail Canyon,
COS, 16 May-mid-Jun 1998 (RT; ph. MMS). There have been only five previously
accepted records for Arizona, three of which were of nesting pairs. The first recorded
male, in April 1985 (Morse and Monson 1985), was also mated with a Western
Tanager, and a hybrid male tanager at Bog Spring in Madera Canyon (1995 and
1996) showed characteristics of both the Flame-colored and Western tanagers.

FIELD SPARROW Spizella pusilla. One alona the S.P.R. near Hereford, COS, 12
Dec 1998-21 Feb 1999 (CSm, CDB, GHR; ph. MMS, GHR) provided only a third
Arizona record.

LAPLAND LONGSPUR Calcarius lapponicus. Accepted records are of one near
Hfrida, COS, 20 Feb-4 Mar 1984 (AMo) and one near Topock, L.C.R.V., MOH, 27
Nov 1999 (RMJ). This species is still considered casual in Arizona with fewer than ten
accepted records in all.

RUSTY BLACKBIRD Euphagus carolinus. One accepted record of a bird seen on
both sides of the Colorado R. near Ehrenberg, LAP, 24 Nov 1988 (ph. PL).

COMMON GRACKLE Quiscalus quiscula. One on the Salt River Indian Res.,
MAR, 21 Dec 1987 (RBr) represents only the eighth accepted record for the state. A
very low percentage of reports from Arizona have been submitted to the ABC,

ORCHARD ORIOLE Icterus spurius. One female remained at Fountain Hills,
MAR, 2 Jan-10 Feb 1992 (JSo, ph. SFi, PL). Additional accepted records are of one
at the Phoenix Zoo, MAR, 20-24 Dec 1997 (RMJ; ph. RD) and one in the Avra
Valley, PIM, 31 Jan-28 Feb 1998 (HMc; ph, MMS), As with the previous species,
very few of the Arizona reports have been written up and submitted to the ABC. The
Orchard Oriole is still casual in the state at best and remains a review species.

STREAK-BACKED ORIOLE Icterus pustulotus. One well-described individual
from the bottom of the Grand Canyon (RM 246), MOH, 22 Jan 1998 (CL)
represented the first n. Arizona record. Critical in the identification (distinguishing the
Streak-backed from the immature Bullock’s Oriole) was a combination of reddish
orange in the face and a lack of orange-yellow in the tail (see Kaufman 1983 for a
discussion of this complex). This record is only the fourth accepted of this species
away from the lower S.P.R. , where it has bred in the recent past.

BALTIMORE ORIOLE Icterus galbula. Accepted records are of one male in Chino
Valley, YAV, 3 May 1991 (LMu), one male 6 mi. n. of Camp Verde, YAV, 29 Apr
1998 (TLi), and another male in s.w. Phoenix 30 May-11 Jun 1998 (RWi, RMJ).
There have been very few recent reports of this species from Arizona. Because of the
difficulty of distinguishing females from Bullock’s Oriole this species remains on the
review list.

REPORTS NOT ACCEPTED

RED-THROATED LOON Gauio stellate. The description of one seen at a great
distance at P.R.D., MAR, 13 Jan 1993 did not rule out a Pacific Loon (G. pacified).

LEAST GREBE Tachybaptus dominicus. Details of one reported in Scottsdale.
MAR, 16 Apr 1998 did not rule out the Eared ( Podiceps auritus) or Pied-billed
(Podilymbus podiceps ) grebes.

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

LEACH’S STORM-PETREL Oceanodroma leucorhoa. One reported after Tropi-
cal Storm Nora from Lake Havasu, MOH, 27 Sep 1997 lacked details specific
enough to rule out other storm-petrel species. A photograph submitted with the
report was intriguing, but most committee members believed that a pale area
appearing on the rump was a photographic artifact and that the bird in the photo was
likely a Black Storm-Petrel.

YELLOW-CROWNED NIGHT-HERON Nyctanassa violacea. An immature re-
ported from Kino Springs, SCR, 10 Jul 1992 may have been correctly identified, but
the description was not complete enough to rule out a Black-crowned Night-Heron
( Nycticorax nycticorax). Furthermore, the observer was not confident of the identifi-
cation, a refreshing admission!

WHITE IBIS Eudocimus albus. A brief description of two at P.R.D., MAR, 23 Jul
1995 was not detailed enough for acceptance, and the sighting coincided with the
occurrence of a Sacred Ibis ( Threskiornis aethiopicus) there. A report of three adults
at Mittry L. near Yuma, YUM, 26 Sep 1998 was thought by many of the committee
(after two rounds) to be correct, but three members were still troubled by the lack of
description of bill and leg characteristics.

RED-SHOULDERED HAWK Buteo lineatus . Single reports from near Chino
Valley, YAV, 9 Jan 1990, from Picacho Res., PIN, 5 Aug 1992, from near Mayer,
YAV, 21 Feb 1999, and from near Liguarta, Gila Mts,, YUM, 15 Apr 1999, were all
lacking details specific enough to eliminate similar species.

BROAD-WINGED HAWK Buteo platypterus. An immature hawk reported from
Patagonia, SCR, 2 Dec 1998 was described as lacking a “dark trailing edge border”
to the wing, which committee members thought better fit a Gray Hawk.

WHITE-TAILED HAWK Buteo albicaudatus. Two reports, one from near Kirkland,
YAV, 30 Dec 1996, the other from the Empire Cienega Ranch, SCR, 6 Mar 1997
were not detailed enough to accept. Because of the lack of substantiated reports this
century (see Rosenberg and Witzeman 1998), the committee requires at least
photographic evidence accompanying any report of this species.

APLOMADO FALCON Falco femoralis. A description of a falcon from n.e. of
Douglas, COS, 24 Sep 1999 lacked the detail to substantiate this sighting as the first
credible record of the Aplomado Falcon for Arizona since 1940 (Monson and Philips
1981). As the number of valid records from New Mexico has been on the increase in
recent years, it is only a matter of time until an Aplomado Falcon is sighted again in
Arizona. The ABC encourages that any report of this species include some sort of
physical documentation.

SAGE GROUSE Centrocercus urophasianus. One male reported near Globe,
PIN, 15 Sep 1995 was thought perhaps to have been a raptor; the closest that the
Sage Grouse occurs to Arizona is central Colorado.

ELEGANT QUAIL Callipepla douglasii. An adult present for several months in
Douglas, COS, first seen 17 Jan 1998, was considered by the committee to likely
have been an escapee. As this species ranges north to within 100 miles of Arizona’s
border with Sonora, it is possible that one could occur naturally in Arizona. The
committee would like to see a pattern of vagrancy before accepting one as a first
Arizona (and United States) record.

AMERICAN GOLDEN-PLOVER Pluvialis dominica. The description of one
reported from Willcox, COS, 16 Sep 1992 lacked sufficient detail to be accepted.

YELLOW-FOOTED GULL Larus livens. An adult gull with a “black” mantle was
described from Willow L., YAV, 8 May 1999, but the bird was seen at a distance of at

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

least 3000 feet, so critical features that would eliminate other dark-mantled species
were not discerned.

WESTERN GULL La rus occidentalis. A description of a juvenile or first-winter gull
from Willow L., YAV, 16 Dec 1998 lacked enough critical detail to determine the
species and did not eliminate a Herring Gull (L. argentatus smithsonianus).

BLACK-BILLED CUCKOO Coccyzus erythropthalmus. An intriguing report of
one near Carrizo, NAV, 26 May 1995 included a fairly good description, but the call
was said to be a series of six to eight “coo” notes, incorrect for this species.

GROOVE-BILLED ANI Crotophaga sulcirostris. The description of one reported
from Camp Verde, YAV, 2 May 1998 lacked enough detail for acceptance.

BUFF-COLLARED NIGHTJAR Caprimulgus ridgwayi. A very interesting report
of a nightjar on the road at night (seen in the headlights) in Guadalupe Canyon, COS,
28 Jan 1995 was perhaps of this species, but the details did not rule out other
nightjars (particularly the Whip-poor-will, C. vociferus) which, at times, can show a
tawny collar. As this record would be a first in winter for the U.S., the ABC was unable
to accept it without more substantiation.

BERYLLINE HUMMINGBIRD Amazilia beryllina. The following reports of this
species lacked detail sufficient for acceptance: one in Guadalupe Canyon, COS, 27
May 1985, one at Patagonia, SCR, 8 Jun 1985, one in Cave Creek Canyon, COS,
31 Jul 1996, and one in Madera Canyon, SCR, 6 Aug 1998. It should be noted once
again (see Rosenberg and Witzeman 1998) that virtually all Arizona records for this
species are from a narrow elevation zone (5000-6000 feet) within oak woodland.

EARED TROGON Euptilotis neoxenus. The description of a trogon from open
pine-oak habitat at 7000 feet in the Huachuca Mts. (exact location not mentioned!),
COS, 21 May 1989 certainly suggested this species, but at least three committee
members believed the report was too marginal for acceptance.

YELLOW-BELLIED FLYCATCHER Empidonax flavtventris. A report of one
from Spruce Mt. near Prescott, YAV, 20 Aug 1991 was not detailed enough to
determine the species within this difficult complex of flycatchers.

LEAST FLYCATCHER Empidonax minimus. A winter report from Buenos Aires
N.W.R., PIM, 19 Dec 1993 did not eliminate other Empidonax species. Another
mid-winter report of a silent individual from Patagonia, SCR, 20 Feb 1999 had too
many inconsistencies with the Least Flycatcher (general shape and eye-ring shape);
the committee felt that Hammond’s and Dusky flycatchers were not eliminated.

NUTTING’S FLYCATCHER Myiarchus nuttingi. On the heels of a well-docu-
mented Nutting’s Flycatcher from Patagonia Lake during the winter of 1997-98 (see
under Accepted Records), two additional reports of this species were received, one
from Kino Springs, SCR, 29 Dec 1998, the other from Patagonia L., SCR, 11 Jan
1999. In both cases, vocalizations were not described well enough (not heard in the
Patagonia L. bird) to rule out the Ash-throated Flycatcher. Furthermore, other
observers reported an Ash-throated Flycatcher from Kino Springs during the same
period that showed a tail pattern more suggestive of a Nutting’s. The separation of
Nutting’s and Ash-throated Flycatchers is subtle enough that only well-documented
(tape-recorded or extensively photographed) individuals are acceptable to the ABC.

GREAT CRESTED FLYCATCHER Myiarchus crinitus. A sketchy report of this
species from along the Hassyampa R. near Wickenburg, MAR, 5 Sep 1998 was felt
to have not dealt properly with the range of variation within this genus; most
committee members felt that Brown-crested Flycatcher (M. tyrannulus ) was not
eliminated.

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

GREAT KISKADEE Pitangus sufphuratus. An honest account of a strange
flycatcher at the Grand Canyon, COC, 2 Aug 1995 was thought to apply to this
species, but the description was not detailed enough to accept this report as a third
Arizona record.

FORK-TAILED FLYCATCHER Tyrannus savana. The description of one reported
from along the S.P.R. near Dudleyville, PIN, 2 Aug 1995 lacked detail sufficient to
substantiate a first Arizona record.

WHITE-EYED VIREO Vireo griseus. A report from Safford, GRA, 25 JUN 1996
did not include enough detail for acceptance.

YELLOW-THROATED VIREO Vireo flavifrons. Details of one from s. of Willcox
1 Apr 1993 were not sufficient to accept a sighting of this species nearly a month
earlier than the next earliest record in s.e. Arizona.

BLUE-HEADED VIREO Vireo solitarius. A description of an individual reported
from Phoenix, MAR, 8 Jan 1990 did not adequately rule out Cassin’s Vireo. The
committee urges extreme caution in the differentiation of these two species (see
Heindef 1996).

RED-EYED VIREO Vireo olivaceus. A report from Chiricahua N.M., COS, 4 Oct
1985 did not rule out other vireos, such as the Yellow-green.

YELLOW-GREEN VIREO Vireo flauoviridis. The details of one reported from
Cave Creek Canyon, COS, 9 Mar 1982 were insufficient to support a sighting far
outside the span of dates of the species’ regular occurrence in Arizona.

BLACK-CAPPED GNATCATCHER Polioptila nigriceps. A single individual re-
ported from Sabino Canyon, P1M, 18 Apr 1998 was well away from areas of previous
occurrence, and the description did not rule out the common Black-tailed Gnat-
catcher. Another report of one wintering in Sycamore Canyon, SCR, 26 Dec 1985
was almost certainly correct (there are accepted reports from that locality from before
and after this sighting), but the details submitted did not substantiate the record. One
additional report from Sycamore Canyon 4 Jun 1994 also lacked the critical detail
necessary to eliminate the Black-tailed or a hybrid between the Black-capped and
Black-tailed. A male at Chino Canyon, SCR, from April 1995 through 1999 is
suspected of being such a hybrid. Its head pattern was perfect for a Black-capped, but
the amount of white in the tail, the bill length, and the vocalizations all appeared
intermediate between the two species. It was originally found with a female Black-
capped but was subsequently found mated with a female Black-tailed.

VEERY Catharus fuscescens. Reports of individuals at Watson Wood near
Prescott, YAV, 4 Apr 1997, at Madera Canyon, SCR, 6 Apr 1997, and at the
Hassayampa River Preserve near Wickenburg, MAR, 17 May 1998 all lacked detail
sufficient to eliminate other species in this complex genus. There is only one
physically documented record of the Veery in Arizona away from historic nesting
areas near Springerville (Rosenberg and Witzeman 1999).

WOOD THRUSH Hylociehla musteline. One reported from Ramsey Canyon,
COS, 18 May 1997 was not described adequately for acceptance.

RUFOUS-BACKED ROBIN Turdus rufopalliatus . Reports of individuals at Here-
ford, COS, 28 Mar 1981, at Tucson Mt. Park, PIM, 21 Dec 1988, and in Huachuca
Canyon, COS, on the late date of 5 Jun 1999 were likely correct, but the details
supplied did not substantiate the reports.

BLUE MOCKINGBIRD Melanotis caerulescens. An individual seen in n.w.
Tucson, PIM, 23 Sep 1992 was not accepted mainly because the observer felt it was
likely an escapee and because the observation time was so short. The committee

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

believed it better to wait for additional early fall reports before perhaps reevaluating
this report.

RED-THROATED PIPIT Anthus ceruinus. A very intriguing report from two
highly experienced observers of a calling individual heard only at the P.A.P. pecan
grove 26 Oct 1991 was not accepted because several members of the committee (as
well as the observers themselves) felt uncomfortable accepting such a rarity in the state
(second Arizona record) on the basis of call alone. Whereas many on the committee
had little doubt that the bird was correctly identified, they felt that an identification
based solely on a call and descriptions written several years after the “sighting” did not
constitute an acceptable record. It should be noted that the fall of 1991 was far and
away the best ever for Red-throated Pipits in California, with several found at desert
oases as in Kern County and Death Valley.

GRAY SILKY-FLYCATCHER Ptilogonys cinereus. An interesting report of two
adults and one juvenile along Ruby Road w. of Sycamore Canyon, SCR, 10 Aug 1993
did not include enough information to support a first state record. Also, the brief
descriptions of both the juvenile and female did not support the identification.

BLUE-WINGED WARBLER Vermiuora pinus. A report of one from Tempe,
MAR, 14 May 1995 was likely correct but not thorough enough for the record to be
accepted. A description of one near Hereford, COS, 1 May 1998 also lacked enough
critical detail for acceptance.

TENNESSEE WARBLER Vermiuora peregrina. Reports not accepted by the ABC
are of one from Yuma, YUM, 20 Dec 1986, one from the Empire Cienega Ranch,
SCR, 6 May 1993, and one from along Granite Creek near Prescott, YAV, 14 Sep
1994.

BLACK-THROATED GREEN WARBLER Dendroica uirens. A report of one from
Phoenix, MAR, 13 Aug 1981 did not adequately eliminate similar species such as
Townsend’s (D. townsendi) and Hermit (D. occidentalis) warblers.

BLACKBURNIAN WARBLER Dendroica fusca. A report of one in Sawmill
Canyon, COS, 20 May 1999 was not detailed enough for acceptance.

WORM-EATING WARBLER Helmitheros uermiuorus. A report from below Glen
Canyon Dam, COC, 15 Jun 1992 was too brief for acceptance. This species has been
removed as a review species.

KENTUCKY WARBLER Oporornis formosus. Two reports were not accepted,
one from Beaver Dam Creek, MOH, 24 May 1997 and one from near Kirkland,
MOH, 22 Jun 1997.

MOURNING WARBLER Oporornis Philadelphia. A report from Florida Wash,
PIM, 31 Aug 1993 lacked certain critical features necessary to substantiate it.

SLATE-THROATED REDSTART Myioborus miniatus. An odd report of one
associating closely with a juvenile Painted Redstart (that apparently wanted to be fed)
in Cave Creek Canyon, COS, 18 Jun 1995 lacked certain critical characters. Perhaps
not coincidentally, a researcher at the Southwest Research Station in Cave Creek
Canyon was apparently coloring the white parts of Painted Redstarts in the canyon,
possibly accounting for the report.

SCARLET TANAGER Piranga olivacea. A winter report from near the confluence
of the Salt and Verde rivers, MAR, 10 Dec 1988 was likely correct, but the observer did
not note characters to eliminate a greenish-yellow Summer Tanager definitively. There
is only one winter record accepted for the state (see Rosenberg and Witzeman 1999).

RED-HEADED TANAGER Piranga ergthrocephala. A male reported from Carr
Canyon, COS, 14 May 1996 was, from the description of voice and plumage,

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

thought by most on the committee to likely have been a one-year-old Summer
Tanager with a yellow-green body and red head. Some form of physical documenta-
tion is needed for acceptance of a first Arizona (and United States) record.

AMERICAN TREE SPARROW Spizelia arborea. Two reports, one from near
Gadsden s. of Yuma, YUM, 20 Jan 1981, the other from Gila Farms Pond s. of
Phoenix, MAR, 25 Dec 1994 were both too sketchy for acceptance. There still
remains only one accepted southern Arizona record (see Rosenberg and Witzeman
1999).

FIELD SPARROW Spizelia pusilla. A report of a flock of five from Kitt Peak, PIM,
24 Sep 1997 clearly pertained to some other sparrow, perhaps the Chipping.

LAPLAND LONGSPUR Calcarius lapponicus. One reported from near Elfrida,
COS, 4 Feb 1997 was likely correctly identified, but the details were too sketchy for
acceptance.

COMMON GRACKLE Quisca/us quiscula. A report of an individual seen only in
flight at Springerville, APA, 26 Jun 1994 was almost certainly correct, but, given that
the bird was never seen perched, the committee felt the report was best left not
accepted.

ORCHARD ORIOLE Icterus spiurus. Descriptions of one at Cave Creek Canyon,
COS, 24 Apr 1994 and one at Madera Canyon, SCR, 21 May 1996 were both too
brief to be accepted.

BALTIMORE ORIOLE Icterus galbula. Two reports of females lacked enough
detail to eliminate the similar Bullock’s Oriole: one at Springerville, APA, 24 Sep
1985 and one at Prescott, YAV, 19 Aug 1987.

PINE GROSBEAK Pinicola enucleator. A report of three from Sedona, YAV, 31
Jan 1998 was intriguing but lacked enough detail for acceptance of an extralimital
record of this species in Arizona. Similarly, a report from Glendale, MAR, 9 Mar 1999
was not conclusive enough to support a first lowland record for the state.

PURPLE FINCH Carpodacus purpureus. One reported from Sedona, YAV, 1 Apr
1999 did not eliminate the similar Cassin’s Finch (C. cassinii).

CORRIGENDA

The following records were inadvertently published in the previous Ari-
zona Bird Committee reports (Rosenberg and Witzeman 1998 and 1999) as
“accepted” when in fact they were not accepted by the committee. The ABC
apologizes for the errors: Eurasian Wigeon (Anas penelope) at the
confluence of the Salt and Verde rivers, MAR, 10 Dec 1991; Red-shoul-
dered Hawk 16 mi s. of Chino Valley, YAV, 9 Jan 1990; Red-shouldered
Hawk at Picacho Res., PIN, 5 Aug 1992; Broad-winged Hawk at Barfoot
Lookout, Chiricahua Mts., COS, 6 Aug 1995; Purple Gallinule ( Porphyrula
martinica ) at Gila Farms Pond, MAR, 1 Aug 1991; American Golden-
Plover at Willcox, COS, 18 Sep 1992; Tennessee Warbler at the Empire
Cienega, SCR, 6 May 1993; Orchard Oriole in Cave Creek Canyon, COS,
24 Apr 1994.

CONTRIBUTORS

D. Alexander, C. Babbitt, D. Bailey, J. Bartley (JB1), J. Bates, R. Bates, J. Bealer,
C. D. Benesh, E. Bennett, T. Bishop, J. Bock, R. Bowers, R. Bradley, J. Braley, F.

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

Brandt, C. Brown, M. Brown, N. Brown, K. Brunson, J. Burns, W. Cady, S.
Capawana, B. Carrell, C. Cathers, J. Chace, R. Chapman, D. Clark, M. Collie, J.
Coons, T. Corman, N. Crook, D. Crumb, V. Dayhoff, B. Demaree, K. Diem, R. Ditch,
J. L. Dunn, D. Edwards, F. Fekel, R. Ferguson, S. Finnegan, D. Fischer, L. Frederick,

S. Ganley, B. Given, S. Goldwasser, S. Goodchild, C. Gordon, C. Green, R.
Grohman, B. Grossi, P. Hammerton, J. Hand, T. & J. Heindel, G. Hentz, R. Hicks,
J. Hirth, C. Hohenberger, D. Hook, E. Hough, B. Howe, R. Hoyer, C, Hunter, B.
Jackson, D. Jasper, B. Johnson, R. Jones, C. Kangas, B. Kerr, C. Kolesar, H. Koons,

T. Koronkiewicz, J, Krebs, J. Kreitzer, D. Krueper, C. LaRue, P. Lehman, W. Leitner,
J. Levine, T. Linda, R. Long, B, Lyon, M. Mammoser, C. Marrantz, B. McAneny, L.
McCloskey, A. McCready, H. McCrystal, V. Miller, G. S. Mills, S. Mlodinow, G.
Monson, A. Moorhouse, N. Moore-Craig, D. Morrison, P, Moulton, L. Muelbach, G.
Nation, D. Nelson, K. Newlon, P. Norton, J, Oldenettel, J. Owen, R. Palmer, J. Paris,
D. Pearson, S. Peterson, D. Pierce, L. Piest, J. Pike, B. Pranter, M. Pretti, J. Price, B,
Principe, R. Radd, G. H. Rosenberg, R. Ray, W. Russell, J. Saba, P. Salomon, C.
Sandell, M. SanMiguel, L. Sansone, M. Sennett, C. Sherman, J. Simon, C. Smith, M.
Sogge, J. Sommers, D. Stejskal, M. M. Stevenson, B. Sutton, D. Taylor, J. Taylor, R.
Taylor, B. Thomen, I. Tolinson, C. Tomoff, M. Vandzura, J. Whetstone, B. Whitney,
D. Wight, R. Witzeman, B. Wotten, B. Zimmer.

ACKNOWLEDGMENTS

I thank the many observers who submitted their sightings to the ABC for review;
Arizona ornithology has benefited greatly from their efforts. Chris Benesh, Roy
Jones, Narca Moore-Craig, Mark Stevenson, and Janet Witzeman all contributed
greatly to the improvement of the manuscript.

LITERATURE CITED

American Ornithologists’ Union. 1998. Check-list of North American Birds, 7th ed.
Am. Ornithol. Union, Washington, D.C.

Bowers, R., and Dunning, J. B. 1987. Nutting’s Flycatcher in Arizona. Am. Birds
4L5-10.

Heindel, M. 1996. Field identification of the Solitary Vireo complex. Birding 28:458-
471.

Heindel, M., and Howell, S. N. G. 2000. A hybrid hummingbird in southeast Arizona.
W. Birds 31:265-266.

Jones, R. M. 1999. Seabirds carried inland by tropical storm Nora. W. Birds 30: 185-
192.

Kaufman, K. 1977. The changing seasons. Am. Birds 31:141-152.

Kaufman, K. 1983. Identifying Streak-backed Orioles: A note of caution. Am. Birds
37:140-141.

Monson, G., and Phillips, A. R. 1981. Annotated Checklist of the Birds of Arizona,
2nd ed. Univ. of Ariz. Press, Tucson.

Morse, R., and Monson, G. 1985. Flame-colored Tanager in Arizona. Am. Birds
39:843-844.

Phillips, A. R., Speich, S., and Harrison, W. 1973. Black-capped Gnatcatcher, a new
breeding bird for the United States; with a key to the North American species of
PolioptUa. Auk 90:257-262.

Rosenberg, G. H., and Stejskal, D. 1994. The Arizona Bird Committee’s Field
Checklist of the Birds of Arizona. Ariz. Bird Committee, G. H. Rosenberg, P. O.
Box 91856, Tucson, A Z 85752-1856.

ARIZONA BIRD COMMITTEE REPORT: 1996-1999 RECORDS

Rosenberg, G. H., and Witzeman, J. L. 1998. Arizona Bird Committee Report,
1974-1996: Part 1 (nonpasserines). W. Birds 29:199-224.

Rosenberg, G. H,, and Witzeman, J, L. 1999, Arizona Bird Committee Report,
1974-1996: Part 2 (passerines). W. Birds 30:94-120.

Rosenberg, K. V., Ohmart, R. D., Hunter, W. C., and Anderson, B. W. 1991. Birds
of the Lower Colorado River Valley. Univ. of Ariz. Press, Tucson.

Speich, S,, and Parker, T. A. 1973. Arizona Bird Records, 1972. W. Birds 4-53-57.

Speich, S. M., and Witzeman, J. L. 1975. Arizona Bird Records, 1973, with
additional notes. W. Birds 6:145-155.

Terrill, S. B., and Terrill, L. 1981. On the field identification of Yellow-green, Red-
eyed, Philadelphia, and Warbling Vireos. Continental Birdlife 2:144-149.

Witzeman, J., Demaree, S., and Radke, E. 1997. Birds of Phoenix and Maricopa
County, Arizona. Maricopa Audubon Soc,, Phoenix.

Accepted 29 September 2000

RECOLONIZATION OF THE FLICKER AND OTHER
NOTES FROM ISLA GUADALUPE, MEXICO

PAUL R. SWEET and GEORGE F. BARROWCLOUGH, Department of Ornithol-
ogy, American Museum of Natural History, Central Park West at 79th Street, New
York, New York 10024

JOHN T. KLICKA, J. F. Bell Museum of Natural History, University of Minnesota, St.
Paul, Minnesota 55108 (current address Barrick Museum, University of Nevada, Las
Vegas, Nevada 89154)

LILIANA MONTANEZ-GODOY and PATRICIA ESCALANTE-PLIEGO, Instituto de
Biologia, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-153,
04510 Distrito Federal, Mexico

ABSTRACT: During a visit to Isla Guadalupe from 31 May to 3 June 1996, we
documented three species new to the island, the Barn Owl, Swainson’s Thrush, and
Hooded Oriole, and established first breeding records for the European Starling and
Western Meadowlark. Red-shafted Flickers are now breeding on the island, represent-
ing a recent recolonization from the mainland following the extinction of the endemic
population. We investigated the validity of Colaptes auratus rufipileus and con-
cluded that it does not meet the standard for phylogenetic species but differs from C.
a. collaris at the 75% level usually associated with subspecific rank. Damage to the
cypress forest by goats continues, and all species dependent on these trees are
threatened by loss of habitat.

Isla Guadalupe is a volcanic oceanic island lying 260 km west of the coast
of Baja California (29° 00' N, 118° 20' W). It is some 37 km long with an
area of 250 km 2 and reaches an elevation of 1298 m. The history and status
of the avifauna have been reviewed by Howell and Cade (1954) and more
recently by Jehl and Everett (1985). Subsequent observations have been
reported by Dunlap (1988), Oberbauer et al. (1989), Mellink and Palacios
(1990), Howell and Webb (1992), and Gallo and Figueroa (1996). Here we
report on birds observed and collected on a visit to Isla Guadalupe between
31 May and 3 June 1996. Maps of the island, showing localities mentioned
here, have been provided by Jehl and Everett (1985) and Moran (1996).
Three of the species we recorded represent first records for the island; in
addition, we confirmed the breeding of two recently colonizing species and
noted the recolonization of a previously extirpated species whose taxonomic
status we reexamined.

ITINERARY

We spent a few hours at the naval base (Melpomene Cove or Punta Sur)
upon our arrival on the island and then traveled the dirt road from there to
the airstrip (Campo Pista: 29° 01' N, 118° 17' W), where we spent one night
and a morning observing and collecting. We then continued to the cypress
grove (29° 07' N, 118° 20' W, 1165m), near the highest point on the island,
where we spent two nights. One night was spent at the fishing village
(Campo Tepeyac or Campo Oeste). We returned to the naval base by
launch.

Western Birds 32:71-80, 2001

NOTES FROM ISLA GUADALUPE

CONSERVATION

Unfortunately the decimation of the island’s vegetation by feral goats is
continuing; we saw large numbers of goats throughout the island. They
appeared to be most numerous in the central and northern portions of the
island, nearer the major source of fresh water. Moran (1996) reviewed the
history of goat damage to the flora of the island and estimated that the
youngest of the endemic Guadalupe Cypress ( Cupressus guadalupensis )
were well over 100 years old. Apparently, in excess of 20,000 goats were
removed from the island in 1971, reportedly leaving only 239 animals at
that time (Agraz Garcia 1978). Moran (1996) estimated that the population
had rebounded to at least 7000 in 1994. Low-intensity hunting by fisher-
men and marines has had little impact on the population in recent years. In
addition, attempts at protecting the remaining cypress forest fragment with
a wire fence have failed. The fence is breached in many places, and a gate
is missing; large herds of goats were observed trooping through the
cypresses at all hours, leaving virtually no vegetation of consequence within
the understory of the grove {Figures 1 and 2). In addition, the bark of many
of the trees showed evidence of damage by goats. Clearly only the complete
removal of goats from the island or a secure fence with a full-time warden will
guarantee long-term survival of the cypresses and the birds dependent on
them. We also saw feral dogs and cats on the island, but only in small
numbers.

ANNOTATED LIST

Laysan Albatross ( Phoebastria immutabilis). First recorded breeding on
Isla Guadalupe in 1986 (Dunlap 1988). Its status up to 1992 was reviewed
by Gallo and Figueroa (1996). We briefly surveyed the rocky plateau above
the naval base and observed six full-grown chicks and one adult bird. The
young birds were close to fledging with down remaining only on the head
and neck.

Brandt’s Cormorant { Phalacrocorax pencillatus). A pair was seen flying
past Islote Zapato at the south anchorage.

American Kestrel ( Falco sparverius). Fairly common and observed
throughout the island.

Western Gull ( Larus occiderttalis). A few were seen along the coast
between Campo Tepeyac and Melpomene Cove.

Mourning Dove ( Zenaida macroura). Common throughout the island.
Many were observed coming to drink at the fresh water spring below the
north end of the cypress grove.

Barn Owl ( Tyto alba). A single flank feather (Coleccion Nacional de Aves
25550) found near the airstrip provides the first documentation of the
occurrence of this species on the island, although we saw or heard none.
There have been several anecdotal reports of large owls on the island, and
previous authors assumed that these refer to the Great Horned Owl ( Bubo
uirginianus).

During Edward Palmer’s initial study of the avifauna of the island (Ridgway
1876), two unidentified species of owls were observed but not collected.

NOTES FROM ISLA GUADALUPE

Accounts of B. virginianus on the island appear to originate with Palmer’s
assistant (Bryant 1887) who reported a “Horned Owl {Bubo)” and that “the
Mexicans” reported a “large owl (“ Tecolote ”).” It is possible this represents
a misunderstanding on behalf of the assistant: tecolote in Mexican Spanish
could refer to any small owl, bubo (interpreted as Bubo?) to any large owl.
Presumably the tecolote is the Burrowing Owl, and Bryant (1887) assumed
that the large owl was a Great Horned. However, it now appears plausible
that these early reports refer to the Barn Owl, a species that is known for its
ability to colonize islands, including Isla Socorro some 500 km from the
southern tip of Baja California. No Great Horned Owls were heard during
our visit.

Burrowing Owl ( Athene cunicularia). Fairly common; several pairs were
seen between the south end and the cypress grove.

Anna’s Hummingbird ( Calypte anna). Common in the cypress grove.

Northern Flicker ( Colaptes auratus [cafer group]). Fairly common in the
cypress grove; we found several active nests and collected two birds. A male
(CNAV 24795) had enlarged testes and a female (CNAV 24794) had yolking
eggs. The endemic form, C. a. rufipileus, has not been collected since 1906
and has been considered extinct. We believe the birds we saw and collected
were mainland Red-shafted Flickers and that Isla Guadalupe has been
successfully recolonized by flickers following the extirpation of the endemic
subspecies (see below).

Rock Wren ( Salpinctes obsoletus). Abundant from the beaches up to the
cypress forest.

Swainson’s Thrush ( Catharus ustulatus ). We collected a male with
moderately enlarged testes (CNAV 24746) in the cypress grove; no other
individuals were seen or heard. This is the first record of this species on Isla
Guadalupe. Presumably it represents a vagrant; Swainson’s Thrush occurs
throughout Baja California as a migrant (Howell and Webb 1995) and has
been recorded and presumed to be migrating in the mountains of Baja
California as late as early June (Wilbur 1987). Escalante-Pliego compared
the specimen to series at CNAV and tentatively identified it as nominate C.
u. ustulatus, common in migration on the nearby mainland.

Northern Mockingbird ( Mimus polyglottos). We saw two together in an
open area near the cypress grove but could not determine if they were a pair.
Bryant (1887) observed two birds in 1886, and subsequently individuals
were seen near the airstrip in January 1988 (Howell and Webb 1992) and
November 1989 (Mellink and Palacios 1990).

European Starling ( Sturnus vulgaris). This species is now common on Isla
Guadalupe. We saw a flock of over 100 birds near the spring below the
cypress grove. Previous authors noted a few starlings on the island but
suspected that they might represent only winter visitors (Howell and Webb
1992). However, we confirmed nesting in tree cavities in the cypress grove
and collected one juvenile (CNAV 24826).

Guadalupe Junco ( Junco insularis). This distinctive, endemic taxon has
been recognized as a species in recent treatments (Howell and Webb 1995).
We found it common within the cypress grove but did not see it anywhere
else on the island. At the time of our visit, fledglings in streaky juvenal
plumage were abundant and some males were still singing. Although other

NOTES FROM ISLA GUADALUPE

authors have found juncos down to sea level outside of the nesting season,
we saw them only in the remnant stand of cypress.

Western Meadowlark ( Sturnella neglecta). Jehl and Everett (1985) re-
ported only a record from 1886, but Howell and Webb (1992) saw 35-40
near the airstrip in January 1988 and suggested that the species might
breed. Mellink and Palacios (1990) also observed it in November 1989. We
found this species to be common throughout the island, particularly in the
extensive grasslands of the central plateau, with flocks of up to 50 birds.
Males were singing from prominent perches. We collected two birds, a male
with enlarged testes (CNAV 24798) and a female with a regressing brood
patch (CNAV 24836). Evidently this species has successfully colonized the
island.

Hooded Oriole ( Icterus cucullatus). We saw and collected a single male,
which had slightly enlarged testes, in a solitary eucalyptus tree at Campo
Pista (CNAV 24756). This is the first island record and presumably a
vagrant; however, we were unable to reach the palm grove on the north
slope of the island (Moran 1996), which perhaps could harbor a small
breeding population.

House Finch ( Carpodacus mexicanus). Common from sea level to the
cypress grove. Recently fledged young were abundant during our visit and
males were singing.

SYSTEMATIC STATUS OF THE FLICKERS OF ISLA GUADALUPE

Ridgway (1876) originally described the subspecies of the Red-shafted
Flicker from Isla Guadalupe, emphasizing the “bright tawny forehead” —
hence the name rufipileus — as the diagnostic character. He suggested rump
color, bill length, wing length, tail length, and the amount of black on the
underside of the tail as additional characters. Bryant (1886) treated the
flickers of Isla Guadalupe as a full species.

Here we reevaluate the taxonomic status and characteristics of the
Guadalupe Flicker in order to determine the provenance of the flickers we
observed on the island. A series of C. a. rufipileus is available in the
ornithological collections of the American Museum of Natural History; these
birds were collected in the months of May, July, and August. For compara-
tive material of mainland flickers that might represent the source for a
possible recolonizing population, we borrowed specimens from a number of
museums (see Acknowledgments). To ensure that we were working with
individuals from breeding populations, and not migrants, we used adult
specimens of both sexes from late spring and summer from mainland
breeding localities. Few specimens were available from any one locality for
the breeding season; therefore, our mainland sample was composed of Red-
shafted Flickers from the mountains of northern Baja California, the
southern California ranges from San Diego north to the San Bernardinos,
the coastal ranges north to Monterey, and a few birds from the Sierra
Nevada. These samples represent C. a. collaris, a form with a range
proximal to and a phenotype similar to the recent Guadalupe birds (a
comparison of extremes of C. a. collaris and the paler C. a. canescens,

NOTES FROM ISLA GUADALUPE

courtesy P. Unitt, indicates that the two recent island birds are not typical of
the highly migratory canescens ). In all, our final sample consisted of one
recent male and one recent female flicker from Isla Guadalupe, which we
treated as of unknown origin, 1 1 males and 13 females from Isla Guadalupe
from the late 19th and early 20th centuries, representing C. a. rufipileus,
and 1 3 male and 1 5 female specimens from Baja California and southern
California, representing C. a. col laris.

Sweet and Barrowclough independently measured, for all specimens,
culmen length (from base of skull), wing chord (bend of wing to longest
primary), tail length (to tip of longest central rectrix), and width of the
terminal black band on the ventral surface of one of the central reetrices;
some measurements could not be taken because of molt or broken feathers
or bill. In addition, we independently arranged the specimens into graded
series of crown/forehead color, by sex, from most to least rufescent; we then
assigned the value of one to the most reddish bird, the value two to the next
bird in the series, etc. (R. W. Dickerman, pers. comm, suggested that foxing
was not a significant problem in flickers). In this way, we obtained two
estimates for each of four mensural characters and a color character for the
Guadalupe, mainland, and two new flickers. We averaged the two values,
reducing measurement sampling error.

We used the computer package SAS (Windows version 6.12: procedure
univariate; SAS Inst. 1988) to produce box plots for the crown color
estimates. Because the color scores we assigned the birds are on an arbitrary
scale, which is undoubtedly nonlinear, we used a nonparametric, descriptive
technique for analyzing those data. Box plots simply encode frequency
information and require no assumptions about the underlying distribution:
the heavy vertical lines indicate the range, the solid lower and upper edges
of the box correspond to the 25th and 75th percentiles of the distribution,
the dashed line is the 50th percentile (median), and the cross is the mean of
the distribution (Figure 3). Crown color, the principal character originally
used to diagnose the Guadalupe Flicker, clearly varies substantially between
the mainland and the island for both sexes. The two new specimens, a male
and a female, both have scores unequivocally placing them with the
mainland series.

Ridgway (1876) also mentioned a pink wash on the rump as a character
for the island race, but we were unable to find a consistent difference in rump
color and did not investigate that trait further. In the four measurements, the
island and mainland forms completely overlapped in culmen and tail length.
In wing length and width of the black tail bar, the means of the two samples
for males and females differed, though with substantial overlap in the
distributions (box plots not shown here). However, neither measurement had
as great a power for discrimination as the crown color. Because these four
measurements showed varying patterns of correlation (Table 1), we used a
principal-component (PC) analysis to determine whether there was a linear
combination of measurements that, independent of crown color, yielded a
segregation of the island birds. We adopted a PC rather than a discriminant-
function analysis (DFA) because our sample sizes were small and PC analysis
identifies the “natural” combinations of the measurements representing

NOTES FROM ISLA GUADALUPE

Figure 1. View northwest from remaining cypress grove. Young trees do not exist and
older trees (such as the one in foreground) have had pieces of bark stripped by goats.

Photo by Paul R. Sweet

Figure 2. View into remnants of cypress grove, showing lack of understory.

Photo by Paul R. Sweet

NOTES FROM ISLA GUADALUPE

Guadalupe Mainland Guadalupe Mainland

Figure 3. Box plots for crown color scores for male and female specimens of Red-
shafted Flickers from Isla Guadalupe (historical sample), the southwestern mainland,
and two recent Isla Guadalupe specimens, (triangles).

most of the variation in a set of data; in DFA, desired groupings are made on
an a priori basis and high discrimination among groups that represents a
very small fraction of the actual total variation is sometimes found. Using the
matrix of character correlations, we found PC axes, separately for the two
sexes, that summarized most of the variation in measurements with two
vectors (SAS Inst. 1988: procedure princomp). For males, the first two PC
axes explain 45% and 27% of the total variation, respectively; for females,
the corresponding values are 41% and 38%. The character loadings on the
first two PC axes are available from the authors. In Figure 4 we have plotted

Table 1 Matrix of Correlation Coefficients between
Mensural Measurements of Isla Guadalupe and Main-
land Red-shafted Flickers 0

Culmen

Wing

Tail

Tail Tip

Culmen

-0.076

-0.031

0.292

Wing

-0.182

—

0.091

-0.640

Tail

0.276

0.515

—

0.372

Tail Tip

0.409

-0.321

0.198

—

a Males above and females below diagonal.

NOTES FROM ISLA GUADALUPE

PCI

Figure 4. Scores of Isla Guadalupe (solid circles) and mainland (open circles) Red-
shafted Flickers on first two PC axes based on measurements only. The recent female
from Isla Guadalupe is indicated by a triangle; the recent male specimen was
incomplete and so cannot be included.

the PC scores for the Isla Guadalupe, mainland, and recent flickers for which
a full set of measurements were available. Unfortunately, some birds,
including one of the recent specimens from Isla Guadalupe, had missing
values and could not be included in the PC analysis.

For both sexes, the first PC axis yielded a good, but not perfect discrimi-
nation between the island and mainland specimens. In both cases the island
birds have greater average PCI scores than do the mainland specimens. The
pattern of character loadings indicates that for both sexes the PCI axis is
largely a contrast of wing length vs. tail tip. For the males, sample location
appears to be independent of the second PC axis; for females, island
specimens have somewhat lower average scores on PC2 than do those from
the mainland. The pattern of character loadings indicates that PC2 is at least
in part a wing length plus tail length axis. The recent island female is clearly
associated with the mainland specimens.

Our analysis of crown color plus four measurements indicates that the two
recent flickers collected on Isla Guadalupe have characteristics placing them
with mainland flickers rather than with the historical population. Green way
(1967) summarized the historical status of the Guadalupe Flicker; it was last
collected in June 1906. None were recorded after that in spite of a number
of expeditions and searches. However, Jehl and Everett (1985) reported that
in late 1972 flickers were once again seen on the island; such observations
have continued (e.g., Howell and Webb 1992), but the subspecific status of
the recently observed birds was in doubt. The long historical gap in
observations of flickers between 1906 and 1972, the continuing presence
of flickers since then, and our character analysis, taken together, suggest that
Isla Guadalupe was recolonized by mainland Red-shafted Hickers in the late
1960s or early 1970s and that the endemic subspecies is extinct.

NOTES FROM ISLA GUADALUPE

Like most birds, the Guadalupe Flicker was described before the invention
of statistical tests and quantitative studies of population variability. In part our
detailed analysis of these flickers was based on an interest in ascertaining
whether the subspecies C. c. rufipileus actually designates a distinctive
endemic population (e.g., Barrowclough 1982). One modern, statistical
standard for the recognition of subspecies is the “75% rule” (e.g., Mayr
1969). One interpretation of this rule is that subspecific recognition is
warranted if 90% of one subspecies can be distinguished from 90% of the
second (this is the 75% rule for symmetrical distributions). For crown color,
the box plots indicate that females meet this standard, but males do not. For
the PC analysis, based on measurements alone, the results are even less
conclusive; no single PC axis can separate the island and mainland birds in
accord with the 75% rule for either sex. For the females, a linear combina-
tion of PCI and PC2 can do so, but the pattern of Figure 4 is such that it
appears this would not hold up with an increased sample size. With the
specimens currently available — that is, with few specimens from Isla
Guadalupe in fresh (recently molted) plumage — the now extinct Guadalupe
Flicker does not approach the 100% diagnosably different status required
for recognition of a phylogenetic species (e.g., McKitrick and Zink 1988).
However, females meet the 75% standard for subspecies. We therefore
believe that subspecies status is (was?) warranted for this island form. It is
clear that the flickers of Isla Guadalupe differed on average from those of the
mainland; however, we did not find the degree of differentiation to be
extensive. There may have been sufficient continuing gene flow to prevent
complete isolation. An alternative possibility is that a series of fresh August
or September specimens would have been largely diagnosable. Molecular
methods may someday have the power to address such questions.

ACKNOWLEDGMENTS

Our trip to Isla Guadalupe would not have been possible without the assistance of
the Armada de Mexico, which provided transport to and from Isla Guadalupe; we
particularly thank Commandante Francisco Perez-Rico and the officers and crew of
C-81 Zarco for their hospitality while we were at sea. The fishermen of Cooperativa
de Langosteros y Abuloneros de Ensenada provided much needed logistic support on
the island and taught us the noble art of “chivo” hunting. We thank the curatorial staffs
of the U.S. National Museum of Natural History (Philip Angle), the Los Angeles
County Museum of Natural History (Kimball Garrett), the California Academy of
Sciences (Karen Cebra), and the Museum of Vertebrate Zoology (Carla Cicero) for
providing loans of flickers under their care. We thank the Secretaria del Medio
Ambiente, Recursos Naturales y Pesca, for providing permits. We are grateful to
Jeffrey Groth for preparing two figures and to Philip Unitt, William Everett, and an
anonymous reviewer for helpful comments on an earlier version of this paper. This
research was supported in part by the Leonard J. Sanford Trust.

LITERATURE CITED

Agraz Garcia, A. A. 1978. La cabra cimarrona ( Capra hircus ) en la Isla de Guadalupe,

B. C. Ganadero 3:35-49.

Barrowclough, G. F. 1982. Geographic variation, predictiveness, and subspecies.

Auk 99:601-603.

NOTES FROM ISLA GUADALUPE

Bryant, W. E. 1887. Additions to the ornithology of Guadalupe Island. Bull. Calif.
Acad. Sci. 2:269-318.

Dunlap, E. 1988 Laysan Albatross nesting on Guadalupe Island, Mexico. Am. Birds
42:180-181.

Gallo-Reynoso, J.-P., and Figueroa-Carranza, A.-L. 1996. The breeding colony of
Laysan Albatrosses on Isla de Guadalupe, Mexico. W. Birds 27:70-76.

Greenway, J. C., Jr. 1967. Extinct and Vanishing Birds of the World, 2nd ed. Dover
Publ., New York.

Howell, S. N. G., and Webb, S. 1992. Observations of birds from Isla Guadalupe,
Mexico. Euphonia 1:1-6.

Howell, S. N. G., and Webb, S. 1995. A Guide to the Birds of Mexico and Northern
Central America. Oxford Univ. Press, Oxford, England.

Howell, T. R,, and Cade, T. J. 1954. The birds of Guadalupe Island in 1953. Condor
56:283-294.

Jehl, J. R., and Everett, W. T. 1985. History and status of the avifauna of Isla
Guadalupe, Mexico. Trans. San Diego Soc. Nat. Hist. 20:313-336.

Mayr, E. 1969. Principles of Systematic Zoology. McGraw-Hill, New York.

McKitrick, M. C., and Zink, R. M. 1988. Species concepts in ornithology. Condor
90:1-14.

Mellink, E., and Palacios, E. 1990. Observations on Isla Guadalupe in November
1989. W. Birds 21:177-180.

Moran, R 1996. The Flora of Guadalupe Island, Mexico. Memoirs Calif. Acad. Sci. 19.

Oberbauer, T. A., Cibit, C., and Lichtwardt, E. 1989. Notes from Isla Guadalupe. W.
Birds 20:89-90.

Ridgway, R. 1876. Ornithology of Guadalupe Island, based on notes and collections
made by Dr. Edward Palmer. Bull. U.S. Geol. Geogr. Surv. Terr. 2:183-195.

SAS Institute Inc., 1988. SAS Language Guide for Personal Computers, release 6.03
ed. SAS Inst., Cary, NC.

Wilbur, S. R. 1987. Birds of Baja California. Univ. Calif. Press, Berkeley.

Accepted 30 October 2000

NOTES

ORANGE BISHOPS BREEDING IN PHOENIX, ARIZONA

THOMAS A. GATZ, U. S. Fish and Wildlife Service, 2321 W. Royal Palm Road,
Suite 103, Phoenix, Arizona 85021

In late summer of 1998 and 1999, 1 observed a small colony of approximately ten
Orange Bishops (Euplectes franciscanus ) in north Phoenix, Arizona. The colony was
in a grassy tree-lined partially channelized desert wash in a highly urbanized area south
of the intersection of First Drive and Greenway Parkway. A small amount of standing
water was present through most of the year. In June of 2000, the 1998-1999 site was
still occupied and I located a second group of six birds approximately 1 . 1 km east of the
first location in a small cattail marsh with surface water in the same wash southwest of
the intersection of Seventh Street and Greenway Parkway. The cattail marsh formed
as a result of water ponded below a street culvert. The bishops at both locations were
feeding on seeds of Johnson Grass ( Sorghum hatepense), a nonnative species from
the Mediterranean region. Males, and occasionally females, often perched in nearby
native and nonnative trees. I visited these specific locations and the surrounding area
frequently from 1994 to 1997 but observed no bishops prior to 1998-

Evidence of breeding included alternate-plumaged males (Figure 1) displaying and
chasing females from June through September, a male carrying a long blade of grass,
apparently for nesting material, on 4 July, and a recently constructed but unoccupied
nest in the cattail marsh on 6 August (Figure 2). The roundish nest, made of dried

Figure 1. Adult male Orange Bishop in alternate plumage, Phoenix, Arizona, July
2000.

Photo by T. Gatz

Western Birds 32 81-82, 2001

NOTES

Figure 2. Nest of Orange Bishop, Phoenix, Arizona, August 2000.

Photo by T. Gatz

grass, was 10 cm tall by 7.5 cm wide with an opening near the top. It was woven
around several stems of Johnson Grass, 1 m above the water surface. In September,
I observed a female feeding a fledged young.

This species, a member of the mainly African weaver family, the Ploceidae, is
native to sub-Saharan Africa and is now well established in southern California with
flocks of 50 to 100 birds routinely noted in some flood-control basins near Los
Angeles [Garrett, K. L. 1998. Field separation of bishops { Euplectes ) from North
American emberizids. W. Birds 29:231-232]. Both the California and Arizona birds
are assumed to have originated from escaped cage birds. Small colonies of this species
are now established in the West Indies and are also believed to have originated from
captive birds (Raffaele, H., J. Wiley, O. Garrido, A. Keith, and J. Raffaele. 1998. A
Guide to the Birds of the W 7 est Indies, p. 446. Princeton Univ. Press, Princeton, N.J.).

Although no additional cattail marsh/Johnson Grass habitat occurs in the area
immediately surrounding these sightings, a considerable amount of similar habitat,
into which this species could spread, exists in riparian areas, around artificial
impoundments for flood control, and in agricultural sections of central and southern
Arizona.

I thank Kimball L. Garrett and Scott Smithson for sharing useful information on
Orange Bishops with me. Garrett and Kathy Molina reviewed an earlier draft of the
manuscript.

Accepted 14 October 2000

NOTES

BREEDING-SEASON HOME RANGES

OF SPOTTED OWLS IN THE

SAN BERNARDINO MOUNTAINS, CALIFORNIA

GUTHRIE S, ZIMMERMAN and WILLIAM S. LaHAYE, Department of Fisheries and
Wildlife, University of Minnesota, 174 McNeal Hall, 1985 Buford Ave., St. Paul,
Minnesota 55108

R. J. GUTIERREZ, Department of Wildlife, Humboldt State University, Areata,
California 95521 and Department of Fisheries and Wildlife, University of Minnesota,
St. Paul, Minnesota 55108

Home ranges of the Northern Spotted Owl ( Strix occidentalis caurina) in the
Pacific Northwest (Forsman et al. 1984, Solis and Gutierrez 1990, Carey et al. 1992,
Zabel et al. 1995), of the Mexican Spotted Owl [S. o. lucida) in the southwestern U.S.
(Ganey and Baida 1989, Zwank et al. 1994, Ganey et al. 1999), and of the California
Spotted Owl (S. o, occidentalis ) in the Sierra Nevada (Call et al. 1992, Zabel et al.
1992) have all been quantified. No home-range estimates exist, however, for isolated
populations of the California Spotted Owl in the southern portion of its range
(Gutierrez and Pritchard 1992, Gutierrez et al. 1995). Therefore, we report breeding-
season home-range size for two pairs of radio-marked Spotted Owls in the San
Bernardino Mountains, which support the largest population of the subspecies in
southern California (LaHaye et al. 1997).

Our study area is approximately 140 km east of Los Angeles, California (34° 15'
N, 117° 55' E). The San Bernardino Mountains are oriented east/west with elevations
ranging from 800 to 3500 rn and are surrounded by desert and chaparral vegetation
(Barbour and Major 1988). The climate is Mediterranean, with most precipitation
falling during the winter in the form of snow above 2000 m and rain at lower
elevations. Precipitation, influenced by elevation and slope aspect, ranges from 25 to
100 cm (Minnich et al. 1995). Vegetation grades from Mojave desert scrub and
coastal scrub at lower elevations to alpine at higher elevations (Barbour and Major
1988). Within this continuum, local aspect and topography form a complex mosaic of
forest, chaparral, desert, and wetland vegetation. In this range, Spotted Owls occur
between 800 and 2600 m and occupy forests composed of Canyon Live Oak
( Quercus chrysolepis), Black Oak (Q. kelloggii), Big-cone Douglas Fir ( Pseudotsuga
macrocarpa ), White Fir (Abies concolor), Incense Cedar ( Calocedrus decurrens),
Jeffrey Pine ( Pinus jeffregi), Ponderosa Pine (P. ponderosa), and Sugar Pine ( P.
larnbertiana).

Using radio telemetry, we monitored two pairs of Spotted Owls from July 1987 to
August 1988. We captured the owls with noose poles or mist nets. Each owl was fitted
with a radio transmitter (Telonics Inc., Mesa, Arizona) by means of a backpack harness
(Guetterman et al. 1991). The total mass of the transmitter package was approxi-
mately 18 g. We received transmitter signals through TR-2 receivers and four-element
hand-held Yagi antennas (Telonics Inc.). Otis and White (1999) demonstrated that
autocorrelation of telemetry locations does not bias estimates of home ranges when
animals are considered the sampling unit. Nonetheless, we separated all owl locations
in this study by at least 24 hours. We followed techniques outlined by Guetterman et
al. (1991) and estimated nocturnal locations from triangulation of three to six
compass bearings taken from fixed telemetry points. Triangulations resulting in
polygons larger than 2 ha were removed from analyses.

We defined a breeding-season home range as the area used by owls during their
nightly activities (Burt 1943) between March and August. We used the program
CALHOME (Kie et al. 1996) to estimate home ranges with a minimum convex
polygon (MCP) and the program KERNELHR (Seaman et al. 1998) to produce fixed-

Western Birds 32:83-87, 2001

NOTES

and adaptive-kernel (Worton 1989) estimates. We used kernel estimators because
they require no unrealistic assumptions about space use (Worton 1989) and perform
better than other estimators in simulations (Worton 1995). The fixed-kernel estimator
with least-squares cross validation outperformed the adaptive-kernel estimator in
simulations (Seaman and Powell 1996, Seaman et al. 1999), so we focused our
results and discussion on home ranges estimated with this procedure. The adaptive
kernel (Ganey et al. 1999) and MCP have been used commonly as home-range
estimators in studies of Spotted Owls (e.g., Forsman et al. 1984, Call et al. 1992,
Zabel et al. 1995). Thus, given similar sample sizes, the adaptive, kernel and MCP
provided estimates comparable to those of other studies. We calculated the 95% fixed
kernel, 95% adaptive kernel, 95% MCP, and 100% MCP for individual owls. We
combined locations from individuals of each pair to estimate the pairs’ home ranges
(Table 1). We used the field techniques outlined by Franklin et al. (1996) to assess
reproductive activity of radio-marked owls.

The number of locations per owl varied from 51 to 65 (Table 1). Fixed-kernel
estimates of individual owls’ home ranges varied from 223 to 654 ha. Considered
individually or as a pair, the Pine Knot owls had a larger range than the Fawnskin owls.
Fixed-kernel estimates for the pairs indicated that the Pine Knot pair’s home range
was almost twice as large as the Fawnskin pair’s (Table 2). The Fawnskin pair nested
during both years of the study, the Pine Knot pair during only the first year, but 60%
of the latter’s telemetry locations were obtained the second year when they did not
nest. Furthermore, locations for the Pine Knot pair during the first year were
concentrated near the center of the home range and nest; the second year the female
used a larger area.

Kernel home ranges are estimates based on probability-density functions and are
subject to sampling error (Seaman et al. 1999), which decreases as sample size
increases. Seaman et al. (1999) reported that the bias and variance of kernel
estimators reached an asymptote at >50 locations and recommended that home-
range estimates be based on 50 or more locations. Alt home-range estimates in our
analysis were based on >50 locations. However, our fixed- and adaptive-kernel
estimates of home-range size for each pair may be slightly underestimated. By
combining locations from members of a pair, we assumed that nocturnal locations of
pairs are independent. If foraging locations for individuals of mated pairs are
dependent, the sample size will be smaller than the sum of locations of members of the
pair because the pair is acting as a single unit (Burnham and Anderson 1998:52).

Table 1 Home-range Estimates (ha) Based on Nocturnal Radiote-
lemetry Locations for Individual Spotted Owls during the Breeding
Season in the San Bernardino Mountains, 1987-1988

Estimation Method 0

Territory

Locations

100% MCP

95% MCP

95% FK

95% AK

Fawnskin

Female

153

122

223

262

Male

325

229

430

568

Pine Knot

Female

660

495

654

831

Male

648

377

448

619

a MCP, minimum convex polygon; FK, fixed kernel; AK, adaptive kernel.

NOTES

Table 2 Home-range Estimates (ha) Based on Nocturnal Radiote-
lemetry Locations for Pairs of Spotted Owls during the Breeding
Season in the San Bernardino Mountains, 1987-1988

Estimation Method 0

Territory

Locations

100% MCP

95% MCP

95% FK

95% AK

Fawnskin

116

325

210

333

415

Pine Knot

128

816

632

598

810

°MCP, minimum convex polygon; FK, fixed kernel; AK, adaptive kernel.

However, Forsman et al. (1984) reported that paired Spotted Owls they studied
foraged at the same locations only 4% to 10% of the time, indicating largely
independent foraging behavior in this species. In contrast, if the pair’s foraging
locations in our study were not independent, we believe that the bias in our estimates
of home-range size is small because we have >50 independent locations for each pair.

Pairs of Spotted Owls are more strongly associated with a central place (nest or
roost area) during the breeding season than during the nonbreeding season (Forsman
et al. 1984). Consequently, home ranges during the breeding season are smaller (e.g. ,
Forsman et al. 1984, Zabel et al 1992, Gutierrez et al. 1995).

Our 100% MCP estimates of breeding-season home ranges for individual Califor-
nia Spotted Owls are larger than estimates reported for the Mexican Spotted Owl
(range 278-361 ha; Zwank et al. 1994. Willey and van Riper 1995, respectively) but
smaller than most estimates for the Northern Spotted Owl (range 413-817 ha; Solis
and Gutierrez 1990, Zabel et al. 1995, respectively). In general, our estimates are
smaller than most previous estimates for California Spotted Owls. Reported home
ranges for California Spotted Owls range from 289 ha in the southern Sierra Nevada
(Zabel et al. 1992) to 2195 ha in the northern Sierra Nevada (Zabel et al. 1992).
Zwank et al. (1994) reported home ranges about 30% smaller than ours for an isolated
population of Mexican Spotted Owls in New Mexico. Our estimates of pairs’ home
ranges differ from those of other studies in a pattern similar to that described for
individuals. Differences in home-range size of Spotted Owls among study areas may
be due to variations in habitat (Zabel et al. 1992), prey base (Zabel et al. 1995),
foraging behavior, or weather.

The variation in home-range size within our study is consistent with other studies of
Spotted Owls (Forsman et al. 1984, Ganey and Baida 1989, Call et al. 1992, Zabel
et al. 1995). Hypotheses for differences in size of home ranges include differences in
habitat (Forsman et al. 1984, Carey et al. 1992), prey type and abundance ( Zabel et
al. 1995), prey-renewal rates (Carey et a!.1992), and habitat fragmentation (Carey et
al. 1992). Home-range size may also be related to nesting status, with nesting owls
having smaller home ranges because they are strongly associated with the nest.

Densities of the Dusky-footed Woodrat (Neotoma fuscipes), the primary prey of
Spotted Owls in our study area (Smith et al. 1999), can vary greatly (Williams et al.
1992). The habitat in both territories we studied is similar, and both pairs nested
during the study. Therefore, we suspect that the differences in home-range size
between the two pairs were due to differences in prey availability or random variation
within the population. We could not investigate whether prey, habitat, nesting status,
or the combination of these factors correlated with home-range size because our
sample size is small. However, this study is the first to document home ranges of
California Spotted Owls from isolated populations in southern California.

NOTES

This study was funded by Snow Summit Sid Corporation and Bear Mountain Ltd.
Additional support was provided by the University of Minnesota. We thank JoAnn
Gronski, Mike Hollister, Richard Tanner, Richard Smith and John Stephensen for
helping to monitor radio-marked Spotted Owls. J. L. Ganey, R. LeValley, and an
anonymous reviewer gave helpful suggestions that improved the quality of the
manuscript.

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Forsman, E. D., Meslow, E. C., and Wight, H. M. 1984. Distribution and biology of
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Ganey, J. L., Block, W. M., Jenness, J. S., and Wilson, R. A. 1999. Mexican Spotted
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Otis, D. L., and White, G. C. 1999. Autocorrelation of location estimates and the
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the Sierra Nevada, in A Technical Assessment for the California Spotted Owl. (J.
Verner, K. McKelvey, B. R. Noon, R. J. Gutierrez, G. I. Gould. Jr., and T. W.
Beck, eds.). U. S. Forest Service, Pacific Southwest Res. Sta. PSW-GTR-133.

Zabel, C. J., McKelvey, K,, and Ward, J. P., Jr. 1995. Influence of primary prey on
home-range size and habitat-use patterns of Northern Spotted Owls ( Strix
occiderttalis caurina). Can. J. Zool. 73:433-439.

Zwank, P. J., Kroel, K. W., Levin, D. M., Southward, G. M., and Romme, R. C. 1994.
Habitat characteristics of Mexican Spotted Owls in southern New Mexico. J.
Field Ornithol. 65:324-334.

Accepted 28 November 2000

NOTES

FIRST REPORT OF THE GRAY HERON
IN THE UNITED STATES

KENNETH M. BURTON, P. O. Box 716, Inverness, California 94937

SEAN D. SMITH, Saint Paul Island Tours, 1500 West 33rd Avenue Suite 220,
Anchorage, Alaska 99503

On 1 August 1999, at about 1400 ADT, Mike Greenfelder flushed a large Ardea
heron from the shore of Weather Bureau Lake on St. Paul Island in the Pribilof
archipelago, Alaska (57° 09' N, 170° 14' W). The bird disappeared into dense fog
before it could be identified to species. Greenfelder and Smith searched fruitlessly the
rest of the afternoon, and in the evening they were joined by Burton and several other
birders. We finally saw the bird in flight near its original location. The heron alighted
briefly at Rocky Lake, then continued flying west, calling repeatedly. Although the
light was poor and our views were distant, we tentatively identified the bird as an adult
Gray Heron, Ardea cinerea, in breeding plumage, on the basis of coloration and
voice. We followed it by automobile to Southwest Point, where the road becomes
essentially impassable and the heron disappeared behind bluffs, heading north as if to
circumnavigate the island.

The following morning, we found the bird standing in a hunched posture on a rock
at Webster Lake (11 km from Weather Bureau Lake and 20 km from Southwest
Point). We observed the now stationary bird for almost an hour through spotting
scopes from a distance of about 300 m and took detailed notes, on which the
following description is based. This period of observation confirmed the previous
evening’s tentative identification. We were too far for photos and decided against
closer approach until others had seen the bird and a video camera had been obtained.
The heron was still in the same place when Burton saw it again several hours later, but
it was wading actively when Smith returned with other observers. Before photos or
videos could be obtained, the bird flushed inexplicably, and it was not seen again
despite several days of intensive searching.

This observation has been accepted on the Alaska unsubstantiated list and repre-
sents the first report of a Gray Heron in the United States.

In general appearance the bird resembled a Great Blue Heron ( Ardea herodias),
a species with which all the observers are quite familiar, but had a less massive bill. The
features that distinguished it from that species were its whitish, not rusty, thighs and
complete lack of rufous on the shoulders. In flight, the upperparts showed stronger
contrast between the black remiges and the gray back and wing coverts than is typical
of a Great Blue Heron, and the underwings were a fairly uniform bluish gray with a
pale leading edge. Its call, uttered frequently in flight, was a throaty “kraak,” higher
pitched than the croak of a Great Blue Heron.

The distal part of the bill was dull yellowish, becoming darker toward the base,
especially on the culmen. The bird had a whitish crown, paler than the gray of the
forehead and lores. Single black supraocular stripes extended posteriorly from the
eyes, broadening and joining at the nape and forming nuchal plumes. White on the
lower part of the face blended into gray on the sides of the neck; this was a paler gray
than that of the mantle and secondary coverts. Several whitish plumes extended from
the scapulars. At rest, the bird showed a black shoulder patch bordered on the sides
with white, with no rufous anywhere on the wing.

Short black streaks extended in two lines down the whitish foreneck. The breast,
belly, thighs, and undertail coverts appeared creamy white overall; the sides of the
belly were black. There was a dusky wash, from which a few creamy plumes
protruded, across the breast and a dusky band across the lower belly. Grayish

Western Birds 32:88-90, 2001

NOTES

streaking extended along the flanks, and the undertail coverts showed sparse dingy
streaking. The legs were dull yellowish green, paler than is typical of a Great Blue
Heron.

Our sighting was preceded by a week of predominantly southwest and west-
southwest winds averaging 15-21 knots daily. We found no other Asiatic vagrants on
St. Paul associated with this weather system, but similar conditions produced a
Chinese Pond-Heron ( Ardeola hocchus) on 4 August 1996 (Hoyer and Smith 1997).
The Pribilofs’ only other heron records are of single Black-crowned Night-Herons
(Nycticorax nycticorax ) on 3 April 1979 and 6 August 1986. The early-August
occurrence of three of the Pribilofs’ four heron records is notable.

The Gray Heron breeds widely across Eurasia and Africa, withdrawing from most
northern areas in winter (del Hoyo et al. 1992). In northeast Asia, the nominate race
extends to Sakhalin Island and the Aldan River in the Russian Far East, roughly 3000
km west of St. Paul, while A. c. jouyi reaches Korea and Japan (Dement’ev and
Gladkov 1951, Howard and Moore 1991, del Hoyo et al. 1992). A. c. jouyi tends to
be paler than A. c. cirierea on the neck and upperwing coverts, with no buff or mauve
tinge on the neck (Cramp and Simmons 1977, Hancock and Kushlan 1984).
However, these differences are subtle, relative, and obscured by intergradation and
clinal variation (Cramp and Simmons 1977, Hancock and Kushlan 1984), making
subspecific identification of the St. Paul bird impossible.

Gray Herons disperse widely after the breeding season (Hancock and Kushlan
1984), which typically extends into the third week of July in northern Europe (Cramp
and Simmons 1977) and early July in Japan (Brazil 1991). Migratory movement of
most populations is to the southwest (Moreau 1972, Hancock and Kushlan 1984),
though some individuals may move in other directions (Ali and Ripley 1968). There
are many records of vagrants, and in North America the Gray Heron has occurred in
the lesser Antilles and Bermuda (Hancock and Kushlan 1984, American Ornitholo-
gists’ Union 1998), although the open sea is a major barrier to dispersal (Cramp and
Simmons 1977). The Gray Heron has experienced exponential population growth in
east Asia in recent decades (del Hoyo et al. 1992), increasing the likelihood of strays.

The closely related and very similar Great Blue Heron is resident in southeastern
and south-coastal Alaska west to Prince William Sound, approximately 1400 km east-
northeast of St. Paul (AOU 1998). It wanders north and west after the breeding
season but so far has not been recorded west of Kodiak Island.

We thank our employer, Tanadgusix Corporation, for enabling us to spend the
summer on St. Paul, Mike Greenf elder for his sharp eyes, and Daniel D. Gibson,
Steven C. Heinl, Peter Pyle, and Theodore G. Tobish for reviewing the manuscript.

LITERATURE CITED

Ali, S,, and Ripley, S. D. 1968. Handbook of the Birds of India and Pakistan, vol. 1.
Oxford Univ, Press, Bombay.

American Ornithologists’ Union. 1998. Check-list of North American Birds, 7th ed.
Am. Ornithol. Union, Washington, D.C.

Brazil, M. A. 1991. The Birds of Japan. Smithsonian Inst. Press, Washington, D.C.

Cramp, S., and Simmons, K. E L. 1977. Handbook of the Birds of Europe, the
Middle East and North Africa, vol. 1. Oxford Univ. Press, Oxford, England.

Del Hoyo, J., Elliott, A., and Sargatal, J. 1992. Handbook of the Birds of the World,
vol. I. Lynx Edicions, Barcelona.

Dement’ev, G. P., and Gladkov, N. A., eds. 1951. Birds of the Soviet Union, vol. II.
Gosudarstvennoe Izdatel’stvo, Moscow.

NOTES

Hancock, J., and Kushlan, J. 1984. The Herons Handbook. Harper & Row, New
York.

Howard, R., and Moore, A. 1991. A Complete Checklist of the Birds of the World,
2nd ed. Academic Press, San Diego.

Hoyer, R. C., and Smith, S. D. 1997. Chinese Pond-Heron in Alaska. Field Notes
51:953-956.

Moreau, R. E. 1972. The Palearctic-African Bird Migration Systems. Academic
Press, London.

Accepted 5 October 2000

NOTES

CLOACAL INSPECTION OR PECKING
IN ALLEN S HUMMINGBIRD

JANET L. LEONARD, Joseph M. Long Marine Laboratory, 100 Shaffer Road,
University of California, Santa Cruz, California 95060

Cloacal pecking, in which a male pecks at the cloaca of a female, causing her to
void sperm, was first described in the Dunnock ( Prunella modularis), a species with
a very complex group-breeding system (Davies 1983). It has been interpreted as a
mechanism whereby males ensure paternity of a female’s offspring by eliminating the
sperm of previous mates. Comparable behavior has been observed occasionally in
other species of birds (N. Davies pers. comm.), but its taxonomic range and ecological
context are not yet clear. On 14 April 2000 at approximately midday, I observed a
somewhat similar behavior between two Allen’s Hummingbirds ( Selasphorus sasin )
in a suburban backyard in Half Moon Bay, California. It was a bright sunny day, and
the birds were observed from a window of the house from about 3 meters without
binoculars. When I first noticed them, an adult male Allen’s Hummingbird and what I
took to be a female Allen’s were interacting face to face and less than 30 cm apart
about 3 to 4 meters above the ground. While I watched, the male flew to a position
below the female and, facing her, and put the tip of his bill in the general area of her
cloaca. The pair remained in this position while sinking slowly, in hovering flight,
almost exactly vertically, until the male’s tail was approximately 30 cm above the
ground, at which point the male and female separated and flew into cover where I lost
sight of them. The episode was prolonged, taking about 30 seconds, and appeared to
require coordination between the two birds to allow the slow, sinking, vertical
hovering flight. Allen’ s Hummingbird is a summer resident in central California, and
the first adult male of the season that could be definitely identified as Allen’s rather
than the transient Rufous Hummingbird (S. rufus) was observed in this location on 19
March in 2000 and on 16 March in 1999. Both Allen’s and Anna’s (Calypte anna)
Hummingbirds appear to establish breeding territories in or near the yard, although I
have observed no nests.

There are several potential explanations for this behavior. The first would be a
simple cloacal inspection by the male, which might serve to assess the reproductive
condition and/or recent mating history of the female, serving a function analogous to
the anogenital sniffing common in mammalian courtship and social behavior. The
second would be to stimulate the female to void sperm from a previous mating, as in
the Dunnock. No droplet of semen was observed but this might have been missed
given the rapid movement of the male and female at the bottom of the descent. A third
possibility, given the long tongue and characteristic feeding behavior of humming-
birds, is that the male might actually remove sperm from the reproductive tract of the
female (Jeffrey R. Baylis pers. comm.). Physical removal of sperm by males was first
demonstrated in damselflies (Waage 1979) and is known from other insects (Simmons
and Siva-Jothy 1998). All of these explanations focus on the phenomenon of sperm
competition, in which males continue to compete to fertilize a female’s eggs even after
mating (for birds see Birkhead 1998). The observations reported here suggest that
novel mechanisms of sperm competition remain to be described in birds.

LITERATURE CITED

Birkhead, T. R. 1998. Sperm competition in birds: Mechanisms and functions, in
Sperm Competition and Sexual Selection (T. R. Birkhead and A. P. Moller, eds.),
pp. 579-622. Academic Press, San Diego.

Western Birds 32:91-92, 2001

NOTES

Davies, N. B. 1983. Polyandry, cloaca-pecking and sperm competition in dunnocks.
Nature 302:334-336.

Simmons, L. W., and Siva-Jothy, M. T. 1998. Sperm competition in insects:
Mechanisms and the potential for selection, in Sperm Competition and Sexual
Selection (T. R. Birkhead and A. P. Moller, eds.), pp. 341-434. Academic Press,
San Diego.

Waage, J. K. 1979. Dual function of the damselfly penis: Sperm removal and transfer.
Science 203:916-918.

Accepted 14 October 2000

Burrowing Owl Sketch © by Marni Fylling

BOOK REVIEWS

Birds of North America, by Kenn Kaufman. 2000. Houghton Mifflin, New York.
384 pages. Paperback, $20. ISBN 0-395-96464-4.

The year 2000 saw the publication of two completely new field guides to North
American birds — the Sibley guide and the Kaufman guide. This simultaneity compels
us to draw parallels — but are we comparing apples with apples? Before the details of
the Kaufman guide are addressed, some background information should be appreci-
ated. Kaufman is a well-known figure in North American birding circles. His accom-
plishments include editorship of the sadly short-lived but pioneering journal Continen-
tal Birdlife (1979-1981) and authorship of numerous publications including the
Peterson series Field Guide to Advanced Birding (1990). Such associations with the
cutting edge of bird identification may have led to certain expectations from his new
field guide.

This guide, however, is aimed at entry-level and beginning birdwatchers, that is,
anybody. This huge demographic is largely excluded (albeit inadvertently) by most
other popular field guides. Excluded? This depends on how one defines a birdwatcher.
Kaufman’s intent is to enhance appreciation of birds in the general populace, many of
whom we, as more advanced practitioners, might not even consider as birdwatchers.
Conservation depends ultimately on political decisions, and the greater the public’s
awareness of birds, the greater the chance for their conservation. Ornithologists
constitute a tiny minority that can help bring about conservation of endangered
habitats or species. But if everybody appreciates birds, at some level, then the grass-
roots support for conservation could be monumental. A dream, perhaps, but a worthy
one.

Departing from the seminal Peterson field guides, Kaufman chose to use photo-
graphs for illustrations. Making the leap from a bird one sees to a field-guide painting
is one experienced birders take for granted, but 1 suspect most people relate more
easily to photographs. Really good photographs are not always easy to find, so
Kaufman edited photos using a computer and his extensive field experience.

The book is compact (it fits into a back pocket) and arranged in conventional field-
guide format. Short introductory sections in user-friendly prose cover birding basics,
bird topography, field marks (ten photos of House Finches convey variation more fully
than in any other guide with which I am familiar), taxonomy, and geographic
distribution. Then come the species accounts, with photos arranged opposite succinct
text. Comparable poses were chosen for similar species, when possible, but photos
cannot work as well as good paintings to facilitate direct comparisons. Most species
are represented by at least two images that help convey differences in posture (useful
for beginners) and plumage. Taxonomy and nomenclature, but not sequence, follow
the American Ornithologists’ Union (through the 2000 supplement to the 1998
checklist). First come ducks, then other swimming birds, aerial waterbirds, birds of
prey, chickenlike birds, wading birds, shorebirds, medium-sized landbirds, and finally
other landbirds (arranged in seven groupings). One can question why flycatchers or
sparrows are not “typical songbirds,” but the divisions may be helpful to a beginner.
For example, “everybody” knows what a duck is, so that’s a good place to start, and
then comes the coot — “non-birders” at a local park 1 visit in my attempts to identify
hybrid gulls often ask “what’s this black duck?” Give them the National Geographic
Society (NGS) guide and see them struggle to even find, let alone identify, an
American Coot. The Kaufman guide should get them to this identification on page 2,
in the pictorial table of contents.

The very first page has color-coded tabs that help locate a particular group. An
important innovation is the pictorial table of contents at the front of the book, as one
turns the first page. Photos of a selection of species from each group are presented
right away, so that someone wanting to identify a bird can get (one hopes) to the right

Western Birds 32:93-96, 2001

BOOK REVIEWS

group quickly, without wading through introductory text that might frustrate a “non-
birder.” The ability to put a name to a bird one sees is a powerful hook, and the
pictorial table of contents is a good way to facilitate this step in incipient birders. Each
of these groups (ducks, aerial waterbirds, etc.) is introduced in the text by a pictorial
section that further narrows the choices and provides background information.
Additional information is provided for problem groups: the summary of gulls on pages
68-69 is as helpful and concise as one could wish for a beginner, while the detailed
range map (p. 273) for the Black-capped and Carolina chickadees is useful for these
commonly seen garden birds.

On the basis of a few random comparisons, the color range maps seem on a par
with the NGS for overall accuracy and further discriminate between common and
scarce occurrence by different shades. The text for each species opens with a synopsis
of abundance, habitats, and habits, followed by field marks, then voice. It seems user-
friendly for the intended audience and could also benefit more experienced birders:
the Short-tailed Shearwater is “much like Sooty Shearwater, not always identifiable;”
or Cassin's Vireo is “Like a duller version of Blue-headed Vireo; best separated by
range. Where they overlap some may not be identifiable.”

Which species are covered? Although not stated in the introduction, it appears that
all regularly breeding North American species are included, plus all regular migrants,
commoner “vagrants,” and even some very rare vagrants that could be found in
gardens or at feeders (e.g., the Green Violet-ear and Fieldfare). Oddballs from Alaska
islands and the like are not included.

What of the illustrations, the edited photos? In general these are well chosen, and
pointers highlight field marks, but many minor problems pervade the photos, and in
some cases their captions. This aspect of the book could have benefited from more
thorough review. As examples, juvenile White-tailed Kites don’t have ruby-red eyes,
the wing-tips of the perched adult Glaucous-winged Gull look too pale, the wing-tips
of the standing adult Western Gull are too short (primaries 8-10 appear to be
lacking!), the right-hand illustration of the “Ashy Storm-Petrel” on page 99 is a dead
ringer in shape for a Black Storm-Petrel, the wing-tips of the left perched Calliope
Hummingbirds fall well short of a strongly graduated tail (rather than falling slightly
beyond a more squared tail), the right wing of the center Ruby-crowned Kinglet on p.
287 appears deformed, the “immature” Black-throated Sparrow is actually a juvenile,
and so on. While these facts could annoy or irritate more advanced birders, they may
not detract from the overall goal of the book. The photos also are a potentially useful
resource for more experienced birders, but the fact they’ve been “edited” cautions
against their being used too literally.

Most birders you and I know may not need this new guide, but what about the kid
next door, or the curious onlookers you attract at the local park? This book has
potential for a huge audience, and I congratulate Kaufman for his pioneering spirit
and broad-based goals. The back cover proclaims that this guide “cuts through the
clutter to focus on the essentials.” I agree, but the success of this guide will be
measured by how it works for the intended audience. While I prefer the Sibley Guide
and the NGS, I believe the Kaufman guide is more useful for beginning birders or “non
birders,” and I suspect we all can learn from this book and its approach to birding.

Steve N. G. Howell

BOOK REVIEWS

The Sibley Guide to Birds, by David Allen Sibley. 2000. Alfred A. Knopf, New
York. 544 pp. Paperback. $35.00. ISBN 0-679-45122-6.

“There is order in the universe, and birds are no exception.” Welcome to the Sibley
guide (p. 10) and the sixth-order tantric chakra, related to the act of seeing, both
physically and intuitively. This long-awaited work provides an American answer to the
increasingly detailed volumes covering other continents, particularly Europe. What-
ever quibbling follows, let me emphasize that no student of birds is too green or jaded
to benefit greatly from the art and observations in this guide.

Sibley treats approximately 744 native and vagrant species plus 66 introduced and
domestic species. The third edition of the National Geographic Society’s Field Guide
to the Birds of North America (NG3) treats about 60 additional vagrants and species
of far offshore waters, so most serious birders will want both guides. I would have
preferred more complete coverage, particularly of species that pose identification
pitfalls (e.g., the Red-tailed Tropicbird, which likely occurs regularly in North Ameri-
can waters), but the Sibley guide’s omission of ultra-rare species can be viewed as a
progressive step toward a less ego-driven world — one where birders more clearly
recognize that our most profound contributions to field ornithology and conservation
are made through such communitarian undertakings as breeding-bird atlases, Christ-
mas Bird Counts, and purposeful bird-banding. Such projects require sound ground-
ing in the local avifauna rather than esoteric knowledge of Siberian specialties.

Acknowledging an increasingly chaotic state of affairs around the species level, and
that most subspecies cannot be identified reliably in the field, Sibley opted to portray
intraspecific variability by a system of “natural ecological regions” in place of
subspecific designations. Thus, Gambel’s White-crowned Sparrow ( Zonotrichia
leucophrys gambelii) becomes the “west taiga” form, while the partially migratory
Puget Sound [Z. 1. pugetensis) and sedentary NuttalPs (Z. /. nuttalli) races constitute
the “Pacific” group. Motivated readers are directed to admirably detailed subspecies
accounts posted at www.sibleyart.com. This approach may be as valid as any, given
the deep split between practitioners of the phylogenetic and biological species
concepts, but I perceive no compelling reason why currently recognized subspecies
names were not correlated to Sibley’s alternative system in the guide — what is gained
by banishing this basic information to a web page that many readers will never visit?

Fourteen pages of introductory material warrant a close read, as they outline
Sibley’s approach to the subject material and provide unusually insightful information
on bird topography, hybrids, aberrant plumages, molt, and other topics central to
birding and ornithology. Species accounts stretch vertically, and each is headed by at
least two in-flight illustrations, with flight silhouettes for selected species. Each family
or major group begins with a summary page or spread describing the group’s
characteristics and showing small images of each species, arranged by genera. Not
only will newer birders find their match quicker, but I expect that those who start by
learning the genera, rather than each species independently, will cultivate a deeper
knowledge of birds and their identification. This is one subtle, but important, way in
which the Sibley guide has the potential to advance American birding.

The benefits of the book's distinctive layout (e.g., visual appeal and ease of
comparison between plates) are not without costs. Most importantly, the rigid
columnar format limits the possibility of image sizes being modified to show greater
detail where warranted, or to otherwise use space judiciously. Readers will find
scattered inconsistencies of scale, such as those between the Least and American
bitterns and the Bonaparte’s and Black-headed gulls, and note that sexual dimorphism
is lacking in the genus Accipiter. Groups that could have benefited from larger image
sizes include the tropiebirds, boobies, several hawks and gulls, and the Oporornis and
Wilsonia warblers.

Birders have long expected field guides to feature in-flight depictions of seabirds,
ducks, hawks, and gulls, but I was somewhat skeptical about the value of extending this

BOOK REVIEWS

convention to every species. As it turns out, these flight shots significantly improve
Sibley’s presentation by showing important wing and tail details and helping to convey
each species’ unique character. Considering the author’s reputation for identifying
birds by sounds as seemingly anonymous as a flight note, I was pleased to find the
voice descriptions unusually detailed and helpful. The occasional eastern bias creeps
through, however, such as the comparison of the Orange-crowned Warbler’s call note
to that of a Field Sparrow — western readers can substitute here the Black-chinned
Sparrow (or a simple “tsit”). Special sections focused on topics such as the identifica-
tion of swans, scaup, peeps, Spizella spa nows, and meadowlarks are stimulating and
informative, often discussing plumages, structural features, and even behaviors that
open both the eyes and the mind. Reminders that some birds may not be identifiable
appear with welcome regularity.

Above all, Sibley is a formidable and attentive field ornithologist, and his distinctive
artwork melds the birder’s eye for proportion, posture, and feather patterns with the
artist’s gift for breathing depth and life into two dimensions. He employs annotated
pointers to draw attention to key identifying features more quickly and effectively than
text ever could. Particularly impressive plates include the shorebirds, hummingbirds
(despite some tail-pattern miscues that could have benefited from a check of museum
specimens), Empidonax flycatchers, chickadees through creepers, pipits and wag-
tails, tanagers, sparrows, and icterids. Larophiles will appreciate 26 nicely executed
Herring Gull images, but Sibley’s semi-impressionistic style fails to capture fine details
characteristic of certain other medium-sized and large gulls, such as Thayer’s, and
stark the white backgrounds detract from all of the gull and tern plates. The warblers
are generally excellent — exceptionally dull Pine Warblers were a piece of cake for me
on a recent Maryland trip — although western Orange-crowned Warblers appear too
coarsely streaked and lack their distinctive pale marginal coverts. Apparent printing
irregularities in my copy include overly intense rufous tones (on the Brown Thrasher,
for example) and washed-out greens on the vireos. When will publishers care enough
to reproduce colors faithfully? All things considered, however, Sibley’s artwork
outshines that available elsewhere, and no other guide approaches the range of
plumage variation depicted here.

Range maps constitute the book’s only true disappointment. Among numerous
errors evident in southern California and adjacent areas, the Yellow-rumped Warbler,
Summer Tanager, and Green-tailed Towhee are shown breeding along the southern
California coast, the coastal range of the Chestnut-backed Chickadee stops around
San Francisco Bay (this species occurs south to Santa Barbara County), the west coast
is mistakenly shown as a “main migration route” for the American Golden-Plover,
Baja California Sur lacks its wintering Clay-colored Sparrows, and many seabirds
strictly pelagic in this region are shown ranging along our immediate coast. Addition-
ally, the use of green dots to illustrate broad patterns of rare occurrence is problem-
atic, at least in California. For example, the Painted and American redstarts are
depicted similarly in southern California although the latter species is about a hundred
times more common than the former, and the exceptionally scarce Cape May Warbler
is granted considerably more California dots than most regularly occurring eastern
vagrants. For now, the maps in NG3 are far more readable and reliable — another
good reason not to relegate “old faithful” to the shelf just yet.

An accomplished guide can facilitate the student’s journey toward the rarified
echelon of wisdom and consciousness represented by the seventh, or crown, chakra.
Most birders alive today were assisted along their paths by Roger Tory Peterson’s
remarkable combination of observational, writing, and artistic talents, and it is
gratifying to see David Sibley emerge from Peterson’s long shadow to lead a new
generation of seekers toward birding’s next level.

Robert A. Hamilton

FEATURED PHOTO

FIELD IDENTIFICATION OF FEMALE ALLEN S
AND RUFOUS HUMMINGBIRDS

STEVE N. G. HOWELL, Point Reyes Bird Observatory, 4990 Shoreline Highway,
Stinson Beach, California 94970

Probably no other pair of North American bird species poses greater field
identification problems than the Rufous (Selasphorus rufus) and Allen’s {S. sasin )
hummingbirds. Observations of anything other than rufous-backed adult males (at
least outside of known breeding ranges and breeding seasons) are usually lumped as
“Rufous/Allen’s,” since even a small percentage of adult male Rufous are fully green
backed, matching the pattern of adult male Allen’s (McKenzie and Robbins 1999).
Females and immatures are generally considered unidentifiable to species in the field
although, with excellent views and comparative experience, some immature males
may be distinguishable by details of rectrix ’width and shape (Stiles 1972, Pyle 1997).
While researching identification criteria for a photographic guide to North American
hummingbirds, I found two features helpful in the separation of adult female Allen’s
and Rufous hummingbirds.

The most striking feature pertains to the race sedentarius of Allen’s Hummingbird,
which is endemic to southern California. This taxon is distinguished from nominate
sasin by measurements, especially bill length, which averages longer in sedentarius,
but no consistent plumage differences have been reported (Grinnell 1929, Stiles
1972, Mitchell 2000). Examination of adult female museum specimens revealed that
sedentarius (n = 24; upper photo) has relatively dull and poorly contrasting cinna-
mon-rufous sides and flanks with moderate to extensive mottling of iridescent green
spots. By contrast, nominate sasin (n = 60; lower photo) has brighter cinnamon-
rufous sides and flanks that contrast more sharply with a white forecollar and white
median stripe on the underparts. Only about 30% of nominate sasin (n - 60), as well
as 30% of adult female Rufous Hummingbirds (n = 50), have one to a few iridescent
green spots on the chest sides, rarely if ever approaching the extent of spotting on
sedentarius; most have solidly cinnamon-rufous sides and flanks that lack iridescent
green spotting, a pattern not shown by sedentarius.

Sedentarius is resident on most of the California Channel Islands, whence it spread
in the 1960s and 1970s to the adjacent mainland coast (Wells and Baptista 1979). In
recent years, its range has expanded inland through much of the coastal slope of Los
Angeles County and parts of Orange County (Hamilton and Willick 1996, Gallagher
1997), and resident populations of presumed sedentarius also occur along the coast
nearly to the edge of the breeding range of nominate sasin in Ventura County (K. L.
Garrett pers. comm., D. E. Mitchell, pers. comm.). There is also some post-breeding
movement of sedentarius upslope into nearby mountains (Stiles 1972), and the taxon
has occurred casually south to San Diego County (Unitt 1984). Identification criteria
proposed here may help document the nesting ranges of these two subspecies, and
also the detection of wintering Selasphorus hummingbirds other than sedentarius in
southern California. I encourage observers and banders in a position to examine
known sedentarius (e.g., on the Channel Islands) to test the usefulness of flank color
and pattern and to examine whether this feature is helpful for immatures (of which I
did not see adequate samples); immatures of nominate sasin do not show extensive
green mottling on their sides and resemble adult females in flank color.

A second feature worthy of critical examination in the separation of adult female
Allen’s and Rufous hummingbirds is uppertail-covert pattern and color. About 30% of
specimens of both sedentarius and nominate sasin show relatively extensive rufous

Western Birds 32:97-98, 2001

FEATURED PHOTO

edgings on their uppertail coverts (forming a distinctive rufous “rump patch”), in
contrast to narrow or virtually absent rufous edgings on adult female Rufous (n = 50).
Thus, on adult females, extensive rufous on the uppertail coverts suggests Allen’s
Hummingbird, a difference illustrated, although not mentioned specifically, by Sibley
(2000). A smaller sample suggests the same trend in immature females, but because
10% of immature female Rufous (n = 20 specimens) have fairly distinct rufous fringes
on their uppertail coverts, the presence of a rufous “rump patch” is not diagnostic of
immature female Allen’s. Also note that immature males of both Allen’s and Rufous
hummingbirds typically have extensively rufous uppertail coverts, so correctly deter-
mining the age and sex of any bird is a prerequisite to specific identification (see Pyle
1997).

I thank personnel at the California Academy of Sciences (the late Luis Baptista,
Douglas J. Long), the Museum of Vertebrate Zoology, University of California,
Berkeley (Carla Cicero, Ned Johnson), the American Museum of Natural History,
New York (R. Terry Chesser, Jacqueline Weicker), the National Museum of Natural
History (Smithsonian Institution), Washington D. C. (James Dean, Gary R. Graves),
and the Western Foundation of Vertebrate Zoology (Jon Fisher) for access to
specimens in their care. Kimball L. Garrett (Natural History Museum of Los Angeles
County) and Peter Pyle helped with specimen examination. I am indebted to Larry
Sansone for use of his photo of a female s edentarius, taken in Los Angeles County,
California, March 1992, and to Ian C. Tait for his photo of a female sasin taken in
Marin County, California, June 1971. Garrett and Don E. Mitchell contributed
information on the range of sedentarius, and the manuscript benefited from review
by Robert A. Hamilton, Mitchell, and Pyle. This is contribution number 945 of the
Point Reyes Bird Observatory.

LITERATURE CITED

Gallagher. S. R. 1997. Atlas of Breeding Birds, Orange County, California. Sea and
Sage Audubon Press, Irvine, CA.

Grinnell, J. 1929. An island race of the Allen Hummingbird. Condor 31:226-227.

Hamilton, R. A., and Willick, D. R. 1996. The Birds of Orange County, California:
Status and Distribution. Sea and Sage Press, Irvine, CA.

McKenzie, P. M., and Robbins, M. B. 1999. Identification of adult male Rufous and
Allen’s hummingbirds, with specific comments on dorsal coloration. W. Birds
30:86-93.

Mitchell, D. E. 2000. Allen’s Hummingbird ( Selasphorus sasin), in The Birds of
North America (A. Poole and F. Gill, eds.), no. 501. Birds N. Am., Philadelphia.

Pyle, P. 1997. Identification Guide to North American Birds, part 1. Slate Creek
Press, Bolinas, CA.

Sibley, D. A. 2000. The Sibley Guide to Birds. Knopf, New York.

Stiles, F. G. 1972. Age and sex determination in Rufous and Allen’s hummingbirds.
Condor 74:25-32.

Unitt, P. 1984. The birds of San Diego County. San Diego Soc. Nat. Hist. Mem. 13.

Wells, S. A., and Baptista, L, F. 1979. Breeding of Allen’s Hummingbird ( Selasphorus
sasin sedentarius ) on the southern California mainland. W. Birds 10:83-85.

WESTERN FIELD ORNITHOLOGISTS
26TH ANNUAL MEETING

27-30 September 2001 • Reno, Nevada

Registration over the Internet will be available on the WFO website,
www.wfo-cbrc.org, by 1 June 2001. For conference information, contact
Lucie Clark at luclark@sierra.net; 335 Ski Way #300, Incline Village, NV
89451; 775-831-2909)

Call for Papers and Poster Presentations

Guidelines:

1 . Oral and poster presentations should reflect original research, or summa-
rize existing unpublished information, and be presented in a manner that will
be of interest to serious amateur field ornithologists. Talks and posters
relating to the following general themes are especially solicited for the
current meeting, but other topics are also welcome.

• Systematics, biogeography, and geographic variation of birds of the
Pacific Coast region, the North American interior, and the interface
between the two

• New information on field identification problems relevant to the birds
of western North America and the eastern Pacific Ocean

• Techniques for field study of birds, including censusing, monitoring,
and other studies; results of studies resulting from the application of
such techniques

• Ecology, population biology, and conservation of birds in the state of
Nevada or any of the bioregions or habitats it represents (Great Basin,
Mojave Desert, Sierra Nevada, Columbia Plateau)

2. We expect to allot 20 minutes per oral presentation, which should
include 5 minutes for questions and discussion; longer time slots (30
minutes) are negotiable.

3. Posters should fit within a width of 6 feet.

4. An abstract of your presentation or poster should be submitted electroni-
cally to Ted Floyd (tedfloyd57@hotmail.com) or as hard copy (Ted Floyd,
Great Basin Bird Observatory, 1 East First Street, Suite 500, Reno, NV
89501), no later than 30 June 2001. All abstracts should be submitted in
the following format:

• Your Last Name, Your First Name. Your affiliation (if any), complete
mailing address, e-mail address (optional). Title of Your Talk. Brief (300
word maximum) summary of the goals, results, and conclusions of your
study.

We look forward to seeing you in Reno!

Silent Auction:

Top-of-the-Line Kowa Spotting Scope

WFO is conducting a silent auction of a Kowa TSN-824 spotting scope (straight, 82
mm, fluorite lens) with a TSE-27, 20-60x zoom eyepiece. All proceeds from the
auction will go to the publication fund for Western Birds. The suggested retail price
of the scope and eyepiece is $1395; some discount retailers sell them for as low as
$1200. Bidding for the scope and eyepiece will start at $1100. The successful bidder
will be announced at the Saturday night dinner at WFO's meeting in Reno (29
September 2001). Bidders will have until the day before the dinner to submit bids;
sealed bids will be accepted at the meeting. Mail-in bids should be postmarked no later
than 15 September 2001 and sent to:

Lucie Clark, Recording Secretary
Western Field Ornithologists
335 Ski Way #300
Incline Village, NV 89431

Good luck!

Mike San Miguel

President, Western Field Ornithologists

100

World Wide Web site:

WESTERN BIRDS www.wfo-cbrc.org

Quarterly Journal of Western Field Ornithologists

President: Mike San Miguel, 2132 Highland Oaks Dr., Arcadia, CA 91006;
sanmigbird@aol.com

Vice-President: Daniel D. Gibson, University of Alaska Museum, 907 Yukon Dr.,
Fairbanks, AK 99775-6960

Treasurer/Membership Secretary: Dori Myers, 6011 Saddletree Lane, Yorba
Linda, CA 92886

Recording Secretary: Lucie Clark, 9889 Tahoe Blvd., #56, Incline Village, NV
89451

Directors: Kimball Garrett, Daniel D. Gibson, Bob Gill, Gjon Hazard, Dave Krueper,
Mike San Miguel, W. David Shuford, Mark K. Sogge, David Yee

Editor: Philip Unitt, San Diego Natural History Museum, P.O. Box 121390, San Diego,
CA 92112-1390; birds@sdnhm.org

Associate Editors . Daniel D. Gibson, Robert A. Hamilton, Ronald R. LeValley,
Tim Manolis, Kathy Molina, Mark K. Sogge

Graphics Manager: Virginia P. Johnson, 4637 Del Mar Ave., San Diego, CA 92107

Photo Editor: Peter La Tourrette, 1019 Loma Prieta Ct., Los Altos, CA 94024

Featured Photo: Robert A. Hamilton, 34 Rivo Alto Canal, Long Beach, CA 90803

Book Reviews: Steve N.G, Howell, Point Reyes Bird Observatory, 4990 Shoreline
Highway, Stinson Beach, CA 94970

Secretary, California Bird Records Committee: Guy McCaskie, P.O. Box 275,
Imperial Beach, CA 91933-0275; guymcc@pacbell.net

Chairman, California Bird Records Committee: Richard A. Erickson, LSA Associ-
ates, 1 Park Plaza, Suite 500, Irvine, CA 92614; richard.erickson@lsa-assoc.com

Membership dues, for individuals and institutions, including subscription to Western
Birds- Patron, $1000.00; Life, $400.00 (payable in four equal annual installments);
Supporting, $60 annually; Contributing, $34 annually; Family, $26; Regular U S.
$22 for one year, $41 for two years, $60 for three years, outside U.S. $27 for one
year, $51 for two years, $73 for three years. Dues and contributions are tax-
deductible to the extent allowed by law.

Send membership dues, changes of address, correspondence regarding missing
issues, and orders for back issues and special publications to the Treasurer. Make
checks payable to Western Field Ornithologists.

Back issues of Western Birds within U.S. $24 per volume, $6.00 for single issues,
plus $1.00 for postage. Outside the U.S. $30 per volume, $7.50 for single issues.

The California Bird Records Committee of Western Field Ornithologists recently
revised its 10-column Field List of California Birds (January 2000). The last list covered
606 accepted species; the new list covers 613 species. Please send orders to WFO,
c/o Dori Myers, Treasurer, 6011 Saddletree Lane, Yorba Linda, CA 92886.
California addresses please add 7.75% sales tax.

Quantity: 1-9, $1.50 each, includes shipping and handling. 10-39, $1.30 each, add $2.00
for shipping and handling. 40 or more, $1.15 each, add $4.00 for shipping and handling.

Published June 15, 2001

ISSN 0045-3897

Vol. 32, No. 2, 2001

Volume 32, Number 2, 2001

Recent Bird Records From the Grand Canyon Region, 1974-2000

Charles T. LaRue, Lara L. Dickson, Nikolle L. Brown,

John R. Spence, and Lawrence E. Stevens 101

Occurrence Patterns of Peregrine Falcons on Southeast Farallon
Island, California, by Subspecies, Age, and Sex
Sasha Earnheart-Gold and Peter Pyle 119

NOTES

Low-Elevation Nesting by Calliope Hummingbirds in the Western

Sierra Nevada Foothills Brian D. C. Williams 127

Rapid Second Nesting by Anna’s Hummingbird Near Its Northern

Breeding Limits Ann Scarf e and J. Cam Finlay 131

Nesting of Brandt’s Cormorants in the Northern Gulf of California

Juan Ceroantes-Sanchez and Eric Mellink 134

A Potential Threat to Bald Eagles in Baja California Sur, Mexico

Gustavo Arnaud, Edgar Amador, and Marcos Acevedo 136

Book Review Howard L. Cogswell 137

Featured Photo Walter Wehtje 141

Cover photo by © Martin Meyers of Truckee, California: Le Conte’s
Sparrow {Ammodramus teconteii). Miller’s Rest Stop, Nevada, October,
2000. If accepted, this will be the second record of Le Conte’s Sparrow
for the state of Nevada.

Reprints can be ordered at author’s expense from the Editor when proof is returned or
earlier.

WESTERN BIRDS

Volume 32, Number 2, 2001

RECENT BIRD RECORDS FROM THE GRAND
CANYON REGION, 1974-2000

CHARLES T. LaRUE, 3525 W. Lois Lane, Flagstaff, Arizona 86001

LARA L. DICKSON, Grand Canyon National Park, 823 N. San Francisco St., Suite
B, Flagstaff, Arizona 86001

NIKOLLE L. BROWN, 7779 N. Leonard, Clovis, California 93611

JOHN R. SPENCE, Glen Canyon National Recreation Area, P. O. Box 1507, Page,
Arizona 86040

LAWRENCE E. STEVENS, P. O. Box 1315, Flagstaff, Arizona 86002

ABSTRACT: We report information on 100 species from the Grand Canyon
region from 1974 to 2000; of these, 98 are from the Colorado River and 18 species
are new to the Grand Canyon region. We compiled new seasonal information on 33
species and breeding information on 11 species. Changes are due, among other
factors, to a change in habitats resulting from the construction and operation of Glen
Canyon Dam. Flow regulation from the dam increased water clarity, and numbers of
many waterbirds (primarily Anseriformes) subsequently increased. For example, the
Common Goldeneye did not occur in Grand Canyon before the late 1980s, but since
then it has become the most abundant wintering waterfowl. Stabilization of the river’s
flow has also allowed the growth and expansion of riparian vegetation. Birds we
believe are responding to this increase in vegetation include Bell’s Vireo, Sharp-
shinned Hawk, and wintering Empidonax flycatchers and sparrows. Also, there has
been an increase in coverage, e.g., bird-monitoring river trips in winter. Some species
are increasing in number and/or expanding their ranges in Arizona, such as the
Double-crested Cormorant, Cattle Egret, Ross’s Goose, White-winged Dove, Anna’s
Hummingbird, Black Phoebe, Brown-crested Flycatcher, Crissal Thrasher, Summer
Tanager, and Common Crackle. Last, improved field identification has helped in
discerning closely related species.

This report discusses bird observations from the Grand Canyon region from
1974 through 2000. We report information on 100 species, of which 18 are
new to the region. The Grand Canyon, located in northern Arizona, covers
approximately 1000 km 2 and several life zones from lower Sonoran along the
Colorado River (elevation 350 m) to boreal forests (2800 m; Figure 1). The
physiographic Grand Canyon falls within the complex boundaries of six land-

Western Birds 32:101-118, 2001

101

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

Figure 1 . The Grand Canyon region, showing the Colorado River corridor and major
tributaries.

management jurisdictions, including the National Park Service (Grand Canyon
National Park, Lake Mead National Recreation Area, Glen Canyon National
Recreation Area), the Bureau of Land Management* the U. S. Forest Service
(Kaibab National Forest), the Navajo Nation, the Hualapai Nation, and the
Havasupai Nation (Billingsley and Hampton 1999).

Bird diversity and distribution in the Grand Canyon region have been
summarized by Bailey (1939) and Brown et al. (1984, 1987, 1993); Stevens
et al. (1997) and Sogge et al. (1998) made additional studies of riparian and
waterbirds along the Colorado River. The completion of Glen Canyon Dam
in 1963 eliminated the nearly annual floods that scoured the banks of the
Colorado River through the Grand Canyon and allowed the growth and
expansion of native and nonnative riparian thickets (primarily tamarisk,
Tamarix ramosissima ) the length of the corridor (Turner and Karpiscak
1980, Johnson 1991). Flow regulation has increased the populations of
waterbirds (primarily Anseriformes) along the Colorado River in lower Glen
Canyon and the upper Grand Canyon, where density is a function of water
clarity (Stevens et al. 1997, Glen Canyon N.R.A. files).

The majority of observations we report were recorded during investiga-
tions of ecological impacts of Glen Canyon Dam on the river and adjacent
riparian zones. Most of our data were obtained during projects funded by the
Bureau of Reclamation and administered by Glen Canyon Environmental

102

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

Studies and Grand Canyon Research and Monitoring Center. Several
projects were administered by Glen Canyon National Recreation Area,
including 12 bird-monitoring trips in the Grand Canyon from 1997 to 1999
during January, February, April, May, and June and a bird-monitoring
project in Glen Canyon N.R.A. from 1992 to present. Sources of our other
records include >200 research and commercial river trips from 1975
through 1999 by Stevens, projects on both the river and canyon rims by
Grand Canyon National Park staff, and personal time and personal commu-
nications.

Trips on the Colorado River were conducted via motor and rowboats
during all seasons. River trips were from river mile (RM) 0 at Lee’s Ferry to
RM 2S0 at Pearce Ferry (elevation 950 m to 350 m). We covered the Glen
Canyon reach (RM 0 to RM -16 at Glen Canyon Dam) via motorboat.
Locations on the Colorado River are given in river miles from Lee’s Ferry
(Stevens 1983) followed by L (left bank looking downstream) or R (right
bank), where applicable. Records are given in a seasonal order; for example,
observations of a winter resident start in the fall and go through the spring.
Observers are noted in the text with their initials for each species, and their
full names are given alphabetically in the acknowledgments.

Our reasons for reporting these observations include new species for the
Grand Canyon region, new seasonal records, new breeding records, changes
in status, including distribution and abundance, rarely encountered species,
and range expansion. The published sources of status and distribution
information from which we determined the significance of our records are
Woodbury and Russell (1945), Phillips et al. (1964), Monson and Phillips
(1981), Brown et al. (1984, 1987, 1993), Brown (1985), Stevens et
al.(1997), and Sogge et al. (1998). For a broader regional perspective, we
referred to the account by Rosenberg et al. (1991) of the lower Colorado
River Valley (LCRV), from Davis Dam to Mexico (primarily the Arizona-
California border) and to Monson and Phillips (1981) for the state of
Arizona. For current information on the status of unusual species and
records in Arizona, we referred to Rosenberg and Witzeman (1998, 1999).

We report 18 species new to the Grand Canyon region: the Least Bittern,
Greater White-fronted Goose, Ross’s Goose, Trumpeter Swan, Sanderling,
Caspian Tern, White-winged Dove, Yellow-bellied Sapsucker, Eastern
Phoebe, Scissor-tailed Flycatcher, Hutton’s Vireo, Blue Jay, Northern Parula,
Prairie Warbler, Prothonotary Warbler, Bobolink, Common Grackle, and
Streak-backed Oriole. Our data bring the total number of waterbird species
in the Grand Canyon region to 91, adding six species (and one corrected
identification) to the list by Stevens et al. (1997).

SPECIES ACCOUNTS

COMMON LOON Gavia immer. Sogge et al. (1998) reported one previous record
from the river corridor. Six of our seven records indicate that the Common Loon is a
rare transient primarily in fall. We observed individuals at Lee’s Ferry on 8 October
1992 (ACP), RM 51.5 on 19 October 1992 (LES), RM -3.6 on 2 November 1998
(JRS, CTL), RM -1.8L on 7 November 1996 (BKR, TMH), RM -12.0 on 12
November 1993 (ACP, BKR), and RM 1.4 on 12 February 1999 (PGF, RKR, LLD).

103

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

A very unusual summer occurrence was of one at RM 214 on 24 July 1998 (NLB,
photo). The Common Loon is an uncommon fall and winter migrant at lakes
throughout Arizona and is most frequent in the LCRV.

PACIFIC LOON Gauia pacifico. One was at Lee’s Ferry 9-26 February 2000
(KSB, BRB, CTL). There is one other record from the Grand Canyon region, also
from Lee’s Ferry in winter. This species is rare but regular in winter on lakes in the
LCRV and elsewhere in central and southern Arizona.

HORNED GREBE Podiceps auritus. We report the first records from the river
corridor, seven from Glen Canyon: one at Lee’s Ferry 27-31 October 1996 (CTL),
one each at RM -13.5L and -2.5L on 7 November 1996 (BKR, TMH), one at Lee’s
Ferry on21 December 1997 (JRS), two at Lee’s Ferry on 1 January 1998 (JRS, BKR,
CEG), one at RM -3.5 on 8 January 1997 (JRS, BKR, CTL), and two at RM -9.4 on
30 March 1995 (ACP). This species is a rare to uncommon migrant and winter visitor
throughout Arizona.

AMERICAN WHITE PELICAN Pelecartus erythrorhynchos. One was at the base
of Glen Canyon Dam on 30 January 1995 (ACP); this is the first winter record of the
species from northern Arizona. Five were at RM 209.0 on 12 April 1999 (BHD,
LLD, JAH). A flock of approximately 40 birds was at RM 8 on 8 May 1999 (reported
to LES by TV). Nine were at RM 133 on 28 May 1999 (reported to LES by AP). A
flock of 50 was at RM 120 in late August 1990 or 1991 (reported to LES by SH). Two
river guides reported (to LES) a flock of 200 birds at RM 150 in mid-summer 1998.
There are five previous records from the Grand Canyon region. The White Pelican is
a rare but irregular transient throughout the year in Arizona.

BROWN PELICAN Pelecartus occidentalis. One was observed in Glen Canyon at
RM -14.5 on 9 June 1992 (ACP), and another was at RM 170R on 4 August 2000
(NLB, photo). There is one other report from the Grand Canyon region. This species
is a rare but irregular late summer and fall wanderer to lakes in the LCRV and
elsewhere in Arizona.

DOUBLE-CRESTED CORMORANT Phalacrocorax auritus. Brown et al. (1984)
reported this species as a common permanent resident in the upper portion of Lake
Mead and an irregular transient along the river upstream from there. Beginning as
early as 1985 this species began appearing in winter at the base of Glen Canyon
Dam, and since 1992 the numbers have steadily increased to a high of 22 individuals
in 1999 (JRS).

LEAST BITTERN Ixobrychus exilis. We report the first record of this species from
the Grand Canyon region: one at Quartermaster Canyon, RM 260. 1L, upper Lake
Mead, on 22 January 1999 (CTL, JRS, photo NLB, BHD). This species is rare in
winter in the upper LCRV. There are two other northern Arizona records.

GREAT BLUE HERON Ardea herodias. Incubating birds were seen on 10 nests at
RM 275.0 on 7 April 2000 (CTL, LLD). Four pairs were on nests in tamarisks at the
mouth of Burnt Springs Canyon (RM 259R) on 15 May 1990 (LES). The species nested
in tamarisks at RM 0L (Lee’s Ferry) in 1998 and 1999, successfully raising young both
years (LES, JRS, NLB). Another nesting attempt (on a ledge 100 m above the river) at
RM -13. 3R in 1998 was unsuccessful (BKR, TMH). These are the first nesting attempts
in the Grand Canyon region of this common wanderer along the Colorado River.

CATTLE EGRET Bubulcus ibis. Four records: one at Marble Canyon Lodge on 24
March 1999 (LLD, JAH), one at Glen Canyon Dam on 21 April 1994 (JDG), one at
Lee’s Feny on 25 April 1995 (JDG), and three between RM -8.8 and -10.8 on 26
April 1995 (ACP). There were two previous records from the Grand Canyon region.
This species has recently become more abundant as a migrant in northern Arizona
(CTL unpubl. data).

104

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

GREATER WHITE-FRONTED GOOSE Anser albifrons. The first record of this
species from the Grand Canyon region is of a single bird observed at RM 158 on 11
September 1997 (reported to LES by SH). The White-fronted Goose is a rare fall
migrant in northern Arizona; there are seven records from the adjacent Navajo Nation
(CTL unpubl. data).

ROSS’S GOOSE Chen rossii. One was observed at RM 2 on 8 March 1993
(reported to LES by KJB, CG), and another (or the same) was seen at RM -12.0 on
19 March 1993 (ACP, photo JRS). These are the first records of this species from the
Grand Canyon region. Ross's Goose is a rare winter resident in the LCRV and has
recently increased throughout Arizona as a migrant and winter resident.

TRUMPETER SWAN Cygnus buccinator. Two first-year birds that had been
painted bright pink on one side were observed between RM 7 and 9.5 on 14 and 15
February 1997 (LES), observed and photographed 25-27 February 1997 between
RM 4 and 20.5 by VM (reported to LES), and at RM 5 on 10 March 1997 (DH),
Presumably the same two birds were seen near RM 6 on 12 January 1998 (JRS, NLB,
KME, CTL), at RM 10.6 on 4 January 1999 (LES) and 8 January 1999 (DGS, NLB,
CTL), and at RM 12 on 22 January 1999 (reported to LES by RGB). These marked
individuals originated in Wyoming, through a cooperative effort to augment the
population there (S. Patla pers. comm.). These are the first records of this species
from the Grand Canyon region.

WOOD DUCK Aix sponsa. We accumulated nine records from the river corridor,
seven from the Glen Canyon reach and Marble Canyon, two from RM 180-194. Five
sightings were in spring (from 22 April to 8 June), four in fall or early winter (24
September to 30 December). To our knowledge, these are the first records of this
species from the river corridor. This species is sparse in fall and winter throughout
Arizona, a status reflected in these Grand Canyon region records.

EURASIAN WIGEON Anas penelope. An adult male was at RM -1.8L on 13
March 1998 (CEG, BKR). There was one previous report from the river corridor.
There are more than 50 records of this rare migrant and winter visitor in Arizona.

MALLARD Anas platyrhynchos. The first breeding record of this species in the
river corridor was in 1983 (Brown et al. 1987), and the population increased greatly
after 1986 (Stevens et al. 1997). At present, Mallards breed commonly from Glen
Canyon Dam to the Little Colorado River (RM 61) but apparently not farther
downstream. Nests with up to 10 eggs have been found in dense stands of horsetail
(. Equisetum spp.) slightly above the typical high water mark from 15 April through 15
June (LES). The relatively long incubation period and the nests’ proximity to the
water’s edge make this species highly susceptible to inundation as dam operations
change.

A probable female Cinnamon Teal { Anas cyanoptera) with three young was
observed at RM 47. 8L on 8 June 1987 (LES, WB). Although this and the Blue-winged
Teal (A. discors) are common migrants, neither has been recorded previously
breeding on the Colorado River in the Grand Canyon region.

GREATER SCAUP Aythya marila. Since 1995 up to 30 individuals have been
found wintering from Lee’s Ferry upstream to RM -7.0 (Glen Canyon N.R.A. files).
These are the first records from the river corridor in the Grand Canyon region.
Monson and Phillips (1981) reported four records for Arizona based on specimens but
noted that the species may be more common in the state. It has since been recognized
as a rare but regular winter resident in the LCRV 7 and elsewhere in Arizona (Brown
1985), a status reflected in the Grand Canyon region.

SURF SCOTER Melanitta perspicillata. There is one prior record from the Grand
Canyon region. We report an additional four: a male at Lee’s Ferry from 19

105

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

September 1991 to 26 April 1994 (ACP, JDG), a female at Glen Canyon Dam on 22
October 1993 (ACP), two birds at Lee’s Ferry on 4 November 1995 (ACP), and one
at Lee’s Ferry on 26 April 1995 (ACP). This species is a rare but regular migrant and
winter visitor throughout Arizona.

WHITE- WINGED SCOTER Melanitta fusca. We report five records from the Glen
Canyon reach: one at Lee’s Ferry from 21 November 1996 to 8 February 1997
(CTL, JRS), four at Lee’s Ferry on 10 December 1990, with two there on 31
December 1990 (LES), one at Lee’s Ferry on 25 January 1998 (CTL et al.), and one
at RM -14.5 on 27 February 1995 (ACP). These observations represent the first
records from the river corridor in the Grand Canyon region. This species is a rare
migrant and winter visitor in Arizona,

LONG-TAILED DUCK Clartgula hpemalis. We report eight records: one at Glen
Canyon Dam on 30 November 1993 (ACP), one at Lee’s Ferry on 10 December
1990 (NCK), an immature at Glen Canyon Dam from 2 January to 2 March 1999
(CTL, RKR, CEG, LLD, JAH), a male near Lee’s Ferry from 16 January to 4 March
1992 (ACP, NCK), one on the Glen Canyon reach from 27 January to 9 April 1996
(JEH, JDG, JRS, ACP, BKR), one at RM -9.9 from 27 February to 19 March 1995
(ACP, MKS), one at Lee’s Ferry on 19 March 1993 (ACP), and one at Glen Canyon
Dam 27-28 March 2000 (CTL, BRB). These represent the first records from the river
corridor and indicate that this species is a sparse winter resident in the Glen Canyon
reach. This species is rare and irregular in winter in the upper LCRV.

BUFFLEHEAD Bucephala albeola. One was seen at Lee’s Ferry on 23 June 1995
(JDG), a female was below Glen Canyon Dam on 24 June 1998, and a male was at
RM -9.5 on 25 and 26 June 1998 (CTL, NLB). These are the first summer stragglers
reported from the Grand Canyon region. A few have also been noted in summer in
the LCRV.

COMMON GOLDENEYE Bucephala clangula. Brown et al. (1987) did not list this
species as occurring in Grand Canyon. Since the late 1980s, however, it has become
the most abundant wintering waterfowl along the Colorado River in the Grand
Canyon, being observed commonly from Glen Canyon Dam to RM 61 from
November through March (Stevens et al. 1997, Spence et al. 1998). The largest
single-day count from the Glen Canyon reach was 2380 on 8 January 1998 (JRS,
CTL, TMH). Records of nonbreeding birds remaining into summer include nine below
Glen Canyon Dam on 3 June 1999 (CTL), single birds at RM -4.6 and RM -9.8 on
23 June 1995 (JDG), one male and two females in the Glen Canyon reach from 19
May to 19 August 1998 (CTL, NLB), and two below Glen Canyon Dam on 16 August
2000 (CTL). This species has increased in the LCRV since 1960,

BARROW’S GOLDENEYE Bucephala islandica. Since 1992, this species has
been found annually in winter below Glen Canyon Dam (Spence et al. 1998) with up
to 80 present in some years. The birds are generally present from late October to early
March; however, two lingered until 15 June in 1999 (CTL, LLD). A female observed
at RM 66.0 on 11 January 1999 (CTL, BHD) is the only record of this species below
Lee’s Ferry. Barrow’s Goldeneye is a rare but irregular winter visitor below dams in the
LCRV.

HOODED MERGANSER Lophodptes cucullatus. One to four males were seen at
Lee’s Ferry from 20 November 1990 to 11 February 1991, and two males were
observed there on 7 January 1992 (LES, NCK). From 1992 through 1999, 24
records of 61 individuals were recorded from mid-November through April during
waterfowl surveys in the Glen Canyon reach (Glen Canyon N.R.A. files). Brown et al.
(1987) listed this species as casual in the region. To our knowledge these are the first
records from the river corridor and indicate that this species is an uncommon migrant
and winter resident in the Glen Canyon reach, as it is in the LCRV.

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RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

RED-BREASTED MERGANSER Mergus senator. Brown et al. (1984, 1987)
listed four records from the Grand Canyon region and described the species as casual
in the region; however, our observations represent the first records from the Colorado
River corridor. Four were seen at RM -6.2 on 13 February 1998 (CTL, CEG). Single
males were seen at RM 64.0 on 5 April 1999 and RM 221 on 13 April 1999 (CTL,
LLD, JAH, BHD). A mortally wounded female, probably struck by a Peregrine Falcon,
was examined at RM 211L on 30 April 1994 (LES). The Red-breasted Merganser is
a sparse migrant throughout Arizona and is occasionally a common migrant in LCRV.

OSPREY Pandiort haliaetus. We report the first winter records from both the
Grand Canyon region and northern Arizona. Individuals were observed at Lee’s
Ferry on 10 December 1990 (NCK) and in January 1991 (KJB), in Glen Canyon at
RM -14.0 on 9 January 1998 (JDG) and on 18 January 1997 (JRS).

SHARP-SHINNED HAWK Accipiter striatus. We accumulated seventeen winter
records from the river corridor in January and February of 1998 and 1999 (CTL,
NLB, JRS, LLD, RKR, DGS). These and four other winter records (Brown et al.
1984, Sogge et al. 1998) indicate that this species is an uncommon winter resident of
the river corridor, probably exploiting small birds wintering in the dense riparian
vegetation that has proliferated since the building of the dam.

COMMON BLACK-HAWK Buteogallus anthracinus. We report three records:
individuals were seen at RM 60.5 on 10 April 1998 (LES), RM 205.0 on 19 April
2000 (SEO, DS, DT), and Pumpkin Spring (RM 212) on 28 June 1997 (reported to
LES by JC). These three stragglers and a few previous records from the Grand
Canyon (B. T. Brown pers. comm.) represent the first records in northern Arizona
aside from the extreme northwest corner (cf. Monson and Phillips 1981). Addition-
ally, the Black Hawk is a casual transient and recent summer visitor in the LCRV and
a summer resident of permanent streams, primarily in central Arizona.

RED-SHOULDERED HAWK Buteo lineatus. An immature, likely of the distinc-
tive California race B. I. elegans , was seen at Quartermaster Canyon, RM 260. 1L,
upper Lake Mead, 26-27 February 1998 (CTL, RKR, NLB, CAL). This represents
the second record from the Grand Canyon region. This species is a rare transient in
Arizona that appears to be nearly annual in its occurrence.

ZONE-TAILED HAWK Buteo albonotatus. Listed as casual by Brown et al.
(1984), this hawk is now confirmed as a breeding species. Six successful breeding
attempts were recorded from 1995 to 1999 on the south rim (Grand Canyon N.P.
files, reported to LLD by EFL).

VIRGINIA RAIL Rallus iimicola. One was seen at RM -8.7L on 2 January 1999
(RKR, CTL), one. was seen at RM 52R on 10 January 2000 (JRS), and one was heard
at RM 246. 0L on 21 January 1998 (CTL, JRS, BHD, NLB, KME). These are the first
winter records from the Grand Canyon region, though the species is a common to
abundant winter resident in the LCRV.

SORA Porzana Carolina. One and two were heard calling at RM 246. 0L and
RM 265. 0L, respectively, on 22 January 1998 (CTL, JRS, NLB). Nine and one were
seen at RM 260. 0L and RM 265. 0L, respectively, on 27 February 1998 (CTL, RKR,
CAL, NLB). One was observed at RM 259.5R on 4 April 2000 (CTL, LLD). There were
two previous records from the Grand Canyon region. The Sora is a common winter
resident and transient in the LCRV and a common transient throughout Arizona.

COMMON MOORHEN Gallinula chloropus. Three were at RM 260. 0L on 22
January 1998 and 27 February 1998 (JRS, NLB, BHD, CTL), two were there on 13 May
1998 (NLB, CTL), one was at RM 255.5R on 3 April 2000 (CTL, LLD), and one was at
Lee’s Ferry on 22 July 1994 (JDG). There was one previous record from the Grand
Canyon region. This species is a fairly common but local permanent resident in LCRV.

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RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

SOLITARY SANDPIPER Tringa solitaria. One was observed at RM -6.5 on 10
September 1992 (CTL). Although this is only the third record from the river corridor,
the species is a fairly common migrant throughout Arizona.

SPOTTED SANDPIPER Actitis macularia. Brown et at (1984) and Sogge et al.
(1998) each reported one winter record from the river. We accumulated seven
additional winter records from RM 1 to 73, indicating that this species winters in small
numbers along the Colorado River. Additionally, three adults with one young were
observed at RM -8.0 on 1 July 1998 (CTL, NLB), and one adult and one young were
observed at RM 55.5 R in early July 1987 (LJES). These represent the third and fourth
breeding records from the river corridor.

SANDERLING Calidris alba. An immature bird was photographed by John
Blaustein at RM 11 OR on 28 August 1974. This bird was initially identified as a
Semipalmated Sandpiper ( Calidris pusilla) and is the basis for that species’ being
ascribed to the Grand Canyon (B. T. Brown pers. comm., Brown et al. 1984, 1937,
Stevens et al. 1997). A photograph of this individual in The Hidden Canyon
(Blaustein 1999) is labeled as a Semipalmated Sandpiper, although it is identifiable as
an immature Sanderling. Figure 2 is a more diagnostic photograph of the same bird.
Sanderling is a sparse migrant through the region, and this photograph documents
the only record from the Grand Canyon region.

CASPIAN TERN Sterna caspia. We report the first records from the Grand
Canyon region. One was seen at RM 171.3 on 9 April 1999 (LLD, JAH, CTL, BHD),
another at Pearce Ferry (RM 280) on 13 May 1998 (NLB, CTL). Although a rare to
fairly common transient in the LCRV, the Caspian Tern is sparse in northern Arizona.

WHITE-WINGED DOVE Zenaida asiatica. We report the first records from the
Grand Canyon region. Single birds were seen at Lee’s Ferry on 27 April 1982 (GMS),

Figure 2. Sanderling at river mile 110 on 28 August 1974.

Photo by John Blaustein

108

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

8 May 1999 (CEG), and 20 May 1992 (JRS). This species is a rare transient in
northern Arizona, where records have recently increased (CTL unpubl, data).

INCA DOVE Columbina inca. One was at RM 98. OR on 15 October 1993 (JB,
CG), two were at Phantom Ranch (RM 87. 8R) on 17 October 1998 (NLB), one was
at Lonely Dell, near Lee’s Ferry, on 24 October 1982 (ARL, CTL), and three were at
Lee’s Ferry on 2 December 1995 (JDG). There are two previous records from the
Grand Canyon region. This species is an occasional transient in northern Arizona.

COMMON GROUND-DOVE Columbina passerina. One was observed at Lee’s
Ferry on 14 October 1991 (SRG). It represents the second record of this species from
the Grand Canyon region and northern Arizona.

YELLOW-BILLED CUCKOO Coccpzus americanus. One was at RM -14.2 on 6
June 1995, and another (or the same) was at Lee’s Ferry on 21 June 1995 (JDG).
Brown et al. (1984) reported only one record from the Grand Canyon region since
1950. This species has declined sharply in the western U.S. (Hughes 1999).

GROOVE-BILLED ANI Crotophaga sulcirostris. One was at Cardenas Marsh,
RM 71.0L, from 10 to 13 October 1993 (photo CG, Figure 3; JB). Another was
photographed at the mouth of Salt Trail Canyon in the Little Colorado River gorge 6
miles above the confluence on 21 October 1992 (reported to CTL by PFR), A third
was at RM 80.5R on 23 October 1992 (LES). There was one prior record from the
Grand Canyon region. This is a casual transient primarily in summer and fall in central
and southern Arizona and elsewhere in the Southwest (Mlodinow and Karlson 1999).

FLAMMULATED OWL Otus flammeolus. This species is a common summer
resident of pine forest on the canyon rims, occurring as late as 25 October (on the South
Bass Trail at the top of the Redwall Limestone in 1999, LES). A migrant was mist-netted

Figure 3. Groove-billed Ani at Cardenas Marsh, river mile 71, on 10 October 1993.

Photo by Chris Geanious

109

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

at RM 72R in dense riparian vegetation of Goodding willow (Salix gooddingii) and
tamarisk on 5 May 1975 (LES). This species is occasionally found at lowland sites
throughout Arizona, including two prior records from the bottom of Grand Canyon.

LONG-EARED OWL Asio otus. An adult with three fledglings and the nest site (on
the ground in dense tamarisk) were found at Cardenas Marsh (RM 71.0L) on 6 June
1998 (NLB, TJT, CTL). Although this species was reported calling throughout the
night at Cardenas Marsh from 1 to 3 May 1975 (SWC) and sporadically in subsequent
years (LES), the 1998 record represents one of the few breeding records from Grand
Canyon and the first verified from the Colorado River corridor. The Long-eared Owl
breeds sparsely throughout Arizona.

NORTHERN SAW- WHET OWL Aegolius acadicus. One was observed at Kwagunt
Marsh at RM 55. 5R on 20 February 1996 (MJK, JB). Although irregularly present
(occasionally in large numbers) on the canyon rims, and casually at lowland sites in the
LCRV, this is the first report from the river corridor.

COMMON POORWILL Phaiaenoptilus nuttallii. One was seen RM 246. OR,
upper Lake Mead, on 22 February 1999 (LLD, RKR, CTL). This is the first winter
record from the Grand Canyon region; however, whether this bird overwintered
(perhaps hibernating) or was an early migrant is unknown. The presence of an
overwintering population downstream in the LCRV has yet to be demonstrated.

WEIIP-POOR-WILL Caprimulgus uociferus. Two birds were heard at Swamp
Point on the north rim on 27 June 1999 (reported to LLD by JPD, JVJ, NEP). This
is the third record from the Grand Canyon region; the two previous records were from
the same location (Brown et al. 1984). This is the northernmost locality for this
species in Arizona.

ANNA’S HUMMINGBIRD Calypte anna. Single males were seen at RM 196. OR
and 198. OR on 16 January 1999, RM 200.5Ron 17 January 1999, and RM 207.8L
on 12 April 1999 (CTL). These are the first records from the Colorado River corridor
and are likely associated with recent population increases and expansion in the LCRV,
elsewhere in Arizona (Monson and Phillips 1981, Rosenberg et al. 1991), and in
several other western states (DeSante and George 1994).

COSTA’S HUMMINGBIRD Calypte costae. Brown et al. (1984) and Sogge et al.
(1998) reported this species along the river corridor primarily from RM 140
downstream. A remarkable influx occurred in April and May of 1999. We recorded 60
males throughout the corridor, including 16 from RM 0 to 65 (LLD, JAH, CTL, NLB).
Single males were also seen as far upstream as RM -8.4R on 26 April 1999 and RM
-10.0L on 27 April 1999 (LLD, CTL). This influx may be related to the severe
drought that prevailed in the desert Southwest during the winter. An influx of Costa’s
Hummingbirds occurred in 1984 (Brown et al.1987), which was also an exception-
ally dry winter in the Southwest. One was observed at RM -6.0 on 10 April 1984
(BTB, KDG).

YELLOW-BELLIED SAPSUCKER Sphyrapicus varius. A first-winter individual
was at Lee's Ferry from 16 to 30 January 1994 (CTL), and an adult male was at RM
1.0R on 12 February 1999 (RKR, CTL, LLD). These are the first reports of this
species from the Grand Canyon region. The Yellow-bellied Sapsucker is a rare winter
visitor in the southwestern half of Arizona, including the LCRV.

WILLOW FLYCATCHER Empidonax trail l ii. The decline and virtual disappear-
ance of the breeding population of this species along the river corridor has been
documented by Sogge et al. (1997) and Brown (1988). A territorial male was
observed at RM -7.0L from 27 May to 15 June 1999 (LLD, CTL, JAH); it is the first
to be noted from the Glen Canyon reach (M. Sogge pers. comm.).

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RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

HAMMOND S FLYCATCHER Empidonax hammondii. One seen at RM 193. 8R
on 23 February 1998 (CTL, RKR) represents the first winter record from the Grand
Canyon region and northern Arizona. The species is a rare and irregular winter
resident in the LCRV.

GRAY FLYCATCHER Empidonax wrightii. The first winter record from the
Grand Canyon region is of one at RM 207. 5L on 21 February 1999 (CTL, RKR). The
Gray Flycatcher is a locally uncommon winter resident in the LCRV.

DUSKY FLYCATCHER Empidonax oberholseri. One was seen and heard at
RM 49. 1R on 18 February 1998 (RKR, CTL, NLB, CAL). This represents the first
winter record of the Dusky Flycatcher from the Grand Canyon region. The species is
a rare and irregular winter resident in the LCRV.

BLACK PHOEBE Sayornis nigricans. We report the first winter and breeding
records from the Glen Canyon reach. At RM -12.0L, one bird was seen on 2 January
1999 (RKR, CTL) and two were seen on 3 and 30 January 2000 (RKR, LLD, JDG).
Another bird was at RM -11. 5R on 2 February 1999 (CTL, LLD). A bird was seen at
a newly constructed nest at RM -12 . OR on 20 April 1999; this nest contained two eggs
on 16 June 1999, and a second nest found the same day at RM -13.4L contained four
eggs (CTL, JAH). The nest at RM -12. OR contained four eggs on 27 April 2000
(CTL). A family group was seen at the base of Glen Canyon Dam on 7 July 1997 (CTL,
DGS, BKR). This species has expanded its range in Arizona, particularly in the LCRV,
and our records suggest this expansion includes the Grand Canyon region.

EASTERN PHOEBE Sayornis phoebe. We report the first records of this species
from the Grand Canyon region. Individuals were observed at RM 1.0R and 1.8R on
1 April 1999 (CTL, JAH, KGM, BHD, MC, LLD) and at RM 155.2 on 8 April 1999
(CTL, JAH, LLD, BHD). The Eastern Phoebe is an uncommon migrant/winter
resident in much of Arizona, but its status in northern Arizona is unclear.

VERMILION FLYCATCHER Pyrocephalus rubinus. A male was at Lonely Dell,
Lee’s Ferry, from 25 May to 4 June 1997 (LSB, CEG). This is the sixth record from
the river corridor. Although a common summer resident in southern Arizona, this
species is a sparse transient in northern Arizona.

BROWN-CRESTED FLYCATCHER Mgiarchus tyrannulus. Brown et al. (1984,
1987) speculated on this species’ occurrence in Grand Canyon. Sogge et al. (1998)
confirmed its restricted range in the immediate area of RM 198, and LES observed
one to two pairs in the cottonwoods at Supai Campground in Havasu Canyon
periodically during the 1980s and 1990s. From 1997 to 1999 we recorded 12
observations (a maximum of 18 individuals) from RM 194 to 204 (CTL, LLD, NLB,
JAH, TJT). Remarkably, one was observed at RM 5.2R on 30 May 1999 (reported to
LLD by TJT, LA, KB). Our records suggest this species is continuing its expansion into
the Grand Canyon region, as noted in the LCRV (Rosenberg et al. 1991) and
elsewhere in the Southwest (Johnson 1994).

EASTERN KINGBIRD Tyrannus tyrannus. One was observed at Lee’s Ferry on
14 July 1994 (JDG). This is the fourth record from the river corridor of this rare
annual migrant in Arizona.

SCISSOR-TAILED FLYCATCHER Tyrannus forficatus. We report the first record
of this species from the Grand Canyon region: one at RM 74R on 14 June 1996
(reported to LES by SH, JC). A different (or the same) bird was reported at Thunder
River ten days later (reported to LES by TF). This species is a recurring summer visitor
(over 45 records) in Arizona.

NORTHERN SHRIKE Lanius excubitor. There was one previous record from the
river corridor. We report four additional records: an adult at RM 5.8R on 17
December 1999 (CTL, CAB), and at Lee’s Ferry an adult on 1 January 1998 (JRS),

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RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

an immature on 15 January 1997 (CTL), and an adult found dead on 1 February
2000 (CAB; specimen to Univ. of Ariz.). This species is a regular and uncommon
winter resident in northern Arizona,

BELL’S VIREO Vireo bellii. Both Brown et al. (1984) and Sogge et al. (1998)
reported this species as a breeding resident as far upstream as RM 50, with occasional
vagrants as far as Lee’s Ferry. We report three records above Lee’s Ferry: two at
RM -8.8L on 2 June 1993 (JRS), two at RM -8.3 on 6 June 1995 (JDG), and one at
RM -2.3L on 7 July 1997 (CTL, NLB). The presence of two birds each in June of
1993 and 1995 in Glen Canyon may indicate breeding. Our records suggest that the
range expansion in the Grand Canyon region documented by Brown et al. (1983) is
continuing.

CASSIN’S VIREO Vireo cassirtii. One was seen at RM 193.8R on 10 April 1999
(CTL, LLD, JAH) and at RM 198. OR on 11 April 1999 (CTL). These records are
nearly a month earlier than the known spring passage in northern Arizona (Phillips et
al. 1964) and may represent individuals that wintered locally. This species is known to
winter in the LCRV and is a common migrant throughout Arizona.

HUTTON’S VIREO Vireo huttoni. We report the first record of this species from
the Grand Canyon region and the northernmost record from Arizona. One was heard
singing and later observed at RM 204. 1R on 21 February 1999 (CTL, LLD, RKR).
Hutton’s Vireo is a common summer and uncommon winter resident in central and
southeastern Arizona and a casual transient and winter visitor to the LCRV.

RED-EYED VIREO Vireo olivaceus. One was obseived at Lonely Dell, Lee’s Ferry,
on 23 September 1998 (CTL, NLB). There were six previous records from the Grand
Canyon region. This species is a sparse transient throughout Arizona, but reports
have declined in recent years.

BLUE JAY Cyanocitta cristata. One was observed at RM 175.8 on 7 May 1998
(CTL, PW, photo NLB). This represents the first record of this species from the Grand
Canyon region and the sixth report from Arizona (Rosenberg and Witzeman 1999).

TREE SWALLOW Tachycineta bicolor. One was seen at RM 204.0 on 24
February 1998, and two were seen at RM 223.0 on 25 February 1998 (CTL, RKR,
CAL). These represent the earliest spring records from the Grand Canyon region and
were probably early spring arrivals.

NORTHERN ROUGH-WINGED SWALLOW Stelgidopteryx serripenrtis. One
was at RM 208.7 on 21 February 1999 (AMD, CTL, LLD), and six were between
RM 260.2 and Pearce Ferry on 26 and 27 February 1998 (CAL, RKR, NLB). These
represent the earliest records from the Grand Canyon region and were probably early
spring migrants. Additionally, one was seen at Lee’s Ferry on 16 January 2000 (CAB)
during a period of unusually mild weather. Breeding by this species on upper Lake
Mead was recorded by Brown et al. (1993) and R. McKernan (pers, comm,). We
report nests farther upstream than has previously been noted. At RM 196.0, a nest
was observed 10 May 1999 (NLB, BHD), and adults with fledglings were observed on
10 June 1998 (NLB, PW).

CACTUS WREN Campylorhynchus brurtneicopillus. This species is a rare to
uncommon permanent resident in the upper Lake Mead area (Brown et al. 1984) and
the middle reaches of Peach Springs Wash (LES). A nest containing three eggs was
found at RM 207. 5L on 12 April 1999 (CTL). To our knowledge, this is the farthest
upstream Cactus Wren breeding has been reported.

HOUSE WREN Troglodytes aedon. We report the first seven known winter
records from the Grand Canyon region: one each at RM 203. 0L, 204. 3R, and
209. 0L on 17 January 1999 (CTL, NLB, RKR), Spencer Canyon, RM 246. 0L, on

112

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

18 January 1999 and 26 February 1998 (CTL, NLB, RKR), and RM 209. 0L on 20
January 1998 (JRS, CTL) and 21 February 1999 (LLD, RKR). This species is a fairly
common winter resident in the LCRV but is sparse in winter in northern Arizona.

WINTER WREN Troglodytes troglodytes. Both Brown et al (1984) and Sogge et
al. (1998) considered this species to be a rare transient and winter visitor in riparian
vegetation of the Colorado River and its lower tributaries. Our series of records
indicates that it may be more common. We recorded 21 observations of 26 individuals
from the length of the river corridor in 1998 and 1999. These records extend the
known period of occurrence in the Grand Canyon region from 16 October 1999 (at
Indian Gardens; CTL) to 1 April 1999 (at RM 5.8R; JAH). The Winter Wren is a rare
winter resident throughout riparian areas in central and southern Arizona.

BLUE-GRAY GNATCATCHER Polioptila eaerulea. There was one previous
winter record from the river corridor, and we add two more. Three were at Lee’s Ferry
on 5 December 1995 (JDG), three at RM -11. OR on 30 January 2000 (JDG). This
species is common in southern Arizona in winter but sparse in the northern portions.

HERMIT THRUSH Catharus guttatus. There were three previous winter records
(Brown et al. 1984, Sogge et al. 1998). From 1998 to 2000, we accumulated 12
winter records extending from RM -7.0 to 265.0, with the majority below RM 200.
These records establish that this species is an uncommon winter resident in riparian
vegetation along the river corridor, primarily in the lower western portions of the
Grand Canyon. The Hermit Thrush is a common winter resident in riparian areas in
central and southern Arizona and the LCRV.

NORTHERN MOCKINGBIRD Mimus polyglottos. At “Dox Seep" at RM 70L on
1 June 1995, an adult Blue-gray Gnatcatcher was observed landing on the head of a
fledgling Northern Mockingbird and unsuccessfully attempting to place a geometrid
moth larva in the panting mockingbird’s bright yellow mouth (LES). This was the first
evidence of nesting mockingbirds known to us in the river corridor in the Grand
Canyon, although singing males are heard here sporadically.

SAGE THRASHER Oreoscoptes montanus. One was observed at RM 196. OR on
20 February 1999 (CTL, LLD). This is the third record from the Colorado River in the
Grand Canyon region and likely represents an early spring migrant. This species is a
migrant and sparse summer resident on adjacent arid plateaus.

CRISSAL THRASHER Toxostoma crissale. The status and distribution of this
species in northern Arizona are poorly known (Phillips et al. 1964, Brown et al.
1984), but recent field work is clarifying its distribution in the region Brown et al.
(1984) speculated that it is a locally rare resident in the western Grand Canyon and
noted only two records from the Colorado River. Sogge et al. (1998) reported four
additional records from the Colorado River from RM 173.8 to 204. 5R during winter
and spring surveys. We add five records: one each at RM 246. OR on 22 January
(CTL, JRS) and 26 February 1998 (RKR, CAL), seven at RM 265.0L on 27 February
1998 (CTL, RKR, CAL), and one at RM 45. 5R on 2 April 1998 (NLB, CTL). Last,
one remained at Lonely Dell, Lee’s Ferry, from 30 November 1999 to 9 February
2000 (CAB, CTL). The Arizona breeding-bird atlas project documented breeding
across north-central and northwestern Arizona from the Echo Cliffs west (T. Corman
pers. comm.), and there are several winter records from the western Navajo Nation
(CTL unpubl. data). It may be concluded that this species is a sparse permanent
resident throughout much of northwestern Arizona. In the Grand Canyon region, it is
found primarily on plateaus in open sage desert and juniper woodlands, and along the
Colorado River from RM 175 downstream to Grand Wash Cliffs (RM 280).

EUROPEAN STARLING Sturnus vulgaris. Although nonnative starlings are
widespread throughout the United States, their distribution and ecological role in

113

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

Grand Canyon are poorly known. Although single birds are occasionally seen during
summer, a flock of 50 birds was seen for a full day at Granite Park (RM 209L) on 13
November 1993 (LES). This record corresponds to a marked period of migratory
passage in northeastern Arizona (CTL unpubl. data).

BOHEMIAN WAXWING Bombycilla garrulus. One was observed at Lonely Dell,
Lee’s Ferry, on 20 May 1992 (JRS). This represents the third record from the Grand
Canyon region and is perhaps the latest in spring that this species has been reported
from Arizona (cf. Phillips et al. 1964). The Bohemian Waxwing is a sparse and erratic
winter visitor to northern Arizona.

ORANGE-CROWNED WARBLER Vermivora celata. There were no winter
records prior to our observations. From 1998 to 2000, we accumulated 23 winter
records from RM -10 to 265. Although these records extend the length of the river
conidor, the majority are from the lower western end. These records establish that this
species is an uncommon winter resident in riparian vegetation along the Colorado
River in the Grand Canyon region, perhaps becoming so only since completion of
Glen Canyon Dam. Furthermore, it is a common winter resident along the LCRV.

NORTHERN PARULA Parula amerieana. We report the first record of this
species from the Grand Canyon region. An immature male was at Lee’s Ferry from 19
November to 29 December 1999 (CTL, CEG). The Parula is a rare but regular
migrant and winter resident in the LCRV and throughout Arizona, with reports
increasing in recent years.

PRAIRIE WARBLER Dendroica discolor. We report the first record of this
species from the Grand Canyon region. An adult male was seen at Spencer Canyon,
RM 246. 0L, on 22 January and 26 February 1998 (JRS, CTL, KME, CAL, RKR).
This species is casual in Arizona.

AMERICAN REDSTART Setophaga ruticilla. We report three records: a male at
RM 131. 6L on 13 May 2000 (LLD, BTM, LKM), one at Lonely Dell, Lee’s Ferry, on
3 June 1986 (CTL), and one at RM 11.3R on 13 October 2000 (JDG). There were
four previous records, two from the river corridor, one in spring, one in fall, and two
fall records from the rim. This is a sparse but regular transient throughout Arizona.

PROTHONOTARY WARBLER Protonotaria citrea. We report the first record of
this species from the Grand Canyon region. One was observed at RM -14. 3R on 26
May 1994 (JDG). This species is a sparse transient throughout Arizona.

COMMON YELLOWTHROAT Geothlypis trichas. We report the first winter
record of this species from the Grand Canyon region. An adult male was at RM 50. 0L
on 10 January and 14 February 1999 (CTL, RKR, PGF). The species is a fairly
common winter resident in the LCRV.

PAINTED REDSTART Myioborus pictus. Brown et al. (1984) reported three
previous records from the Grand Canyon region. We report one at RM 31.5R on 4
April 1999 (reported to CTL by CBN, BJB, TD). These are the only reports of this
species from northern Arizona. Our record corresponds to the unusual occurrence of
this species at nearly 20 lowland sites in Arizona in the spring of 1999 (Rosenberg and
Benesh 1999).

SUMMER TANAGER Piranga rubra. This species has recently colonized and
become a rare summer resident in lowland riparian areas in the Grand Canyon
(Brown et al. 1984). Sogge et al. (1998) reported singing males as far upstream as
RM46.7 but no evidence of nesting. We accumulated four sightings that seem to
indicate that this expansion is continuing upstream into the Glen Canyon reach: a
subadult male at RM -13. 4L on 22 May 1998 (CTL), a subadult male at RM -3. OR on
25 May 1999 (CTL, LLD), one at RM -6.1R on 21 June 1995 (JDG), and an adult
male at RM -8.6R on 21 July 1993 (JRS). Although this species has recently

114

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

increased in the Grand Canyon region, it has decreased dramatically in the LCRV.

CHIPPING SPARROW Spizella passerina. We report four winter records: two at
RM 209. 0L on 21 January 1998 (JRS, CTL), two on 25 February 1998 (NLB, RKR),
and one there on 18 January 1999 (CTL, NLB), and two at RM 196. OR on 23
February 1998 (RKR, CTL}. There were two previous winter records from the river
corridor. The species is rare in northern Arizona in winter.

CLAY-COLORED SPARROW Spizella pallida. We report the first record of this
species from the Grand Canyon region. One was observed at RM 1.0R (Paria Beach)
on 2 May 1995 (JDG).

BREWER’S SPARROW Spizella breweri. We report the first winter records of this
species from the Grand Canyon region. One was at RM 5.2R on 12 January 1998
(CTL, NLB), 25 were at RM -3. OR on 13 February 1998 (CTL, CEG), and two were
at RM 56. 1R on 19 February 1998 (RKR, CAL, NLB). This species is generally
sparse in winter in northern Arizona, and our records may be a result of favorable
weather and/or food conditions.

BLACK-THROATED SPARROW Amphispiza bilineata . This species is known as
a common summer resident in desert habitats throughout northern Arizona with
rather abrupt arrival and departure from the region in mid-March and early September
(Phillips et al. 1964). Although it is not known as a winter resident in this area (Brown
et al. 1984, Sogge et al. 1998), we accumulated 11 records of more than 20
individuals from desert scrub adjacent to the Colorado River from October through
February. From these records, it is apparent that this species winters in small numbers
in the lowlands along the Colorado River in the Grand Canyon region.

GRASSHOPPER SPARROW Am mod ram us sauannarum. One was seen at
RM 1.0R on 27 and 31 October 1996 (CTL). This observation is the first report
from the river corridor and the third from the Grand Canyon region. This species is
a sparse migrant in northern Arizona (CTL unpubl. data) and more common
elsewhere in the state.

FOX SPARROW Passerella iliaca. “Slate-colored” individuals were observed at
Lee’s Ferry on 27 October 1996 (CTL), RM -7.0L on 3 February 2000 (CTL, JRS),
RM -8.8L on 18 March 1996 (JRS), and Spring Canyon (RM 204. 4R) on 11 April
1999 (CTL, JAH). There were two previous records from the river corridor. This
species is a rare transient and winter resident throughout Arizona.

LINCOLN’S SPARROW Melospiza lincolrtii. Both Brown et al. (1987) and Sogge
et al. (1998) speculated that this species may winter in the Grand Canyon region.
During winter survey trips along the Colorado River in January and February, we
recorded 60 in 1998 and 16 in 1999 (CTL, JRS, NLB, RKR, LLD). These records
indicate that this species winters in the riparian vegetation along the Colorado River
in the Grand Canyon region with high year-to-year variability. It is common in winter
in southern Arizona.

SWAMP SPARROW Melospiza georgiana. The two previous records were of one
in October (Brown et al. 1984) and one in April (Sogge et al. 1998). We report six
records, the first winter records from the Grand Canyon region. Individuals were
observed at RM -8.7L on 4 February 2000 (CTL), RM 1.6R on 17 February 1998
(CTL. RKR) and 30 November 1999-23 February 2000 (CTL), Phantom Ranch
(RM 87.8R) on 20 February 1998 (RKR), RM 204.3R on 24 February 1998 (RKR),
and RM 209. OR on 25 February 1998 (RKR, NLB). This species is a rare winter
resident in northern Arizona.

WHITE-THROATED SPARROW Zonotrichia albicollis. We report seven records.
Individuals were observed at RM -14.3R on 29 October 1998 (CTL), at Lee’s Ferry

115

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

from 5 December 1994 to 7 March 1995 (JDG) and on 5 December 1995 (JDG,
CTL), at RM 87. 8R on 15 January 1998 (JRS), and at RM -0.5L on 27 March 2000
(CTL). There were four previous records from the Grand Canyon region, two from the
Colorado River corridor. The White-throated Sparrow is an uncommon winter
resident throughout Arizona but is considered rare in the LCRV.

GOLDEN-CROWNED SPARROW Zonotrichia atricapilla. Individuals were ob-
served at RM -8. 8R on 8 January 1998 (CTL, JRS), upper Deer Creek on 13 January
1999 (CTL), RM 136.3R on 2 April 1997 (CTL, JRS, AF), and RM 53.0R on 5 April
1999 (CTL, JAH). There were four previous records from the Grand Canyon region.
This species is an uncommon winter visitor throughout Arizona, although less
numerous in the northern portions.

BOBOLINK Dolichonyx oryzivorus. The first record of this species from the
Grand Canyon region is of one at Lonely Del!, Lee’s Ferry, on 15 September 1994
(JDG). The Bobolink is a sparse, primarily fall, migrant throughout Arizona.

COMMON GRACKLE Quiscalus quiscula. We report the first records of this
species from the Grand Canyon region. One was observed with a female Great-tailed
Grackle (Q. mexicanus) at RM 198. OR on 9 and 10 June 1997 (CTL, NLB, MDY),
another was in the Lee’s Ferry area from 28 May to 31 July 1997 (CTL, CEG, DGS),
with two present there on 29 and 31 July 1997 (CTL, CEG, DGS), and another was
at RM 217.8 on 16 November 1993 (LES). This species is a recent sparse transient
to Arizona (LaRue and Ellis 1992).

STREAK-BACKED ORIOLE Icterus pustulatus. One was seen and heard at
Spencer Canyon, RM 246. 0L, upper Lake Mead, on 22 January 1998 (JRS, CTL,
NLB, KME). This represents the first record of this Mexican oriole from the Grand
Canyon region. This species is known for its rare breeding (Corman and Monson
1995) and rare but regular winter northward dispersal from Mexico into southern
Arizona (Monson and Phillips 1981, Rosenberg and Witzeman 1999). This is the
northernmost occurrence in Arizona.

RED CROSSBILL Loxia curuirostra. One was seen at RM 51. 5L on 13 January
1998 (CTL, JRS). There were no previous records from the river corridor. This
species is a rare irregular transient at lowland sites throughout Arizona.

ACKNOWLEDGMENTS

The following is the list of observers with initials cited in text: LA, Lawrence Abbott;
KB, Karen Barnett; JB, Jeffery Bennett; CAB, Catherine A. Bland; BRB, Ben R.
Bobowski;-KSB, Katie S. Bobowski; WB, W 7 illiam Boecklen; BJB, Byron J. Boyle;
RGB, Robert G. Bramblett; CB, Christopher Brod; BTB, Bryan T. Brown; NLB,
Nikolle L. Brown; KJB, Kelly J. Burke; LSB, Lori S. Bush; SWC, Steven W.
Carothers; MC, Matt Clifford; JC, Jerry Cox; TD, Tim Dale; JPD, John P. DeLong;
BHD, Brian H. Dierker; LLD, Lara L. Dickson; AMD, A. Murphy Doty; KME, Kristin
M. Enos; TF, Thomas Fergason; AF, Aaron Flesch; PGF, Peter G. Friederici; SRG,
Steve R. Ganley; CG, Chris Geanious; CEG, Christine E. Goetze; JDG, John D.
Grahame; KDG, Kathy D Groschupf; KG and DG, Kenton and Diane Grua; TMH,
Tom M. Haberle; DH, Dan Hall; SH, Sharon Hester; JEH, John E. Hildebandt; JAH,
Jennifer A. Holmes; SMJ, Sarah M. James; MJK, Michael J. Kearsley; JVJ, Jessica
V. Jewell; NCK, Natasha C. Kline; ARL, Anne R. LaRue; CTL, Charles T. LaRue;
EFL, Elaine F. Leslie; CAL, Casey A. Lott; BTM, Brian T. Meiering; LKM, Lisa K.
Miller; VM, Velma McMeekin; KGM, Ken G. McMullen; CBN, Clay B. Nelson; SEO,
Sue E. Ordway; NEP, Nicolas E. Pappani; AP, Alan Peterson; ACP, A. Clive Pinnock;
RKR, Roger K. Radd; BKR, Brenda K. Russell; PFR, Patrick F. Ryan; DS, Drifter
Smith; DGS, Dwight G. Smith; JRS, John R. Spence; MKS, Mark K. Sogge; LES,

116

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

Lawrence E. Stevens; GMS, Gary M. Stolz; DT, DrewThate; TJT, Timothy J. Tibbitts;
TV, Tom Vail; PW, Peter Weiss; MDY, Mike D. Yard.

We acknowledge Clive Pinnock and John Grahame for their years of field work at
Glen Canyon National Recreation Area. We are grateful to the following individuals
for their assistance in the field: Tony Anderson, Ken Baker, Jeff Behan, Jeff Bennett,
Steve Bledsoe, Lewis Boobar, Kelly Burke, Matt Clifford, Sarah Davidson, Brian
Dierker, Murphy Doty, Kristin Enos, Peter Friederici, Chris Geanious, Jimmy Hall,
Tom Haberle, Jennifer Holmes, Casey Lott, Ken McMullan, Lars Niemi, Nels Niemi,
Roger Radd, Brenda Russell, Dwight Smith. Tom Swartz, Tim Tibbitts, Peter Weiss,
and Mike Yard. We thank Elaine Leslie, Pat Ryan, and Tim Tibbitts for providing
records. Special thanks to John Blaustein for providing the Sanderling photograph
and to Chris Geanious for providing the Groove-billed Ani photograph. Portions of
these projects were funded by Glen Canyon Environmental Studies, Grand Canyon
Research and Monitoring Center, and National Park Service grants to Spence and
Stevens. We thank Dan Gibson, Gale Monson, Gary Rosenberg, and Janet Witzeman
for their thoughtful and thorough reviews.

LITERATURE CITED

Bailey, F. M. 1939. Among the Birds in the Grand Canyon Country. U.S. Natl. Park
Service, Grand Canyon, AZ.

Behle, W, H., and Higgins, H. G. 1959. Birds of Glen Canyon, in Ecological Studies
of Flora and Fauna in Glen Canyon (A. M. Woodbury, ed.), pp. 107-133.
Anthropol. Papers 40, Glen Canyon Ser. 7, Univ. Utah.

Benesh, C. D., and Rosenberg, G. H. 1998. The winter season. Arizona region. Field
Notes 52:234-237.

Billingsley, G. H,, and Hampton, H. M. 1999. Physiographic rim of the Grand
Canyon, Arizona. U.S. Geol. Surv. Open-File Rep. 99-30, scale 1:250,000.

Blaustein, J. 1999. The Hidden Canyon: A River Journey. Chronicle Books, San
Francisco.

Brown, B.T. 1988. Breeding ecology of a Willow Flycatcher population in the Grand
Canyon, Arizona. W. Birds 19:25-33.

Brown, B. X, Carothers, S. W., and Johnson, R. R. 1983. Breeding range expansion
of Bell’s Vireo in Grand Canyon, Arizona. Condor 85:499-500.

Brown, B. T., Carothers, S. W., Haight, L. X, Johnson, R. R., and Riffey, M. M.
1984. Birds of the Grand Canyon region: An annotated checklist, 2nd ed. Grand
Canyon Nat. Hist. Assoc. Monogr. 1.

Brown, B. X, Carothers, S. W., and Johnson, R. R. 1987. Grand Canyon Birds.
Univ. of Ariz. Press, Tucson.

Brown, B. T., Carothers, S. W, Johnson, R. R., Riffey, M. M., and Stevens, L. E.
1993. Checklist of the Birds of the Grand Canyon Region. Grand Canyon Nat.
Hist. Assoc., Grand Canyon, AZ.

Brown, D. E. 1985. Arizona Wetlands and Waterfowl. Univ. of Ariz. Press, Tucson.

Corman, T., and Monson, G. 1995. First United States nesting records of the Streak-
backed Oriole. W. Birds 26:49-53.

DeSante, D. F., and George, T. L. 1994. Population trends in the landbirds of western
North America, in A century of avifaunal change in western North America (J. R.
Jehl, Jr., and N. K. Johnson, eds.), pp. 173-190. Studies Avian Biol. 15.

Hughes, J.M., 1999. Yeliow-biiled Cuckoo (Coccyzus americanus), in The Birds of
North America (A. Poole and F, Gill, eds.), no. 418. Birds N. Am., Philadelphia.

117

RECENT BIRD RECORDS FROM THE GRAND CANYON REGION, 1974-2000

Johnson, N. K. 1994. Pioneering and natural expansion of breeding distributions in
western North American birds, in A century of avifaunal change in western
North America (J. R. Jehl, Jr., and N. K. Johnson, eds.), pp. 27-44. Studies
Avian Biol. 15.

Johnson, R. R. 1991. Historic changes in vegetation along the Colorado River in the
Grand Canyon, in Colorado River Ecology and Dam Management (G. R.
Marzolf, ed.), pp. 178-206. Natl. Academy Press, Washington, D.C.

LaRue, C. T., and Ellis, D. H. 1992. The Common Grackle in Arizona: First specimen
record and notes on occurrence. W. Birds 23:84-86.

Mlodinow, S. G., and Karlson, K.T. 1999. Anis in the United States and Canada. N.
Am. Birds 53:237-245.

Monson, G., and Phillips, A. R. 1981. Annotated Checklist of the Birds of Arizona,
2nd ed. Univ. of Ariz. Press, Tucson.

Phillips, A., Marshall, J., and Monson, G. 1964. The Birds of Arizona. Univ. of Ariz.
Press, Tucson.

Rosenberg, G. H., and Witzeman, J. L. 1998. Arizona Bird Committee report,
1974-1996: Part 1 (nonpasserines). W. Birds 29:199-224.

Rosenberg, G. H., and Witzeman, J. L. 1999. Arizona Bird Committee report,
1974-1996: Part 2 (passerines). W. Birds 30:94-120.

Rosenberg, G. H., and Benesh, C. D. 1999. Spring migration. Arizona region. N.
Am. Birds 53:309-311.

Rosenberg, K. V., Ohmart, R. D., Hunter, W. C., and Anderson, B. W. 1991. Birds
of the Lower Colorado River Valley. Univ. of Ariz. Press, Tucson.

Sogge, M. K., Tibbitts, T. J., and Petterson, J. R. 1997, Status and breeding ecology of
the Southwestern Willow Flycatcher in the Grand Canyon. W. Birds 28:142-157.

Sogge, M. K., Felley, D., and Wotawa, M. 1998. Annotated species list and summary
in riparian bird community ecology in the Grand Canyon — Final report. U. S.
Geol. Surv., Colo. Plateau Field Station, N. Ariz. Univ., Flagstaff, AZ 86011.

Spence, J. R., LaRue, C. T., Muller, J. R., and Brown, N. L. 1998. 1997 avian
community monitoring along the Colorado River from Lee’s Ferry to Lake Mead.
Final report submitted to Grand Canyon Monitoring and Research Center,
Flagstaff; order from Glen Canyon National Recreation Area, P. O. Box 1507,
Page, AZ 86040.

Stevens, L. 1983. The Colorado River in Grand Canyon: A Comprehensive Guide.
Red Lake Books, Flagstaff, AZ.

Stevens, L. E., Buck, K. A., Brown, B. T., and Kline, N, 1997. Dam and geomorphic
influences on Colorado River waterbird distribution, Grand Canyon, Arizona.
Regulated Rivers: Research & Management 13:151-169.

Turner, R. M., and Karpiscak, M. M. 1980. Recent vegetational changes along the
Colorado River between Glen Canyon Dam and Lake Mead, Arizona. U.S. Geol.
Surv. Prof. Paper 1132.

Woodbury, A. M., and Russell Jr., H. N. 1945. Birds of the Navajo Country. Bull.
Univ. LItah 35 (41), Biol. Ser. 9 (1).

Accepted 12 December 2000

118

OCCURRENCE PATTERNS OF PEREGRINE
FALCONS ON SOUTHEAST FARALLON ISLAND,
CALIFORNIA, BY SUBSPECIES, AGE, AND SEX

SASHA EARNHEART-GOLD and PETER PYLE, Point Reyes Bird Observatory,
4990 Shoreline Hwy., Stinson Beach, California 94970

ABSTRACT: We summarize observations of 201 Peregrine Falcons ( Falco
peregrinus ) at Southeast Farallon Island during the fall and winter from 1990 to 1999
by age, sex, and subspecies. The northwestern subspecies F. p. pealei and the
continental subspecies F. p. anatum occurred with roughly equal frequency. We
recorded 10 individuals of the arctic subspecies F. p. tundrius. During fall, adults
occurred significantly earlier than immatures. Males tended to occur earlier than
females; anatum tended to occur earlier than pealei. Four to six birds per year (of both
anatum and pealei) remained through the winter. Under the assumption that
wintering individuals returned each year to the maximum extent possible allowed by
the observed variation by age, sex, and subspecies, their survival rate was 0.78.

Although the Peregrine Falcon (Falco peregrinus) was recently removed
from the federal endangered-species list (Federal Register 64 FR 46541
46558), there is still much interest in this species (e.g., Ratcliffe 1980, Cade
et al. 1988). On Southeast Farallon Island, 42 km off San Francisco,
California, numbers of Peregrines increased significantly during fall migration
from 1974 to 1993 (Pyle and DeSante 1994); the negative (but nonsignifi-
cant) curvilinear relationship found in that analysis suggested that the increase
was leveling off by the early 1990s. This species has also become a regular
winter resident at Southeast Farallon (Pyle and Henderson 1991).

Currently, there are about 19 recognized subspecies of the Peregrine
Falcon in the world (White and Boyce 1988). The AOU (1957) listed two
subspecies in California, P. f. anatum, which breeds and winters throughout
the state, and P. f. pealei, which is reported to winter “rarely to California.”
Grinnell and Miller (1944) listed three specimens of pealei from California,
as far south as San Diego County (Swarth 1933), but Beebe (1960) seemed
to question most reports of this subspecies south of Washington, and Hunt
et al. (1975) believed few if any Peregrines migrate down the Pacific coast.
Anderson et al. (1988) listed two records of pealei banded as nestlings in
British Columbia and recovered in San Diego and Santa Cruz; they sug-
gested on the basis of sight reports that it is a regular visitor to Southeast
Farallon and elsewhere in California.

A third subspecies, P f. tundrius, breeding in arctic North America, was
described by White (1968). He suggested that it is a rare or uncommon
migrant along the west coast of North America and listed one specimen (of
213 tundrius examined) from California (March, Del Ray, Fresno County)
and four specimens from Baja California (March and April). Anderson et al.
(1988) listed a second California specimen of a banded tundrius recovered
on San Miguel Island, and Hamilton and Willick (1996) listed two records of
banded birds from Orange County. Otherwise, little has been published
about the occurrence of pealei and tundrius in California.

During the past ten years Point Reyes Bird Observatory biologists have
made an effort to identify Peregrines on Southeast Farallon Island by

Western Birds 32:119-126, 2001

119

OCCURRENCE PATTERNS OF PEREGRINE FALCONS ON FARALLON ISLAND

subspecies, age, and sex. Here we summarize our findings from 1990 to
1999 for both fall and winter, when a majority of migrant and resident
individuals were recorded. Arrivals from spring and summer are excluded
because sample sizes are much smaller (Pyle and Henderson 1991) and
critical subspecies, age, and sex determinations were not recorded.

METHODS

The standardized daily census for migrant and wintering birds on South-
east Farallon, uninterrupted since 1968, has been described by DeSante and
Ainley (1980) and Pyle and Henderson (1991). Birds censused each day
during the fall/winter period (15 July-1 March) were identified as arrivals if
banding data and/or plumage observation, coupled with data from previous
days, suggested that they had arrived at the island that day. Between 1990
and 1999 the size, shape, and plumage of most arriving and winter resident
Peregrine Falcons were examined critically for subspecies, age, and sex. We
defined as winter residents those remaining for at least 21 days between 15
December and 1 March.

All subspecific, age, and sex determinations of Peregrines were made
either by Pyle (78.6% of 126 identifications) or long-term interns (including
Earnheart-Gold) that had been trained for this by Pyle. Plumage criteria used
in these determinations included those presented by Brooks (1926), Beebe
(1960), Brown and Amadon (1968), White (1968), and White and Boyce
(1988), supplemented by examination of specimens at the California
Academy of Sciences (CAS), San Francisco, and Museum of Vertebrate
Zoology (MVZ), Berkeley. Determinations were usually made in the order
age, subspecies, sex. During most (91.2%) determinations there were one to
five other Peregrines at Southeast Farallon on the same day, often interact-
ing with each other, allowing direct comparisons of size and plumage.
Peregrines for which determinations were not made were not observed
adequately or were difficult to categorize by known criteria. There is much
variation within each subspecies, leading to overlap in size and/or plumage,
especially between anatum and each of the other two subspecies. Because
of this intrasubspecific variation we identified only typical examples and left
many birds unidentified to subspecies. The following criteria were used to
identify subspecies:

F. p. anatum : Medium sized; stocky build. Adults with medium-dark gray upper-
parts, contrastingly black hood extending to the bill, and buffy- or rosy-tinged
underparts with medium-heavy spotting. Immatures medium brownish, sometimes
tinged rufous, with little or no buffy in the crown, a medium-thick malar stripe, and a
thin buffy terminal band on the tail.

F. p. pealei: Large; medium-stocky build. Adults with medium-dark grayish upper-
parts blending to a slightly darker crown and hood, often interrupted by a white band
at the base of the bill, and whitish underparts with heavy barring throughout the breast
and belly. Immatures dark gray to blackish without buffy in the crown, a thick malar
stripe, and a thin or no buffy terminal band on the tail.

F. p. tundrius: Medium-small; slender and long-winged in build. Adults with
medium-pale grayish to bluish upperparts contrasting somewhat with a blackish
crown and hood, interrupted by a white band at the base of the bill, and white

120

OCCURRENCE PATTERNS OF PEREGRINE FALCONS ON FARALLON ISLAND

underparts with light barring on the belly but little or no barring on the upper breast.
Immatures brownish with extensive buffy in the crown and nape, a reduced malar
stripe, and an extensive buffy terminal band on the tail.

We used simple and multiple linear regression and analysis of variance
(ANOVA) to help describe the occurrence patterns and look for significant
variation in these patterns among subspecies, ages, and sexes.

RESULTS

We counted 201 Peregrine Falcons during fall and winter, 1990-1999
(Table 1); 126 birds identified to subspecies included 56 of anatum, 57 of
pealei , and 10 of tundrius. Of 87 birds that were sexed, 47 were females
and 40 were males, and of 121 birds that were aged, 50 were adults and 71
were immatures. There was no significant linear trend in number of arrivals
during the 10-year period taken as a whole (Figure 1; linear regression; t =
0.363, P = 0.719). Evidently, however, fewer Peregrines arrived immedi-
ately after El Nino years (1992 and 1997-1998), followed by gradual
increases in arrivals until the next El Nino (Figure 1). For example, the
positive linear trend in arrivals between 1993 and 1998 was significant ( t =
7.86, P = 0.001). The 10-year trend for identified anatum was slightly and
nonsignificantly positive ( t = 0.147, P = 0.887), and that for identified
pealei was positive and nearly significant ( t = 2.193, P = 0.060). It should
be noted that biases related to the 75 Peregrines (37.3%) not identified to
subspecies could affect these analyses.

All ten individuals of tundrius noted during the study period were
observed and identified by Pyle. They were recorded in only five of the ten

Table 1 Arrival Dates of Peregrine Falcons on Southeast
Farallon Island during Fall and Winter (15 July-1 March),
1990-1999

Subspecies/Age/Sex n

Mean

Minimum

Maximum

Total

201

14 Oct

22 Jul

31 Dec

F. p. anatum

14 Oct

6 Aug

1 Dec

Male

30 Sep

6 Aug

23 Nov

Female

22 Oct

13 Aug

27 Nov

Adult

3 Oct

6 Aug

1 Dec

Immature

24 Oct

13 Aug

27 Nov

F. p. pealei

20 Oct

26 Aug

3 Dec

Male

24 Oct

7 Sep

24 Nov

Female

20 Oct

26 Aug

3 Dec

Adult

13 Oct

13 Sep

13 Nov

Immature

26 Oct

7 Sep

3 Dec

F. p. tundrius

19 Oct

2 Oct

17 Nov

Male

11 Oct

7 Oct

14 Oct

Female

14 Oct

7 Oct

22 Oct

Adult

11 Oct

7 Oct

14 Oct

Immature

21 Oct

2 Oct

17 Nov

121

OCCURRENCE PATTERNS OF PEREGRINE FALCONS ON FARALLON ISLAND

^ 30 n

Year

Figure 1. Numbers of Peregrine Falcon arriving (see text) on Southeast Farallon
Island, by year, 1990-1999.

years, 1992 (two birds), 1993 (one), 1994 (one), 1995 (two), and 1997
(four), despite a similar amount of observation effort each year. Both adults
(see Table 1) were males, recorded on single days in 1997. Seven of the ten
birds were recorded between 7 and 22 October. There are also at least six
records of this subspecies (all immatures) observed and described or photo-
graphed (e.g., Figure 2) by Pyle or other biologists between 26 September
and 6 November, 1981-1988. All birds identified as tundrius fit the
description above, and most were seen in direct comparison with other
Peregrines.

Examination of mean arrival dates (Table 1) reveals several patterns
according to subspecies, age, and sex. In all three subspecies identified males
apparently tended to arrive before females, but this pattern was not
signifcant for the species as a whole (F<i,99) = 1 .50, P = 0.299; F(3,83) = 1.62,
P = 0.207, adjusting for subspecies) or for pealei (P(i,42) = 0.38, P = 0.543).
It was almost significant for anatum (F( i,34) = 3.98, P = 0.054). In all three
subspecies identified adults arrived before immatures, and this pattern was
significant for the species as a whole (Fu,i54) = 11.32, P = 0.001; F(3,ii8) =
15.14, P < 0.001, adjusting for subspecies), for anatum [F( 1 , 52 ) = 6.87, P =
0.012), and for pealei (Fa, 54) = 7.32, P = 0.009). The mean arrival date of
anatum was not significantly earlier than that of pealei (Fa.nu = 1 .29, P =
0.259) when all age/sex groups were combined. When the ages and sexes
were separated, this comparison was significant for males (Fa, 34) = 6.53, P
= 0.015) but not for females, immatures, or adults (F< 1.72, P> 0.197). As
in analyses of subspecies, it should be noted that biases among birds not
identified to age (n = 80; 39.8% of the sample) or sex (n = 114; 56.7% of

122

OCCURRENCE PATTERNS OF PEREGRINE FALCONS ON FARALLON ISLAND

Figure 2. Immature Peregrine Falcon of the tundra subspecies F. p. tundrius, Southeast
Farallon Island, 6 November 1987.

Photo by Scot Anderson

the sample) might affect these results. The sample of tundrius was too small
for these analyses to be meaningful.

The winter resident population consisted of four to six individuals, up to
three of anatum and three of pealei of various ages and sexes (Table 2).
Under the (perhaps tenuous) assumption that winter residents return in
consecutive years, the table implies a minimum of 13 wintering individuals

Table 2 Winter Resident Peregrine Falcons on Southeast Farallon Island,
1990-1999

Year Summary by subspecies/age/sex

1990- 91

1991- 92

1992- 93

1993- 94

1994- 95

1995- 96

1996- 97

1997- 98

1998- 99

1999- 00

Four adults; subspecies unknown

anatum: 2 adults, 1 immature; pealei: 2 adults

anatum: 2 adults; pealei: 1 adult Cf, 1 adult 9

anatum ; 1 adult <f , 1 adult 9; pealei: 1 adult <f, 1 adult 9

anatum: 1 adult C f, 1 immature C f; pealei: 1 adult (f, 2 immature 9

anatum: 1 adult cf, 1 adult 9, 1 immature 9; pealei: 1 adult cf,

1 adult 9, 1 immature 9

anatum: 1 adult C f, 1 adult 9; pealei: 1 adult 9, 1 immature

anatum: 1 adult C f, 1 adult 9; pealei: 1 adult cf, 1 adult 9

anatum: 1 adult cf, 1 immature cf, 1 immature 9; pealei: 1 adult cf,
1 immature

anatum: 1 adult <$ , 1 adult 9; pealei: 1 adult 9, 1 immature cf,

1 immature 9

123

OCCURRENCE PATTERNS OF PEREGRINE FALCONS ON FARALLON ISLAND

over the 10-year period, five of ana turn (two males and three females) and
eight of pealei (three males and five females). If returning winter resident
adults of the same sex represented the same individuals, six adults (two of
anatum and four of pealei ) disappeared and 21 adults returned for an
annual adult survival rate of 0.78 (0.86 for anatum and 0.69 for pealei) over
the 10-year period.

DISCUSSION

Our finding no linear trend in Peregrine numbers between 1990 and
1999 suggests that populations have stabilized since recovery from their
pesticide-related reductions from the 1950s to the 1970s and that our
proportions may represent historical distributions in population size and
range. It is also possible, however, that distributions have shifted since the
population bottlenecks of the 1950s-1970s, especially if seabird popula-
tions or other prey resources have changed. Our data further suggest that
mortality of Peregrines is higher and/or fall and winter populations shift
during El Nino periods (e.g., 1992 and 1997-1998), perhaps in response to
reduced abundance of seabird prey off central California during these events
(Ainley and Boekelheide 1990).

The regularity of pealei in California (similar in abundance to anatum at
Southeast Farallon) has not been previously appreciated in the literature
(e.g., AOU 1957, Beebe 1960, Hunt et al. 1975), although suspected by
Anderson et al. (1988) and confirmed by museum specimen examination
(C. White pers. comm.) and unpublished data collected by the Santa Cruz
Predatory Bird Research Group (B. Walton pers. comm.). It is possible that
the abundant alcid populations at Southeast Farallon (Ainley and Boekelheide
1990) provide a food resource for pealei, an alcid specialist where it breeds
(Beebe 1960). Because the colony at Southeast Farallon represents the
southernmost point of such alcid abundance (Carter et al. 1992), the island
may represent the southern limit of the regular winter range of pealei.
Individuals of pealei, though, winter or wander as far south as San Diego and
even Baja California but are greatly outnumbered by anatum south of
Southeast Farallon (B. Walton pers. comm.).

Our data suggest that tundrius is an uncommon but regular transient
down the California coast from late September through mid November, as
proposed by White (1968) and Anderson et al. (1988) and confirmed with
unpublished data from the Santa Cruz Predatory Bird Research Group (B.
Walton pers. comm.). It is possible that these birds winter in Baja California
(White 1968), although residents of anatum of that region, particularly
immatures, may resemble tundrius in size and plumage more closely than
those of California-breeding populations (C. White, M. A. Patten, pers.
comm.; Pyle, specimen examination at CAS and MVZ). We suggest that the
identification of the four specimens of tundrius from Baja California listed
by White (1968) be reconfirmed.

Our data on arrival patterns of anatum and pealei by age and sex are
consistent with patterns widely known in birds: smaller males depart nesting
grounds for winter areas slightly before larger females, and adults migrate
and arrive on winter grounds well before immatures. The more local and

124

OCCURRENCE PATTERNS OF PEREGRINE FALCONS ON FARALLON ISLAND

southern anatum arriving before the more northern pealei, especially
among males, is also to be expected (Anderson et al. 1988).

ACKNOWLEDGMENTS

We thank the U.S. Fish and Wildlife Service, managers of the Farallon National
Wildlife Refuge, for supporting our work at Southeast Farallon Island, Douglas J. Long
at CAS and Ned K. Johnson at MVZ for permitting our examination of Peregrine
specimens, and Michael Patten for information on Peregrines in California and Baja
California. We especially thank Clayton White and Brian Walton for expert advice
during reviews of the manuscript and Walton further for sharing unpublished data
collected by the Santa Cruz Predatory Bird Research Group. This is Point Reyes Bird
Observatory contribution 930.

LITERATURE CITED

Ainley, D. G., and Boekelheide, R. J. 1990. Seabirds of the Farallon Islands: Ecology,
Dynamics, and Structure of an Upwelling-system Community. Stanford Univ.
Press, Stanford, CA.

American Ornithologists' Union. 1957. Check-list of North American Birds, 5th ed.
Am. Ornithol. Union, Baltimore.

Anderson, C. M., Roseneau, D. G., Walton, B. J., and Bente, P. J. 1988. New
evidence of a Peregrine migration on the west coast of North America, in
Peregrine Falcon Populations: Their Management and Recovery (T. J. Cade, J.
H. Enderson, C. G. Thelander, and C. M. White, eds.), pp. 507-516. Braun-
Brumfield, San Francisco.

Beebe, F. L. 1960, The marine Peregrines of the northwest Pacific coast. Condor
62:145-189.

Brooks, A. 1926. Notes on the status of the Peale Falcon. Condor 28:77-79.

Brown, L., and D. Amadon. 1968. Eagles, Hawks and Falcons of the World.
McGraw-Hill, New York.

Cade, T. J., Enderson, J. H., Thelander, C. G., and White, C. M. (eds.). 1988.
Peregrine Falcon Populations: Their Management and Recovery. Braun-
Brumfield, San Francisco.

Carter, H. R., McChesney, G. J., Jaques, D. L., Strong, C. S., Parker, M. W.,
Takekawa, J, E., Jory, D. L,, and Whitworth, D. L. 1992. Breeding populations
of seabirds on the northern and central California coasts in 1989-1991. U.S.
Fish & Wildlife Serv., 6924 Tremont Rd., Dixon, CA 95620.

DeSante, D. F., and Ainley, D. G. 1980. The Avifauna of the South Farallon Islands,
California. Studies Avian Biol. 4.

Grinnell, J., and Miller, A. H. 1944. The distribution of the birds of California. Pac.
Coast Avifauna 27.

Hamilton, R. A., and Willick, D. R. 1996. The Birds of Orange County, California:
Status and Distribution. Sage & Sea Press, Irvine, CA.

Hunt, W. G., Rogers, R. R., and Slowe, D. G. 1975. Migratory and foraging behavior
of Peregrine Falcons on the Texas coast. Can. Field-Nat. 89:111-123.

Pyle, P., and Henderson, R. P. 1991. The birds of Southeast Farallon Island:
Occurrence and seasonal distribution of migratory species. W. Birds 22:41-84.

Pyle, P., and DeSante, D. F. 1994. Trends in waterbirds and raptors at Southeast
Farallon Island, California, 1974—1993. Bird Populations 2:33-43.

125

OCCURRENCE PATTERNS OF PEREGRINE FALCONS ON FARALLON ISLAND

Ratcliffe, D. 1980. The Peregrine Falcon. Poyser, Stafford, England.

Swarth, H. S. 1933. Peale Falcon in California. Condor 35:233-234.

White. C. M. 1968. Diagnosis and relationships of the North American tundra-
inhabiting Peregrine Falcons. Auk 85:179-191.

White, C. M., and Boyce, D. A., Jr. 1988. An overview of Peregrine Falcon
subspecies, in Peregrine Falcon Populations: Their Management and Recovery
(T. J. Cade, J. H. Enderson, C. G. Thelander, and C. M. White, eds.), pp. 789-
810. Braun-Brumfield, San Francisco.

Accepted 14 May 2001

NOTES

LOW-ELEVATION NESTING BY CALLIOPE
HUMMINGBIRDS IN THE WESTERN
SIERRA NEVADA FOOTHILLS

BRIAN D. C. WILLIAMS, 8200 Turner Dr., Granite Bay, California 95746

The Calliope Hummingbird breeds uncommonly to fairly commonly in the Sierra
Nevada and other high mountain ranges in California. In the Sierra it typically nests
above 4000 feet elevation (Grinnell and Miller 1944, Gaines 1992, pers. obs.),
usually near moist meadows or other relatively level and wet sites with a mixture of
deciduous and coniferous trees, shrubs, and flowering plants (Grinnell and Miller
1944, Verner et al. 1980, Gaines 1992, pers. obs.). Although it can be locally fairly
common as a migrant in the more arid lowlands during spring migration (pers. obs.),
it generally avoids dense forests, dry ridges, or other relatively exposed and hot sites
for breeding. Consequently, 1 was quite surprised to find a Calliope Hummingbird
raising young in relatively arid Blue Oak (Quercus douglasii) woodland well below
1000 feet elevation.

On 6 June 1993, I found a female Calliope Hummingbird feeding a dependent
fledgling in a California Buckeye ( Aesculus californica ) near Granite Bay in Folsom
Lake State Park, Placer County, elevation 420 feet, at the western edge of the Sierra
Nevada foothills. Both birds were clearly smaller than Anna’s Hummingbird ( Ca\ypte
anna), a common resident in the area, and they were also smaller but chunkier than
the slender-necked Black-chinned Hummingbird ( Archilochus alexandri), also fairly
common there. Both Calliopes had buffy flanks with faint buffy breast bands (see
Kaufmann 1990). They both had a pattern of symmetrical columns of dark throat
spots, not concentrated in the center of the throat and lacking apparent iridescence.
The female Calliope’s primaries extended just slightly beyond her short tail, and the
four central retrices lacked white tips. I distinguished the juvenile mostly by behavior
as it made only short uncoordinated flights of no more than a few feet and often had
difficulty perching, though its plumage also seemed buffier plumage than the adult
female’s (Baltosser 1994). The juvenile usually remained stationary in the buckeye
until the female returned to feed it, inserting her bill into its gape. To make sure of the
identification and to document this rare event, I called Bill Grenfell, a local wildlife
photographer, who took a few photographs on the afternoon of 6 June (Figure 1).
The birds were quite approachable, and we were able to stand closer than 12 feet
without flushing either of them. They also appeared to ignore other birds in the area,
except for a Black-chinned Hummingbird (unknown sex) that was chased from the
area by the female Calliope on my single return visit about 10:00 on 7 June. On that
visit I returned to the same tree and immediately found the juvenile still perched there;
presumably the nest was nearby. The female was still making repeated foraging trips
and returned regularly to feed the juvenile.

The Calliope Hummingbird is a regular spring migrant at Folsom Lake State Park,
and two to five adult males can usually be found daily in the Granite Bay-Beek’s Bight
area from mid-April to early May. They concentrate in an area of mixed oak woodland
and patchy Chamise (Adenostoma fasciculatum ) chaparral where sticky monkey-
flowers ( Mimulus aurantiacus ) and buckeyes are numerous and Indian paintbrush
{Castilleja sp.), yerba santa ( Eriodictyon californicum), and other flowering plants
are scattered about in the chaparral. This female and her fledgling, however, were
about 0.5 mile southwest of that area within a woodland dominated by the Blue Oak
and situated on a gentle north-facing slope with a sparse understory of Poison Oak

Western Birds 32:127-130, 2001

127

NOTES

Figure 1. Female Calliope Hummingbird feeding fledgling in California Buckeye,
Folsom Lake State Park, 6 June 1993.

Photo by Bill Grenfell

(' Toxicodendron diuersilobum) and flowering California buckeye. The woodland s
canopy closure is approximately 80% (visually estimated), though the Blue Oak
canopy is generally high, not very dense, and admits plenty of filtered light for a
ground cover of mostly nonnative grasses and forbs. Otherwise there are no nearby
concentrations of typical hummingbird-pollinated plants within at least 100 m. The
site is also at the edge of an almost level drainage that stays moist relatively late into
the spring and probably still contained some open water at the time of nest initiation.
The north aspect, high canopy cover, relatively mesic conditions, and position at the
bottom of a local basin (into which cooler air collects) likely give this spot one of the
coolest microclimates within roughly a half-mile radius. The Calliope Hummingbird
generally prefers cool microhabitats (Calder and Calder 1994). Gaines (1992),
however, reported the species using arid ridges in Yosemite, and in 1978 Ted Beedy
(pers. comm.) found two nests in junipers on a dry slope about 2 miles south of
Highway 20 and >100 m from Yosemite Creek (>6000 feet elevation).

Surprisingly. I later learned of a previous breeding attempt by a Calliope Humming-
bird about 0.5 mile from the site, described above. On 20 April 1985 Tim Fitzer, Jack
Wilburn, and Dan Brown saw a female Calliope fly from a nest. Excited by their
discovery, Wilburn and Brown returned two days later to photograph the nesting
Calliope (Figure 2). On a later visit Wilburn did not see the female and assumed the
nest was abandoned. It is not known whether the bird laid any eggs or fledged young.
The date of probable nest initiation in 1985 was very near that in 1993. If the juvenile
fledged on 6 June 1993 (the last possible date) and incubation (15-16 days) and
fledging (18-21 days) took 33-37 days (Calder and Calder 1994), the last possible
dates for egg laying were 1-5 May.

The only other probable or possible extralimital nesting records I was able to locate

128

NOTES

Figure 2. Calliope Hummingbird on nest at Beek’s Bight, Folsom Lake State Park, 22
April 1985.

Photo by Dan Brown

were by San Miguel (1985) and in the editors’ files for the Middle Pacific Coast region
of American Birds and its various successors (1955-1991; 1997-1998). I subse-
quently confirmed all of these records with the observers. Bob Yutzy found one at
Lake Shasta, Shasta Co., on 21 June 1980. Richard A. Erickson found a pair
copulating at 2000 feet elevation 1 mile north of Hyampom, Trinity Co., 16 June
1983 (Le Valley and Evens 1983, Harris 1991). Jeri M. Langham found a male along
French Hill Road about 1000 feet elevation near Shingle Springs, El Dorado Co., 8
June 1985. David G. Yee found a female apparently on territory at 2000 feet elevaton
near Mokelumne Hill, Calaveras Co., 1 June 1985. Yutzy reported a pair visiting a
feeder at 1300 feet elevation west of Redding in mid-July 1985, and a female at a
feeder in Redding 11 June 1987; he also saw a female on a nest at about 2000 feet
elevation along Gilrnan Road northeast of Lake Shasta on 31 May 1997 and has seen
the species a few other times in late May sightings at his feeders near Shasta (> 1 000
feet) west of Redding (pers. comm.). Even though the various observers considered
these records either out of range or at the margins of the species’ range, all of these
localities are in or near coniferous forest (Ponderosa Pine, Pinus ponderosa, or
Douglas Fir, Pseudotsuga menziesii; the Gilman Road nest was in a Douglas Fir),
nesting habitat more typical Blue Oak woodland.

Records accumulated over the years suggest the American River may serve as a
migratory corridor, hummingbirds roughly following the progression of blooming
flowers to more typical nest sites at higher elevations (mostly above 5000 feet in this
part of the Sierra). This phenomenon was hypothesized by San Miguel (1985) for the
Kaweah River of the southern Sierra and may be a common strategy of migrating
hummingbirds. Possibly the nestings at Folsom Lake were responses to locally
favorable food supplies (e.g., Sealy 1979) and/or suitable microclimate and nesting
sites (e.g., Walley 1977, Roberson 1993), but the role of premature reproductive

129

NOTES

development (in this and other extralimital nesting species) is unknown. Either way, I
urge other observers to watch for signs of nesting Calliope Hummingbirds at other
favorable sites outside of the recognized breeding range, especially in the Sierra
Nevada foothills where other montane birds may nest locally well outside of their
known range. Such nesting also raises the possibility of multiple broods (see also the
hint by Calder and Calder 1994), as it seems possible for a Calliope Hummingbird
nesting at a low elevation early to nest at a higher elevation later in the year, in June
and July as is typical for the species (Orr and Moffitt 1971).

Thanks to Bill Grenfell for quickly responding to my plea for photos, to David Yee,
Don Roberson, and Steve Glover for providing copies of the editors’ files for
American Birds and its successors, and to the many observers who, by recording and
submitting their sightings, make distributional studies possible. Thanks also to Tim
Manolis, Steve Speich, Tim Fitzer, and Jack Wilburn for information on previous local
records, and to Dan Brown for contributing a photo of the nest. Tim Manolis and Ted
Beedy provided very helpful suggestions on an earlier draft.

LITERATURE CITED

Baltosser, W. H. 1994. Age and sex determination in the Calliope Hummingbird. W.
Birds 25:104-109.

Calder, W. A., and Calder, L. L. 1994. Calliope Hummingbird (Stellula calliope ), in
The Birds of North America (A. Poole and F. Gill, edsj, no. 135. Acad. Nat. Sci.,
Philadelphia.

Gaines, David. 1992. Birds of Yosemite and the East Slope. Artemisia Press, Lee
Vining, CA.

Grinnell, J., and Miller, A. H. 1944. Distribution of the birds of California. Pac. Coast
Avifauna 27.

Harris, S. W. 1991. Northwestern California Birds. Humboldt State Univ. Press,
Areata, CA.

Kaufmann, K. 1990. Advanced Birding. Houghton Mifflin, Boston.

LeValley, R., and Evens, J. 1983. Middle Pacific Coast region. Am. Birds 37:1022-
1026.

Orr, R. T.. and Moffitt, J. 1971. Birds of the Lake Tahoe Region. Calif. Acad. Sci.,
San Francisco.

Roberson, D. 1993. Northern Parula, in Atlas of the Breeding Birds of Monterey
County (D. Roberson and C. Tenney, eds.), p. 402. Monterey Peninsula
Audubon Soc., Carmel, CA.

San Miguel, G. L. 1985. Lower elevation breeding in the Sierra foothills. W. Tanager
52 (3): 1-4.

Sealy, S. G. 1979. Extralimital nesting of Bay-breasted Warblers: Response to forest
tent caterpillars? Auk 96:600-603.

Verner, J., Beedy, E. C., Granholm, S. L., Ritter, L. V., and Toth, E. F. 1980. Birds,
in California wildlife and their habitats: Western Sierra Nevada (J. Verner and A.
S. Boss, tech, coords.), pp. 75-319 . Gen. Tech. Rep. PSW-37. USDA Forest
Service, Pacific Southwest Forest and Range Experiment Station, Berkeley, CA.

Walley, W. J. 1977. An extra-limital nesting of the Wood Thrush in Manitoba. Blue
Jay 35:82-86.

Accepted 8 February 2001

130

NOTES

RAPID SECOND NESTING BY
ANNA S HUMMINGBIRD NEAR ITS
NORTHERN BREEDING LIMITS

ANN SCARFE, 4090 Gordon Head Road, Victoria, British Columbia V8N 3Y1
J. CAM FINLAY, 270 Trevlac PL, Victoria, British Columbia V9E 2C4

Anna’s Hummingbirds ( Calypte anna) were first reported in Victoria, British
Columbia, in December 1944 and again each winter until 13 January 1947.
Sightings continued through the 1950s (Taylor and Harper 1987), increased in
numbers each year, and by 1970 the first individual was noted on the Victoria
Christmas bird count. Numbers increased on subsequent counts, with 177 noted in
1998 (D. Pearce pers. comm.). With these data and our banding records over the past
two years, we estimate a minimum of 300 Anna’s Hummingbirds spend the winter
and spring on the southeastern tip of Vancouver Island (greater Victoria). Given these
numbers, we suspect this species might exhibit nesting overlap here as it does in
Arizona and California (Russell 1996, Maender et al. 1996).

The first documented nest of Anna’s Hummingbird in Canada was found near
Duncan, 50 km north of Victoria, in July 1958. In Victoria a nest was first seen 30
years later on 29 February 1988 (Campbell et al. 1990). Since then, nests have been
found in increasing numbers each spring.

Our study was conducted in Scarfe’s private garden approximately 1.5 km
northeast of the University of Victoria, near the south end of Vancouver Island, from
February to mid April in both 1998 and 1999. The female discussed here that laid two
clutches was caught by means of a feeder within a wire cage trap. We banded her and
colored the top of her head orange with Liquitex Value Series Basics acrylic color, a
water-based paint that lasts about five months. Nest observations were made with the
aid of a mirror on a long handle, with 7,8, and 9x binoculars and a 27x spotting
scope. We obtained temperature data from the weather station on the campus of the
University of Victoria.

By the end of February 1998, Scarfe had located four active Anna’s Hummingbird
nests in the greater Victoria region. When first spotted on 19 February, one of these
(nest 1) was being built by a female 3.3 m above ground in Scarfe’s yard. The nest sat
on a bare Douglas fir ( Pseudotsuga menziesii ) branch, 4 cm in diameter, with dense
needle coverage above it and on its north and south sides. The north-facing wall of
Scarfe’s residence was 2 m away, providing shelter from winds from the southeast.
This nest contained two eggs when was first checked for eggs on 21 February. By 3
March, nestlings were being fed, the first of which fledged on 20 March, the second
on 23 March. The adult female was never trapped or color marked.

On 22 March, only 33 m to the southwest of nest 1, Scarfe discovered a second
female building a nest on the topmost, unsheltered branch of an apple tree ( Malus
sp.), 4.75 m above ground. This female was trapped, banded, and color marked on
23 March. That day we watched the unmarked female feeding one newly fledged
juvenile. Also on 23 March, the marked female was seen feeding two newly fledged
young (estimated 1-3 days out of the nest) in dense shrubbery about 8 m from the new
nest tree. On 25 March we noted this female sitting on her nest at 10:00 when she left
to feed the nearby fledglings about 7 m away. At 10:30 that day, we noted two eggs
in the new nest.

On 30 March, the marked female was incubating eggs and feeding her two
fledglings, which were now more than 25 m away from nest 2 but still calling for food.
By 3 April only one fledgling, being fed by the female, could be located. The next day
it too disappeared.

Western Birds 32:131-133, 2001

131

NOTES

The marked female’s eggs hatched on, or just before, 14 April. We noted the
female feeding nestlings and a small bill poking above the nest’s rim on that day. The
two nestlings were present on 23 April, but the nest was empty on 27 April. The nest
remained intact. The marked female remained around for several days and then
disappeared. Over the summer both nests were gone. Feeders were available all
summer but were seldom used.

All four nests of Anna’s Hummingbirds that Scarfe found in 1998 had incubating
females by the end of February. Another nest 2.5 km southeast of Scarfe’s residence
fledged two young on 28 and 29 March 1998.

The marked female was trapped again on 18 September 1998 and remarked. On
12 February 1999 this marked female was seen building a nest in the exact spot where
the unmarked female built the previous year. An egg was present on 19 February,
almost a year from when the unmarked female began laying in 1998. A second egg
appeared the next day. Both had hatched by the morning of 7 March, but the nestlings
died that day.

The southeast side of Vancouver Island has a Mediterranean-type climate with cold,
wet winters. January temperatures sometimes fall below 5° C at night, but by mid
February, overnight low temperatures seldom go below freezing and, if so, to only
-1° or -2° C.

In both 1998 and 1999 eggs were laid on or just before 19 February. Since the
mean temperature for February was 5.5° C in 1998 but only 3.6°Cin 1999, it would
seem that similarities in time of nest construction and egg laying in the two years were
not entirely temperature dependent. We suggest that the early breeding has been
aided by the increased numbers of hummingbird feeders being left filled all year, a
result of public knowledge of the presence of this species.

Because Anna’s Hummingbirds do raise two broods in California and Arizona
(Russell 1996) and have been confirmed breeders on southern Vancouver Island for at
least 40 years it was not surprising to find two broods being raised in Victoria.

In 1999, the marked female selected the exact site used in 1998 by the unmarked
female the previous year. Because this was a more sheltered site than the marked
female had used the previous year, perhaps it was selected to avoid the effects of cold
stress. Calder (1974) found that an Anna’s Hummingbird selected a sheltered nest site
located so that the temperature within the nest was slightly warmer than the
surrounding ambient air.

Overlap of two broods (a female feeding late nestlings and incubating a second
clutch simultaneously) was observed in the Broad-tailed Hummingbird ( Selasphorus
platycercus ) by Bailey (1974).

The use of the same spot two years in a row by an Anna’s Hummingbird is relatively
uncommon but does occur. One of the earliest citations is by Bendire (1895). W. M.
Tyler (in Bent 1940) noted that several other species of hummingbirds, including the
Ruby-throated ( Archilochus colubris), Costa’s (C. costae), Rufous (S. ru/us), and
Allen’s (S. sasin), have renested on the same site in two or more consecutive years.
Tim Manolis (pers. comm.) has observed Black-chinned Hummingbirds (A. alexandri)
reusing the same site in California.

We express our appreciation to Environment Canada, Vancouver Island Special
Production Office, for supplying temperature data. Thanks to Stephen M. Russell,
William A. Calder, Tim Manolis, and an anonymous reviewer for providing construc-
tive comments on the manuscript. We thank the James L. Baillie Memorial Fund of
Bird Studies Canada for funding assistance.

LITERATURE CITED

Bailey, A. H. 1974. Second nesting of Broad-tailed Hummingbirds. Condor 76:350.

Bendire, C. E. 1895. Life histories of North American birds from the parrots to the
grackles. U. S. Natl. Mus. Spec. Bull. 3.

132

NOTES

Bent, A. C. 1940. Life histories of North American cuckoos, goatsuckers, humming-
birds and their allies. U. S. Natl. Mus. Bull. 176.

Calder, W. A. Jr. 1974. The thermal radiant environment of a winter hummingbird
nest. Condor 76:268-273.

Campbell, R. W., Da we, N. K., McTaggart-Cowan, I., Cooper, J. M., Kaiser, G. W.,
and McNall, M. C. E. 1990. The Birds of British Columbia, vol. 2. Royal Br.
Columbia Mus., Victoria.

Maender, G. J., Hiett, K. L., and Bailey, S. J. 1996. Nesting Anna’s Hummingbirds
in urban Tucson, Arizona. W. Birds 27:78-80.

Russell, S. M. 1996. Anna’s Hummingbird ( Calypte anna), in The Birds of North
America (A. Poole and F. Gill, eds.), no. 226. Acad. Nat. Sci., Philadelphia.

Taylor, K., and Harper, C. 1987. Anna’s Hummingbird (Calypte anna) on Vancouver
Island. Victoria Nat. 43 (6):9— 1 1 .

Accepted 8 January 2001

NOTES

NESTING OF BRANDT S CORMORANTS
IN THE NORTHERN GULF OF CALIFORNIA

JUAN CERVANTES-SANCHEZ, C/ Nueva Zelanda 69 6A, 28035 Madrid, Spain

ERIC MELLINK, Centro de Investigacion Cientifica y Educacion Superior de
Ensenada, Apdo. Postal 2732, 22860 Ensenada, Baja California, Mexico (U.S.
mailing address: P.O. Box 434844, San Diego, California 92143-4844)

In Mexico, Brandt’s Cormorant ( Phalacrocorax penicillatus) breeds mostly on
islands and offshore rocks along the Pacific coast of the peninsula of Baja California
(Everett and Anderson 1991, Grinnell 1928, Wilbur 1987). The southernmost
known colony on the Pacific coast is at the north end of Isla Margarita (approximately
24° 30' N, 112° W; Guzman in Everett and Anderson 1991). Colonies in the Pacific
can contain thousands of individuals.

In the Gulf of California documented Brandt’s Cormorant breeding has been
restricted to the Midriff Islands. In this region it nests or has nested on Roca Vela, on
islands in Bahia de los Angeles, including Calavera, Smith, and Flecha, on Roca
Partida (near Isla Partida Norte), Isla Partida (or Cardonosa), Isla Salsipuedes, Isla San
Esteban, and Isla San Pedro Martir (Ainley et al. 1981, Banks 1963, Everett and
Anderson 1991, Osorio-Tafall and del Toro-Aviles 1945, Tershy and Breese 1997,
van Rossem and Hachisuka 1937, E. Palacios pers. comm.). In addition, van Rossem
(1945) suspected some offshore rocks near Guaymas as a breeding locality for this
species. Brandt’s Cormorant breeding colonies in the Gulf of California are small,
rarely exceeding 250 pairs, and the total population in this area has been estimated
at 500 to 1000 pairs (Everett and Anderson 1991). It is possible, however, that some
colonies have been overlooked, through confusion of this species with the Double-
crested Cormorant ( P. auritus ) (Russell and Monson 1998, Wilbur 1987).

Here we report a breeding colony of Brandt’s Cormorant on Isla San Jorge in the
northern Gulf of California, Mailliard (1923) and Mellink and Palacios (1993)
previously reported on the breeding birds of this island, and neither recorded nesting
Brandt’s Cormorants. Isla San Jorge (31° 01' N, 113° 15' W) comprises a series of
small bare rocky islets located in the northeastern Gulf of California.

On 9 November 1 999 we found a small breeding colony of Brandt’s Cormorant on
the northeastern side of the southernmost islet (Figure 1). The colony, located on a
30° slope, about 10 meters above mean sea level, was surrounded by a small
congregation of California Sea Lions ( Zalophus californianus ) and some nesting
Brown Boobies ( Sula leucogaster). Double-crested Cormorants were nesting on the
upper ridges of the islet. We counted about 40 Brandt’s Cormorants, including
breeding adults and first-year birds, and 24 nests, 19 of which contained one to four
eggs. On 31 January 2000 we recorded 31 adults and 13 juveniles. Five adults were
still attending nests. A small chick, yet to fledge, was visible in one of these. On 9
January 2001 there were 39 adults and 26 young in the colony. Eight of the adults
were attending nests.

Our field work was supported by a grant from Conacyt (Mexico) to Mellink. We
thank the Sociedad Cooperativa Ejidal Bahia de San Jorge for logistical support,
Mario Machado and Carmelo Gil for transportation to the island, and Eduardo
Palacios and Kimball Garrett for editorial assistance.

LITERATURE CITED

Ainley, D. G., Anderson, D. W., and Kelly, P. R. 1981. Feeding ecology of marine
cormorants in southwestern North America. Condor 83:120-131.

134

Western Birds 32:134-135, 2001

NOTES

Figure 1 . Brandt’s Cormorant colony at Isla San Jorge, showing chicks three quarters
grown and one incubating adult. Also visible are Blue-footed and Brown Boobies and
California Sea Lions.

Photo by Eric Mel link

Banks, R. C. 1963. Birds of the Belvedere Expedition to the Gulf of California. Trans.
San Diego Soc. Nat. Hist. 13:49-60.

Everett, W. T., and Anderson, D. W. 1991. Status and conservation of the breeding
seasons on offshore Pacific islands of Baja California and the Gulf of California.
Int. Council Bird Protection Tech. Publ. 11:116-139.

Grinnell, J. 1928. A distributional summation of the ornithology of Lower California.
Univ. Calif. Publ. Zool. 32:1-300.

Mailliard, J. 1923. Expedition of the California Academy of Sciences to the Gulf of
California in 1921. Proc. Calif. Acad. Sci. 12:443-456.

Mellink, E., and Palacios, E. 1993. Notes on breeding coastal waterbirds in northwest-
ern Sonora. W. Birds 24:39-37.

Osorio-Tafall, B. F., and del Toro-Aviles, M. 1945. Notas sobre la distribution de
Phalacrocorax penicillatus (Brandt) en el Golfo de Cortes y la costa occidental
de Baja California. Rev. Soc. Mex. Hist. Nat. 6:85-93.

Russell, S. M., and Monson, G. 1998. The Birds of Sonora. Univ. of Ariz. Press,
Tucson.

Tershy, B. R., and Breese, D. 1997. The birds of San Pedro Martir Island, Gulf of
California, Mexico. W. Birds 28:96-107.

Van Rossem, A. J. 1945. A distributional survey of the birds of Sonora. Occ. Pap.
Mus, Zool. La. State Univ. 21.

Van Rossem, A. J., and Hachisuka, M. 1937. A further report on birds form Sonora,
Mexico, with descriptions of two new races. Trans. San Diego Soc. Nat. Hist.
8:321-336.

Wilbur, S. R. 1987. The Birds of Baja California. Univ. of Calif. Press, Berkeley.

Accepted 12 February 2001

135

NOTES

A POTENTIAL THREAT TO BALD EAGLES
IN BAJA CALIFORNIA SUR, MEXICO

GUSTAVO ARNAUD, EDGAR AMADOR, AND MARCOS ACEVEDO, Centro de
Investigaciones Biologicas del Noroeste, S.C., Apdo. Postal 128, La Paz, Baja
California Sur, Mexico 23000

The Southern Bald Eagle ( Haliaeetus leucocephalus leucocephalus ) is a resident
species in the state of Baja California Sur (Grinnell 1928), occurring in mainly coastal
habitats. Nesting is now known only from Bahia Magdalena- Alrnejas on the west
coast (Henny et al. 1993, Amador-Silva and Guzman-Poo 1994, Rodriguez-Estrella
et al. 1995) where no more than three pairs are found annually. The physiography of
Baja California Sur is composed of extensive plains and hills, the principal mountain
ranges are the sierras la Giganta and la Laguna, and predominant vegetation is desert
scrub, which covers 92% of the state area (INEGI 1995). Freshwater habitats are
scarce and largely temporary across the state.

During bimonthly visits to the Sierra de la Giganta that commenced in June 1995 and
continue to date, we have observed Bald Eagles on two occasions: On 13 April 1996
we observed two adults, and on 27 March 1997 a single adult, soaring over a canyon
located at 24° 50' N and 1 1 1° 00' W (80 km west of Bahia Magdalena), at 250 meters
above sea level. This canyon includes a series of permanent fresh-water ponds (locally
known as “pozas”) ranging in size from 35 to 100 m long and from 1 to 3 m deep.
Unlike most other oases in Baja California Sur, these ponds contain abundant fish of at
least two introduced species ( Oreochromis urolepis hornorum and Tilapia spp.).

We have observed Ospreys ( Pandion haliaetus ) fishing in these ponds on several
occasions and it seems likely that Bald Eagles may also utilize this resource, at least
occasionally. Local informants report that fisherman occasionally shoot Ospreys,
arguing that these birds take the fish they use for food. The hunting of Osprey is illegal,
suggesting that fish-eating Bald Eagles could also be targeted, a potentially serious
threat to the relatively small and vulnerable population nesting at Bahia Magdalena.
Education of the fishermen in this area regarding the rarity of Bald Eagles in Baja
California could be effective in helping to ensure the future of the peninsula’s last
remaining nesting population of this endangered raptor.

We thank Eduardo Palacios and Leopoldo Moreno for their critical review. Charles
Henny and Peter Bloom also reviewed and improved this note.

LITERATURE CITED

Amador-Silva, E., and Guzman-Poo, J. 1994. El Aguila Calva (Haliaeetus
leucocephalus ) en Isla Santa Margarita, Baja California Sur, Mexico. Revista de
Investigaciones Cientificas, Serie Ciencias del Mar UABCS 5(l):33-35.

Garcia, E. 1981. Modificaciones al sistema de clasificacion climatica de Koppen.

Universidad Autonoma de Mexico, Mexico City.

Grinnell, J. 1928. A distributional summation of the ornithology of Lower California.
Univ. Calif. Publ. Zool. 32:1-300.

Henny, C. J., Conant, B., and Anderson, D. W. 1993. Recent distribution and status
of Bald Eagles in Baja California, Mexico. J. Raptor Res. 27:203-209.

INEGI (Institute) Nacional de Estadistica Geografia Informatica). 1995. Sintesis
Geografica de Baja California Sur. Publicaciones INEGI, Mexico City.

Poole, A.F. 1989. Ospreys. Cambridge Univ. Press, Cambridge, England.
Rodriguez-Estrella, R., Donazar, J, A., and Hiraldo, F. 1995. Fishermen and their
gear may threaten Bald Eagles at Magdalena Bay, B.C.S. , Mexico. J. Raptor Res.
29:144.

Accepted 15 November 2000

136

Western Birds 32:136, 2001

BOOK REVIEW

The California Condor: A Saga of Natural History and Conservation, by

Noel Snyder and Helen Snyder. 2000, Academic Press, San Diego. 410 pp., 118
color and 21 black-and-white photos, 22 tables, 8 graphs, 4 maps. Hardback,
$29.95. ISBN 0-12-654005-5.

This nearly folio-sized book of 4 Vi pounds is aptly subtitled, given the history of the
major study and conservation programs directed toward this species since the 1940s.
A prologue tells of the authors’ first experience with California Condors and expresses
the book’s goal, “to give the reader an appreciation of both the basic biology of the
condor and the dynamics of condor conservation from a viewpoint mainly inside the
conservation and research program.” The book is then organized into six “parts,” the
first of which is “historical and background matters.” chapter 1, on “perspectives,”
summarizes the species’ natural history and compares it with that of the Andean
Condor and several Old World vultures. Chapter 2 provides an excellent account of
the ceremonial and other uses made of California and Andean Condors by native
peoples within their ranges.

Part 1 concludes with the 39-page chapter 3, “Condor Research and Conservation
in the Early-Mid 20th Century.” Much of this is derived directly from the same
authors’ 1989 account “Biology and Conservation of the California Condor (Current
Biology 6:175-267). Some of the text is identical, but other parts are rewritten and
updated where, appropriate. As in their earlier account, the Snyders divided studies
preceding theirs into segments that they now call “eras,” each named for one or two
of the chief investigators or proponents: Finley (early 1900s), Robinson-Easton
(1930s), Koford (the first detailed field study, 1939-46), Miller-McMillan (late 1950s
into 1970s), [Fred] Sibley (1966-1969), and Wilbur (1970s). Throughout this
chapter, the Snyders trace the developing knowledge of the condor’s behavior and
ecology, along with changes in ideas as to its apparent decline. Each era is also
credited with a special advance in knowledge or a particular emphasis that had a
subsequent effect on the effort to conserve the species. Interaction of the sometimes
conflicting ideas is discussed freely whenever it seems appropriate, and the authors
give their own evaluation of the major advances and diversions. Thus the stage is set
for Part II.

This is titled “Struggles to Launch a New Program,” and its three chapters are
“Battles in the Political Arena,” “Africa and Peru,” and “Development and Testing of
Research Techniques.” Noel Snyder, of the U.S. Fish and Wildlife Service, and John
Ogden, of the National Audubon Society, were named as joint managers of an
expanded condor-conservation program beginning in early 1980. Noel’s wife Helen
was also involved as an Audubon employee in much of the work of the research
center, established in Ventura. Although they left those positions in 1986, and the
recovery [advisory] team was subsequently discontinued by the Fish and Wildlife
Service, it seems to me the Snyders are the best choice to tell the story of the often
controversial efforts to conserve this endangered species, and this book is it!

Chapter 4 details the campaign to establish and expand refuges and wilderness
areas for the condor’s nesting. The Snyders believed from the outset that the very
mobile condors should be studied first by radio-telemetry to discern the foraging range
of individuals, and to aid in learning just what factors were involved in their population
decline. They describe the controversies they encountered, including a tense meeting
at the home of one of the chief proponents of the “hands-off” approach, and a “gag
order” from their superiors in the Fish and Wildlife Service that prohibited them from
contacting high-level California Department of Fish and Game officials directly. When
freer communications were allowed in 1982, a more reasoned plan emerged. A
permit issued in 1980 by the California Department of Fish and Game allowed the
center to capture and radio-tag 10 birds, with the stipulation that one female be

Western Birds 32:137-140, 2001

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BOOK REVIEW

retained as a mate for the then lone California Condor in captivity — the first admission
by “hands-off” proponents that any efforts should be made toward building a captive
population. But after the second chick handled died from stress, the California
Department of Fish and Game permit was revoked, and only after two years was a
new one issued.

Without a permit to handle any California Condors, Snyder and Ogden went to
Peru to observe, and sometimes participate in, research on the Andean Condor, thus
learning much about capturing, radio-tagging, and behavior of condors. They also
visited European research teams in South Africa, Zimbabwe, and Namibia working
with the Cape Griffon and the Lappet-faced Vulture, the latter species showing
breeding characteristics similar to the two condors’. Chapter 5, describing these trips,
includes some interesting accounts of encounters with local peoples and even a
narrow escape from being targets of a victorious but not yet disbanded army unit!

Chapter 6 details the development of techniques for capturing condors (they
selected cannon-netting), handling, blood-sampling, and sexing the birds, and radios
for tracking of the birds so marked. The excitement attendant on establishing methods
that would provide the data needed on the movement and lives of the marked birds
comes through very nicely in this chapter.

Part 111 is titled “Research Results of the New Program.” Its six chapters take up
more than 100 pages, organized under censusing, movements and food, nest sites,
breeding behavior, breeding effort and success, and mortality. Only a few highlights
can be mentioned from this meaty basis for the rescue program that was finally
adopted. The use of frequent photos of flying condors proved by far the most reliable
tool for counting the number of birds still alive. California Condors obtained little food
near their nest areas but traveled great distances to ranch lands around the southern
San Joaquin Valley. When nesting, the adults used parts of that foraging range closer
to their nest sites, but some young birds roved over the entire range. Characteristics
of nest sites of different pairs varied, but most were difficult of access by humans or
ground-based predators. Ravens, however, were watchful of many sites and quick to
enter for a meal if the egg was left unguarded. Most pairs that lost an egg or young
chick readily initiated another breeding effort the same year, but almost always at a
different site and often miles away. This was not possible to detect without telemetry.
Courtship postures are described, and one photo from the wild and one of a captive
pair are included.

Tables provide data pertinent to courtship, copulation, incubation shifts, percent-
age of daylight hours adults were at or near nest sites, number of feedings of young by
male and female parents, pairs breeding in the 1980s and the success of each, and
dates when individual photo-documented birds were last seen. These are reported pair
by pair or by individual, by means of identification codes of which only two are
explained in the book (pp. 213-214). The other codes also probably have a
geographic indication and were no doubt left unpublished to minimize potential
disturbance when birds were still free-flying and nesting in those areas. Those familiar
with California geography can guess at several others, so the continued secrecy may
be of questionable value. More disconcerting, however, is the lack of any list of tables
in the front of the book. Diligent readers should prepare such a list for themselves as
not all of the text references to them are within two or three pages of the table.

Chapter 12 discusses the known and potential causes of death of condors — from
shooting, collisions with wires and wind turbines, possible effects of eating poisoned
ground squirrels or coyotes, to cyanide guns set for coyote control. Strong evidence is
presented that the predominant factor killing wild condors, at least in recent years, has
been lead poisoning from bullet fragments ingested with food. The case histories of
three radio-marked birds and one other found dead by a ranch foreman build the case
like an intriguing detective story. This culminates in a step-by-step description of a
January 1984 lab demonstration to skeptical state and federal officials that the last

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BOOK REVIEW

bird had, indeed, died from the cyanide-tracerite powder from a coyote-poisoning
device. Only then was any restriction placed on the widespread use of such devices in
the condors’ foraging range.

In part IV, Conservation in the 1980s, chapter 13 surveys several efforts made to
improve suboptimal nest sites by altering the slope of the cavity, building an external
“porch” where the nearly fledged young could exercise their wings without falling off,
by reducing the number of ravens in the area, etc. Of three ways to reduce the
likelihood of condor deaths from lead poisoning, neither the conversion of the
foraging range into a no-hunting zone nor prohibiting use of lead ammunition by
hunters was ever tried, because of bureaucratic hurdles and lack of time. The third
method, providing clean lead- and poison-free carcasses for the wild condors to eat,
was tried on the Hudson Ranch in southwestern Kern County. But the condors shifted
locations when deer-hunting season began in other parts of their range and so
continued to eat meat with lead embedded. There is also a list of 30 steps taken from
1937 to 1992, mostly by the federal government, that set aside or improved
protection of areas to benefit the California Condor.

Chapter 14, “Formation of a Captive Flock,” documents the controversies and
slow stages in 1982-84 of this effort, the success in replacement clutching when
removal of first-laid eggs of wild pairs was finally allowed and then hatched in
incubators, and the questions as to the fraction of the population to which such efforts
could be applied. Only after the winter of 1984—85 saw the disappearance of one or
both members of all but one of the breeding pairs was the emphasis shifted to rapid
development of a captive breeding flock, by taking the nine remaining birds into
captivity. Another interplay of opposing views is described without rancor for those
who didn’t agree with that goal and insisted that at least a few birds be left in the wild.
Foremost among these proponents was the National Audubon Society, which sued to
prevent the last captures. Most of chapter 15 is devoted to this topic, after precursor
events described in chapter 14. This part ends with a summary of the “alternative
plan” dependent on captive breeding to preserve the species “near term” but with
eventual releases into the wild after safe numbers and genetic variety were in the
population and after release techniques had been tested on Andean Condors
temporarily released in the area.

In part V, “Restoration,” chapter 16 describes the facilities built to house captives
and the methods developed to promote pairing and at the same time preserve or even
heighten the genetic diversity of this small population. Table 16 (p. 320) shows for
each facility the number of mated pairs, eggs laid, and young fledged each year from
1988 through 1998. The overall total, obtained only by adding yearly totals, was 141
fledglings — very impressive from a start of only 9 adults and 18 immatures in 1987!
Elsewhere in the chapter results are tabulated by each parent bird, and various
comparisons are made of reproductive output with the few pairs followed in the wild
(mostly in the early 1980s). Incubation periods averaged 57.2 days, slightly shorter
than that of Andean Condors. This chapter also contains a host of other natural
history information that would have been extremely difficult to obtain from wild birds
even though critical to the planning for their survival.

Techniques and results (through 1998) of “Releases to the Wild” (chapter 17) are
described, with several appropriate photos. Results for each of 61 birds released in
California and 28 in northern Arizona are summarized in table 22. The gist of the
findings is that young raised by captive parents are much better at surviving when free
to fly than those that are fed early in life only by “puppets” (gloves of very realistic
condor head shapes) operated by hidden keepers. Those that undergo “aversive
conditioning” to rectangular human-built structures fare somewhat better than those
that don’t. Various release locations already tried, and several others with potential,
are described. So also is the question of food subsidy and the conditions that might
make it work by reducing the likelihood of the birds foraging widely and eating

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BOOK REVIEW

carcasses containing lead fragments. The authors give their own recommendations
for releases and general captive propagation in this chapter, and those interested in
the ultimate survival of the species should read them carefully.

Part VI, “A General Evaluation,” includes in chapter 18 the authors’ philosophy of
how efforts to conserve endangered species in general should be organized, with
interplay of private and government units, intensive research and captive breeding if
needed, but overall allowing for diversity of input and implementation guided by well-
constructed recovery teams. These are distinguished from those that rely just on
“recovery plans,” many of which have been written with inadequate supporting
knowledge and are too detailed to allow for the constant alteration necessary as new
facts emerge. The Snyders warn of the danger of goal substitution — of the preserva-
tion of recovery programs being substituted for the recovery of the species itself. The
chapter ends with nine recommendations specific to the recovery of the California
Condor. The authors say, “[we] remain optimistic that unmanaged and viable wild
condor populations can be reestablished, but we are deeply concerned about the
recent rate of progress toward that goal.”

Maybe those who want to know just about the California Condor’s natural history,
without wading through this history of the research and conservation efforts directed
toward its survival, will tire of all the accounts of controversies. However, for those
interested in complex species-conservation problems and the associated negotiations
and politics, this is a really valuable story. Many additions to the natural history saga are
to be found only embedded in the conservation saga that forms the bulk of the book.
Most technical aspects of the book’s production are also of high quality: heavy glossy
paper, attractive layout, superb photos (drawings in two cases where more pertinent),
a generous set of acknowledgments (and a special list of credits in front for all the
photos), a bibliography of 382 cited references, and a thorough index. I noted only
about three typographical errors. In short, anyone interested in the California Condor
or in the conservation of endangered species in general should study this book.

Howard L, Cogswell

140

FEATURED PHOTO

RANGE EXPANSION OF THE GREAT-TAILED
GRACKLE IN WESTERN NORTH AMERICA

WALTER WEHTJE, Geography Program, Department of Earth Sciences, University
of California, Riverside 92521

The spread of the Great-tailed Grackle (Quiscalus mexicanus) is one of the most
impressive range expansions to occur in North America during the 20th century. The
U,S. breeding range was limited to southernmost Texas in 1900 (Ridgway 1902), but
a century later Great-tailed Grackles breed in 19 states, from Arkansas in the East
north to Minnesota and west to California and Oregon (Dinsmore and Dinsmore
1993, Scheuering and Ivey 1995, Price 1997, Granlund 1999), with sightings in
Washington, British Columbia, Montana, North Dakota, Wisconsin, and Ontario
(Dinsmore and Dinsmore 1993, Granlund 1999).

The northward spread of Great-tailed Grackles in North America has occurred on
three fronts.- Birds from south Texas, of the subspecies Q. m. prosopidicola, moved
north and east and are currently found east of a north-south line through western
Texas and eastern Colorado. A separate population from Chihuahua invaded New
Mexico in 1913, with breeding confirmed in eastern Arizona in 1937 and Colorado
in 1973 (Bailey 1928, Phillips et al. 1964, Stepney 1975). Phillips (1950) described
this population as a new subspecies, Q. m. monsoni, with a range that encompassed
north-central Mexico, western Texas, southern and central New Mexico, and eastern
Arizona. By 2000, monsoni was present in New Mexico, southeastern Nevada,
Arizona, and California. The third subspecies, Q. m. nelson i , originated in coastal
Sonora, Mexico, and adjacent areas (Friedmann et al. 1957), arriving in southern
Arizona by the late 1930s (Phillips et al. 1964). After moving into Arizona, nelsoni
expanded west and was first noted in California in 1964 (McCaskie et al. 1966); it is
now found in Arizona, California, and southwestern Nevada. The subspecific affinities
of Great-tailed Grackles breeding in Oregon, Idaho, Utah, and central Nevada have
not been established (Dinsmore and Dinsmore 1993, Scheuering and Ivey 1995).

Great-tailed Grackle subspecies differ in both size and color. Adult males of Q. m.
monsoni are nearly 20% heavier than adult males of Q. m. nelsoni, with average
(flattened) wing lengths of 191 mm vs, 167 mm (14% longer) and tail lengths of 210
mm vs. 165 mm (27% longer; W. Wehtje unpublished data; monsoni n = 7, nelsoni
n = 8). Adult females of monsoni are at least 10% heavier than females of nelsoni,
with average (flattened) wing lengths of 150 mm vs. 136 mm (10% longer) and tail
lengths of 150 mm vs. 126 mm (19% longer; W. Wehtje unpublished data; monsoni
n = 23, nelsoni n = 6). In addition to the size differences, females of the two
subspecies differ in plumage color: nelsoni shows pale grayish buffy underparts,
monsoni darker brownish gray underparts (Phillips 1950, Rea 1969).

Clockwise from upper left, birds shown in the featured photo on the back cover are
an immature female nelsoni (26 January 2000, Oxnard, California), adult male
nelsoni (10 December 1999, Tucson, Arizona), immature female monsoni (12
December 1999, Arlington, Arizona), adult male monsoni (2 June 2000, Bill
Williams National Wildlife Refuge [NWR], Arizona), adult female monsoni (10
December 1999, Tucson), adult female monsoni (5 June 2000, Pena Blanca Lake,
Arizona), adult female monsoni (2 June 2000, Bill Williams NWR), and immature
female nelsoni (15 May 1994, Salton Sea NWR, California). It bears noting that
recent specimens of adult female nelsoni in fresh plumage are, apparently, lacking
from collections.

In an ideal world, identifying Great-tailed Grackles to subspecies in the western US

Western Birds 32:141-143, 2001

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FEATURED PHOTO

would be simple: large males and dark females would be of the subspecies monsoni,
and small males and pale females would be of the subspecies nelsoni. In reality, this
approach is complicated by plumage differences between adult and immature birds,
and the degree to which female Great-tailed Grackles fade during the spring. The
presence of intergrades complicates the picture further.

In common with several other icterids, Great-tailed Grackles have distinct first-year
and adult plumages (Pyle 1997). Immature birds have duller plumages, shorter wings,
and shorter tails than adults. Juvenile males molt into their first basic plumage, a dull
black, by late summer. Not until their second fall do they molt into the long-tailed and
glossy plumage of the adult males; therefore, meaningful comparisons between males
can be made only with birds of the same age. The featured photo illustrates the size
difference between adult males ( monsoni flat wing 184 mm, tail 201 mm; nelsoni flat
wing 174 mm, tail 174 mm).

Determining the subspecies of female Great-tailed Grackles is more difficult, While
size differences are useful, plumage characteristics are of greater importance. Deter-
mining a bird’s age is essential to assigning it to either nelsoni or monsoni. Adult
females have cream-colored irises, while immatures have khaki-colored irises with
dark flecking until at least June of their second year. Immature females are smaller and
duller than adults, and their feathers tend to wear and fade more rapidly and
extensively than those of adults. The difference between adults and immatures
becomes most pronounced in late spring, when immatures can have pale gray
underparts with no hint of brown in them. By late summer both adults and immatures
have faded underparts and should not be identified to subspecies.

The two females on the upper row of the photograph are newly molted immatures.
The left-hand bird is an unusually gray nelsoni (flat wing 134 mm, tail 122 mm), and
the right-hand bird is a more or less typical monsoni (flat wing 139 mm, tail 127 mm).
The size difference between adult females would normally be greater than this, but
even a more typical nelsoni would be obviously paler than the rich brown character-
istic of immature female monsoni.

The bird in the lower right-hand corner of the featured photo is a fresh adult female
monsoni showing underparts that are a deeper brown than ever shown by female
nelsoni. The two middle birds demonstrate the range of fading shown by adult female
monsoni by early June (these birds were collected within three days of each other).
While each of these birds has faded significantly, neither is as worn as the immature
nelsoni on the far left, which was collected at the Salton Sea in mid-May. Birds in this
extreme environment tend to have completely pale underparts by late spring.

In most of central California and Nevada, the plumage of grackles is often visibly
faded by March and April, when these migratory populations arrive from southern
Arizona and southern California. Since these grackles head back south in late summer
before undergoing prebasic molt, they are difficult to observe in fresh plumage on the
breeding grounds and therefore difficult to identify with certainty. Judicious collecting
early in the nesting season should shed light on the interaction between the two
subspecies as they continue to spread across western North America.

Another confounding factor in distinguishing between the two western subspecies
is the presence of intergrades between them. Interbreeding between monsoni and
nelsoni was observed in Arizona in the mid 1960s (Rea 1969) and has continued to
the present. In California, male Great-tailed Grackles tend to be intermediate in size
between the two subspecies, while females are as dark as monsoni but closer in size
to nelsoni. The degree of interbreeding in other states is not known.

I would like to thank the curators and collection managers of the following
institutions for the opportunity to examine their Great-tailed Grackle skins: Carnegie
Museum, Los Angeles County Museum of Natural History, Museum of Southwest
Biology, Museum of Vertebrate Zoology, San Bernardino County Museum, San
Diego Natural History Museum, Santa Barbara Museum of Natural History, University

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FEATURED PHOTO

of Arizona Vertebrate Museum, University of California Santa Barbara Vertebrate
Museum, and the Western Foundation of Vertebrate Zoology. I also thank the
agencies and individuals who gave me permission to collect grackles. A Frank M.
Chapman Memorial Grant from the American Museum of Natural History funded
portions of this research. Finally, I thank Robb Hamilton for suggesting I write this
article and Amadeo Rea for reviewing and improving the manuscript.

LITERATURE CITED

Bailey, F. M. 1928. Birds of New Mexico. N. M. Dept. Game and Fish, Santa Fe.

Dinsmore J. J., and Dinsmore, S. J. 1993. Range expansion of the Great-tailed
Crackle in the 1900s. J. Iowa Acad. Sci. 100:54-59.

Friedmann, H., Griscom, L., and Moore, R. T. 1957. Distributional checklist of the
birds of Mexico. Pac, Coast Avifauna 29.

Granlund, J. 1999. Western Great Lakes region. N. Am. Birds 53:281-283.

McCaskie, G., Stallcup, R., and DeBenedictis, P. 1966. Notes on the distribution of
certain icterids and tanagers in California. Condor 68:595-597.

Phillips, A. R. 1950. The Great-tailed Grackles of the Southwest. Condor 52:78-81.

Phillips, A., Marshall, J., and Monson, G. 1964. The Birds of Arizona. Univ. of Ariz.
Press, Tucson. -

Price, J. 1997. Changing seasons. Natl. Audubon Soc. Field Notes 51:832-835.

Pyle, P. 1997. Identification Guide to North American Birds, part I, Columbidae to
Ploceidae. Slate Creek Press, Bolinas, CA.

Rea, A. M. 1969. The interbreeding of two subspecies of Boat-tailed Grackle
Cassidix mexicanus nelsoni and Cassidix mexicanus monsoni in secondary
contact in central Arizona. M.S. thesis, Univ. Ariz., Tempe.

Ridgway, R. 1902. Birds of Middle and North America, part II. Bull. U. S. Natl. Mus.
50:1-834.

Scheuering, E. J., and Ivey, G. L. 1995. First nesting of the Great-tailed Grackle in
Oregon. Wilson Bull. 107:562-563.

Stepney, P. H. R., and Power, D. M. 1975. First recorded breeding of the Great-tailed
Grackle in Colorado. Condor 77:208-210.

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143

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Published September 15, 2001

ISSN 0045-3897

Vol. 32, No. 3, 2001

Volume 32, Number 3, 2001

Distribution and Abundance of Winter Shorebirds on Tomales Bay,

California: Implications for Conservation John P. Kelly 145

A Targeted Mist Net Capture Technique for the Willow Flycatcher
Mark K, Sogge, Jennifer C. Owen, Eben H. Paxton,

Suzanne M. Langridge, and Thomas J. Koronkiewicz 167

NOTES

Further Evidence for a Population Decline in the Western

Warbling Vireo Thomas Gardali and Alvaro Jaramillo 173

Brandt’s Cormorant Sinks At Sea Terence R Wahl 177

First Record of the European Golden- Plover from the Pacific

Andrew W. Piston and Steven C. Hein l 179

Book Reviews Steve N. G. Howell, Gregory H. Golet 182

Featured Photo Jon L. Dunn and Kimball L. Garrett 186

Cover photo by © Jim Burns/NATURAL IMPACTS of Scottsdale,
Arizona: Rufous-capped Warbler ( Basileuterus rufifrons), French
Joe Canyon, Arizona, August, 2000.

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earlier.

WESTERN BIRDS

Volume 32, Number 3, 2001

DISTRIBUTION AND ABUNDANCE OF WINTER
SHOREBIRDS ON TOMALES BAY, CALIFORNIA:
IMPLICATIONS FOR CONSERVATION

JOHN P. KELLY, Cypress Grove Research Center, Audubon Canyon Ranch, Marshall,
California 94940

ABSTRACT: 1 analyzed the distribution and abundance of wintering shorebirds
(Scolopacidae, Charadriidae, and Recurvirostridae) in Tomales Bay, California, on the
basis of 57 baywide counts conducted over 10 years, from 1989-90 to 1998-99.
Tomales Bay supports up to 20,689 shorebirds in early winter, thus qualifying as a
wetland of “regional” importance in the Western Hemisphere Shorebird Reserve
Network. Minimum overall shorebird abundance fell as low as 1291 in late winter.
Tomales Bay supported approximately a third of the wintering shorebirds in the Point
Reyes/Bodega area in early winter. Observations of tidally structured flock move-
ments of several species suggested that the northern and southern ends of Tomales
Bay are occupied by different wintering groups. In association with cumulative
seasonal rainfall, most species declined in abundance significantly in midwinter. The
Sanderling and Marbled Godwit increased with cumulative rainfall in the north and
south bay, respectively, suggesting weather- related influxes from outer coastal beaches.
After accounting for the effects of cumulative seasonal rainfall and a 10-year trend in
annual rainfall, I detected no trends in species’ abundances. Foraging and roosting
shorebirds at the northern end of the bay were vulnerable to direct disturbance from
concentrated recreational use. Long water-residence times in southern Tomales Bay
suggest that shorebirds there may be particularly vulnerable to toxic spills or anthro-
pogenic eutrophication. The closeness of San Francisco Bay implies a high potential
for invasion of nonnative organisms established there, which could alter the availabil-
ity of benthic prey to shorebirds in Tomales Bay. Shorebird feeding habitat at the
deltas of Walker and Lagunitas creeks may be adversely affected by heavy rainfall
leading to the deposition of sediment. Daily influxes of roosting gulls from a local
landfill were associated with reduced shorebird use of tide flats. Shorebirds’ use of
open tide flats developed for mariculture is reduced, although floating oyster bags
provide roosting areas during high tides. Breaching levees that isolate historic
wetlands may increase shorebird use in some areas. The likelihood of regular or
episodic intraseasonal movements among Point Reyes/Bodega area wetlands sug-
gests Tomales Bay and other nearby wetlands are worthy of broad protection.

Western Birds 32:145-166, 2001

145

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

Tomales Bay is one of California’s largest and least disturbed estuaries. It
has been recognized as a wetland of “regional importance” on the basis of
its supporting up to 20,000 shorebirds, a criterion for inclusion in the
Western Hemisphere Shorebird Reserve Network {WHSRN; Harrington
and Perry 1995, Page and Shuford 2000). An analysis of shorebird
abundance and distribution on the Pacific coast of the United States
identified Tomales Bay as a key wetland for shorebird conservation because
it supports in at least one season at least 1% of the total population of 8 of
13 shorebird species that concentrate in estuaries and brackish wetlands
(Page et al. 1999). In spite of this recognition, little has been published on
the spatial or temporal variations in shorebird abundance on Tomales Bay,
or the birds’ vulnerability to environmental threats. Kelly and Tappen (1998)
reported previously on the value of Tomales Bay to other winter waterbirds.

Shuford et al. (1989) analyzed the results of up to 10 consecutive years of
shorebird counts in the adjacent Point Reyes area between 1965 and 1982
but provided little information on shorebird use of Tomales Bay. As part of
a statewide survey, Jurek (1974) reported on five years of monthly shorebird
counts at the Walker Creek delta, in the northern part of the Tomales Bay,
but did not survey abundances baywide. Over recent decades, Tomales Bay
has been suggested for protection as habitat for shorebirds (Smail 1972,
National Oceanic and Atmospheric Administration 1987, Neubacher et al.
1995, Page and Shuford 2000). However, with one exception dealing with
the effects of aquaculture on shorebirds (Kelly et al. 1996), evaluations of
conservation issues in Tomales Bay have not directly addressed patterns of
shorebird use.

In this paper, 1 (1) present results from 10 years of baywide winter
shorebird censuses on Tomales Bay; (2) compare these results with other
studies to provide a historical and geographical perspective on the impor-
tance of Tomales Bay to shorebirds; (3) evaluate species’ distributions within
the bay with regard to the importance of particular areas used by shorebirds;
(4) examine processes that influenced abundance trends over the 10 years of
study, and (5) identify needs for conservation of wintering shorebirds on
Tomales Bay. I address these objectives with regard to all Scolopacidae,
Charadriidae, and Recurvirostridae associated with Tomales Bay and imme-
diately adjacent seasonal wetlands (Figure 1).

STUDY AREA

Tomales Bay floods the lower 20 km of the fault-rift Olema Valley on the
central California coast, about 45 km northwest of San Francisco (Figure 1 ;
Galloway 1977). Approximately 18% of the bay’s 28.5-km 2 area is inter-
tidal, providing primarily sand or mud flats suitable for foraging shorebirds
and cobblestone beaches along the east shore. In general, sediments grade
from primarily fine to coarse sand in the northern reaches of the bay to
muddier substrates in southern portions of the bay (Daetwyler 1966).

Two primary points of freshwater inflow, Lagunitas Creek at the south
end of the bay and Walker Creek near the north end of the bay, are
associated with large tidal deltas suitable for foraging shorebirds (Figure 1).
Numerous smaller delta marshes and tidal flats occur where small perennial

146

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

Dillon

Figure 1. Shorebird count areas on Tomales Bay, California. 1, White Gulch;
2, Lawson’s Meadow; 3, Sand Point; 4, Tom’s Point; 5, Walker Creek delta; 6, North
Marshall; 7, South Marshall; 8, Lagunitas Creek delta; 9, Giacomini Pasture; 10,
Inverness shoreline. Arrows indicate length of shoreline in each count area; labels
indicate extent (ha) of exposed tidal flat at MLLW.

and ephemeral streams enter the bay. Adjacent seasonal wetlands suitable
for shorebirds are normally limited to about 15 ha of a 200-ha diked pasture
at the south end of the bay and approximately 20 ha of wet meadow
surrounded by sand dunes at the north end of the bay. Additional seasonal
wetlands, used by shorebirds during periods of heavy flooding, occur in
agricultural areas northeast of the bay.

Most (95%) of the annual rain falls when wintering shorebirds are present,
from October through April, with 55% falling from December through
February (Audubon Canyon Ranch, unpublished data). Constraints on tidal
exchange with the ocean, imposed by the linear shape of the bay, interact
with winter runoff to create contrasting habitats at the two ends of the bay.
In the southern half of the bay, variably high levels of freshwater inflow
during winter, low flows in summer, and long water-residence times result in
highly variable salinities (Hollibaugh et al. 1988). Salinities range from nearly

147

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

fresh after heavy winter runoff to slightly hypersaline in late fall (Smith and
Hollibaugh 1997). In northern Tomales Bay, regular tidal mixing maintains
salinities that consistently reflect those of nearshore waters along the outer
coast. The difference between mean high and mean low tides is about 1.1m,
with an average annual maximum tide swing of about 2.5 m (U. S. National
Oceanic and Atmospheric Administration harmonics and correction tables;
Tides and Currents, Nautical Software, Inc.).

METHODS

I divided Tomales Bay into 10 subareas within which all shorebirds could
be counted in 60 to 90 minutes (Figure 1). These areas include almost all of
the intertidal flats in the bay, with the exception of a few small areas at creek
mouths along the west shore. Teams of qualified observers counted all
shorebirds by species in all subareas simultaneously.

Observers counted during rising tides, at tide levels between 0.76 and
1.22 m above mean lower low water (MLLW) at Blake’s Landing (Figure 1).
Count-area protocols were coordinated so that adjacent areas were surveyed
simultaneously. Abundances generally represented counts of foraging indi-
viduals, with estimates of large mobile flocks made only rarely. During three
workshops held to examine and reduce observer bias in estimating flock size,
biases were inconsistent and without a clear central tendency. Therefore
observer bias was assumed not to affect overall estimates of abundance. The
time and direction of all flock movements, departures, and arrivals during
count periods were recorded and examined later to minimize chances of
birds being double counted. Counts were conducted only on days with
weather suitable for using telescopes to identify shorebirds.

Each year from 1989-90 to 1998-99, we completed approximately
three counts in each of two intraseasonal periods (n = 57): early winter
(mean 2.8, range 1-4; 1 November-19 December) and late winter (mean
2.9, range 2-3; 15 January-4 March). I summarized results within
intraseasonal groups to compare early- and late- winter population levels.
Most individual shorebirds were identified to species. Occasionally, individu-
als were not identified to species and were recorded in pooled species groups
such Least/Western sandpiper. Individuals recorded in pooled species groups
were allocated to single species groups in direct proportion to the number of
identified birds of each species in each count area on each day (Page et al.
1999). Such adjustments were made, however, only if the number of
identified individuals exceeded the number of undifferentiated individuals and
was >50 for groups of two species or >100 for groups of three species.

Observations of shorebird flocks revealed restricted movements in the
middle section of the bay. Of 19 flocks of several shorebird species observed
departing as the tide inundated the feeding area at Walker Creek delta,
100% were oriented to the northwest and only one flock flew by from farther
south. In southern Tomales Bay, 56 flocks of several species were observed
departing north from feeding areas during rising tides, but only one flock
(2%) was seen flying north past Cypress Point in Marshall (Figure 1). These
observations suggest that several species winter in discrete groups. In
addition, a reciprocal translocation of color-banded Dunlins, the most

148

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

abundant species in the bay, revealed that wintering populations at the two
ends of the bay were separate (Kelly 2000). Therefore, I analyzed the results
separately for subregions of Tomales Bay north (areas 1-6) and south (areas
7-10) of Cypress Point, Marshall, in addition to analyzing them for the bay
as a whole (Figure 1).

I transformed abundance data into densities, based on the extent of
exposed mudflat in each count area, estimated at MLLW with a planimeter
on a bathymetric chart (Figure 1; U. S. National Oceanic and Atmospheric
Administration Chart 18643, 16th ed., Dec 1995). Estimates of shorebird
preferences based on densities among different habitat types may be
sensitive to different measures of availability (Warnock and Takekawa
1995), particularly if birds concentrate along the edge of the rising tide
(Recher 1966, Burger et al. 1977) and the linear extent of the tide line is not
closely correlated with areal extent of the habitat. However, suitable shore-
bird habitat on Tomales Bay is limited primarily to tidal flats, and each count
area represented a similar proportion of the area available for foraging along
the tide line at any particular tide level. Consequently, densities based on
different widths of tidal exposure did not significantly alter estimates of
relative shorebird use by count area.

To examine the effects of count-area location, intraseasonal period, and
year on patterns of shorebird use, I used mixed-model analysis of covariance
of shorebird densities, controlling for days since the beginning of each
intraseasonal (early or late winter) period and treating year as a random
effect. Shorebird densities were log-transformed to improve normality and
stabilize the variance of residuals. Significant count-area effects were fol-
lowed by multiple pairwise comparisons within the northern and southern
subregions of the bay. I inspected bivariate scatterplots of shorebird abun-
dance on cumulative seasonal rainfall, using Cleveland’s robust locally
weighted regression algorithm (LOWESS; Cleveland 1979, Chambers et al.
1983), to look for nonlinear thresholds and trends. I selected this method
because it uses locally weighted least squares and a robust fitting procedure
to define smoothed points that are relatively insensitive to outlying values,
and it allows a flexible degree of smoothing by adjusting the proportion of
data scanned (/) for each fitted value. To improve the normality of abun-
dances used in the analysis, I based trends for the Semipalmated Plover,
Black Turnstone, and Least Sandpiper on the natural logarithms (In) of the
counts; distributions of other species’ abundances were approximately
normal without this transformation. Annual and cumulative seasonal rainfall
were derived from daily rainfall measured at Cypress Point (Figure 1;
Audubon Canyon Ranch, unpubl. data). 1 estimated annual trends in species
abundance within subregions as partial regression coefficients on year,
independent of the linear effect of cumulative seasonal rainfall. I compared
these results with correlated trends in annual rainfall.

RESULTS

Tomales Bay supported as many as 20,689 shorebirds in early winter,
with minimum numbers falling as low as 1291 in late winter. The most
abundant winter shorebird in Tomales Bay was the Dunlin, accounting for

149

Table 1 Mean, Minimum, and Maximum Abundances of Wintering Shorebirds on Tomales Bay, 1989-90 to 1998-99°

North bay South bay Baywide

urintpr I ate winter Earlu winter Late winter Early winter Late winter

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Umosafedoa 799 (78.0) 916 (90.2) 85 (14.1) 152 (19.0)*** 885 (80.4) 100-1564 1067 (96 8) 73-2233

Ruddy Turnstone

Arenaria interpres 3 (0.8) 3 (1.2) 2 (1.7) + (0.1) 4 (2.0) 0-54 3 (1 2) 0-26

Black Turnstone

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Q Ba s ed on 29 counts in early winter and 28 counts in late winter. Asterisks specify significant differences between early and late winter; ‘P < 0.05; **P < 0.01- ***P < 0 001 + Mean
abundance <0.5. See Figure 1 for count areas included in north and south bay subregions. ’ ’

fa SE, standard error.

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

over half (53%) of all shorebirds in early winter and nearly a third (29%) in
late winter. The second most abundant species was the Western Sandpiper,
representing 13% in early winter and 20% in late winter (Table 1). The total
number of shorebirds declined significantly from early to late winter in
northern ( t = 4.67, df = 56, P < 0.001) and southern ( t = 4.80, df = 54, P
< 0.001) Tomales Bay, as did several individual species (Table 1). In contrast
to this pattern, the Marbled Godwit increased significantly during winter in
southern Tomales Bay, and the Sanderling increased significantly in the
northern bay and baywide (Table 1).

Maximum annual abundance varied by a factor of 8.9 in the Dunlin, 8.0
in the Marbled Godwit, 6.7 in the Killdeer, 6.2 in the Greater Yellowlegs, 4.4
in the Sanderling, 4.2 in the Western Sandpiper, 3.5 in the Spotted
Sandpiper, 3.4 in the Willet, 3.2 in the Black Turnstone, 2.3 in the Black-
bellied Plover, and 4. 1 in all species combined. Maximum annual abundance
varied substantially more in some species, by a factor of 17.8 in the
dowitchers, 16.7 in the Semipalmated Plover, 15.5 in the Least Sandpiper,
and 12.0 in the Pacific Golden-Plover, reflecting proportional changes in
smaller populations and/or difficulties in detecting inconspicuous birds.
Densities in most species varied significantly from year to year (Table 2).

Winter shorebird densities differed significantly from count area to count
area within both subregions of Tomales Bay (Table 2). Most species showed
significant annual and intraseasonal shifts in distribution of densities among
count areas, indicated by significant interaction terms in analyses of covari-
ance (Table 2). Although average midwinter declines in count-area density,
weighted equally for large and small areas, were significant only for the
Dunlin and dowitchers (Table 2), several species decreased significantly in
overall abundance on the basis of north bay, south bay, and baywide totals
(Table 1).

Northern Tomales Bay supported more shorebirds, overall, than southern
Tomales Bay in early winter (t= 2.92, df=55, P< 0.05) and late winter (t =
4.57, df = 55, P < 0.001). The Walker Creek (area 5) and Lagunitas Creek
(area 8) deltas not only supported the greatest concentrations of shorebirds
but also the highest densities for more shorebird species than other areas in
Tomales Bay (Table 2, Figure 2). The northeast shoreline from Sand Point
(area 3) to Vincent’s Landing south of Tom’s Point (area 4) also supported
relatively high abundances of several species (Table 2, Figure 2). Shorebird
use of seasonal wetlands at Lawson’s Meadow (area 2) and Giacomini
Pasture (area 9) was highly variable; consequently, mean shorebird densities
in these areas could not be distinguished clearly from those in other areas
(Table 2). Greater Yellowlegs concentrated primarily in the extreme south
end of Tomales Bay, while Sanderlings and Marbled Godwits concentrated
primarily at the north end of the bay (Figure 2). The Pacific Golden-Plover,
Snowy Plover, and Red Knot occurred exclusively in northern Tomales Bay.

Cumulative seasonal rainfall was associated with significant decreases in
the use of Tomales Bay by most shorebird species but significant increases by
the Marbled Godwit and Sanderling (Figure 3). Bivariate plots suggested that
25-30 cm of rain must fall in a season to trigger the declines of the Western
Sandpiper, Least Sandpiper, and dowitchers (Figure 3). Alternatively, rain-
fall correlations might be the result of intraseasonal changes in abundance

152

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DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

3 4 5 6 7 8

Count Location

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Count Location

Figure 2. Mean winter abundance of shorebirds, by count area, in northern (solid
bars) and southern (striped bars) Tomales Bay, California, 1989-90 to 1998-99.
Error bars indicate standard errors; numbers above bars indicate maximum abun-
dance observed during the study period.

unrelated to rainfall. When count date and year were included as covariates,
residual (uncorrelated) effects of cumulative seasonal rainfall in the north bay
were significant for the Black-bellied Plover (b = -1 ,31, P < 0.05), Willet (b
= 2.56, P < 0.05), Dunlin (b = -27.30, P < 0.05), and (In) Least Sandpiper
(b = -0.06, P < 0.001); residual effects in the south bay were significant for
the (In) Least Sandpiper (b = -0.06, P < 0.05). Conversely, intraseasonal
trends independent of cumulative seasonal rainfall and year were significant
for the Willet (north bay: b = -1.74, P < 0.01; south bay: b = 1.01, P <
0.05), Dunlin (north bay: b = -17.96, P < 0.01; south bay: b = -22.25; P
< 0.01), and (In) Black Turnstone (south bay: b = -0.03; P = 0.01).

154

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

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Figure 2 ( continued ).

After the linear effects of cumulative seasonal rainfall and date are
accounted for, residual annual trends were not significant (P > 0.05), except
in five cases. In the south bay, significant linear trends independent of
cumulative seasonal rainfall and date suggested 10-year declines in the
Black-bellied Plover ( b = -5.62; P < 0.001), (In) Semipalmated Plover (b =
-0.32; P<0.05), (In) Least Sandpiper (b = -0.32; P<0.05), and Dunlin (b =
-223.21; P < 0.001), and increases in the Willet (b = 14.43, P < 0.01) and
Marbled Godwit (b = 10.68, P < 0.05). In northern Tomales Bay, significant
10-year declines independent of cumulative rainfall and date were evident in
the Willet (b = -13.10, P < 0.05) and Dunlin (b = -330.26, P < 0.01).
Although these changes in shorebird use were independent of cumulative
seasonal rainfall, they might have reflected escalating effects of successive
increases in annual rainfall (b = 5.3 cm/year, P < 0.05; Figure 4). The 10-
year duration of this study was too short to distinguish between the influence
of annual rainfall trend and possible underlying (correlated) population

155

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

123456789 10 123456789 10

d) 4000

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Figure 2 ( continued ).

Count Location

trends. Annual trends in maximum (fall) abundance were nonsignificant for
all species (n = 10, P > 0.05), after differences associated with cumulative
rainfall through November and in the previous year were accounted for.

DISCUSSION

Winter Abundance and Distribution

My results confirm Tomales Bay as a wetland of “regional” importance on
the basis of its supporting more than 20,000 shorebirds, a criterion for
inclusion in the WHSRN (Harrington and Perry 1995, Page and Shuford
2000). Relative abundances of wintering shorebird species were similar to
those reported for other Point Reyes area wetlands (Page et al. 1983, Page
et al. 1992). Concurrent counts conducted in 1989-90 in other nearby
wetlands indicated that Tomales Bay supported approximately a third of the

156

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

Cumulative Cumulative Cumulative

seasonal rainfall (cm) seasonal rainfall (cm) seasonal rainfall (cm)

Figure 3, Bivariate plots of baywide shorebird abundance (In) on cumulative seasonal
rainfall in Tomales Bay, Lines represent LOWESS trends, with smoothing parameter
/ = 0,6. Slope of linear regression ( b ) is indicated in each plot: *P < 0.05, **P < 0.01,
***P < 0.001. Between northern and southern Tomales Bay linear slopes did not
differ significantly (P < 0,05). Abundances of the Marbled Godwit and Black
Turnstone are not ln-transformed.

157

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

Figure 4. Means and standard errors of cumulative seasonal rainfall measured on
shorebird count days on Tomales Bay, from 1989-90 to 1998-99. Dashed line
indicates total annual rainfall (July-June) across years. Horizontal dashed line indi-
cates long-term average annual rainfall.

wintering shorebirds in the greater Point Reyes area, which includes Bolinas
Lagoon, Drake’s and Limantour esteros, Estero Americano, and Bodega
Harbor (this study and unpublished data from P. Connors and G. Page).

The only other baywide counts of shorebirds in Tomales Bay are aerial
surveys conducted from August 1968 to April 1970 (Smail 1972). Un-
known differences in detectability, however, preclude comparisons with
these aerial counts, which detected far fewer shorebirds than my study. The
aerial counts did indicate that Tomales Bay supported more shorebirds than
other Point Reyes area wetlands, including Drake’s and Limantour esteros
and Bolinas Lagoon (Smail 1972). Jurek (1974) conducted counts at the
Walker Creek delta from 1969-70 to 1973-74 (area 5, Figure 1) and
reported abundances that do not differ significantly from those I report;
however, population trends could be obscured by substantial variability in
shorebird use from year to year and count area to count area (Table 2).

Among several species, shorebirds wintering at the northern and southern
ends of Tomales Bay appear to represent different groups (this study, Kelly
2000). The apparent separation of shorebirds into local wintering groups in
the northern and southern portions of Tomales Bay is consistent with the
spatial scale of winter site fidelity demonstrated by other studies along the
California coast (Kelly and Cogswell 1979, Warnock and Takekawa 1996).

Although the composition of shorebird species in the northern and
southern portions of the bay was similar, habitat conditions differed substan-

158

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

tially. Habitat differences resulted from spatial and temporal hydrographic
gradients in the estuary that affect salinity (lower and more variable in the
south), sediment size (finer in the south), turbidity (greater and more variable
in the south), and flood disturbance (more frequent and intense in the south;
Daetwyler 1966, Hollibaugh et al. 1988). Such differences are likely to
influence the composition, abundance, or availability of invertebrate prey
(Johnson 1971, Wolff 1969, 1983) and, consequently, may be associated
with spatial or temporal patterns of shorebird use. For example, Marbled
Godwits concentrated in northern Tomales Bay, where substrates are
composed predominantly of well-sorted medium and fine sand, but not in
the southern portion of the bay, where substrates are composed of finer
particles (Daetwyler 1966). Within the Point Reyes/Bodega area, godwits
also concentrate in nearby Bodega Harbor (Page et al. 1983), where
sediments are similar to substrates in northern but not southern Tomales Bay
(Standing et al. 1975).

Midwinter influxes of the Sanderling and Marbled Godwit were signifi-
cantly associated with cumulative seasonal rainfall. These species occur
commonly on nearby beaches along the outer coast and are known to switch
habitats with the tides (Shuford et al. 1989, Connors et al. 1981, Colwell
and Sundeen 2000). My study suggested an intraseasonal influx of these
species into estuarine tide flats, correlated with cumulative rainfall and
independent of tides. Connors et al (1981) linked tide-associated move-
ments between habitats with enhanced foraging profitability and found that
variation in the timing of these movements varies seasonally to enhance
profitability. Thus midwinter influxes of Sanderlings and Marbled Godwits
into Tomales Bay might reflect an intraseasonal increase in the profitability
of foraging in tide flats over foraging on beaches. Alternatively, movements
into Tomales Bay may result from a thermal advantage of refuge from
harsher weather along the outer coast.

The significant midwinter declines in several species using Tomales Bay
suggest local or regional movements to alternative wintering areas. At
Humboldt Bay Colwell (1994) also reported midwinter declines in several
shorebirds. Nonmigratory movements of wintering shorebirds, ranging from
use of local alternative habitats to interestuarine movements to large-scale
flights from the coast inland, have been documented at several California
estuaries, but in different areas intraseasonal patterns are not necessarily
similar (Page et al. 1979, Ruiz et al 1989, Shuford et al. 1989, Warnock et
al. 1995).

Four of six principal wetlands in the Point Reyes/Bodega area are
considered, independently, to have potential regional importance by the
WHSRN (Harrington and Perry 1995, Page et al. 1999). These are Bolinas
Lagoon (Page et al. 1979), Drake’s and Limantour esteros (Page et al.
1983, Shuford et al. 1989), Tomales Bay (this study), and Bodega Harbor
(Page et al. 1983, Ruiz 1987). The closeness of these areas, along with
other locally important wetlands, within approximately 60 km of coast line
indicates substantial importance of this area to wintering and migrating
shorebirds. Movements of wintering shorebirds among wetlands in the Point
Reyes/Bodega area have been suggested by my results and by those of
others (Page et al. 1979, Myers et al. 1980, Shuford et al. 1989, Ruiz et al.

159

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

1989). Although strong site fidelity often distinguishes wintering groups of
coastal shorebirds (War nock and Takekawa 1996, Kelly 2000), the ability to
respond with intraseasonal or episodic movements among wetlands may be
crucial to maximizing winter survival in the face of unpredictable changes in
foraging conditions (Connors et al. 1981, Myers 1980, Ruiz et al. 1989,
Colwell 1993, Warnock et al. 1995). Thus, regional complexes of wetlands
such as those in the Point Reyes/Bodega area may need broad protection
and cooperation by the numerous agencies responsible for their manage-
ment (Laubhan and Fredrickson 1993).

Page et al. (1992) reported on the use of Tomales Bay by migrating
shorebirds in the context of other sites in the Pacific Flyway. Further
information on shorebird use during spring and fall is needed for the
importance of Tomales Bay to migrating shorebirds to be understood fully.
The spatial scale and flexibility of stopover-site selection by migrating
shorebirds within systems of coastal wetlands is poorly understood but might
involve short-flight hopping (Iverson et al. 1996) or local movements related
to changing habitat conditions, as found at inland wetlands (Skagen and
Knopf 1993, 1994). If so, Point Reyes/Bodega area wetlands may provide
extended stopover support for migrating shorebirds.

Conservation Implications

Shorebirds tend to concentrate where the density (Goss-Custard et al.
1977, Bryant 1979) or availability (Recher 1966, Goss-Custard 1984) of
invertebrate prey is greatest. Midwinter declines in several shorebird species
observed in this study may be associated with the adverse effects of heavy
freshwater runoff and associated sediment deposition on prey (Wolff 1983,
Holland 1985, Anima et al. 1988, Nordby and Zedler 1991). Because of
water-residence times as long as four months, prey in southern Tomales Bay
may be particularly vulnerable to the effects of toxic spills or anthropogenic
eutrophication (Smith and Hollibaugh 1989, 1997). Midwinter changes in
shorebird use of key feeding areas at Lagunitas and Walker creeks are
consistent with a hypothesis that deposition of sandy sediment during heavy
runoff reduces the suitability of some areas to foraging shorebirds. Core
samples collected in these areas 4-7 weeks after a major flood in 1982
revealed a surface layer of sandy material that was several centimeters thick
and virtually devoid of invertebrates (Anima et al. 1988). Gerstenberg
(1979) reported reduced shorebird use in Humboldt Bay after siltation of tide
flats during heavy rains. Quammen (1982) found reduced feeding success
and abandonment of preferred feeding areas by Dunlins, Western Sandpip-
ers, and dowitchers when tidal feeding areas were treated with a thin layer of
sand. Periods of increased sedimentation in Tomales Bay have been associ-
ated with logging and intensive farming in the watershed (Rooney and Smith
1999) and could also result from development, overgrazing, or other
disturbance of upland soils (Storm 1972).

Daily, tidal, or intraseasonal movements of shorebirds to alternative sites
in seasonal wetlands and upland fields have been reported in several areas
along the central and northern coast of California (Gerstenberg 1979, Ruiz
etal. 1989, Rameretal. 1991, Colwell 1993). Near Tomales Bay, however,
alternative foraging areas are relatively limited, and use of alternative

160

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

habitats was generally limited to seasonal wetlands at Lawson’s Meadow and
Giacomini Pasture (Figure 1). Breaching levees that isolate the Giacomini
Pasture would restore approximately 150 ha of tidal marsh and at least 36
ha of tidal flats (elevation less than 1.2 m above MLLW) for shorebirds at the
southern end of the bay (Philip Williams and Associates et al. 1993). The
protection of routinely used seasonal wetlands at Lawson’s Meadow adja-
cent to the north end of the bay may be especially important. During heavy
rainfall and flooding, some shorebirds flew to seasonal wetlands 5-15 km
northeast of the bay (pers. obs.).

Direct disturbance by people or dogs can have detrimental effects on the
continuing use of foraging (Burger 1986, Burger and Gochfield 1991) and
roosting (Burger 1981, Kirby et al. 1993) areas by wintering shorebirds. In
Tomales Bay, aggregations of roosting and feeding shorebirds along the
shoreline below sand dunes at Brazil Beach, and on offshore tide flats north
of Tom’s Point (areas 3 and 4, Figure 1), were frequently disturbed by people
from an adjacent 1000-site campground (Shannon and Associates 1998),
who come for clamming or other activities (pers. obs.; Page and Shuford
2000). Dune beaches near the mouth of Tomales Bay may provide critical
winter habitat for the threatened Western Snowy Plover ( Charadrius
alexandrinus niuosus; U.S. Fish and Wildlife Service 1995). Direct distur-
bance of roosting and feeding Snowy Plovers by recreational users in this
area was evident during winter; during spring and summer such disturbance
may prevent nesting by this species in otherwise suitable habitat (Page and
Shuford 2000).

Gulls may interfere with shorebird foraging (Thompson and Lendrem
1985, Warnock 1989, Amat and Aguilera 1990). During winter low tides at
the Walker Creek delta (area 5, Figure 1), large concentrations of gulls were
inversely correlated with shorebird use of exposed tidal flats, suggesting that
gulls displaced shorebirds from otherwise suitable foraging habitat (Kelly et
al. 1996). The gulls arrived daily from .a garbage dump approximately 20 km
to the northeast. Possible indirect adverse effects of local landfills on
shorebird use of estuaries should be investigated further, and the use of such
landfills by wintering gulls could be reduced.

Currently, leases for commercial oyster culture occupy 208 ha of Tomales
Bay, but the limit placed on mariculture leases by the Marin County local
coastal plan is 365 ha. (Tom Moore, Calif. Dept. Fish and Game, pers.
comm.). Shorebirds’ use of open tide flats decreases when these are
developed for mariculture (Kelly et al. 1996). The two most abundant
shorebirds in Tomales Bay, the Dunlin and Western Sandpiper, avoided
areas devoted to mariculture significantly, although Willets were attracted to
oyster plots. Expansion of mariculture, or its redistribution to be concen-
trated more heavily on particular tidal strata, could further reduce foraging
opportunities and possibly abundances of wintering shorebirds. The occa-
sional use by roosting Dunlin and Western Sandpipers of floating oyster
culture bags in subtidal areas during high tides (pers. obs.) suggests possible
benefits to shorebirds.

The invasive nonindigenous European green crab (Ca rein us maenas ) has
become established in Tomales Bay and can alter the abundances of benthic
invertebrate prey dramatically, although the consequences for shorebirds

161

DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

are unknown (Grosholz and Ruiz 1995, Grosholz et al. 2000). The closeness
of San Francisco Bay implies a high potential for invasion by nonindigenous
cordgrass (Spartina alterni flora), which is established there and known to
affect shorebirds adversely (Goss-Custard and Moser 1988, Daehler and
Strong 1996). These concerns, along with those related to watershed
effects, limited availability of alternative habitats, and human disturbance
associated with recreation, mariculture, and garbage dumps, indicate broad
management needs for protecting shorebird foraging areas in Tomales Bay.

ACKNOWLEDGMENTS

The following observers provided expertise in the field: Russ Agnew, Sarah Allen,
Bob Baez, Norah & Hugh Bain, Gordon Bennett, Gay Bishop, Ellen Blustein, John
W. Boyd, Brian Bullick, Ken Burton, Yvonne Chan, Lisa Cohen, Rigdon Currie, Ann
& Eric Davis, Mark Dean, Linda Devere, Jim Devore, John Dillon, Caroline Dutton,
Lew & Marilyn Edmondson, Steve Engel, Gayanne Enquist, Katie Etienne, Jules
Evens, Gary A. Falxa, Katie Fehring, Grant & Ginny Fletcher, Carol Fraker, Dan
Froehlich, Nicole Gallagher, Robert Gleason, Quinton Goodrich, Gayle Greeley, Sue
Gueres, Catherine M. Hickey, Terry Horrigan, Lisa Hug, Maggie Hynes, Jeri
Jacobson, Lynnette Kahn, Mary Ellen King, Richard Kirschman, Carol Kuelper,
Darlene Lam, Sarah Lynch, Flora Maclise, Aspen Mayers, John Me Donagh, Dan
Murphy, Terry Nordbye, David Press, Jim Rappold, Ellen Sabine, Dave Schurr, Craig
Scott, Anne Spencer, Rich Stallcup, Judy Temko, Stephen Thai, Janet Thiessen,
Wayne Thompson, Gil Thomson, Forest Tomlinson, Tanis Walters, Diane Williams,
David Wimpfheimer, and Chris Wood. Susan Kelly, Sarah Tappen, and Katie Etienne
provided valuable assistance in the coordination of shorebird counts and management
of data. Peter Connors, Gary Page, David Shuford, and Rich Stallcup provided
valuable advice in designing the monitoring program. Thomas R. Famula, Robert E.
Gill, William J. Hamilton III, Lewis W. Oring, and Wesley W. Weathers provided
valuable review of the manuscript. This paper is a contribution of Audubon Canyon
Ranch.

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DISTRIBUTION AND ABUNDANCE OF WINTER SHOREBIRDS ON TOMALES BAY

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Accepted 2 June 2001

Western Sandpipers

Sketch by George C. West

A TARGETED MIST NET CAPTURE TECHNIQUE
FOR THE WILLOW FLYCATCHER

MARK K. SOGGE, JENNIFER C. OWEN, EBEN H. PAXTON, SUZANNE M.
LANGRIDGE, and THOMAS J, KORONKIEWICZ, U.S. Geological Sun/ey, Forest
and Rangeland Ecosystem Science Center, Colorado Plateau Field Station, P, O. Box
5614, Flagstaff, Arizona 86011 (current address of Owen Department of Biological
Sciences, University of Southern Mississippi, Hattiesburg, Mississippi 39406-5018;
current address of Langridge Department of Environmental Studies, University of
California, Santa Cruz, California 95064)

ABSTRACT: We developed a targeted mist-netting technique designed to capture
Willow Hycatchers (Empidonax traillii ) at their breeding sites. The technique uses a
variety of conspecific vocalizations to lure territorial flycatchers into mist nets. Songs
and calls are broadcast from a portable CD player with speakers placed on both sides
of the net. By playing vocalizations commonly heard during territorial interactions,
and switching the sound output from one speaker to the other, flycatchers are readily
drawn into the nets. This capture technique is highly effective, captures birds of both
sexes, and worked at sites throughout the Willow Flycatcher’s breeding range and on
its Central American wintering grounds.

Mist netting is an important tool in many avian research projects. Passive
netting by deploying and periodically checking nets works well for many
studies, especially those set where vegetation is relatively short (approxi-
mately net height), the target species are active at the heights sampled by the
net, and/or when multiple bird species are sought. Because these conditions
do not apply to all areas or studies, targeted trapping methods have been
developed for many species (e.g., see McClure 1984). By exploiting behav-
ioral characteristics of a particular species, targeted techniques can be
especially effective, even under difficult netting conditions.

Breeding Willow Flycatchers ( Empidonax traillii ) can be captured readily
via passive mist netting, especially in relatively short, linear habitats or where
nets can be placed near active nests (Sedgwick and Klus 1997). In 1996, we
initiated a large-scale Willow Flycatcher research program that required the
capture of hundreds of adult flycatchers over much of the species’ range.
Furthermore, we needed to capture both male and female flycatchers to
study sex-based survivorship and movements. This was especially challeng-
ing in habitats where thick vegetation in the lower strata and tightly
interwoven upper-canopy vegetation often limit the number and location of
net lanes. The Southwestern Willow Flycatcher (£. t. extimus), our primary
target bird, is a federally listed endangered species, so the technique also had
to minimize damage to habitat and pose little risk of capture-related injury.

The Willow Flycatcher is an aggressively territorial species (Sedgwick
2000, Sogge 2000), singing and approaching in response to playback of
conspecific songs ( fitz-bews ) and calls. This behavior underlies current
survey protocols (Sogge et al. 1997) and suggests it can be taken advantage
of during banding efforts (McClure 1984: 222). However, our preliminary
efforts (1994 and 1995) to capture flycatchers by broadcasting fitz-bews
from a tape player placed under a mist net met with only limited success.
Here, we describe a more effective capture technique that includes a variety

Western Birds 32:167-172, 2001

167

A TARGETED MIST NET CAPTURE TECHNIQUE FOR THE WILLOW FLYCATCHER

of flycatcher songs and calls broadcast from a CD player through speakers
set on both sides of a mist net.

METHODS
Study Area

We concentrated our banding effort in central Arizona at two main study
areas, the Salt River and Tonto Creek inflows to Roosevelt Lake (Gila
County) and the lower San Pedro River and its confluence with the Gila River
(Pinal County). At both areas, vegetation ranges from 8 to 15 m tall and is
composed of dense stands of saltcedar ( Tamarix ramosissima ) and broad-
leaf riparian woodland, primarily of Goodding willow { Salix gooddingii) and
Fremont cottonwood ( Populus fremontii ).

Mist Nets

Because of dense vegetation, we typically used short (length 2.6 and 6 m,
height 2.6 m, mesh 38 mm) mist nets suspended between aluminum poles
(diameter 1.6 cm, height 122 cm). The height at which we placed the nets
(3-4 m at top of net) depended on the height and density of the understory
and mid-canopy vegetation. In general, we stayed at least 10 m from active
nests. To provide flight lanes for the flycatchers, we tried to place nets so
vegetation did not encroach within 2 to 3 m above and on the sides of the
net; nets closely surrounded by vegetation worked less well.

Vocalizations

Flycatchers use a variety of vocalizations during their natural interactions
and in response to broadcast recorded vocalizations (vocalizations below
follow terminology in Sedgwick 2000). Highly agitated and aggressive
flycatchers sing at increased rates and use emphatic fitz-bews, creets, whits,
writ-tus ( wee-oos of Stein 1963), and trills { churr of Stein 1963). In some
intense confrontations (e.g., physical chase and aggression), flycatchers
combine these into patterns sounding roughly like a high-pitched squeaker
toy. To obtain vocalizations for our broadcasts, we tape-recorded an array of
Willow Flycatcher vocalizations and from these selected a series that in-
cluded fitz-bews, creets, and whits of varying rate and pitch, writ-tus, and
trills. One recording included an array of calls made during an aggressive
encounter between a flycatcher and a Brown-headed Cowbird (Mo lot hr us
ater). We transferred the recorded vocalizations from cassette tape to audio
CD by using a PC-based CD-ROM writer. The final CD contained 12 tracks,
each track with a 10- to 60-second series of one or more vocalizations.

Broadcast Equipment

To broadcast vocalizations, we used a portable CD player and two
speakers. One speaker was placed on each side of the mist net, 2 to 5 m
from the net perpendicularly. Where possible, speakers were set in dense
vegetation or on branches 1 to 2 m above ground. We used commercially
available monaural amplified speakers and adjusted playback volume with

168

A TARGETED MIST NET CAPTURE TECHNIQUE FOR THE WILLOW FLYCATCHER

the CD player’s controls. The speakers and CD player were connected via
monaural audio cables 8-15 m (25-50 ft) long with Vs-inch male mono or
stereo jacks on both ends. We switched sound output between the two
speakers during a capture attempt by using a handmade toggle switch or
simply plugging and unplugging the appropriate speaker wire into the CD’s
headphone jack.

The Capture Process

The net/speaker combination was placed in a suitable open area near a
song perch or nest. Banders sat quietly 5 to 15 m away from the net (in
dense vegetation whenever possible), where they could clearly see the entire
net and surrounding area. Once the vocalizations were broadcast, flycatch-
ers generally paid little attention to the bander, even when he or she was
clearly visible. The capture process typically began with the bander broad-
casting fitz-bews and/or whits to bring a flycatcher closer to the net, then
trying different tracks to find which vocalizations elicited the strongest
response from that particular flycatcher. This usually stimulated the fly-
catcher to become more aggressive and move toward the speakers, flying
close to whichever speaker was broadcasting. By then switching immedi-
ately to the speaker on the opposite side of the net, the flycatcher could be
drawn into the net as it flew across to pursue the “moving” vocalization. The
bander, able to watch the entire area around the net, could readily manipu-
late the speaker output as the flycatcher moved near the net and could
approach and remove the bird immediately after it hit the net.

RESULTS

The targeted mist-netting technique was very effective in capturing
territorial adult Willow Flycatchers. From 1996 through 2000, we captured
492 adult flycatchers at our primary study sites in Arizona (Luff et al. 2000),
99 elsewhere in Arizona, and 364 in other states ranging from the Pacific
Northwest to the northeastern and southeastern United States. There were
no capture-related injuries or mortalities among these 955 flycatchers. At
our primary study sites, we captured and banded an average of 60 to 75%
of the adult population at each site. Males generally responded more
strongly than females and were therefore captured more often. Outside of
Arizona, where the sex of the captured flycatcher was not important to our
objectives, we captured many more males (262; 72%) than females (102;
28%). At our primary study sites in Arizona, where we focused on catching
both sexes, the proportion of captured males (280; 57%) to captured
females (212; 43%) was much closer.

Targeted netting also worked during the nonbreeding season. Lynn and
Whitfield (2000) reported target-netting 59 wintering flycatchers in El
Salvador and Panama. In Costa Rica, we captured and banded 82 wintering
flycatchers — over 90% of the local wintering population at two study sites
(Koronkiewicz and Sogge 2000); the ratio of males to females was approxi-
mately equal (USGS unpubl. data). As on the breeding grounds, there were
no capture-related injuries or mortality.

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A TARGETED MIST NET CAPTURE TECHNIQUE FOR THE WILLOW FLYCATCHER
DISCUSSION

This targeted capture technique works well because it takes advantage of
the Willow Flycatcher’s strongly territorial nature and aggressive response to
conspecific vocalizations. Three factors were important in developing our
particular capture protocol: incorporating a variety of flycatcher vocaliza-
tions, using a CD player, and using multiple speakers to manipulate the
flycatcher into the net. A variety of recorded vocalizations was useful
because individual flycatchers responded best to different vocalizations. One
series of vocalizations, recorded when a flycatcher chased a cowbird from its
territory, was particularly effective in eliciting aggressive response and
chasing behavior, especially once a flycatcher was near the net. Other types
of calls recorded during territorial squabbles between flycatchers also pro-
duced this effect, though not as strongly. A few flycatchers did not respond
strongly to any vocalizations and simply sang or called from above the nets
or elsewhere within their territory. Although we initially used portable tape
players when netting, we soon switched to CD players because a CD could
hold multiple tracks and allowed rapid, silent, and relatively motion-free
switching from one vocalization to another. Furthermore, CD broadcast had
better clarity and durability than did that of tape players. Use of two speakers
dramatically improved capture success over use of one. By alternately
switching the sound output from one side of the net to the other, we more
naturally mimicked a conspecific territorial intrusion and were better able to
manipulate the responding flycatcher into the net. Flycatchers focusing
intently on and pursuing the source of the vocalizations flew close to and/or
perched near the broadcasting speaker. Placing the speaker high (over 2 m)
often led to flycatchers flying back and forth over the top of the net, so the
positioning of speakers relative to the net was very important. Furthermore,
long speaker wires (>10 m) are important because they allow the bander to
move away from the net, limiting disturbance.

Frequently, both birds of a pair reacted to the broadcast vocalizations, and
we sometimes caught the second bird after its mate was captured. When
females were targeted, nets placed 10-20 m from the nest were more
effective than those placed farther away within the territory. Females often
responded aggressively and sometimes sang during the capture process, so
aggression and song do not always indicate the sex of the responding bird.
The combination of CD vocalizations and aggressive response by territory
holders sometimes stimulated neighboring males to intrude into the territory
and be caught.

A particularly important aspect of this technique is its low impact on the
flycatchers. Based on voluntary reporting, the overall injury and mortality
rates of passerines during mist-netting/banding projects are 0,2% and
0.4%, respectively (Canadian Bird Banding Office, unpubl. data). Even such
relatively low rates could be problematic in work with an endangered
species. Our targeted mist-netting technique, coupled with highly experi-
enced staff, has allowed us to avoid any capture-related injuries or mortality
among the >1000 flycatchers captured on the breeding and wintering
grounds. Because a bird’s degree of entanglement in a net (and thus difficulty
of removal) is directly proportional to its time in the net (McClure 1984), the

170

A TARGETED MIST NET CAPTURE TECHNIQUE FOR THE WILLOW FLYCATCHER

bander’s being present when the bird is captured and removing it immedi-
ately helps minimize stress and avoid injuries. The technique also minimizes
our time within a flycatcher’s territory; birds not previously targeted for
capture were usually caught within 10 minutes (broadcast time).

We believe this technique can be readily adapted to other species as well.
Using only songs and calls from commercially available tapes and CDs, we
have used this technique to capture Alder (£. alnorum), Cordilleran
(£. occidentalis), and Dusky (£. oberholseri ) Flycatchers. Johnson et al.
(1981) identified at least 51 bird species that are responsive to playback
recordings and might therefore respond well to targeted capture. Persons
attempting to use this technique on other species can start with basic songs
and calls from their target species, then augment with additional vocaliza-
tions where possible.

ACKNOWLEDGMENTS

This work has been funded in part with federal financial assistance from the U.S.
Bureau of Reclamation (Boulder City, Phoenix, and Salt Lake City offices), the
National Park Service, and the U.S. Geological Survey, and with funding from the
Arizona Game and Fish Department Heritage Program. Development of this tech-
nique was possible due to the hard work and creativity of the 1996-2000 USGS
banding crews; we extend our sincere thanks to Michelle Davis, Robert Emerson,
Heather English, Kerry Kenwood, Therese Littlefeather, Jennifer Luff, Andrew
McIntyre, Michael Moore, Renee Netter, and John Semones. Darrell Ahlers, Terry
Doyle, Charles Drost, Linda Sogge, and an anonymous reviewer provided helpful
comments on drafts of the manuscript.

LITERATURE CITED

Johnson, R. R., Brown, B. T„, Haight, L. T., and Simpson, J. M. 1981. Playback
recordings as a special avian census technique. Studies Avian Biol. 6:68-75.

Koronkiewicz, T. J., and Sogge, M. K. 2000. Willow Rycatcher (Empidonax traillii)
winter ecology in Costa Rica: 1999/2000. Unpublished report to the U.S.
Bureau of Reclamation (order from U.S. Geological Survey, P.O. Box 5614,
Ragstaff, AZ 86011).

Luff, J. A., Paxton, E. H., Kenwood, K. E., and Sogge, M. K. 2000. Survivorship and
movements of Southwestern Willow Flycatchers in Arizona — 2000. Unpub-
lished report to the U.S. Bureau of Reclamation (order from U.S. Geological
Survey, P.O. Box 5614, Flagstaff, AZ 86011).

Lynn, J. C., and Whitfield M. 2000. Winter distribution of the Willow Rycatcher
( Empidonax traillii ) in Panama and El Salvador. Unpublished report to U.S.
Bureau of Reclamation (order from Southern Sierra Research Station, P.O. Box
1316, Weldon, CA 93283).

McClure, E. 1984. Bird Banding. Boxwood Press, Pacific Grove, CA.

Sedgwick, J. A. 2000. Willow Flycatcher ( Empidonax traillii), in The Birds of North
America (A. Poole and F. Gill, eds.), no. 533. Birds N. Am., Inc.., Philadelphia.

Sedgwick, J. A., and Klus, R. J. 1997. Injury due to leg bands in Willow Rycatchers.
J. Field Ornithol. 68:622-629.

Sogge, M. K. 2000. Breeding season ecology, in Status, Ecology, and Conservation
of the Southwestern Willow Rycatcher (D. M. Finch and S. H. Stoleson, eds.),
pp. 57-70. USDA Forest Serv. Gen. Tech. Rep. RMRS-GTR-60.

171

A TARGETED MIST NET CAPTURE TECHNIQUE FOR THE WILLOW FLYCATCHER

Sogge, M. K., Marshall, R. M., Tibbitts, T. J., and Sferra, S. J. 1997. A Southwestern
Willow Flycatcher natural history summary and survey protocol. Nat. Park Serv.
Tech. Rep. NPS/NAUCPRS/NRTR-97/12 (order from U.S. Geological Survey,
P.O. Box 5614, Flagstaff, AZ 86011).

Stein, R. C. 1963. Isolating mechanisms between populations of Traill’s Flycatchers.
Proc. Am. Philos. Soc. 107:21-50.

Accepted 10 May 2001

Willow Flycatcher

Sketch by John Schmitt

172

NOTES

FURTHER EVIDENCE FOR A POPULATION
DECLINE IN THE WESTERN WARBLING VIREO

THOMAS GARDALI, Point Reyes Bird Observatory, 4990 Shoreline Highway,
Stinson Beach, California 94970

ALVARO JARAMILLO, San Francisco Bay Bird Observatory, P. O. Box 247, Alviso,
California 95002

Recently, Gardali et al. (2000) reported that mist-net capture rates of breeding and
migrating western Warbling Vireos ( Vireo gilvus swainsonii) had declined in Marin
County, California, from 1979 to 1997. Evidence of a population decline from a
single site, though, may be misleading and simply represent site-specific changes in
abundance. Here we report a trend in Warbling Vireo abundance from 12 years
(1987-1998) of mist-net data at another site in California, the Coyote Creek Field
Station of the San Francisco Bay Bird Observatory.

The Coyote Creek Field Station is situated at the extreme south end of San
Francisco Bay, north of San Jose, Santa Clara County (37° 20' N, 122° 10' W). The
site is 80 krn southeast of the Marin County site reported on by Gardali et al. (2000).
The habitat at the Coyote Creek Field Station is a mix of valley riparian forest and an
open weedy field. The latter is within a non-concrete flood-control channel that flows
periodically during wet winters. This overflow channel is mowed every several years to
prevent woody vegetation from colonizing. The forest habitat includes an old stand
immediately adjacent to Coyote Creek as well as two riparian restoration sites, one
planted in 1986, the other in 1994. The forested habitats are dominated by Fremont
cottonwood ( Populus fremontii), willows (Salix spp.), boxelder (Acer rtegundo),
western sycamore ( Platanus racemosa), and coyote brush ( Baccharis pilularis ). For
a more detailed description of the study area see Otahal (1995).

Warbling Vireos were sampled through standardized-effort mist-netting. A total of
48 nets at fixed locations (36 prior to 1995) were operated once weekly throughout
the year. Nets were opened 45 minutes before sunrise and kept open for 5 hours
during each day of operation. A variable number of additional nets were also operated
as part of other research projects over the years, particularly during migration.
However, netting effort remained relatively constant between 1987 and 1998, except
for periods of greater effort in spring 1996 and fall 1998. Captured Warbling Vireos
were banded with standard U.S. Fish and Wildlife Service bands, measured, and
released immediately. Aging of birds in the hand was achieved by noting the extent of
skull pneumatization in the fall (Pyle 1997).

Warbling Vireos do not breed at Coyote Creek, so our analyses were limited to
examining trends for both migratory periods separately, fall (August-October) and
spring (April-May). Our sample consisted of 335 individuals (202 in fall and 133 in
spring). Using the program STATA (Stata Corp. 1997), we examined trends by linear
regression. We used the number of individual birds captured per 1000 net-hours to
standardize capture rate by netting effort. Capture totals were log-transformed in
order to improve the normality of the model residuals (Zar 1996). We examined
whether trends were nonlinear by testing for a significant quadratic coefficient for year
in the presence of a linear term and found no trends to be nonlinear. Significance was
assumed at a level of P < 0.05.

Western Birds 32:173-176, 2001

173

NOTES

Table 1 Fall Netting Effort and Captures of Warbling Vireos
at Coyote Creek Field Station, 1987-1998

Year

Net hours

Vireos captured

Vireos per 1000 net hours

1987

2467.50

6.89

1988

2948.00

8.14

1989

2825.99

19.82

1990

3494.75

5.44

1991

2525.00

2.38

1992

2757.50

9.43

1993

2806.75

4.63

1994

2574.00

5.44

1995

2535.00

3.55

1996

2292.50

5.67

1997

3124.50

2.56

1998

4655.62

1.29

The captures of fall migrants declined significantly over the course of our study ((3
= -0.13, SE = 0.046, P = 0.02; Table 1; Figure 1); the average annual change was
-12.2% per year. Fall captures were primarily of birds that hatched that year (86.8%).
Capture rates of Warbling Vireos migrating through Coyote Creek in spring showed
a negative but nonsignificant trend ((1 = -7.98, SE = 0.0003, P = 0.79).

Over the course of this study there has been an increase in riparian habitat at the
Coyote Creek Field Station due to restoration efforts. Capture rates of several
species that occur at Coyote Creek only as migrants have increased over the study
period (e.g., the Willow Flycatcher, Empidonax traillii ), perhaps in response to
restoration efforts (San Francisco Bay Bird Observatory unpubl. data), while the
Warbling Vireo has declined. However, whether capture rates during migration are
responsive to habitat restoration remains unknown. Our spring capture data suggest
a stable pattern for adult migrants, though our sample size may not have been great
enough to detect a trend. In fall, however, we did detect a decline in abundance of
Warbling Vireos, of which the majority were first-year birds. Hence, the decline in
fall captures probably represents a decline in breeding productivity, as also reported
by Gardali et al. (2000).

Like this study and that of Gardali et al. (2000), the Breeding Bird Survey (BBS) has
detected a decline in Warbling Vireo abundance in California (Sauer et al. 1999). We
recorded a rate of decline, expressed as the slope of log-transformed data, similar to
that of Gardali et al. (2000; p = -0.13 and p = -0.10, respectively). The BBS data
showed a decline of 0.9% per year ( P = 0.06) from 1966 to 1998 compared to our
-12.2%. When the analysis of BBS data was limited to 1980-1998 it showed a more
severe annual decline of 2.3% per year (P = 0.01; Sauer et al. 1999). Total fall
captures at Southeast Farallon Island demonstrated no trend from 1968 to 1992 (Pyle
et al. 1994). The Farallon captures were of both adults and young birds, in contrast
with mostly young birds at Coyote Creek. The Farallon study did report a significant
negative trend in the ratio of young to adult birds, supporting our contention that there
has been a decline in the Warbling Vireo’s breeding productivity.

The mechanisms responsible for a decline in Warbling Vireo abundance in
California are not known. The decline in abundance of this species at Coyote Creek
in autumn, where first-year birds constitute a preponderance of Warbling Vireos
captured, suggests that fewer young have been produced annually; the extent of the

174

NOTES

Figure 1. Trend in fall captures of Warbling Vireos, 1987-1998, at Coyote Creek
Field Station. Each circle represents datum for one year; line is least-square line of best
fit (P = 0.02, r 2 = 0.39).

breeding range sampled by our mist-nets is not known. Gardali et al. (2000) presented
indirect evidence that linked poor reproductive success to population declines. Recent
work in interior British Columbia suggests that local populations of western Warbling
Vireos have the potential to be extirpated by high levels of parasitism by the Brown-
headed Cowbird ( Molothrus ater) but that even at low levels of parasitism vireo
nesting success is low (Ward and Smith 2000). More studies are needed to examine
the specific factors limiting the reproductive success of Warbling Vireos.

Our results, together with the BBS (Sauer et al. 1999) and Gardali et al. (2000),
provide strong evidence that western Warbling Vireo populations are in a decline.

None of these data would be available had it not been for the dedication of the
Coyote Creek Field Station’s volunteer banders. Thank you for the commitment and
the fine data. Part of this work was funded by the Santa Clara Valley Water District’s
Coyote Creek Flood Control Project, Wildlife Monitoring Program. This manuscript
was improved by the thoughtful reviews of Kimball Garrett, Tim Manolis, and Kathy
Molina. Steve N. G. Howell provided valuable editorial comments. This is contribution
769 of the Point Reyes Bird Observatory and 120 of the San Francisco Bay Bird
Observatory.

LITERATURE CITED

Gardali, T., Ballard, G., Nur, N., and Geupel, G. R. 2000. Demography of a declining
population of Warbling Vireos in coastal California, Condor 102:601-609.

Otahal, C. D. 1995. Sexual differences in Wilson’s Warbler migration. J. Field
Ornithol. 66:60-69.

175

NOTES

Pyle, P. 1997. Identification Guide to North American Birds, part I, Columbidae to
Ploceidae. Slate Creek Press, Bolinas, CA.

Pyle, P., Nur, N., and DeSante, D. F. 1994. Trends in nocturnal migrant landbird
populations at Southeast Farallon Island, California, 1968-1992. Studies Avian
Biol. 15:58-74.

Sauer, J. R., Hines, J. E., Thomas, I., Fallon, J., and Gough, G. 1999. The North
American Breeding Bird Survey, results and analysis 1966-1998, version 98.1.
U.S. Geol. Surv., Patuxent Wildlife Research Center, 12100 Beech Forest Rd.,
Suite 4039 Laurel, MD 20708-4039.

Stata Corp, 1997. Stata Statistical Software: Release 5.0. Stata Corporation, 702
University Dr., East College Station, TX 77840.

Ward, D., and Smith, J. N. M. 2000. Brown-headed Cowbird parasitism results in a
sink population in Warbling Vireos. Auk 117:337-344.

Zar, J. H. 1996. Biostatistical Analysis, 3rd ed. Prentice Hall, Englewood Cliffs, N.J.

Accepted 20 April 2001

176

NOTES

BRANDT S CORMORANT SINKS AT SEA

TERENCE R, WAHL, 3041 Eldridge, Bellingham, Washington 98225

Cormorants’ limited degree of plumage waterproofing, the spread-winged posture
attributed to the need to dry their feathers, their need to rest and roost out of the water,
and their nearshore foraging distribution have been commented upon by many (e.g.,
Schneider and Hunt 1984, Boekelheide et al. 1990, Siegel-Causey and Litvinenko
1993). I am unaware of descriptions of consequences for cormorants should they be
unable leave the water before saturation.

Counts of seabirds made on >330 one-day trips off Grays Harbor, Washington,
between 1971 and 2000 (see Wahl and Tweit 2000) included a total of 26,340
Double-crested ( Phalacrocorax auritus), Brandt’s (P. penicillatus ), Pelagic
(P. pelagicus ), and unidentified cormorants. Their nearshore distribution was obvious:
74% of the birds were in Grays Harbor and channel, 22% were between there and a
depth of 20 m, and about 4% were in water 20-50 m deep, most of them just outside
the 20-m contour. Thus essentially all birds were within 20 km of shore — only 97 were
seen from there to the edge of the continental shelf.

In addition to these one-day trips 1 spent several weeks aboard the R./V. Thomas
G. Thompson , of the University of Washington Department of Oceanography, on
research cruises from near shore to 126° 30' W, about 160 km offshore. On 18
September 1976, during one such cruise, I first noted a Brandt’s Cormorant perched
on the bow at 47° 07' N, 124° 54' W, about 138 km offshore. Over the next 5 days
the bird (presumably the same individual) roosted aboard the ship and foraged nearby.
The ship was under way much of the time and, even when it was stopped on station,
people seldom visited the bow but remained on the afterdeck. The ship traveled east
and west on a sampling track to 125° 01' W offshore and closest to land at 124° 41'
W, about 35 km offshore.

On 23 September at 0615 the ship stopped on station at 47° 07’ N, 124° 45’ W,
when the sea was nearly flat. Shortly thereafter scientists and crew had scattered all
over the ship. At 0830 I observed the cormorant in the water, about 50 m away. 1 do
not know how long the bird had been in the water, but the ship had been collecting
phytoplankton samples on a box pattern with stops about 0.7 to 2.2 km apart, and
the bird could have been foraging for 2 to 3 hours with the slow-moving ship easily
within sight. It was apparent that the bird was slowly settling lower in the water. When
it was low in the water, with only its head and neck erect and exposed, two gulls ( Larus
occidentalis or L. glaucescens) approached and pecked at it briefly, eliciting little
response from the cormorant. Just before the ship moved off station at 0850 I noted
only the bird’s head above the surface. My attention was diverted for a few seconds,
and when I looked again the bird had sunk. I saw no evidence of a struggle resulting
from underwater attack. It had appeared healthy the day before and flew normally. I
concluded that the bird was either scared off the ship or, on return from foraging, had
been intimidated by people, would not return to the ship, and became waterlogged
and drowned.

I thank D. Fix for useful review comments.

LITERATURE CITED

Boekelheide, R. J., Ainley, D. G., Morrell, S. H., and Lewis, T. J. 1990. Brandt’s
Cormorant, in Seabirds of the Farallon Islands (D. G. Ainley and R. J.
Boekelheide, eds.), pp. 163-194. Stanford Univ. Press. Stanford, CA.

Schneider, D., and Hunt, G. L., Jr. 1984. A comparison of seabird diets and foraging
distribution around the Pribilof Islands, Alaska, in Marine birds: Their feeding

Western Birds 32:177-178, 2001

177

NOTES

ecology and commercial fisheries relationships (D. N. Nettleship, G. A. Sanger,
and P. F. Springer, eds.), pp. 86-95. Can. Wildlife Serv., Environment Canada,
Ottawa, Ontario K1A 0H3.

Siegel-Causey, D., and Litvinenko, N. M. 1993. Status, ecology and conservation of
shags and cormorants of the temperate North Pacific, in The status, ecology and
conservation of marine birds of the North Pacific (K. Vermeer, K. T. Briggs, K. H.
Morgan, and D. Siegel-Causey, eds.), pp. 122-130. Can. Wildlife Serv., Envi-
ronment Canada, Ottawa, Ontario K1A 0H3.

Wahl, T. R., and Tweit, B. 2000. Seabird abundances off Washington, 1972-1998.
W. Birds 31:69-88.

Accepted 30 August 2001

NOTES

FIRST RECORD OF THE EUROPEAN
GOLDEN-PLOVER ( PLUVIALIS APRICARIA)

FROM THE PACIFIC

ANDREW W. PISTON, P. O. Box 6553, Ketchikan, Alaska 99901
STEVEN C. HEINL, P. O. Box 23101, Ketchikan, Alaska 99901

The European Golden-Plover (Pluvialis opricaria) breeds from Iceland and the
British Isles east to the base of the Taimyr Peninsula, Russia, at about 102° 30' E
(Vaurie 1965). Virtually the entire population migrates to or through Europe to winter
in the British Isles, western Europe, and throughout the Mediterranean Basin; small
numbers winter east to the southern Caspian Sea and casually to eastern India, and
small numbers winter on the Atlantic coast of Africa, casually south to Gambia (Vaurie
1965, Cramp 1983). At the western periphery of this range, the European Golden-
Plover is a regular vagrant to Greenland, where it is also a local breeder in the northeast
(Boertmann 1994). It is a casual visitant to Newfoundland (including Labrador) and
Saint Pierre et Miquelon, with nearly all records in April and May (Tuck 1968,
Mactavish 1988, ABA 1996). There are reports from New Brunswick (Am. Birds [AB]
42: 408, 1988), Nova Scotia (AB 43:56, 1989; AB 44:390 1990; Natl. Audubon
Soc. Field Notes [NASFN] 49:222, 1995), and Quebec (AB 42:1271, 1988).

On 14 January 2001 we collected a European Golden-Plover near the Ketchikan
airport, Gravina Island, Alexander Archipelago, southeast Alaska (55° 17' N, 131°
46' W). In a search of the literature, and contacts with shorebird specialists in Asia and
the Pacific, we found no evidence of the prior occurrence of this species in the Pacific
basin.

Piston discovered the bird on 13 January 2001 and watched it for approximately
one hour as it fed on a rocky gravel-covered beach with a flock of 35 Black Turnstones
(Arenaria melanocephala ), three Rock Sandpipers ( Calidris ptilocnemis ), and two
Surfbirds { Aphriza virgata). Knowing that the occurrence of a golden-plover in Alaska
in the winter was unprecedented, he took photographs and notes in the field. Later
that same day we looked over references and discussed the bird’s field marks. The bird
was brightly colored, with gold speckles over the entire back and a golden wash on the
head and breast. The bird also showed a faint white wing bar when it flew, a field mark
of the European Golden-Plover. Other critical field marks were not noted, and we did
not make much of the wing stripe at the time. We discussed the identification of the
European Golden-Plover, but, quite naturally, did not seriously consider that species a
possibility'. Instead we focused our discussion on the field identification of the
American (P dominico ) and Pacific (P fulva) golden plovers.

We determined to relocate the bird the next day and collect a voucher specimen of
what we figured to be a Pacific Golden-Plover. We based this assumption simply on
the fact that the bird was brightly colored, and also because that species would be the
most likely golden-plover to occur in Alaska in the winter. The Pacific Golden-Plover
winters locally in very small numbers in California (Garrett and Dunn 1981, Flarris
1996), and it has been found casually in winter from Oregon (Gilligan et al. 1994,
Contreras 1998) to the coast of southwestern British Columbia (Campbell et al.
1990). More recently, the Pacific Golden-Plover has been reported in winter at the
Queen Charlotte Islands, British Columbia, only 150 km southwest of Ketchikan. One
at Massett 15 December 1991-February 1992 was reported as the first winter record
for the Queen Charlotte Islands (AB 46: 304, 1992); two golden-plovers at Sandspit,
27 December 1997, were considered ‘'about" the fourth winter record for the Queen
Charlotte Islands (NASFN 52:245, 1998). Although the American Golden-Plover has
been collected in mid-winter in the southeastern United States (Paulson and Lee

Western Birds 32:179-181, 2001

179

NOTES

1992), there are no substantiated midwinter records on the west coast of North
America. No golden-plovers had previously been reported in Alaska in the winter.

On 14 January' 2001 we relocated the bird with the same flock of shorebirds and
again noted that it was relatively brightly colored. When it flew a short distance we saw
that the bird indeed had a distinct narrow white wingstripe across the base of the flight
feathers. At one point the bird flapped its wings and we were both stunned to see that
it clearly had white axillaries and underwing coverts. We then noted that the bird
appeared rather dumpy, with proportionately short legs, a chunky body and a
neckless look, subtly different from the slimmer bodied, longer legged, and longer
necked appearance that we are used to seeing in the Pacific Golden-Plover. We also
noted that the bird had a shortish, slightly conical, deep-based, fine-tipped bill, and a
uniform face pattern that lacked a strong supercilium (the supercilium looked to be the
same dull yellowish color as the auriculars). All of these field marks led us to believe
that the bird was probably a European Golden-Plover. (Excellent treatments of the
field identification of the golden-plovers can be found in Hayman et al. 1986, Jonsson
1992, Beaman and Madge 1998, and Svensson et al. 1999.) We saw the bird fly
again three or four times, but the underwings did not look especially white; either the
light was not good or we did not have the right angle. Each time it flew we noted the
narrow white stripe on the upperwing, which could be seen clearly from at least 100
meters. We agreed that we had never seen a Pacific or an American golden-plover
with such a distinct wing stripe. We collected the bird and were again stunned to see
that the bird had white axillaries and underwing coverts.

We forwarded the specimen to the University of Alaska Museum (UAM), Fairbanks,
where our identification was corroborated by Daniel D. Gibson. Gibson prepared the
specimen as a study skin and preserved partial skeleton, frozen tissues, stomach
contents, and guts (lower digestive tract for disease screening). The specimen (UAM
12100) is a first-winter male, with mass 199.5 g (heavy fat), wing chord 181 mm, tail
length 71.0 mm, bill length (from distal end of naris) 14.3 mm, bill depth 5.2 mm (at
distal end of naris), bill width 4.9 mm (at distal end of naris), and tarsus length 45.0 mm
(D. D. Gibson in litt.). The bird’s stomach contained six species of gastropod mollusks
up to 3 mm in length — four snails ( Lacuna uinita, Margarites helicinus, Lirularia
succincta, Littorina scutulata ) and two limpets ( Lottia sp. and Tectura sp.) — plus at
least one crustacean fragment (Tanaidacea; Nora R. Foster, UAM, in litt.).

We thank Daniel D. Gibson for providing the specimen data and references, and for
helpful comments that improved the quality of this note. We also thank Kimball L.
Garrett and Robert E. Gill for their reviews.

LITERATURE CITED

American Birding Association. 1996, ABA Checklist: Birds of the Continental United
States and Canada, 5th ed. Am. Birding Assoc., Colorado Springs, CO.

Beaman, M., and Madge, S. 1998. The Handbook of Bird Identification for Europe
and the Western Palearctic. Princeton Univ. Press, Princeton, N.J.

Boertmann, D. 1994. A annotated checklist to the birds of Greenland, Meddelelser
om Gronland. Bioscience 38.

Campbell, R. W., Dawe, N. K., McTaggart-Cowan, I., Cooper, J. M., Kaiser, G. W.,
and McNall, M. C. E. 1990. The Birds of British Columbia, vol. 2. Royal British
Columbia Museum, Victoria, B. C.

Contreras, A. 1998. Birds of Coos County, Oregon: Status and Distribution. Cape
Arago Audubon Soc. and Ore. Field Ornithol. Spec. Publ. 12.

Cramp, S. (ed.). 1983. Handbook of the Birds of Europe, the Middle East, and North
Africa, vol. 3. Oxford Univ. Press, Oxford, England.

180

NOTES

Garrett, K., and Dunn, J. 1981. Birds of Southern California. Los Angeles Audubon
Soc., Los Angeles.

Gilligan, J., Smith, M., Rogers, D., and Contreras, A. 1994. Birds of Oregon: Status
and Distribution. Cinclus, McMinnville, OR.

Harris, S. W. 1996. Northwestern California Birds. Humboldt State Univ. Press,
Areata, CA.

Hayman, P., Marchant, J., and Prater, T. 1986. Shorebirds: An Identification Guide.
Houghton Mifflin, Boston.

Jonsson, L. 1992. Birds of Europe with North Africa and the Middle East. Princeton
Univ. Press, Princeton, N.J.

Mactavish, B. 1988. Greater Golden-Plover invasion, 1988. Birding 20:242-249.

Paulson, D. R., and Lee, D. S. 1992. Wintering of Lesser Golden-Plovers in eastern
North America. J, Field Ornithol. 63:121-128.

Svensson, L., Grant, P. J., Mullarney, K., and Zetterstrom, D. 1999. Birds of Europe.
Princeton Univ. Press, Princeton, N.J.

Tuck, L. M. 1968. Recent Newfoundland bird records. Auk 85:304-311.

Vaurie, C. 1965. The Birds of the Palearctic Fauna. H. F. & G. Witherby, London.

Accepted 1 7 August 2001

181

BOOK REVIEWS

United States Shorebird Conservation Plan, by S. Brown, C. Hickey, B.
Harrington, and R. Gill (eds.). Second edition. May 2001. Manomet Center for
Conservation Sciences, Manomet, Massachusetts. Available on request from U.S.
Fish and Wildlife Service, Division of Migratory Bird Management, 4401 North
Fairfax Drive, Room 634, Arlington, VA 22203, or through the World Wide Web
(with accompanying technical documents and regional plans) at http://
www.manomet.org/USSCP/files.htm.

Shorebirds may not be as commercially valuable as waterfowl, or as widely
appreciated by the general public as songbirds, yet they have long held a special
fascination for birders and ornithologists. The spectacular migrations undertaken by
some species, and the wild regions they often inhabit, stir both the soul and the mind.
Until recently, however, most shorebirds have tended to slip through the cracks in
conservation consciousness. Yet their highly migratory habits, their need to concen-
trate at a few food-rich sites, and their use of habitats prone to human disturbance and
development combine to make shorebirds vulnerable at many levels.

The need to conserve these remarkable birds has taken on a new dimension with
the publication of the U.S. Shorebird Conservation Plan (hereafter the plan). The plan
is a partnership of state and federal agencies, nongovernmental organizations,
academic institutions, and individuals committed to restoring and maintaining shore-
bird populations in the U.S. and across the Western Hemisphere. The plan summa-
rizes technical reports and recommendations produced by working groups that
developed the plan and offers a wealth of information concerning what is needed for
practical shorebird conservation in the United States.

The plan has been designed to complement, and be integrated with, the continent-
wide conservation initiatives of the North American Waterfowl Management Plan,
Partners in Flight, and the North American Colonial Waterbird Conservation Plan, all
of which share much common ground. International coordination is also underway
with the Canadian Shorebird Conservation Plan, which shares responsibility for many
of the same species. The need for information to be updated constantly and for goals
to be reassessed means that the plan will be revised every five years over the next 15
years, thereafter as necessary.

Seven parts constitute the plan: an introduction to shorebirds’ general biology and
conservation needs, a vision for shorebird conservation, population sizes and conser-
vation status, national conservation strategies, regional goals and strategies, how the
plan should be implemented, and a listing of associated technical reports (which
should be consulted for greater detail and references). Five appendices give popula-
tion estimates for shorebirds breeding in North America, map the 12 planning regions
in the U.S., rank the relative importance of each species in each region, classify the
level of risk for each species, and list species recorded rarely in North America and not
treated by the plan. The five planning regions most relevant to the western U.S. are
Alaska, Hawaii/Pacific Islands, Northern Pacific, Southern Pacific, and Intermoun-
tain West. Each is based on bird-conservation regions identified by the North
American Bird Conservation Initiative.

The plan has three major goals at different scales: at a regional scale, to identify,
protect, and manage important shorebird habitats; at the national level, to stabilize
population levels of species suspected to be in decline, while keeping common species
common; and at the hemispheric scale, to restore and maintain populations of all
shorebird species in the Western Hemisphere through cooperative international
efforts.

The plan recognizes that effective shorebird conservation strategies should be
based on sound science and that baseline population estimates of all species are a
prerequisite to this. Estimates presented in the plan address geographically disjunct

182

Western Birds 32:182-185, 2001

BOOK REVIEWS

populations (e.g.. Pacific coast and interior Snowy Plovers) as well as formally
recognized subspecies separately and, while crude in most cases, are a starting point
for broad policy goals. The plan also sets population targets and estimates a level of
risk (from “highly imperiled” to “not at risk”) for each population from variables such
as population trend, relative abundance, and specific threats on the breeding and
nonbreeding grounds.

How the worthy aims of the plan should be accomplished is discussed in parts 4
through 6. Part 4 advocates that the conservation strategies of greatest priority at the
national level should be population and habitat monitoring (at an estimated cost of
$1.5 million per year), the establishment of a national shorebird- research program to
address shorebird biology (with annual funding of $2 million for national and $1.75
million for regional research priorities), and concerted public education and outreach
programs (no cost estimate). Part 5 summarizes regional goals and strategies, e.g.,
protecting important stopover sites along the Pacific coast. For the southern Pacific
region, “regional priorities must include increasing populations of breeding species
such as Snowy Plover, Killdeer, . . . Black-necked Stilt , and American Avocet. ” Although
many birders and field ornithologists may question this statement for three of these
species, can we prove otherwise? If nothing else, this should force us to recognize the
need for reliable baseline data and make us question how much we take for granted.
Part 6 proposes a model for the plan’s implementation, to be coordinated by the U.S.
Shorebird Plan Council. Membership of the council is open to any organization, and
current members include the American Bird Conservancy, Canadian Wildlife Service,
Ducks Unlimited, the Nature Conservancy, and several branches of the U.S. govern-
ment.

A phenomenal amount of work went into coordinating and publishing this
ambitious plan, which appears to have included all interested parties. Two observa-
tions might be addressed in future editions. I appreciate that agendas as broad as
nationwide shorebird conservation are difficult to communicate succinctly. With
judicial editing and reorganization, however, the plan’s length could be cut signifi-
cantly — with no loss of content. In this edition, anyone wishing to identify a focused
strategy of action is likely to be lost in a maze of circumlocution. Second, I found no
mention of the plan’s intended audience, although I assume there is one. Identifying
an audience could help focus the plan’s content. The general public, unless fluent in
jargon (e.g., “to enhance funding capabilities and delivery of habitat protection and
restoration activities governed by provisions of...”) will likely “tune out” quickly. Those
with a more scientific background also may be troubled by the nebulous content and
lack of direct citations — but note that these are included in the technical documents
accompanying the electronic version. Even if jargon-literate land managers and
politicians are the intended audience, frequent repetition in the plan is inefficient of
the reader’s time.

The plan represents an overview of shorebird conservation issues, which now need
to be addressed. The technical committees and regional working groups formed
during the plan’s conception are working actively toward its fulfillment, and the best
way for interested parties to become involved is to consult their regional plan and
make contacts from there. Shorebirds need all the help they can get, and I am very
glad that a growing constituency is dedicated to conserving what have long been
among my favorite birds,

Steve N. G. Howell

183

BOOK REVIEWS

The Riparian Bird Conservation Plan, by California Partners in Flight and the
Riparian Habitat Joint Venture, version 1.0. 2000. 88 pp. Available free (in pdf
format) from the Point Reyes Bird Observatory (PRBO) website: http://
www. prbo . org/CPIF/ Consplan . html .

Habitat loss may be the leading cause of population declines and range reductions
among landbirds in western North America. To reverse this trend and maintain
existing populations, remnant high-quality habitats must be protected and degraded
habitats restored. Although efforts to protect and enhance riparian habitats are
underway, land managers designing restoration programs face a high degree of
uncertainty in deciding which management actions will be most effective. To reduce
this uncertainty, the full range of knowledge and skills from the natural and social
sciences should be brought to bear on the problem. In addition, dissemination of
information among scientists, managers, and stakeholders should be rapid, recipro-
cal, and continuous (Mangel et al. 1996).

Recognizing these challenges, California Partners in Right (see Bonney et al. 2000
for a discussion of the Partners-in-Right approach) teamed up in 1994 with a diverse
coalition of federal, state, and nonprofit organizations and landowners to form the
Riparian Habitat Joint Venture (RHJV). The RHJV was modeled after the highly
successful joint ventures of the North American Waterfowl Management Plan, and to
date 19 organizations throughout California have joined this initiative to protect
biodiversity. Broadly stated, the RHJV’s goal is to conserve, increase, and improve
riparian habitats to protect and enhance California’s native bird populations.

As a major step toward achieving this goal, the RHJV, with PRBO as the leading
organization, produced the first edition of the Riparian Bird Conservation Plan
(hereafter “the plan”) in August 2000. The plan’s goal is to provide scientific
information and technical guidance to help private landowners, land managers,
agencies, and conservation organizations select, design, and implement the conserva-
tion and land management projects of highest priority. More specifically, the plan
synthesizes current scientific knowledge of the requirements of birds in riparian habitats
and recommends strategies for habitat protection, restoration, management, monitor-
ing, and policy. The plan’s guidelines are flexible, so that land-management practices
designed to benefit wildlife do not conflict with resource-dependent economies.

Although the plan has a California focus, many of its recommendations are
relevant to other western states. In part this is because the plan presents separate
conservation objectives for eight of California’s ten bioregions. To capture the
conservation needs of these regional avifaunas, fourteen focal species were selected.
It is hoped that the restoration strategies necessary to support these species represent
a multispecies umbrella that will protect the riparian bird community at large
(Lambeck 1997). The plan contains historical and current data on the distribution of
these focal species from more than 350 sites throughout the state and provides
population targets for each species in these eight bioregions. In documents separate
from the plan (links on the PRBO website), each focal species is profiled in detail.
These profiles present valuable information on life history and distribution but differ
from other species accounts (e.g., The Birds of North America series) in that they
focus on species-specific conservation priorities.

The plan has tremendous potential to advance avian conservation efforts and,
given the resources now being devoted to riparian restoration, its release could not be
more timely. Although a landmark effort in its current form, there are aspects of the
plan that could be improved. For example, it would help if there were greater
acknowledgment of the degree to which particular conclusions or recommendations
are based upon speculation versus empirical evidence. Recommendations that are
based on best guesses and/or anecdotal observations could then be tested with
rigorous scientific methods. In this manner the document has the potential to function
as an important hypothesis-generating tool supporting adaptive management. In

184

BOOK REVIEWS

adaptive management, science is used to evaluate current management practices,
design tractable management experiments, monitor their effectiveness, and recom-
mend midstream adjustments (Walters 1986). Although the plan does provide some
research and monitoring recommendations, this section of the plan should be
expanded. In its present form this section informs land managers of the need to
integrate scientific investigation and management actions but offers less to the
research ecologist interested in learning which uncertainties need focused investiga-
tion.

Ultimately the Riparian Bird Conservation Plan takes a heroic step forward in
tightening the link between science and on-the-ground management, integration
sorely needed if we are to meet today’s conservation challenges. The plan is a valuable
resource that should be consulted by all those interested in managing riparian
resources. Additional habitat-based bird-conservation plans (e.g., for oak woodlands)
are being developed by California Partners in Flight, with drafts available at the PRBO
website.

LITERATURE CITED

Bonney, R., Pashley, D. N., Cooper, R. J., and Niles, L.(eds.). 2000. Strategies for
bird conservation: The Partners in Flight planning process. Proceedings of the
3rd Partners in Right Workshop, 1-5 October 1995, Cape May, New Jersey.
Proceedings RMRS-P-16. U.S. Dept, of Agriculture, Ogden, UT.

Lambeck, R. J. 1997. Focal species: A multi-species umbrella for nature conserva-
tion. Conserv, Biol. 11:849-856.

Mangel M., and 41 others. 1996. Principles for the conservation of wild living
resources. Ecol. Appi. 6:338-362.

Walters, C. J. 1986. Adaptive Management of Renewable Resources. McMillan, New
York.

Gregory H. Golet

185

FEATURED PHOTO

PARAPATRY IN WOODHOUSE’S AND
CALIFORNIA SCRUB-JAYS REVISITED

JON L. DUNN, RR2, Box 52R, Bishop, California 93514

KIMBALL L. GARRETT, Section of Vertebrates, Natural History Museum of Los
Angeles County, 900 Exposition Blvd., Los Angeles, California 90007

Geographical variation in the scrub-jays (the Apheiocoma coerulescens species
group) has intrigued and confounded ornithologists both before and since Pitelka’s
(1951) extensive review. In part on the basis of the work of Peterson (1990, 1992),
the American Ornithologists’ Union (1995) elevated the widespread continental
scrub-jays (A. californica, the “Western Scrub-Jay”) and the endemic jay of Santa
Cruz Island (A. insularis, the “Island Scrub-Jay”) to full species rank, restricting the
name Apheiocoma coerulescens to the isolated Florida Scrub-Jay. Components of
the Western Scrub-Jay have at times been given full species rank, in the form of a
division between birds of the Pacific coast (the A. (c.) californica group of subspecies,
hereafter “California Scrub-Jay”) and birds of interior western North America (the A,
[c.] woodhouseii group, “Woodhouse’s Scrub-Jay”); an additional group of subspe-
cies (the “Sumichrast’s Scrub-Jay,” A. [c.] sumichrasti ) occurs on the southern
Mexican plateau. Woodhouse’s and California Scrub-Jays were treated as separate
species most recently by Swarth (1918).

Minor variation in plumage and measurements, differing identifications of type
specimens, and vague type localities for old names have sparked taxonomic disagree-
ments and, indeed, markedly conflicting nomenclature (e.g., Phillips 1986). Pitelka’s
landmark study (1951) did establish limited intergradation between the two groups in
a zone of parapatry around the Pine Nut Mountains of Douglas Co., Nevada, with
intergrades encountered north to the Virginia Mountains and south to the California
border area of northernmost Mono Co. Pitelka also documented intergradation in the
Owens Valley region, Inyo Co., California.

Larry Sansone took the photos on the back cover west of Wellington, Nevada, in
the southernmost Pine Nut Mountains. The upper photo (taken 7 December 1996)
shows a bird apparently typical of Woodhouse’s Scrub Jay in the western Great Basin,
A. c. nevadae according to Pitelka’s (1951) nomenclature. The brighter bird in the
lower photo (15 December 1996) shows characters of Pacific Coast birds (the nearest
subspecies of the California Scrub-Jay being A. c. superciliosa of the 5th edition of
the A.O.U. Check-List) but could represent an intergrade.

Woodhouse’s Scrub-Jays of the western Great Basin are readily told from Califor-
nia Scrub-Jays by several plumage and structural characters. The head, rump, and tail
of nevadae are pale blue washed with gray, recalling a Pinyon Jay, and the underparts
are gray with a blue wash on the undertail coverts; as a result, nevadae shows only a
weak contrast between the bluish head and gray-brown back and between the dull
bluish collar and the blended gray underparts. California Scrub-Jays are deeper blue
dorsally, with strong contrast between the blue head and gray-brown back; they are
mainly whitish below with a deep blue collar that is interrupted medially, and the
undertail coverts only occasionally show a pale blue wash. California Scrub-Jays also
show a blacker auricular patch with a more contrasting white supercilium (again, these
areas appear more blended in nevadae). Structurally, the bill of nevadae has a
distinctly thinner base and less decurved culmen than the stouter bill of coastal birds;
nevadae has relatively longer wings than California Scrub-Jays. We caution here that
more easterly Woodhouse’s Scrub-Jays of the subspecies woodhouseii and texana
are somewhat brighter blue above than nevadae, though the other distinctions from

186

Western Birds 32:186-187, 2001

FEATURED PHOTO

the California group still hold; southward through Mexico, culminating in the
Sumichrast’s Scrub-Jays, the plumage becomes even more “California-like.”

We have found Woodhouse’s Scrub-Jays to be consistently much shyer than
California birds; more easterly Woodhouse’s may tame down in a few picnic areas
(e.g,, in the Davis Mtns. of Texas), but typically nevadae is quite skittish. Vocally, at
least within the core range of nevadae, the common upslurred “jrr-eee?” call is
relatively high pitched and almost two parted, so that the first syllable is level and the
second rises abruptly. California Scrub-Jays have a somewhat lower, harsher and
monosyllabic “shhrreee?” call. The rapid “shreek shreek shreek...” series of
Woodhouse’s is, to our ears, higher pitched and squeakier.

Woodhouse’s Scrub- Jays wander erratically away from their breeding range in fall
and winter, with notable movements occurring every several years (most recently during
the fall and winter of 2000-2001). In invasion years they may move as far as the
southern Mojave Desert, the Imperial Valley, and the lowlands of southeastern Arizona.
Exceptionally birds may wander west over the crest of the Sierra Nevada, e.g., in
Yosemite National Park at Tuolumne Meadows (Gaines 1988) and McGurk Meadow,
where Dunn observed one on 15 September 1996. There may be even more
movement into the Pacific coast region, but vagrants there would be more difficult to
detect than in areas where any scrub-jay is unusual. Eastward movements of California
Scrub-Jays are far more limited, but birds of this group have occurred, for example, on
the northern Mojave Desert at Galileo Hill, Kern Co., California (M. T. Heindel in lift.),
and R. Higson collected one of the subspecies obscura in El Centro, Imperial Co.,
California 1 0 August 1 989 (SDNHM 45999).

The California and Woodhouse's groups of scrub-jays were lumped (American
Ornithologists’ Union 1931) in an era when the polytypic species concept first gained
wide acceptance. Given the recognition of species status for the isolated Island and Honda
scrub-jays, similar status for the Woodhouse’s and California groups is perhaps not
unwarranted. Indeed, Woodhouse’s and California Scrub- Jays seem to us more distinct
from one another than do the Island and California Scrub-Jays. Such a revision, however,
requires further elucidation of the status of the sumichrasti group in south-central Mexico.
Additional field studies of the behavior, vocalizations, ecology, and breeding biology of
scrub-jays in the region of parapatry in western Nevada will also be enlightening.

We thank Larry Sansone for obtaining these instructive photos, and Ed Harper for
sharing some of his photos of Woodhouse’s Scrub-jays from Idaho. Philip Unitt made
a number of very helpful editorial suggestions.

LITERATURE CITED

American Ornithologists’ Union. 1931. Check-list of North American Birds, 4th ed.
Am. Ornithol. Union, Lancaster, PA.

American Ornithologists’ Union. 1995. Fortieth supplement to the American Orni-
thologists’ Union Check-list of North American Birds. Auk 112:819-830.

Gaines, D. A. 1988. Birds of Yosemite and the east slope. Artemisia Press, Lee
Vining, CA.

Peterson, A. T. 1990. Evolutionary relationships of the Aphelocoma jays. Ph.D.
dissertation, Univ. of Chicago.

Peterson, A. T. 1992. Phylogeny and rates of molecular evolution in the Aphelocoma
jays (Corvidae). Auk 109:133-147.

Phillips, A. R. 1986. Known Birds of North and Middle America, part I. Denver Mus.
Nat. Hist. Denver.

Pitelka, F. A. 1951. Speciation and ecologic distribution in American jays of the genus
Aphelocoma. Univ. Calif. Publ. Zool. 50:195-464.

Swarth, H. S. 1918. The Pacific Coast jays of the genus Aphelocoma. Univ. Calif.
Publ. Zool. 17:405-422.

187

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Dave Shu ford
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President, WFO

188

World Wide Web site:
www.wfo-cbrc.org

Quarterly Journal of Western Field Ornithologists

President: Mike San Miguel, 2132 Highland Oaks Dr., Arcadia, CA 91006;
sanmigbird@aol.com

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Directors .- Kimball Garrett, Daniel D. Gibson, Bob Gill, Gjon Hazard, Dave
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Editor: Philip Unitt, San Diego Natural History Museum, P.O. Box 121390, San
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Published December 14, 2001

ISSN 0045-3897

Vol. 32, No. 4, 2001

Volume 32, Number 4, 2001

Breeding Status of the Black Tern in California

IV. David Shuford, Joan M. Humphrey, and Nadav Nur 189

Idaho Black Swifts: Nesting Habitat and a Spatial Analysis of Records
R. Kasten Dumroese, Mark R. Mousseaux,

Shirley Horning Sturts, Daniel A. Stephens,

and Paul A. Holick 218

NOTES

Detections of California Black Rails in the Colorado River Delta, Mexico

Osvel Hinojosa-Huerta, William W. Shaw,

and Stephen DeStefano 228

Book Reviews Steve N, G. Howell, Peter Pyle 233

Featured Photo Kimball L. Garrett 237

President’s Message Mike San Miguel 238

Index Philip Unitt 240

Cover photo by © Brian E. Small of Los Angeles, California: Sharp-tailed
Sandpiper (Calidris acuminata), Bolsa Chica Ecological Preserve, Cali-
fornia, March, 2000.

Western Birds solicits papers that are both useful to and understandable by amateur field
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contributions from both professionals and amateurs. Appropriate topics include
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Send manuscripts to Kathy Molina, Section of Ornithology, Natural
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Bethesda, MD 20814).

Reprints can be ordered at author’s expense from the Editor when proof is returned or
earlier.

WESTERN BIRDS

Volume 32, Number 4, 2001

BREEDING STATUS OF THE BLACK TERN
IN CALIFORNIA

W. DAVID SHUFORD, JOAN M. HUMPHREY, and NADAV NUR, Point Reyes Bird
Observatory, 4990 Shoreline Highway, Stinson Beach, California 94970

The Black Tern is the familiar spirit of all fresh-water swamps in California
north of the Tehachipe — Dawson (1923)

ABSTRACT: We surveyed breeding Black Terns throughout California in 1997
and 1998, following winters of very high runoff. We estimated the state’s nesting
population at about 4150 pairs (±30%), of which 47% were in northeastern
California and 53% in the Central Valley, The 1940 pairs in northeastern California
were at 60 sites; 59% were at 10 sites and 70% were in Modoc County. State and
federal wildlife refuges supported <4% of the regional population; the rest were
mostly on U.S. Forest Service and private lands. Low emergents, primarily spikerush
(Eleocharis spp.) and Juncus spp., dominated most nesting marshes in northeastern
California. Percent cover of emergents (vs. open water) was >80% at 68% of breeding
sites. About 90% of the Central Valley breeding population was in Sacramento Valley
rice fields. The rest were in the San Joaquin Valley, primarily in flooded agricultural
fields with residual crops or weeds and secondarily in rice fields. State, federal, or
private refuges or reserves held <1% of Central Valley terns.

Currently the Black Tern is extirpated locally at Lake Tahoe and in the Sacra-
mento-San Joaquin River Delta. In the San Joaquin Valley, formerly a center of
abundance, terns typically now breed mainly in two small areas of rice fields in the San
Joaquin Basin. The Black Tern is quasi-extirpated in the Tulare Basin, where it nests
irregularly and locally in ephemeral habitats, mainly in extremely wet years. The
160,000 to 200,000 ha of rice currently planted annually in the Sacramento Valley
may far exceed the average amount of natural shallow-water habitat available there
before agriculture.

We recommend a statewide survey of the California breeding population about
once every 10 years, during typical climatic and habitat conditions, and monitoring for
population trends annually. Conservation should focus on restoring, enhancing, and
providing long-term protection for suitable wetlands and on maintaining isolation of
colonies from humans and ground predators. Given the scarcity of water in the
Central Valley in most summers, efforts to enhance tern habitat may be most fruitful
in years of exceptional runoff. Research is needed on nesting and foraging ecology,
habitat suitability, demography, limiting factors, population response to changing
water conditions, and the value of rice fields versus wetlands as breeding habitat.

Western Birds 32:189-217, 2001

189

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Although the New World subspecies of the Black Tern ( ChHdonias niger
surinamensis ) breeds widely across southern Canada and the northern
United States, concern has been expressed because the population declined
across the contintent (Dunn and Agro 1995, Peterjohn and Sauer 1997,
Shuford 1999) during a period of rapid wetland loss (Dahl et al. 1997).
Breeding Bird Survey data imply that the Black Tern declined across the
range surveyed, though not significantly, at an average rate of -1.6% (95%
confidence interval -4. 4-1.1) annually (-41.3% overall) from 1966 to 1999
(Sauer et al. 2000). Although extirpated from only two states, the Black Tern
has declined in at least 14 of the 34 states, provinces, and territories where
it currently breeds (Shuford 1999). Consequently, the Black Tern is listed as
threatened or endangered in six states and variously designated of conserva-
tion concern in 18 other states or provinces. For the United States overall,
the Black Tern is listed as a “migratory nongame bird of management
concern” (USFWS 1995), whereas in Canada it has no official status despite
recommendations for listing as “threatened” by Gerson (1988) and “vulner-
able” by Alvo and Dunn (1996). Knowledge of the Black Tern’s status is
poor in the western United States, including California, where anecdotal
information led to its listing as a species of special concern (CDFG 1992).

To fill gaps in knowledge of breeding Black Terns in California, Point
Reyes Bird Observatory surveyed populations statewide in 1997 and 1998
as the focus of a project to assess the status of seven species of “inland-
breeding seabirds” (Shuford 1998, Shuford et al. 1999). Here we report
current statewide population estimates, breeding distribution, breeding
phenology, and habitat associations of the Black Tern and compare them
with the historical record. We also make recommendations for conservation,
management, and long-term monitoring of the Black Tern in California.

STUDY AREA AND METHODS

Prior to field work, we searched the published and unpublished literature
and contacted various field biologists to identify historic and potential
breeding habitats of the Black Tern in California. We cite data from
Audubon Field Notes (AFN) and American Birds (AB) by volume and page
number and unpublished data from notebooks of the editors of the Middle
Pacific Coast region of North American Birds as MPCR files.

In the field, we contacted additional biologists for further information on
potential breeding habitat. We later obtained egg-set data on Black Terns
from the California Academy of Sciences (CAS), Los Angeles County
Museum of Natural History (LACM), Moore Laboratory of Zoology (MLZ),
Museum of Vertebrate Zoology (MVZ), San Bernardino County Museum
(SBCM), San Diego Natural History Museum (SDNHM), Santa Barbara
Museum of Natural History (SBMNH), and Western Foundation of Verte-
brate Zoology (WFVZ).

We varied field survey methods by region, to match local logistical
constraints, and timed surveys to follow the passage of most migrants and
begin with the initiation of nesting.

190

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Northeastern California

The study area here included valleys of the Cascade Range, Klamath
Mountains, and Sierra Nevada, the Modoc Plateau, and the Great Basin
desert, that is, eastern Siskiyou, northeastern Trinity, eastern Shasta,
Modoc, Lassen, Plumas, Sierra, and El Dorado counties. Potential Black
Tern habitat in marshes, lakes, and reservoirs is scattered widely, primarily
from 4000 to 6000 feet (1220-1830 m) elevation in intermountain valleys
or in depressions in the Modoc Plateau. Precipitation, falling mostly from
October through April as rain and snow, in the climate year (1 July-30 June)
1996-97 was 114.3 cm in the Sacramento Drainage Division and 79.8 cm
in the Northeast Interior Basins Division (results from weather stations
throughout the region averaged). Combined, these divisions encompass
most of the study area. As these figures represent 119% and 147%,
respectively, of the long-term (n = 104) averages for these areas (Western
Regional Climate Center; http://www.wrcc.dri.edu/divisional.html), wet-
lands in the study area were well supplied with water in summer 1997.

From 18 May to 19 July 1997, Shuford and colleagues surveyed most
potential breeding habitat in northeastern California for Black Terns; all sites
surveyed were listed by Shuford (1998). In addition, K. Laves and Shuford
surveyed the south shore of Lake Tahoe, El Dorado County, on 14 June
1998, and M. McVey surveyed most potential breeding wetlands in the
Shasta Valley, Siskiyou County, in spring and summer 1998 and 1999.
Shuford and colleagues also opportunistically resurveyed various sites in the
summers of 1998 to 2001 , as indicated in the text or Table 1 . We conducted
surveys mostly on foot and occasionally by kayak or canoe. We were unable
to survey only a few areas with high potential for nesting terns. We did not
survey Picnic Grove and Lakeshore reservoirs in the Devil’s Garden Ranger
District of Modoc National Forest because of logistical difficulties, and we
w r ere denied access to a few private holdings, the largest being Steele
Swamp, Modoc County, and Dixie Valley, Lassen County.

Early in the season it was possible at many sites to count both adult Black
Terns using the wetland and all or most of their nests. We soon realized we
would be unable to count all nests at all sites because of the time needed and
our inability to count nests accurately once chicks began to leave their nests
shortly after hatching. Thus, depending on circumstances, we obtained
three types of counts and used three corresponding methods to estimate
numbers of pairs of terns, presented here in order of their apparent
reliability and annotated with respect to biases. When data are available to
make more than one estimate, we present only the method of apparent
highest reliability.

(1) Total nests: obtained by systematically walking all of a marsh and
locating all or most nests by visually scanning areas where terns were
agitated, flushing adults from nests, or following terns back to nests. At sites
where a thorough search was impractical, we made partial nest counts,
which served only to document breeding. We estimated the number of
breeding pairs as the total number of nests at the time of the survey. This
method may underestimate the total because of the difficulty of finding all

191

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Table 1 Numbers of Adult Black Terns, Nests, and Estimated Pairs from
Surveys of Wetlands in Northeastern California in 1997

Site Survey date

Number of adults' 1
Disturbed Undisturbed

Number of nests b
Total Partial

Estimated

pairs c

Siskiyou County
Butte Valley WA

14 July

ll 2

Butte Valley National
Grasslands

14 July

2 3

Grass Lake d

12 July

—

22 3

Orr Lake

30 May

—

6 3

24, 26 June

—

Dry Lake (T44N, R1W,
sect. 30, 31) 12 July

3 3

Lower Klamath NWR e
Unit 4E

18 June

~73

37 2

Unit 4D

18 June

—

12+

—

12 1

Barnum Flat Reservoir

1 July

—

54 3

Subtotal

Modoc County?

Dry Lake (T44N, R6E,
sect. 4, 5)

20 June

147

9 3

Fourmile Valley

27 May

—

27 1

Wild Horse Valley

28 May

—

3 1

Buchanan Flat 26-27 May

—

21 1

Weed Valley

3 June

—

203

—

160 3

Baseball Reservoir

26 May

—

42 1

Dry Valley Reservoir

25 May

—

30 1

Hager Basin (North)

24 May

—

14 1

Hager Basin (South)

24 May

—

18 1

Telephone Flat
Reservoir

31 May

7 1

South Mountain

Reservoir 31 May-1 June

2 1

Pease Flat 9

21 May

—

17 July

—

~60

—

47 3

18 July

—

Mud Lake (T46N,
R12E, sect. 16)

22 May

8-10

16 1

Crowder Mt.
Reservoir

1 June

41+

40 1

Whitney Reservoir

20 June

—

5 2

Hackamore Reservoir

20 June

—

10 2

Spaulding Reservoir

21 June

—

20 2

Beeler Reservoir

22 June

—

13 2

Pinky’s Pond

22 June

—

7 2

Widow Valley

22 June

—

64 3

Bucher Swamp

22 June

—

122

—

96 3

Six Shooter Tank

23 June

—

9 2

(continued)

192

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Table 1 ( continued )

Site

Survey date

Number of adults 0
Disturbed Undisturbed

Number of nests b
Total Partial

Estimated

pairs 0

Deadhorse Hat
Reservoir

23 June

35 3

Surveyors Valley

23 June

—

28 3

Boles Meadow

7 June

—

211

—

166 3

Hetcher Creek
Reservoir

16-17 June

31 1

Jack’s Swamp

5 June

—

26 1

Dead Horse Reservoir 29 May

—

ll 1

Jesse Valley

26 June

—

10 3

Whitehorse Flat
Reservoir

1 July

29 3

Egg Lake 30 June-1 July

—

343

—

270 3

Taylor Cr. wetlands

30 June

—

128

—

101 3

Subtotal

Lassen County
Muck Valley

2 July

1367
42 3

Hoover Hat Reservoir 3 July

—

6 3

Moll Reservoir

27 June

—

17 2

16 July

—

Okendine’s Spring

27 June

—

5 2

16 July

—

Ash Valley (main)

27 June

—

52 3

Ash Valley (SE)

19 July

—

7 3

Red Rock Lakes
complex

26-27 June

57 3

Boot Lake

25-26 June

—

12 3

Poison Lake h

5 July

—

38 2

Dry Lake
(Grass Valley)

10 June

5 3

5 July

—

Straylor Lake

26 May

—

9 3

11 July

—

Long Lake (T34N,
R8E, sect. 22)

26 May

5 3

1 1 July

—

Ashurst Lake

26 May

—

13 June

—

2 3

10 July

—

Gordon Lake

9 June

—

9 3

10 July

—

Pine Creek wetlands
(T32N, R9E,
sect. 28)

10 June

7 3

10 July

—

McCoy waterpit

9 June

—

9 3

10 July

—

(continued)

193

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Table 1 ( continued )

Site

Survey date

Number of adults 0
Disturbed Undisturbed

Number of nests b
Total Partial

Estimated

pairs c

Eagle Lake'

8-9 July

142

- 3+

112 3

Willow Creek WA

10 June

—

— —

10 3

Horse Lake
Mountain Meadow

8 July

— 1+

8 2

Reservoir
Honey Lake N

7 July

ll 2

(private)

Subtotal

Total

15 June

— 1

3 2

426

1940

°Numbers of adults from either disturbed or undisturbed counts (see Methods).

,; 'N umbers of nests from either total or partial counts (see Methods).

c Numbers of pairs estimated by three methods, listed here in order of apparent reliability, on the
basis of ’ numbers of total nests, 2 counts of total disturbed adults, and 3 counts of total undisturbed
adults (see Methods). When data enable more than one type of estimate, the estimate presented
is from the method of highest apparent reliability

d A count of 13 undisturbed adults at Grass Lake on 24 June 1999 yields an estimate of 10
breeding pairs that year; no terns were seen there on 28 May during the drought year of 2001.

e Counts of undisturbed adults of 54 in Unit 6B, 220± in Unit 6C, 10 in Unit 10A, and 146 in
Unit 12C on 21 June 2001 yield estimates of 42, 173, 8, and 115 breeding pairs in those units,
respectively, that year.

J 'A count of 57 undisturbed adults on 21 June 1999 yields an estimate of 45 breeding pairs at
Lost Valley, which was mostly dry and devoid of waterbirds on 22 June 1997.

3 A count of 23 undisturbed adults at Pease Flat on 20 June 1999 yields an estimate of 18
breeding pairs that year.

h Five adults at Poison Lake on 23 June 1999 showed no signs of site attachment or other
evidence of breeding.

'A count of 160 undisturbed adults at Eagle Lake on 23 June 1999 yields an estimate of 126
breeding pairs that year.

nests, particularly in large marshes, and, because of asynchronous egg
laying among colonies or subcolonies, some birds may not have initiated or
completed laying at the time of surveys.

(2) Total disturbed adults: taken from within the colony when the observer
(or a predator) disturbed birds, and all or most terns, including adults
attending nests, joined a mobbing flock around the intruder. We estimated
the number of pairs as the best count of total disturbed adults rounded to the
nearest even number and divided by two. This method does not account for
adults foraging far from the colony, hence not attracted to mobbing flocks,
adults not joining the mobbing flock, or failed breeders having left the
colony. We did not use this method at large wetlands, where we were unable
to obtain accurate counts because of many adults swirling rapidly around the
observer and terns continuously joining or leaving the mobbing flock as they

194

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

flushed from, or returned to, nests as the intruder approached or left their
“zone of concern.”

(3) Total visible undisturbed adults: taken from the edge of the wetland or
from a vantage point within where the observer did not attract mobbing
adults. We estimated the number of breeding pairs as the best count divided
by 1.27 {standard error 0. 16), the mean ratio of undisturbed adults counted
to nests at the 10 sites where we collected both types of data (317 total
adults, 247 total nests) during the incubation period. The method’s primary
biases, adjusted by a correction factor, are that it underestimates total adults
or pairs because of the difficulty of seeing many incubating and roosting
terns obscured by vegetation or other visual obstructions and does not
account for adults foraging away from the colony. Also, the number of visible
adults may increase as nests hatch and adults spend more time foraging, or,
conversely, may decrease as nests fail and adults disperse.

To characterize habitat at each breeding site, observers recorded the
dominant species of emergent vegetation and visually estimated the percent
cover of both emergent vegetation and open water. We estimated these
variables for the entire wetland, except at managed refuges where we
estimated them for just the diked wetland units in which terns were breeding
rather than for the entire complex of units.

Central Valley

The Central Valley, surrounded by mountains except at its western outlet
into the San Francisco Bay estuary, averages about 644 km long and 64 km
wide. It is divided into the Sacramento Valley, draining south, the San
Joaquin Valley, draining north, and the Sacramento-San Joaquin River
Delta where these rivers converge. The Sacramento Valley is further divided
into the Colusa, Butte, Sutter, American, and Yolo drainage basins, the San
Joaquin Valley into the San Joaquin Basin and the (usually closed) Tulare
Basin.

Over 90% of the Central Valley’s presettlement wetlands have been lost
(Frayer et al. 1989, Kempka et al. 1991), and the dominant land use is
agriculture. Hence, breeding habitat for waterbirds typically is scarce.
Precipitation, falling mainly from October through April (as rain, or snow in
adjacent mountains), is highly variable. Despite a massive reservoir storage
and drainage system and high summer temperatures, in the wettest years
extensive shallow water can persist through the breeding season. Precipita-
tion in the climate year 1997-98, during El Nino, was 153.7 cm in the
Sacramento Drainage Division and 86.9 cm in the San Joaquin Drainage
Division, representing 161% and 169%, respectively, of the long-term (n =
104) averages for these regions (Western Regional Climate Center; http://
www.wrcc.dri.edu/divisional.html). Hence the breeding season of 1998
provided some of the best conditions for nesting waterbirds in the Central
Valley since the 1950s. Shallow-water breeding habitat increased primarily
in the Tulare Basin, where large areas of agricultural land were flooded,
intentionally or unintentionally, and secondarily near Los Banos, Merced
County, on refuges and in flood-control bypasses.

Large areas of cultivated rice fields in the Sacramento Valley, and smaller
areas in the delta and San Joaquin Basin, typically provide potential nesting

195

BREEDING STATUS OF THE BLACK TERN IN CAUFORNIA

habitat for the Black Tern. In 1998, the intense and extended rainy season
delayed rice planting in the Sacramento Valley by about three weeks, and
only about 75% of the crop had been planted at the time of our surveys (60%
by 31 May, 90% by 7 June; 9 June 1998 “Weekly Weather and Crop
Bulletin,” Natl. Agric. Statistics Serv., Agric. Statistics Board, U.S. Dept.
Agric.). Other habitats in the Central Valley sometimes suitable for breeding
terns include managed wetlands on refuges and duck clubs (limited summer
water) and floodwater storage or recharge facilities (e.g., South Wilbur Flood
Area, Kern Fan Element Water Bank). The average May to July tempera-
tures of 62.5° F (16.9° C) and 66.5° F (19.2° C) for the Sacramento and San
Joaquin drainage divisions, respectively, were the second lowest and lowest
on record (Western Regional Climate Center, http://www.wrcc.dri.edu/
divisional.html; n = 105). These were ideal conditions for both surveying in
this typically very hot climate and delaying desiccation of the tern’s breeding
habitats.

Because of the 187,000 ha of rice planted in the Sacramento Valley in
1998, and limited access to private lands, we were unable to survey all
potential breeding habitat. Instead, from 29 May to 10 June (also 18 June),
seven observers conducted roadside transect surveys along most lightly
traveled roads in the Sacramento Valley rice country (Glenn and Butte
counties south to Yolo County) to estimate densities of Black Terns breeding
there. Single observers covered routes by driving roads at 24 to 32 km/hr
and counting terns seen within the primary census zone of 0. 1 mile (160 m)
on each side of the road. We surveyed without the aid of binoculars, except
when needed to confirm identifications or estimate numbers accurately. We
surveyed from 0600 to 1000 hours, later if temperatures were under 29° C;
as temperatures often were below normal, this meant sometimes all day. We
halted during strong winds (>24 km/hr) or persistent rain.

Observers recorded weather conditions, start and stop times, route cov-
ered, miles driven, distance surveyed (each side of the road tallied separately),
number and age of terns, location(s) and habitat type where terns were
observed, and any breeding evidence, including details of nest locations.
Observers also recorded any terns seen beyond the primary census zone or
off survey routes, but we did not use these data to calculate densities of
breeding terns in rice fields. Observers recorded all observations of terns on
maps in the field for later use in mapping patterns of breeding distribution.
Observers were asked to try to confirm nesting by returning to make
observations after finishing a survey or on a subsequent visit. We considered
confirmed nesting all observations of nests with eggs, adults sitting in
incubation posture on an apparent nest, adults feeding non-flying young,
adults repeatedly carrying food to the same spot (presumably to an unseen
chick), or nonflying or very weakly flying young. Because of delayed planting,
at the time of our surveys little growing rice had emerged above water (15%
emerged on 31 May, 35% on 7 June; 9 June 1998 “Weekly Weather and
Crop Bulletin,” Natl. Agric. Statistics Serv., Agric. Statistics Board, U.S.
Dept. Agric.), and hence most terns sitting on nests were still visible.

We calculated densities of Black Terns in rice fields by first multiplying the
distance surveyed on each route by 160 m, the width of the primary census
zone, then converting this to hectares of habitat surveyed. We next deter-

196

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

mined the mean density of terns per 100 hectares for each county (or
grouping of counties) by calculating the mean density for all of the county’s
routes weighted by distance surveyed. We estimated the total number of
breeding terns in each county by multiplying tern density per county times
the number of hectares of planted rice per county (M. Leighton, Calif. Agric.
Statistics Serv. in litt . ; National Agric. Statistics Serv., http://
www.nass.usda.gov: 100/ipedb/), adjusted by a correction factor of 0.75,
the estimated proportion of rice planted at the time of our surveys. Field
observations did not suggest any evidence of avoidance of, or attraction to,
roads by nesting terns, which might have biased our estimates.

By contrast, in the delta, San Joaquin Valley, and in habitats in the
Sacramento Valley other than rice fields, we surveyed from the ground or by
boat all known potential breeding habitat for Black Terns. See Shuford et al.
(1999) for a list of sites surveyed. In 1998, we surveyed the entire 807,
1817, 2220, and 1211 ha of planted rice in Stanislaus, San Joaquin,
Merced, and Fresno counties, respectively, rather than sampling them as in
the Sacramento Valley. We counted mainly visible undisturbed adults and,
rarely, total nests via thorough nest searches. We did not count total
disturbed adults or total nests at most sites because of the potential to
damage crops by doing so. Partial nest counts at many sites served only to
document breeding. Hence, depending on available data, we estimated
numbers of pairs of Black Terns by either the “total nests” or “undisturbed
adults” methods described above for northeastern California. In the latter
case, the correction factor used for the Central Valley was that derived in
northeastern California in 1997.

RESULTS

Population Size and Distribution

We estimated about 4153 pairs of Black Terns nested in the state in 1997
and 1998, 46.7% in northeastern California and 53.3% in the Central
Valley.

Northeastern California. An estimated 1940 pairs nested at 60 widely
scattered sites in this region (Table 1, Figure 1). About 70.5%, 22.0%, and
7.6% of that population was located in Modoc, Lassen, and Siskiyou
counties, respectively. The 10 sites with >50 pairs of terns, which combined
held 58.7% of the regional population, were Barnum Flat Reservoir,
Siskiyou County; Weed Valley, Widow Valley, Bucher Swamp, Boles
Meadow, Egg Lake, and Taylor Creek wetlands, Modoc County; and Ash
Valley (main), Red Rock Lakes complex, and Eagle Lake, Lassen County.

Central Va//ey. Of the estimated 2213 pairs of Black Terns that bred in
the Central Valley in 1998, 89.8% were in the Sacramento Valley and
10.2% in the San Joaquin Valley (Tables 2 and 3, Figures 2 and 3). From
roadside surveys, we estimated that about 2523 ± 754 (1769-3277) adult
terns, or about 1987 (1393-2581) pairs, bred in Sacramento Valley rice
fields (Table 2). Although the birds were spread widely, the largest numbers
were in the northern Colusa Basin (Table 2, Figure 2). In the San Joaquin
Valley, about 75 pairs bred at five sites in the San Joaquin Basin and 151
pairs bred at six sites in the Tulare Basin (Table 3).

197

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Figure 1 . Distribution and size (number of pairs) of Black Tern colonies in northeastern
California in 1997 (see Table 1), plotted with historical (1899-1960) and other recent
(1961-1998) records of confirmed breeding (see Appendices 1 and 2).

198

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Table 2 Estimated Numbers of Black Terns Breeding in the Sacramento
Valley from Roadside Surveys of Rice Fields, 29 May-10 June 1998

County

Hectares
planted rice a

Survey
routes (n)

Distance
surveyed (km) b

Terns per
100 ha (± SE) C

Terns estimated
(± SE) d

Colusa

Sutter-Yolo-

36,637

370.2

2.67 ± 0.67

978 ± 245

Sacramento 6

36,485/

284.5

0.70 ± 0.23

255 ± 84

Butte

26,645

234.5

0.85 ± 0.31

226 ± 82

Glenn

25.131

352.8

3.68 ± 1.56

925 ± 392

Yuba

11,294

122.1

1.22 ± 0.44

138 ± 50

Placer

4239

47.0

0.00 ± 0.00

Tehama 3

363

—

Totals

140,794

138

1411.11

1.80 ± 0.54”

2523 ± 754

0 Planted rice acreage adjusted to account for estimate that only 75% of the total for the year had
been planted at the time of our surveys (see Methods).

b Each side of road tallied separately.

c Density estimates for each county are means of survey routes, weighted by distance surveyed.
SE, standard error.

a Tern numbers estimated by multiplying densities on roadside surveys times acreage of available
rice fields, Standard errors represent variation in densities of terns on survey routes but do not
account for possible error in the estimate of the amount of planted rice at the time of tern
surveys.

e Data for these counties pooled because of small sample sizes for Yolo and Sacramento counties.
Number of survey routes and distance surveyed, respectively, per county: Sutter, 15, 204.0;
Yolo, 10, 69.4; Sacramento, 1, 11.1.

/Numbers of hectares planted rice per county at time of survey: Sutter, 27,553; Yolo, 6177;
Sacramento, 2755

9 Although we surveyed no routes in Tehama Co. in 1998, coverage since the 1970s there has
shown no evidence of terns there in the breeding season (S. Laymon in litt). If terns breed there
now the number would be small: 7 or 13 if densities were the same as for the entire Sacramento
Valley or for Glenn County, respectively.

h Mean of county density estimates, weighted by hectares of rice.

Nesting Phenology

In northeastern California in 1997, we observed the first nests with eggs
at Mud Lake, Modoc County, on 22 May and the first hatched young at
Fletcher Creek Reservoir on 17 June. On the basis of the species’ 19-21
day incubation period (Dunn and Agro 1995), eggs at Mud Lake likely
hatched by at least 12 June. Collection dates of egg sets for the region
extend from 23 May to 30 June and reach a peak in early June (Figure 4).
Observations in the Central Valley in 1998 were inadequate for assessing
breeding phenology; dates of egg sets collected there extend from 3 May to
5 July and reach a peak from late May to early June (Figure 4).

Habitat Associations

Northeastern California. Of 60 breeding sites in northeastern Califor-
nia, 52 (86.7%) were marshes dominated by low (<1 m) emergents, six

199

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Table 3 Numbers of Adult Black Terns, Nests, and Estimated Pairs in the
San Joaquin Valley in 1998

Number of nests fa

Estimated

Site Survey date Number of Adults' 3 Total Partial Pairs' 3

Merced County
Rice fields SW of Merced

22 June 30 — —

3 July 25 — 2

Raccoon Marsh, West Bear Creek Unit, San Luis NWR

22 June 4 2 —

Cinnamon Slough, Merced NWR

23 June 4 2 —

Fresno County

Rice fields S of Dos Palos, Merced Co.

22-23 June 58

James Bypass S of James Rd.

1 July 2

Kings County

S of Hacienda Ranch Hood Basin (T24S,

19 June 69

S of Hacienda Ranch Hood Basin (T24S,

19 June 28+

13 July —

Tulare County

Vicinity jet. Hwy. 43 and Virginia Ave.

25 June 35+ — 2

2 mi W of Rd. 40 about 3 mi S of Alpaugh

23 June 21 — 1

Just W of Rd. 40 about 4 mi S of Alpaugh

22 June 32 — 3

Kern County

Kern Fan Element Water Bank (pond W-2), W of 1-5

20 June 7 — 1

— 5

1 —

R21E, sect. 31, 32)

— 7
R21E. sect. 28, 33)

— 3

— 3-4

24 2

2 1

46 2

l 1

54 2

22 2

28 2

16 2

25 2

6 2

Total

226

“Numbers of adults from counts of undisturbed birds {see Methods).

^Numbers of nests from either total or partial nest counts (see Methods).

“Numbers of pairs estimated by two methods, listed here in order of apparent reliability, on the
basis of founts of total nests or 2 c.ounts of total undisturbed adults (see Methods). When data
enable more than one type of estimate, the estimate presented is from the method of highest
apparent reliability.

200

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Figure 2. Distribution of breeding Black Terns in California’s Sacramento Valley and
Delta in 1998 (see Table 2), plotted with historical (1886-1960) and other recent
(1961-1999) records of confirmed breeding (see Appendices 1 and 2). Stippling
denotes areas where rice currently is grown.

201

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Figure 3. Distribution and size (number of pairs) of Black Tern colonies in California’s
San Joaquin Valley in 1998 (see Table 3) plotted with historical (1893-1960) and
other recent (1961-1997) records of confirmed breeding (see Appendices 1 and 2).
Stippling denotes areas where rice currently is grown.

202

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

100

CENTRAL VALLEY
NORTHEASTERN CALIFORNIA

80 -

111

§ »-

<12

J>x

—>

“3

—>

“3

<y>

tJ-

■

t —

5-DAY PERIODS

Figure 4. Temporal distribution of egg-set records of the Black Tern in California,
1886-1960. Data from major California museums (see Methods, Appendix 1).

(10%) by a mixture of tall (>1 m) and low emergents. At Lower Klamath
National Wildlife Refuge (NWR), Black Terns nested in shallowly flooded
basins dominated by residual barley stubble and algal mats and lacking much
live emergent vegetation. At Boot Lake, Lassen County, in the Warner
Mountains at 6560 feet (2000 m), the highest colony, breeding habitat was
dominated by the floating yellow pond-lily ( Nuphar luteum ssp.
polpsepalum). Of 58 sites with emergent vegetation, 50 (86.2%) were
dominated or co-dominated by low emergent spikerush ( Eleocharis spp.) or
Jurtcus spp., seven by a mixture of tall emergents such as tules {Scirpus
spp.) or cattails ( Typha spp.) and low emergents, and one by a low emergent
composite ( Arnica sp.).

Percent cover of emergents was >80% at 41 sites (68.3%), between 60%
and 80% at nine sites (15%), between 40% and 60% at three sites (5%),
between 20% and 40% at no sites, and between 0% and 20% at seven sites
(11.7%). All sites with <20% emergent cover, except Lower Klamath NWR,
were lakes or reservoirs with mostly open water fringed by marsh vegetation.
If we had limited estimates of vegetative cover to actual breeding sites, rather

203

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

than the entire wetland, the proportion of total sites with >80% cover would
have been higher.

Central Valley. Of the valleywide total, about 2057 pairs (93.0%) bred in
cultivated rice fields, 151 (6.8%) in agricultural fields with residual crops and
weeds and shallow water remaining from winter floods, and 5 (0.2%) in
emergent wetlands of low stature. Of the four pairs that bred in protected
areas, two each were at Merced and San Luis NWRs in the San Joaquin
Basin. All breeding evidence in the Sacramento Valley was from rice fields,
though one colony in Glenn County was in sedges in the corner of a field
rather than in the rice itself (Shuford pers. obs.). Of the 226 pairs in the San
Joaquin Valley, 66.8% were in flooded agricultural fields with residual crops
or weeds, 31.0% in rice fields, and 2.2% in emergent wetlands of low
stature.

DISCUSSION

Accuracy of 1997-1998 Surveys

Although unable to estimate the precision of all methods used to survey
terns in 1997-1998, we suspect our overall population estimate for the
state was within 30% of the actual number. The 95% confidence interval was
±60% for surveys in rice fields of the Sacramento Valley (Table 2) versus
±25% for the “undisturbed adults” method used in northeastern California
and the San Joaquin Valley (Tables 1 and 3). The precision estimate for the
latter method, though, is applicable only for the incubation period, when it
was derived, even though this method was used for data collected through-
out the breeding season. Although the “total nests” and "disturbed adults”
methods, also used widely in northeastern California and the San Joaquin
Valley (Tables 1 and 3), lack estimates of precision both underestimated
numbers of nesting pairs (see Methods). Another source of underestimation
was our inability to cover some potential tern nesting habitat in northeastern
California. Hence our overall estimate is more likely an under- than an
overestimate of the statewide nesting population during the survey period.

To have conducted the statewide survey in one rather than two years
would have been desirable also. We suspect, though, that numbers from the
1997-98 survey were representative of those statewide in 1998, when we
surveyed the entire Central Valley and water conditions in northeastern
California were similar to those in 1997.

Historical Patterns of Distribution and Abundance

Past data on the distribution and abundance of breeding Black Terns in
California are mostly anecdotal (Grinnell and Miller 1944, Cogswell 1977,
Shuford 1999). Breeding populations were restricted to two distinct areas:

(1) the Modoc Plateau and mountain valleys of northeastern California and

(2) the lowlands of the Central Valley. Today the outlines of the breeding
range remain much the same (Figures 1-3). In northeastern California,
however, the species is extirpated at Lake Tahoe. In the Central Valley it is
extirpated in the delta, and in much of the San Joaquin Valley it is either
extirpated or breeds irregularly, only in exceptionally wet years. Grinnell and

204

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Miller (1944) considered the Black Tern a “locally common” breeder in
California. Evaluating subsequent population trends is very difficult given the
anecdotal nature of early accounts and the lack of recent Breeding Bird
Survey data for California sufficient for trend analysis (Peterjohn and Sauer
1997, Sauer et al. 2000).

Northeastern California. Historic locations of confirmed breeding for
this region include Tule Lake and Alturas Meadow, Modoc County; Grass-
hopper Meadows/Lake and Eagle Lake, Lassen County; and Lake Tahoe, El
Dorado County (Grinnell and Miller 1944; Appendix 1). Assessing popula-
tion trends is problematic given the few known historic breeding areas, the
large number of recent breeding sites (Table 1), few of which have a long
record of occupancy, and the species’ propensity to shift from site to site
with fluctuating environmental conditions. Extensive wetland loss, particu-
larly in the Klamath Basin, may have been partially offset on the Modoc
Plateau by the creation of shallow reservoirs for livestock grazing and recent
enhancement for waterfowl (T. Ratcliff, G. Studinski pers. comm.).

Black Terns have bred at Eagle Lake since at least 1918 (Appendix 1).
Using a combination of nest counts in habitat visited, the behavior and
number of terns in suitable habitat not well surveyed for nests, and the extent
of suitable habitat not visited, Gould (1974, in litt.) estimated 300 breeding
adults at Eagle Lake in 1970 and 150 in 1971. From nest counts, Lederer
(1976) estimated 46 breeding adults in 1974; Shaw (1998) estimated 78 in
1996 and 64 in 1997. Our independent estimate in 1997, based on counts
of undisturbed adults, was 224 breeding adults (112 pairs; Table 1). A count
of 160 undisturbed adults on 23 June 1999 yielded an estimate of 252
breeding adults (126 pairs; Table 1, footnote). Together these numbers may
reflect year-to-year variation in nesting population size, perhaps mirroring
changing patterns of emergent vegetation in response to lake levels (G.
Gould pers. comm.) rather than a population decline followed by recovery,
or, in part, the variation in survey techniques among observers.

Black Terns formerly reached their southeastern breeding limit in the
region at Lake Tahoe, where they nested mainly at Rowlands Marsh near the
mouth of the Upper Truckee River, El Dorado County (Orr and Moffitt
1971). That colony once held over 100 pairs, and, prior to 1920, colonies
of four or five pairs bred near the mouth of Emerald Bay, at Meeks Bay, and
near Tahoe Vista; “a few pairs” also formerly nested annually west of Tallac
(Orr and Moffitt 1971; Appendix 1). Habitat loss and degradation from
development and lowering of water levels eliminated breeding Black Terns at
Lake Tahoe (Orr and Moffitt 1971, Cogswell 1977, K. Laves pers. comm.,
Shuford pers. obs. in 1998). Today the species reaches its southern limit in
the Sierra Nevada at Sierra Valley, Plumas and Sierra counties, and at
Kyburz Hat, Sierra County, where breeding is irregular, particularly at
Kyburz (Appendix 2).

Black Terns have been reported breeding in the extensive marshes of
Sierra Valley since at least the early 197 0s (Appendix 2), primarily by birders
looking off Marble Hot Springs Road (Dyson Lane), Plumas County.
Numbers there fluctuate annually (up to 50 on 27 May 1989, J. McCormick
in litt.), and terns are absent in some drought years, such as 2001 (Shuford

205

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

pers. obs. , 12-16 June) The species also occurs in the Sierra County portion
of the marsh (e.g. , up to nine adults ~4 miles north of Sierraville 15-20 June
1999; J. McCormick, Shuford pers. obs.), but this area gets little coverage.

Small’s (1994) report of ‘the largest regular [breeding] concentration
(1000+) in northern California” in the Klamath Basin is unsubstantiated.
Although Zeiner et al. (1990) mapped the summer range as including the
Shasta Valley, Siskiyou County, and Small (1994) cited Cedar Lakes, Shasta
Valley, as a recent breeding area, we know of no documented breeding
records for that valley (Appendices 1 and 2, R. Ekstrom in litt). M. McVey
(in litt.) did not find evidence of Black Terns breeding at any of numerous
wetlands in the Shasta Valley he surveyed in 1998 and 1999.

Central Valley. Grinnell and Miller (1944) reported Black Terns nesting in
the Central Valley along the Sacramento and San Joaquin rivers (latter near
Merced) and at Los Banos, Merced County, Laton and Firebaugh, Fresno
County, and Buena Vista Lake, Kern County. They also noted the species
had colonized rice fields. Egg-set data provide a minimum of two nesting
records for the Sacramento Valley, 39 for the delta (none reported by
Grinnell and Miller), and 399 for the San Joaquin Valley (Appendix 1).
Although terns were widely scattered in the latter valley, many egg sets were
collected from the Los Banos area of the San Joaquin Basin, perhaps
reflecting local abundance, ease of observer access, or collector bias. In the
early 20th century the San Joaquin Valley was of great importance to
breeding Black Terns; Ray (1906), Chapman (1908), Tyler (1913), and van
Rossem (1933) described the species as very numerous there. Among the
few early quantitative estimates were over 100 nests near Los Banos and
South Dos Palos from 19 to 22 May 1919 (J. G. Tyler et al, Appendix 2),
“many hundreds in sight in all directions” in overflow lands of the San
Joaquin River near Los Banos on 29 May 1941 (W. B. Minturn field notes),
and a colony of “about 200 pairs” at Buena Vista Lake on 21 June 1921 (A.
J. van Rossem egg data slip, WFVZ 2470). Sacramento Valley and delta
records being so few may in part reflect limited egg collecting there.

From the cessation of most egg collecting in the mid-1940s until our
1997-1998 surveys, the limited information on the Black Tern’s status in
the Centra] Valley was primarily anecdotal. Although Grinnell and Miller
(1944) noted the at least partial shift in breeding from reclaimed marshes to
cultivated rice, it is unclear how widespread or numerous terns were in rice
fields, which in 1943 totaled 96,000 ha in California (National Agric.
Statistics Serv.; http://www.nass.usda.gov: 100/ipedb/). The estimate of
1000+ migrant Black Terns at the Woodland Sugar Ponds, Yolo County, 8-
21 May 1955, though notable at the time (AFN 9:355), far exceeds any
such recent estimate for the Sacramento Valley. Black Terns bred at
Sacramento NWR in 1958 (Appendix 2), when rice was regularly grown on
the refuge, but no terns are known to have bred on any federal refuge in the
Sacramento Valley since at least the early 1980s (J. Silveira pers. comm.).
Greenberg (1972) reported up to 48 Black Terns in mid- June on two 6-mile
(9.6-km) road transects in Sutter and Sacramento counties from 1969 to
1971, but data are too few for trend analysis. Cogswell (1977) concluded
that Black Tern numbers declined in the Central Valley with loss of marshes,

206

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

increased with expansion of rice growing, and declined again “recently,”
perhaps from pesticide accumulation. The anecdotal nature of his and
others’ claims of declines (AFN 24:638, AB 32:1205, AB 39:98) or
upswings (AB 31:1185) in tern numbers in the Sacramento Valley in the
1970s and 1980s make them hard to evaluate. Lee (1984) found six
colonies (one in Sacramento Co., five in Sutter Co.) while studying Black
Tern nesting biology in rice fields in 1976 and 1977 but made no population
estimates for the area.

Numbers of Black Terns recorded during surveys of pheasant broods in
Butte County in late June and early July, 1976-1992 (J. Snowden in litt.),
did not show any significant temporal trend but appeared to track the
county’s rice acreage (Figure 5). Similarly, the only Breeding Bird Survey
route in California (no. 148) with moderate numbers of Black Terns (median
9, range 0-54), in Glenn and Colusa counties in the Sacramento Valley,
showed substantial variability in numbers and no clear trend from 1971 to
1999 (USGS Patuxent Wildlife Research Center 2000; http://www.mp2-
pwrc . usgs . gov/bbs/ retrieval/) .

W. B. Minturn (field notes) was still observing up to 500+ at various sites in
the San Joaquin Valley in May through at least 1950. In the Tulare Basin,
Black Terns probably bred regularly at Tulare and Buena Vista lakes until the
1940s and 1950s (Appendix 1), when dams constructed on the rivers feeding
them cut off most runoff. Since then breeding in that basin has been irregular,

YEAR

Figure 5. Numbers of Black Terns on California Department of Fish and Game survey
routes for pheasant broods in Butte County, 1976 to 1992 (see Methods), relative to
yearly totals of rice acreage for that county (National Agricultural Statistics Service
1999; http://www. nass.usda.gov: 100/ipedb/).

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BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

mainly in extremely wet years. On 22 July 1983, following an El Nino winter,
R. Hansen (MPCR files) found “many” nests and up to 70 Black Terns, mostly
fledged young, at the Hacienda Ranch Flood Basin and South Wilbur Flood
Area, Kings County. Also in the early 1980s, Black Terns nested in thick
ditch-grass ( Ruppia maritima ) at J & W Farms agricultural evaporation
ponds, 18 km southwest of Corcoran, Kings County (G. Gerstenberg pers.
comm.). These ponds are no longer active, though, and other evaporation
ponds in the basin currently do not support much emergent growth or any
breeding Black Terns (R. Hansen, J. Seay pers. comm.).

Similar local extirpations have also occurred in the San Joaquin Basin. In
the early to mid-1950s, Black Terns nested where a slough flooded areas of
spiny saltbush ( Atriplex spinifera) interspersed with vernal-pool-like habitat
at Volta Wildlife Area (WA) near Los Banos (R. Wilbur pers. comm.). Black
Terns appear to have been still widespread around Los Banos at that time,
as R. D. Ross (MPCR files) estimated 200-250 terns on a drive across
Highway 152 on 15 June 1956. Subsequently, P. J. Metropulos (in litt.)
found the species “common” in the Los Banos area on 20 June 1970, V.
Remsen and P. Myers (AB 27:914) counted 43 south of Los Banos on 16
June 1973, and R. J. Bacon (MPCR files) sighted two or three nesting pairs
at Merced NWR in summer 1983. Black Terns apparently were nesting in
the Traction Ranch section of Mendota WA, Fresno County, when ponds
were first developed there about 1.990 (S. Bruggemann pers. comm.). Today
terns do not nest regularly at any of the state or federal refuges in the San
Joaquin Valley (J. Allen, S. Bruggemann, R. Wilbur, D. Woolington pers.
comm.). They likely breed regularly, though, in the limited rice acreage near
Merced and South Dos Palos, though this remains to be documented. The
current tenuous status of breeding Black Terns in the San Joaquin Valley
documents a major population decline there over the last 100 years and an
apparent shift of abundance to the Sacramento Valley. It is possible, though,
that the Sacramento Valley has always been an important, though poorly
documented, breeding area.

Extralimital breeding. Apparent nesting at Merritt Lake, near Castroville,
Monterey County (Silliman 1915), likely represents an extralimital attempt,
as the species has not bred elsewhere along the coast of California.

Historical Habitat Shifts

In the past, Black Terns nested in the Central Valley in ephemeral early
successional wetlands created by natural overflow of rivers and lakes
(Mailliard 1904, Tyler 1913, van Rossem 1933) or by flood irrigation of
pasturelands (Chapman 1908). It is hard to estimate the extent of tern
breeding habitat, particularly ephemeral overflow lands, available prior to
the massive alteration of the Central Valley’s natural hydrology. Hall (1880)
estimated 324,000 ha of the Sacramento Valley were subject to inundation
from annual overflow and an additional 117,000 ha by “occasional tempo-
rary overflow.” In the San Joaquin Valley, he estimated 253,000 ha of
swamp land were subject to periodic inundation. In the Tulare Basin alone
the fluctuating margins of Tulare Lake could engulf many thousands of
additional hectares after a series of wet winters.

208

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Although it is unclear how much ephemeral habitat remained through the
terns’ breeding season, the vast flood plains and natural flood basins delayed
transmission of flood flows, reduced peak flows and velocities, and increased
summer river flows, as the flood waters slowly drained back into the rivers,
sometimes through July, or evaporated (Bay Institute 1998). The buffering
effect of the flood basins shifted high upstream flows of January to May to a
period of high river outflow from March to June. Rainfall-induced floods
(December-March) predominated in the Sacramento Valley, whereas pro-
longed snowmelt floods (April-June) were the norm in the San Joaquin
Valley, particularly in the Tulare Basin (Bay Institute 1998). Hence, the latter
region likely had the most ephemeral habitat for breeding terns.

Today’s water-management infrastructure keeps rivers within their banks,
except during extreme floods, after which water usually rapidly drains or is
pumped back into river and bypass channels, leaving few areas of shallow
water where Black Terns could breed. The exception is the closed Tulare
Basin where in extreme winters flood waters are diverted into shallow
storage basins or run unchecked into fields. Flood frequency has decreased
such that floods in the Sacramento Valley that formerly occurred about every
2 years now occur once every 7 to 13 years, 10-year floods every 100 years
(Bay Institute 1998). Valleywide, the volumes of large floods remain largely
unchanged, but only in years of a very heavy snowpack in the Sierra Nevada
do flood flows in the San Joaquin Valley approach historic levels.

The great loss of wetlands was mitigated in the Sacramento Valley by the
expansion of rice to the current annual level of 160,000 to 200,000 ha
(Figure 6), which may far exceed the average extent of shallow-water habitat
available there previously in summer. By contrast, wetlands lost in the San
Joaquin Valley have been replaced to only a tiny degree by rice, which has
declined there since the mid-1950s (Figure 6). Terns formerly bred in rice
fields as far south as Kern County (Appendix 1) but no longer do so.

Migratory Stopovers

From 1949 to 1977, estimated peak counts of Black Terns at Tule Lake
NWR, Siskiyou and Modoc counties, from July to early September ranged
from 2000 to 19,000 (n = 17 years, median 5000, Klamath Basin NWR
files), documenting it as an important postbreeding or migratory stopover
for the species. Estimates of tern numbers at Tule Lake, 15 July-4 August
1997, ranged from 1000 to 6000 (J. Beckstrand, R. Ryno, R. Ekstrom in
Shuford 1998). In five years from 1958 to 1972, peak counts at Lower
Klamath NWR in August exceeded 1000 (maximum 9000, Klamath Basin
NWR files); large numbers have not been reported there in recent years. The
only other key stopover site known in the state is the Salton Sea, Riverside
and Imperial counties, outside the breeding range. Up to 15,000 have been
estimated there in early August (Patten et al. in press), but the only census,
13-16 August 1999, tallied 4011 individuals (Shuford et al. in press). Small
(1994) implied that numbers at the Salton Sea have declined since 1987, but
M. A. Patten (in litt.) has no evidence of this. Numbers of migrants on the
southern California coast have declined greatly since the early 20th century
(Garrett and Dunn 1981).

209

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Figure 6. Historic changes in acreage of planted rice in California, 1912 to 1998, and
in the Sacramento Valley and Delta and San Joaquin Valley, 1953 to 1998. Data from
National Agricultural Statistics Service (1999; http://www.nass.usda.gov: 100/
ipedb/); county and district breakdowns available only since 1953.

Current Threats

Central Valley. Agricultural practices that rapidly draw down water levels
in rice fields have exposed tern nests to rat predation only to destroy
renesting attempts later when fields were reflooded above original levels (Lee
1984). In 1998, Shuford saw terns sitting on nests in muddy fields from
which the water had been temporarily drained, and later some of these nests
were abandoned. The rapid increase in rice cultivation coincided with the
post- World War II boom in chemical use in agriculture. Three egg yolks
collected from a Black Tern colony in rice fields in the Sacramento Valley in
1969 had 8.0, 9.1, and 11.8 ppm DDE (Greenberg 1972), but there is no
evidence of deleterious effects of pesticides or other agricultural chemicals
on terns breeding in rice fields. Dunn and Agro (1995) and Weseloh et al.
(1997) reviewed the literature on contaminants in Black Tern eggs but found
no evidence of reproductive effects. They concluded that direct chemical
toxicity is generally not a problem with these terns, but pesticides may
reduce favored insect foods. Loss of insect diversity or biomass could lead to
chick starvation.

210

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Conservation Priorities

Black Tern conservation should focus on protecting and enhancing high-
quality nesting habitat. Because of the variable and generally arid climate in
much of the California breeding range, the value of management efforts in
years of short versus abundant water supply should be assessed carefully.
Water levels should be regulated to protect important nesting and foraging
habitats from ground predators and human disturbance, and management
for terns should be coordinated with activities to conserve other species
groups via other multi-partner conservation efforts (e.g., Central Valley
Habitat Joint Venture, U.S. Shorebird Conservation Plan). Protection of key
migratory stopovers, such as Tule Lake and the Salton Sea, is also vital.

Northeastern California. Because few Black Terns currently nest on
refuges, it would be valuable to see if spikerush-dominated marshes, the
species’ main breeding habitat in the region, could be established or
expanded in these areas.

Central Valley. Because summer water typically is scarce in the Central
Valley, and because seabirds’ productivity often runs in cycles of boom and
bust, efforts to enhance tern habitat may be most fruitful in years of
exceptional runoff. Recent evidence of extensive, irregular nesting in flooded
fields with residual vegetation or crop stubble in the Tulare Basin indicates
the species would benefit from more of this habitat. Perhaps fields with
marginal crop yields could be retired from production and put in a conserva-
tion bank to be flooded when excess water is available. Such flooding should
be weighed against possible waterbird mortality from botulism outbreaks,
which might be reduced by rotating the fields to be flooded and choosing
areas with no prior evidence of disease. Scant breeding on newly restored
wetlands on refuges near Los Banos perhaps could be increased in the
future, particularly in years of high runoff. In such years, infrastructure
improvements likely could spread water over larger areas within or adjacent
to bypasses, such as the Eastside Bypass near Los Banos and the James
Bypass/Fresno Slough south of Mendota WA. Study also is needed of
whether suitable habitat on refuges adjoining bypasses could be increased
during years of high flow by drawing upstream water, circulating it through
refuge ponds, and draining it back into the bypass downstream. Maintaining
a slow, steady flow likely would reduce the chances of botulism.

Monitoring and Research Needs

Shuford (1999) summarized monitoring and research needs for the Black
Tern across North America. Efforts should be made to coordinate California
surveys and research with those in other states and provinces to establish a
broad perspective on population trends and ecology. Research is particularly
needed on the foraging and nesting ecology of Black Terns in California.
Studies of habitat suitability at both the local and landscape level are needed
to guide wetland protection and acquisition efforts (Naugle et al. 2000).
Banding studies are needed to reveal how terns shift with changing water
conditions, as are demographic studies to identify which breeding habitats
are sources or sinks for the overall population. Researchers should focus on
variation in aspects of reproduction most likely to influence population

211

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

trends and on understanding factors limiting nest success (Servello 2000),
using methods that minimize disturbance to nesting terns (Shealer and
Haverland 2000).

We recommend a statewide survey approximately every 10 years, during
typical climatic and habitat conditions, to document potential range shifts
and calibrate long-term monitoring data. We recommend annual monitoring
by trained observers using sampling protocols incorporating precision
estimates; methods should be suitable for local conditions and responsive to
the shifting of breeding locations.

Northeastern California. Monitoring should be conducted in mid-June
by counting undisturbed adults from points where observers do not attract
mobbing terns. Surveys should be based on a random or stratified sampling
of a subset of potential breeding sites, accounting for the difficulty of
reaching some.

Central Valley. Monitoring should be conducted via standardized road-
side transects in rice fields in the Sacramento Valley. Concern about the
potential effects of agricultural pesticides and cultivation practices on Black
Terns (Lee 1984) begs for expansion of research on these topics. Studies are
needed to assess whether the value of rice fields to Black Terns equals that
of ephemeral overflow lands or natural marshes.

ACKNOWLEDGMENTS

Funding was supplied by the California Department of Fish and Game (CDFG),
Chevron USA, Inc., the Richard Grand Foundation, Klamath Basin NWR Complex,
the Weeden Foundation, U.S. Fish and Wildlife Service’s Nongame Migratory Bird
Program, and individual donors to Point Reyes Bird Observatory. We are very grateful
to the many individuals who provided valuable information, advice, access to private
or restricted public lands, or help in the field, without which this study would not have
been possible. We especially thank Lynne Stenzel for insight on sampling design for
roadside surveys in the Sacramento Valley; A1 DeMartini, Tim Manolis, Jim Snowden,
Brad Stovall, and Bruce Webb for help on roadside surveys; Grant Ballard and Diana
Stralberg for preparing distribution maps; Jim Snowden for sharing long-term data on
Black Terns from CDFG surveys of pheasant broods in Butte County; Martha
Leighton of the California Agricultural Statistics Service for data on acreage by county
of planted rice in the Central Valley; Jay Dee Garr, Cass Mutters, and Jack Williams
for insight on timing of rice planting in 1998 and methods of rice cultivation; Dawn
Harris for unpublished data on Black Terns from surveys of duck ponds in the
Sacramento Valley; Rob Hansen and associates for arranging access and helping on
surveys of the Hacienda Ranch Rood Basin and the South Wilbur Rood Area and for
supplying unpublished field notes of Ward B. Minturn and John G. Tyler; Frances
Bidstrup, Danny Cluck, Mike McVey, Bobby Tatman, and David Wimpfheimer for
surveying remote wetlands in northeastern California; the Devil’s Garden Ranger
District of Modoc National Forest, and particularly George Studinski, for logistical
support and sharing information about wetlands there; various other state and federal
land management agencies statewide for providing access to lands and personnel to
help on surveys; Ken Blum of Tamal Saka, Tomales Bay Kayaking, for kayaking
equipment; Helen Green for providing data from the editors of the Middle Pacific
Coast region of North American Birds on file with Golden Gate Audubon Society;
Karen Cebra, Carla Cicero, Rene Corado, Krista Fahy, Kimball Garrett, Ned Johnson,
Freda Kinoshita, Douglas Long, Bob McKernan, James Northern, and Philip Unitt for
Black Tern egg-set data, or confirmation of a lack thereof, from their respective

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BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

institutions; and Paul Fonteyn, Kevin Hunting, Dave Mauser, Gary Page, Tom Smith,
and Denise Wight for support and encouragement for the project. John Cooper,
Gordon Gould, Kevin Hunting, Tim Manolis, Bruce Peterjohn, and Tara Zimmerman
made helpful comments on drafts of the manuscript. This is contribution 718 of Point
Reyes Bird Observatory.

LITERATURE CITED

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Dawson, W. L. 1923. The Birds of California. South Moulton, San Diego.

Dunn, E. H., and Agro, D. J. 1995. Black Tern ( Chlidonias niger), in the Birds of
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Frayer, W. E., Peters, D. D., and Pywell, H. R. 1989. Wetlands of the California
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Garrett, K., and Dunn, J. 1981. Birds of Southern California: Status and Distribution.
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Gerson, H. 1988. Status report on the Black Tern Chlidonias niger. Unpubl. report,
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Weseloh, D. V. C., Rodrigue, J., Blokpoel, H., and Ewins, P. J. 1997. Contaminant
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Accepted 14 September 2001

Appendix 1. Numbers of egg sets of the Black Tern in California, 1886-
1960, from major California museums.

Northeastern California

Modoc County: Alturas Meadow, 9 June 1918 (2); 3.7 mi W of Alturas, 9 June
1918 (4).

Lassen County: Grasshopper Meadows/Lake, 2-22 June 1918 (20); Spaulding’s,
Eagle Lake, 3 June 1918 (7); Eagle Lake, 3-6 June 1918 (5), 22 June 1928 (1); nr.
Truxell’s, east shore of Eagle Lake, 23 May 1923 (1); Upper Ragar Meadow, 1 June
1935 (1).

El Dorado County: nr. Bijou, Lake Tahoe, 19 June 1899 (1), 9 June 1911 (5), 10
June 1912(2), 6 June 1918(9); Lake Tahoe, 6 June 1910(1); Rowland’s Marsh (i.e.,
Al-Tahoe), Lake Tahoe, 22 June 1902 (1), 10 June 1909 (3), 23 May-15 June 1910
(7), 30 May-9 June 1914 (18), 30 June 1918 (1), 5 June 1919 (1), 30 May 1920 (1),
14 June 1928 (1), 21 June 1930 (1), 15 June 1939 (2); nr. Tallac, Lake Tahoe, 22
June 1911 (1).

Central Valley: Sacramento Valley

Colusa County: Maxwell, 23 June 1939 (1).

Yolo County: Woodland, 11 May 1886 (1).

Central Valley: Sacramento-San Joaquin River Delta

Sacramento County: 0.5 mi S of Freeport, 15 June 1899 (2); Bear Lake, 27 May
1923 (5); vie. Sacramento (Pcounty, ?delta), 7 June 1902 (1), 13 May 1906 (2); Stone
Lake, 15-29 May 1921 (23), 4 June 1922 (1), 13-30 May 1923 (4).

San Joaquin County: White Ranch, 9 mi N of Stockton, 3 June 1921 (1);
Kettleman Swamp, 9.5 mi NW of Stockton, 1 June 1947 (3).

Central Valley: San Joaquin Valley

Madera County: Chowchilla (egg record says “Merced Co.”), 23 June 1900 (5); 15
mi W of Madera, 30 June 1923 (1); “Madera Co.,’ nr. Firebaugh, Fresno Co., 16-17
May 1927 (8); “Madera Co.,” 10 mi E of Firebaugh, Fresno Co., 26 May 1927 (4);
10 mi from Firebaugh (?county), 5 June 1927 (1); “Madera Co.,” 28 May 1928 (1),
9 June 1930 (3).

Merced County: nr. Brito, 21 May 1919 (1); Dos Palos, 17-22 May 1912 (5), 8
June 1927 (1); Gadwall, 16 May 1914 (1), 1-2 July 1917 (6), 12 May-4 June 1918
(14); Gustine, 14 May 1931 (1), 5 June 1932 (1), 12 June 1934 (1), 7 June 1937 (5);

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BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

Los Banos, 17 May 1898 (1), 8 June 1901 (1), 5 June 1905 (3), 2 June 1908 (2), 26
May 1910 (3), 2 July 1913 (1), 7 June 1914 (2), 29 May-25 June 1916 (12), 3-4
June 1918 (4), 26 June 1919 (1). 30 May 1920 (1), 28 May 1921 (1), 3-4 June 1922
(3), 1-18 June 1923 (15), 21 May-21 June 1925 (9), 23 May-20 June 1926 (8), 3
June 1928 (1), 30 Ma^l July 1930 (23), 14 June 1931 (1), 13 May-5 June 1932
(10), 12 May-12 June 1934 (4), 11-13 May 1935 (5), 25 May 1936 (4), 14 May-1
June 1937 (1 1), 4 June 1938 (1), 10 May-7 June 1939 (8), 19 May 1940 (4), 9 June
1941 (1), 9 June 1942 (2); 4-6 mi S of Los Banos, 21-23 May 1919 (2), 30 May
1920 (1), 12-21 June 1931 (5); 8-10 mi E of Los Banos, 7 May 1927 (1), 13 May-
1 June 1935 (5); .5-10 mi NE of Los Banos, 9 May 1936 (1), 14 May 1937 (3), 31
May 1939 (1); “Merced Co.,” 20 May 1899 (1), 25 May-1 July 1908 (16), 26 May
1909 (9), 15-28 May 1926 (2), 28 May 1928 (1), 9 June 1930 (2), 25 June 1931
(1), 12-19 May 1935 (4), 3 May-9 June 1936 (20), 10 May 1939 (1), 5 June 1946
(1), 22-23 June 1948 (4), 22-23 May 1949 (6); San Joaquin R. at Los Banos
Crossing, 15 May 1897 (2).

Fresno County: Columbia Ranch, 24-25 June 1919 (4), 8-9 June 1920 (8), 22-
23 June 1921 (5); Firebaugh, 28 May 1916 (2); “Fresno Co.,” nr. South Dos Palos,
Merced Co., 20 May 1919 (3); nr. Laton, 21 June 1919 (2), 3 June 1922 (1);
McNeil’s Ranch SW of Fresno, 7 June 1920 (1); Mendota, 26 May 1915 (1), 7-21
June 1930 (5); Riverdale, 25 May 1917 (1), 24 May 1919 (1).

Kings County: 12 mi from Corcoran (egg record says “Kern Co.”), 24 May 1940
(1); Gernsey Slough, 3 June 1946 (2); 3 mi E of Hanford, 24 May 1922 (1); nr.
Stratford, 23-24 May 1936 (10); border of Tulare Lake, 4 mi W of Waukena, Tulare
Co., 6 June 1893 (3); Tulare Lake, 8 June 1941 (11); Tulare Lake (Kings Co.), 24
May-8 June 1941 (18); 14 mi NW of Tulare, 6 June 1893 (1).

Kern County: Buena Vista Lake, 10 June 1907 (1), 19-20 June 1914(2), 18 June
1916 (1), 19-21 June 1921 (3), 11 June-5 July 1922 (8), 4 July 1937 (1), 5 June
1938 (4), 6 June 1948 (1), 20 June 1954 (2), 24 June 1956 (1); rice field between
Wheeler Ridge and Buena Vista Lake, 12 June 1960 (2); Kern River, 5 June 1938 (2).

Appendix 2 . Sight records of confirmed breeding of Black Terns in Califor-
nia, 1899 to 1999, other than those listed or summarized in the text.

Northeastern California

Siskiyou County: Lower Klamath NWR, Unit 13A, mid-July 1995 (22 nests,
Klamath Basin NWRs files).

Siskiyou/Modoc County: Tule Lake, early July 1899 (“nests,” Bailey 1902).

Modoc County: Beeler Reservoir, 19 June 1976 (nest, B. E. Deuel).

Lassen County: Eagle Lake, 22 June 1921 (15-20 nests, Grinnell et al. 1930),
summer 1974 (23 nests, Lederer 1976); Delta Bay, Eagle Lake, late May-mid July
1971 (1 nest, Gould 1974); North Basin, Eagle Lake, late May-late June 1996 (29
nests, Shaw 1998), early June-mid July 1997 (21 nests, Shaw 1998); southwest
shore, Eagle Lake, late May-mid July 1971 (6 nests, Gould 1974); nr. Spaulding’s,
Eagle Lake, 9 June 1925 (“many nests,” Grinnell et al. 1930), late May-mid July
1970 (30 nests, Gould 1974), late May-mid July 1971 (33 nests, Gould 1974), early
June-mid July 1997 (11 nests, Shaw 1998); eastside bays (Troxel and Duck Island
bays), Eagle Lake, late May-mid July 1971 (1 1 nests, Gould 1974), late May-late June
1996 (10 nests, Shaw 1998).

Plumas County: Sierra Valley, 23 July 1973 (nest, G. Zamzow), 14 June 1989
(nest, D. Shuford et al.), 13 June 1998 (nest, D. Shuford, J. McCormick).

Sierra County: Kyburz Flat, 28 June 1973 (nest, G. Zamzow), 19 July 1973 (nest,
G. Zamzow).

El Dorado County: Emerald Bay, Lake Tahoe, 10 August 1918 (“parents feeding

216

BREEDING STATUS OF THE BLACK TERN IN CALIFORNIA

young,” J. W. Mailliard in Orr and Moffitt 1971); Rowland’s Marsh (i.e., Al-Tahoe),
Lake Tahoe, 1 June 1909 (“scores of nests,” Ray 1913).

Central Valley: Sacramento Valley

Butte County: W of Biggs, 6 July 1987 (2 nests, J. Snowden in litt.); 3 mi S of
Durham, 1 June 1985 (2 nests, J. Hornstein); 2 mi NE of Richvale, 3 July 1984 (7
nests, J. Snowden in litt.).

Glenn County: Sacramento NWR, 9 June 1958 (2 chicks banded; refuge files).

Colusa County: S side of White Rd. 0.7 mi W of Browning Rd., 26 June 1999 (2+
nests, B. Williams in litt.).

Sutter County: S of Kirkville Rd. adjacent to Sutter Bypass, June-July 1976 (3
nests, Lee 1984); jet. Hwy. 113 and Varney Rd., June-July 1976 (10 nests, Lee
1984); E of Armour Rd. between Kirkville and Varney roads, May-July 1977 (2 nests,
Lee 1984); jet. Hwy. 113 and Kirkville Rd., June-July 1977 (8 nests, Lee 1984); N
of Kirkville Rd. adjacent to Sutter Bypass, June-July 1977 (11 nests, Lee 1984); N of
Robbins, June 1969 (“colony of 12 terns [with] nests,” Greenberg 1972).

Sacramento County: jet. Hwy. 99 and Elkhorn Blvd., 24 May-22 June 1976 (13
nests, Lee 1984).

Central Valley: San Joaquin Valley

Merced County: nr. Los Banos, 16 June 1903 (young of year just beginning to fly,
Chapman 1908), prior to 1923 (photo of chicks, Dawson 1923); San Joaquin River
nr. Merced, prior to 1904 (“number of nests recorded,” Mailliard 1904).

Merced/Fresno County: vie. Los Banos and South Dos Palos, 19-22 May 1919
(>100 nests examined, J. G. Tyler et al.).

Fresno County: nr. Laton, 31 May 1910 (“set of 3 eggs,” C. Lamb in Tyler 1913),
27 May 1917 (colony of about 30 pairs, 8 egg sets, N. K, Carpenter, A. M, Ingersoll
fide J. G. Tyler); Firebaugh, 30 May 1912 (several birds “sitting on nests,” Tyler
1913); Riverdale, 25 May 1917 (colony of 20-25 pairs, 13 egg sets, J. G, Tyler, N.
Carpenter); pond S of Fowler, 30 May 1918 (nest, J. G. Tyler); Mendota, 30 May
1928 (3 nests, W. B. Minturn, J. G. Tyler); White’s Bridge Rd., Mendota, 17 May
1930 (nest, W. B. Minturn), 7 June 1930 (about 20 nests, W. B. Minturn, J. G. Tyler),
1 May 1937 (7 nests being built, W. B. Minturn), 22 May 1937 (8 nests, W. B.
Minturn, C. Chandler), 14 May 1941 (partly completed nest, W. B. Minturn), 7 June
1941 (nest, W. B. Minturn).

Fresno/Madera County: Mendota Dam (i.e., Mendota Pool), 3 June 1933 (8 nests,
W. B. Minturn, J. G. Tyler), 23-24 June 1933 (7 nests, W. B. Minturn, J. G. Tyler).

Madera County: 12 mi W of Madera, 9 June 1934 (2 nests, J. G. Tyler).

Kings County: Hacienda Ranch Flood Basin and South Wilbur Rood Area, 22 July
1983 (“many nests”" one photographed, R. Hansen); East Hacienda Ranch Flood
Basin, 29 June 1997 (5 nests, R. Hansen in litt.)

217

IDAHO BLACK SWIFTS: NESTING HABITAT AND
A SPATIAL ANALYSIS OF RECORDS

R. KASTEN DUMROESE, USDA Forest Service, SRS, 1221 South Main Street,
Moscow, Idaho 83S43

MARK R. MOUSSEAUX, IJSDI Bureau of Land Management, Medford District
Office, 3040 Biddle Road, Medford, Oregon 97504

SHIRLEY HORNING STURTS, East 4615 Fernan Lake Road, Coeur d’Alene, Idaho
83814

DANIEL A. STEPHENS, Department of Biology, Wenatchee Valley College, 1300
Fifth Street, Wenatchee, Washington, 98801

PAUL A. HOLICK, 1037 Showalter Road, Moscow, Idaho, 83843

ABSTRACT: The Black Swift (Cypseloides niger) was first confirmed breeding in
Idaho in 1997 and 1998 when four and five pairs, respectively, nested near Shadow
and Fern falls along the North Fork Coeur d’Alene River, Shoshone County. Nest sites
were on cliffs composed of argillite within the large Precambrian Belt Supergroup
geologic formation and associated with a narrow riparian strip of western redcedar
and devil’s club. The microcommunity along cliff faces consisted of a variety of
mosses, liverworts, and ferns. We analyzed all Black Swift sight records for Idaho,
finding that 7 8% were from the breeding season and most breeding-season records
(96%) were associated with the Precambrian Belt Supergroup.

The Black Swift ( Cypseloides niger) breeds locally in the mountains and
along the coasts of western North America from southeast Alaska south to
Mexico and east to central Colorado (AOU 1983). Nests are associated with
coastal cliffs (Vrooman 1901), waterfalls (Smith 1928), and caves (Davis
1964). Although the Black Swift breeds in adjacent areas in the northern
Rocky Mountains (Kondla 1973, Holroyd and Holroyd 1987, Hunter and
Baldwin 1972), details of its status in Idaho are lacking. Larrison et al. (1967)
considered the Black Swift a rare migrant and possible breeder, while
Burleigh (1972) failed to mention the species. Since 1985, however, reports
of summering Black Swifts have increased, and discovery of four nests in
1997 (Svingen and Trochlell 1998) along the North Fork Coeur d’Alene
River, Shoshone Co., provided the first confirmation of breeding in Idaho
(Stephens and Sturts 1998).

Here we describe the known nesting habitat of Idaho Black Swifts, explore
the relationship of a prominent geologic formation to sight records, and
suggest other potential suitable areas in Idaho for breeding swifts.

STUDY AREA AND METHODS

Black Swifts nested at two waterfalls, Shadow and Fern, on Falls Branch
of Yellow Dog Creek in the North Fork Coeur d’Alene River watershed,
Idaho Panhandle National Forest (47° 45' 13" N, 116° 06' 19" W). The
region, characterized by steeply dissected mountains between 600 and
2570 m elevation, lies over the Precambrian Belt Supergroup, a large
formation of sedimentary rock (Hobbs et al. 1965). Annual precipitation
ranges from 648 to 1415 mm, with 70% falling as snow (R. Kasun pers.

218

Western Birds 32:218-227, 2001

IDAHO BLACK SWIFTS: NESTING HABITAT; SPATIAL ANALYSIS OF RECORDS

comm.). The temperature at nearby Kellogg, Idaho, averages about 8° C,
and the climate receives maritime influence. Winters are relatively mild and
summers are dry (see ecoregion M333Ba, Nesser et al. 1997).

We visited the nesting site on 8, 23, and 24 August 1998 and character-
ized the waterfalls and associated macro- and micro-habitats. We compiled
all known Idaho Black Swift sight records from 1929 through 2001 from
several sources: Stephens and Sturts (1998); Audubon Field Notes , Ameri-
can Birds , and their successors; U.S. Fish and Wildlife Service (USFWS)
Breeding Bird Surveys; unpublished records of M. T. Jollie (Univ. of Idaho);
the database of Thomas Rogers, long-time regional editor for Audubon
Field Notes and American Birds ; and individual birders. Using Black Swift
breeding phenology (Hunter and Baldwin 1962; Marin 1997, 1999) and
our observations, we classified as summer (breeding) sight records from 7
June through 31 August; all others were migration records. Finally, we
mapped records in the context of a USFWS latilong grid over the distribution
of the geology found at the nesting site.

RESULTS
Nest-Site. Habitat

Shadow and Fern falls face east and lie in the bottom of a steeply sloped
(45°) valley. Elevation of the precipices of Shadow and Fern falls is 998 and
980 m, respectively, with Shadow Falls about 100 m upstream of Fern Falls.
Although the creek flows through a narrow riparian macro-community
dominated by western redcedar ( Thuja plicata ) and devil’s club ( Oplopanax
horridum ) (Cooper et al. 1991), this community is in a mostly later serai
state dominated by western hemlock ( Tsuga heterophplla) and lady fern
( Athprium felix-femina). It contains the following key plants: twisted stalk
( Stetopus stretopoides), northern wood fern ( Drpopteris expansa),
Anderson’s swordfern ( Polpstichum andersonii ), Dewey’s sedge ( Carex
dewepana), fool’s huckleberry ( Menziesia ferruginea), and smooth willow-
weed ( Epilobium glaberrimum) . Upslope of the narrow, later successional
riparian zone the plant community quickly grades to a moist western
hemlock/oak fern ( Gpmnocarpium dr pop ter is) community and then to a
drier and younger western hemlock/queencup beadlily ( Clintonia uni flora)
community (Cooper et al. 1991) with few or no species associated with
moist riparian areas. We observed a few old stumps, likely of the western
white pine (Pinus monticola), indicating some historic logging and associ-
ated burning of the residual logging debris that was scattered across the site
(probably before 1940s), but there has been no recent logging nearby.

Rock outcrops at both falls are green or bluish-gray thinly layered (0.2 to
10 cm) argillite, with occasional thicker layers (10 to 15 cm) of impure
quartzite. Argillite layers generally contain abundant mud cracks and erode
more readily than do the quartzites. Thicker, more resistant quartzites
generally form tops of precipices over which water descends, with less
resistant, thinly layered argillite [which dips back (8° to 12°) into the face of
the cliff] forming undercut faces of cliffs. Rocks on undercut faces are
moderately fractured, slumping forward in places until they are almost
horizontal. On the basis of correlations with previously mapped areas, rock

219

IDAHO BLACK SWIFTS: NESTING HABITAT; SPATIAL ANALYSIS OF RECORDS

outcrops most likely represent the upper Wallace Formation within the
Precambrian Belt Supergroup (Hobbs et al. 1965).

Shadow Falls is about 8 m tall, and the curtain (free falling water no longer
in contact with the cliff) is 5 m high, with the back of the falls cut at about a
45° angle and approximately 2 m deep at the base. The main fall is 4 m
wide, with a more fragmented curtain to 5 m, and the total width of dripping
water is 8 m. Fern Falls is approximately 5 m tall; its curtain is 3 m high with
a backcut similar to Shadow Falls’, and the drip zone is about 12 m wide.

We found four nests, each with one nestling, at Shadow Falls in 1998
(Figure 1). The lowest nest was near the southern edge of the curtain, behind
falling water, and about 3.5 m above the bottom of the falls. The second nest
was about 1 m directly above the first nest, behind the curtain, and about 0.3
m below where the curtain began. A third nestling was 0.75 m due north of
the second nest along a nearly horizontal ledge. The fourth nest was not
behind falling water but about 1.5 m due south of the second nest and
underneath an overhang 5 m deep that extended about 8 m to the
southeast. The single nest and nestling at Fern Falls was only 2 m above the
bottom of the falls near the northern edge of the main curtain (Figure 2).

The dominant micro-community on the wet cliff faces included broom
moss ( Dicranium scoparium), eurhynchium moss (Eurhynchium praelon-
gum), stair step moss ( Hylocomium splendens), leucolepis moss ( Leucolepis
menziesii ), platydictya moss ( Platydictya jungermannioides), big redstem
moss ( Pleurozium schreiberii ), bentleaf moss ( Rhytidiadelpus squarrosus),
snake liverwort ( Conocephalum conicum ), lung liverwort ( Marchantia
polymorpha ), yellow-ladle liverwort ( Scapania bolanderi), lady fern, fragile
fern ( Cystopteris fragilis), western polypody ( Polypodium hesperium), and
oak fern. Nests appeared to be made exclusively from some or all of these
bryophytes.

Currently the site is indirectly protected under the USDA Forest Service’s
conservation protocols that require maintaining the riparian community for
50 m on either side of the creek. The falls are a popular tourist spot, with a
well-maintained trail leading to Shadow Falls. Despite heavy visitation, most
persons we talked with were unaware of nests. Black Swifts have high fidelity
to nest sites (Collins and Foerster 1995, Marin 1997), and our observation
that nearby human activity had no impact on breeding concurs with Foerster
and Collins (1990), although Hirshman (1998) found that nestlings closer to
human activity fledged later than those in less disturbed areas.

Knorr (1961) listed five characteristics of Black Swift nest sites: (1) presence
of moving water; (2) high relief so swifts leaving nests are automatically at
potential foraging altitude above surrounding terrain; (3) inaccessibility to
terrestrial predators; (4) sunlight not reaching occupied nests; and (5) unob-
structed flyways immediately in front of nests. After additional work, Knorr
(1994) concluded that high relief is not a requirement, although the character-
istic is almost invariably present, and added a sixth criterion, the presence of
niches in rocks for nest sites.

Flowing water, inaccessible nests, and unobstructed flyways were present
at both Shadow and Fern falls. Nests at Shadow Falls never received direct
sunlight, but the nest at Fern Falls received about 20 minutes of direct
sunlight around 08:30 the last days of August (J. Acton pers. comm.). Smith

220

IDAHO BlY\CK SWIFTS: NESTING HABITAT: SPATIAL ANALYSIS OF RECORDS

Figure 1. Three Black Swift nestlings behind Shadow Falls. Shoshone Co.. Idaho.

Photo by Dave Holick

221

IDAHO BLACK SWIFTS: NESTING HABITAT; SPATIAL ANALYSIS OF RECORDS

Figure 2. A Black Swift nestling at Fern Falls, Shoshone Co., Idaho.

Photo by Dave Holick

(1928) reported sunlight to shine directly on a California nest site for an hour
in early morning. Because of their location in the bottom of a narrow, steep
valley, neither Shadow nor Fern falls offers immediate high-altitude foraging
for adults. Like some Black Swifts in southern California (Foerster and
Collins 1990), birds at Shadow Falls also flew through a maze of tree
branches when exiting the nesting site (Figure 3; D. Johnson pers. comm.).
The area immediately in front of the nests, however, was unobstructed as
defined by Knorr (1961). Farther upstream of Shadow and Fern falls at
1054 m elevation, we found three additional falls, heights 2, 3.5, and 6 m.
that were characterized by the thicker, more resistant quartzites and lacked
layering and nests. Marin (1997) concluded cypseloidine swifts breed by
water to ameliorate daily temperature changes around the nest and that
Knorr's (1961) other criteria were secondary consequences of nesting near
waterfalls. Our observations imply that high relief and lack of direct sunlight
striking an occupied nest are less important ecological characteristics for
successful Black Swift breeding than the presence of moving water, protec-
tion from terrestrial predators, available niches for nest construction, and
unobstructed fly ways.

Statewide Distribution

As annotated in the appendix, Idaho’s 82 sight records of the Black Swift
are from 34 general locations, shown in Figure 4 against the range of
sedimentary rocks of the Precambrian Belt Supergroup. The 1929 sighting
in latilong 5 probably formed the basis for the species being listed by
Larrison et al. (1967:128) and Larrison (1981 : 171). Except for that sighting

222

IDAHO BLACK SWIFTS: NESTING HABITAT; SPATIAL ANALYSIS OF RECORDS

Figure 3. View directly downstream from Shadow Falls. An adult Black Swift was
observed flying through this forest when leaving the nest,

Photo by Dave Holick

and one in 1973 (latilong 1), all records have been since 1985. Most records
(64, 78%) are from the breeding season. Most breeding-season records
(96%) are from Idaho’s panhandle (latilongs 1 through 5) and associated with
the Precambrian Belt Supergroup (Figure 4).

The three observations from latilongs 7,8, 11, and 13 (15 July, 24 June,
12 June, and 8 July, respectively) probably represent widely dispersed

223

IDAHO BLACK SWIFTS: NESTING HABITAT; SPATIAL ANALYSIS OF RECORDS

Figure 4. Latilongs, Black Swift sighting locations, and distribution of Precambrian
Belt Supergroup sedimentary rocks (shaded areas) in Idaho. If the species has been
sighted in both summer and migration at the same location, only a summer sighting
is indicated. Adapted from our appendix, Stephens and Sturts (1998), and Idaho
Geologic Survey (1978).

224

IDAHO BLACK SWIFTS: NESTING HABITAT; SPATIAL ANALYSIS OF RECORDS

foraging adults. Although the Belt Supergroup is a large formation, south of
the Lochsa River (generally latilongs 7 +) the more highly metamorphosed
Precambrian Belt rocks loose some of their layering as they change into
schist, probably reducing the availability of nesting ledges like those at
Shadow and Fern falls. Spring records from latilongs 17, 19, and 23 are too
early for breeding, and fall records in latilong 17 are probably of migrating
birds since adults and fledglings apparently begin migration immediately
(Marin 1997).

Our observations of nest-site habitat at Shadow and Fern falls and the
prevalence of summer sight records in latilongs 1 to 5 suggest that any
northern Idaho waterfall on sedimentary rock may meet the requirements of
nesting Black Swifts and should be investigated. Additional field work should
enhance our knowledge of the distribution of Black Swifts in Idaho.

ACKNOWLEDGMENTS

We thank Debbie and Niklaas Dumroese, Dave Holick, and Kenneth Quick for their
assistance in describing the nesting site, Charles Collins, Manuel Marin, Owen Knorr,
and Kathy Molina for their editorial suggestions, and the following observers who
shared records: Jim Acton, Nancy Aley, Dan Audet, Vivian Bellemere, Kris Buchler,
Roger Burwell, Jay Carlisle, Bev & Earl Chapin, Rich Del Carlo, Pat Cole, Marty
Collar, Mark Collie, Pam & Gordon Comrie, Brian Cooper, Ellen Dietal, Elise and
Dave Faike, Aubrey Fautheree, Dave Finkelnburg, John Gatchet, Dale Goble, Sarah
Hamilton, R. L. Hand, Fran and Brad Haywood, Winifred Hepburn, Dave Holick,
Don Johnson, Marlin Jones, Barry Kendall, Florence Knoll, Merlene Koliner, Cynthia
Langlitz, Louise LaVoie, Joe Lipar, Matthew Moskwik, Barbara North, Eleanor
Pnaett, Jimmy Reynolds, John Shipley, Paul Sieracki, Jim Spohn, Brian Sturges, 11a
and Dan Svingen, Sue and Peder Svingen, Colleen Sweeney, Charles Swift, Dave
Trochlell, Chuck Trost, Carole Vande Vorde, Fred Vanhove, Wendy Warren, John
Weber, and Susan Weller. When this manuscript was submitted, Kas Dumroese was
with the Department of Forest Resources, University of Idaho, Moscow, and Mark
Mousseaux was botanist on the Idaho Panhandle National Forest.

LITERATURE CITED

American Ornithologists’ Union. 1983. Check-list of North American Birds, 6th ed.
Am. Ornithol. Union, Washington, D.C.

Burleigh, T. D. 1972. Birds of Idaho. Caxton, Caldwell, ID.

Collins, C. T., and Foerster, K. S. 1995. Nest-site fidelity and adult longevity in the
Black Swift (CypseJoides niger). North Am. Bird Bander 20:11-14.

Cooper, S. V., Neiman, K. E. and Roberts D. W. 1991. Forest habitat types of
northern Idaho: A second approximation. U.S. Dept. Agric. Forest Serv. Gen.
Tech Rep. INT-236.

Davis, D. G. 1964. Black Swifts nesting in a limestone cave in Colorado. Wilson Bull.
76:295-296.

Foerster, K, S., and Collins, C. T. 1990. Breeding distribution of the Black Swift in
southern California. W. Birds 21:1-7.

Hirshman, S. 1998. Black Swifts (Cypseloides niger) in Box Canyon, Ouray,
Colorado. J. Colo. Field Ornithol. 32 (2):53-60.

Hobbs, S. W., Griggs, A. B, Wallace, R. E., and Campbell, A. B. 1965. Geology of the

225

IDAHO BLACK SWIFTS: NESTING HABITAT; SPATIAL ANALYSIS OF RECORDS

CoeurdAlene District, Shoshone County, Idaho. U.S. Dept. Interior Geol. Surv.
Prof. Paper 478.

Holroyd, G. L., and Holroyd, W. M. 1987. The Black Swift nest at Maligne Canyon,
Jasper National Park. Alberta Nat. 17:46-48.

Hunter, W. F., and Baldwin, P. C. 1962. Nesting of the Black Swift in Montana.
Wilson Bull. 74:409-416.

Hunter, W. F., and Baldwin, P. C. 1972. Black Swift nest in Glacier National Park.
Murrelet 53:50-51.

Idaho Geologic Survey. 1978. Geologic Map of Idaho (1:500,000).

Knorr, O. A. 1961 . The geographical and ecological distribution of the Black Swift in
Colorado. Wilson Bull. 73:155-170.

Knorr, O. A. 1994. Black swift nesting site characteristics: Some new insights.
Avocetta 17:139-140.

Kondla, N. G. 1973. Nesting of the Black Swift at Johnston’s Canyon, Alberta. Can.
Field-Nat. 87:64-65.

Larrison, E. J. 1981. Birds of the Pacific Northwest. Univ. Idaho Press, Moscow, ID.

Larrison, E. J., Tucker, J. L., and Jollie, M. T. 1967. Guide to Idaho Birds. J. Idaho
Acad. Sci. 5.

Marin, M. 1997 . Some aspects of the breeding biology of the Black Swift. Wilson Bull.
109:290-306.

Marin, M. 1999. Food, foraging, and timing of breeding of the Black Swift in
California. Wilson Bull. 111:30-37.

Nesser, J. A., Ford, G. L., Maynard, C. L. and Page-Dumroese, D. S. 1997.
Ecological units of the northern region: Subsections. U.S. Dept. Agric. Forest
Serv. Gen. Tech. Rep. INT-GTR-369.

Smith, E. 1928. Black Swifts nest behind a waterfall. Condor 30:136-138.

Stephens, D. A., and Sturts, S. H. 1998. Idaho bird distribution. Idaho Mus. Nat. Hist.
Spec. Publ. 13.

Svingen, D., and Trochlell, D. 1998. Idaho-western Montana region. Field Notes
52:93-95.

Vrooman, A. G. 1901. Discovery of the egg of the Black Swift Cypseloides niger
borealis. Auk 18:394-395.

Accepted 12 January 2000

APPENDIX — Idaho Black Swift Sightings

See Figure 1 for latilongs. Abbreviations: American Birds (AB), National Audubon
Society Field Notes (FN), North American Birds (NAB), National Wildlife Refuge
(NWR), breeding bird survey (BBS).

Latilong 1 — Boundary Co. Smith Creek drainage (T64N R3W Sec. 4): 1 on 6
Jun 1998. Kootenai NWR: 1 on 20 Jun 1985, 20 during summer 1985 (AB 39:940,
1985), 1 on 16 May 1986, 12 on 20 Jul 1986, 1 on 1 Jun 1988, 20 on 13 Jun
1998, 5 on 24 Jun 2001. Along Farnham Creek (T64N R1W Sec. 33 & 34): 1 seen
often during Jun 1998. Westside Road near Copeland Bridge: 1 with 200 Vaux’s
Swifts 29 Aug 1997. Myrtle Creek Road (T62N R1W): 4 on 15 Jul 1998. Naples
BBS (IDA-001) following Westside Road between Myrtle and Trout creeks: 3 on 11
Jun 1973, 7 on 12 Jun 1988, 6 on 11 Jun 1989, 1 on 23 Jun 1990, 2 on 30 Jun

226

IDAHO BLACK SWIFTS: NESTING HABITAT; SPATIAL ANALYSIS OF RECORDS

1994, 7 on 15 Jun 1997. Pack River Road at Upper Pack River Bridge: 2 with 4
Vaux’s Swifts on 7 Aug 1993. Bonner’s Ferry: 1 on 19 Jun 1989. McArthur Wildlife
Management Area: 1+ on 27 Jul 2000. Bonner Co. Upper Grouse Creek Road: 4
to 6 above 1220 m elevation during Jun and Jul from 1988 through 1994. Clark Fork
River between Clark Fork and the Cabinet Gorge Dam on the Montana border: 25+
on 6 and 24 Jun 1985 (AB 39:940, 1985), 2 on 10 Aug 1985, 1 on 13 Aug 1985
(Idaho Rare Bird Committee 3-88), 2 on 23 Jul 1986 (AB 40:1231, 1986), 4 to 6
each summer from 1988 through 1996. North of Clark Fork along Lightning Creek
(T56N R2E Sec. 13): 11 with Vaux’s Swifts on 16 Jun 1989 (AB 43: 1344," 1989),
“many” on 13 Jun 1991. Schweitzer ski area, Sandpoint: 2 soaring on 18 Jul 1997.
Along the Priest River north of Priest River: 6 Jun 2001.

Latilong 2 — Kootenai Co. North shore Lake Coeur d’Alene in Coeur d’Alene: 1
dead female on 28 May 1998 (Idaho Museum of Natural History 2643), Shoshone
Co. North Fork Coeur d’Alene River near Cinnamon Creek (T52N R3E): 2 on 31
May 1989, 1 with Vaux’s Swift on 1 Jun 1997 (FN 51:1025, 1997), 1 on 30 Aug

1997. North Fork Coeur d’Alene River, Shadow and Fern falls (T51N R3E Sec. 20):
5 including 3 and 1 nestlings, respectively, on 28 and 30 Aug 1997 (FN 52:95,
1998), Fern Falls nestling photographed clinging vertically to its nest was erroneously
published horizontally (FN 52:143, 1998), 1 adult on a Shadow Falls nest on 8 Jun

1998, 1 adult on 22 and 23 Jun 1998, 5 nestlings (4 at Shadow Falls and 1 at Fern
Falls) 26 Aug 1998 (NAB 53:80, 1999), 4 nestlings (3 at Shadow Falls and 1 at Fern
Falls) on 27 Aug 1999; 3 nestlings at Shadow Falls on 9 Aug 2000; 4 nestlings (3 at
Shadow Falls and 1 at Fern Falls) on 24 Aug 2001.

Latilong 3 — Shoshone Co. Middle Sister Lookout: 1 flew by at 2040 m on 4 Aug

2000 .

Latilong 4 — Nez Perce Co. Lewiston Orchards: 5 or 6 on 27 May 1980.

Latilong 5 — Idaho Co. Lochsa River, Wilderness Gateway Campground: 1 on 14
Jul 1984, 3 on 12 Jun 1987, 5 on 17 Jun 1989 (Boulder Creek, T35N R9ESec. 34;
AB 43:1344, 1989), 5 on 20 Aug 1990, 1 on 5 and 6 Jun 1993, 3 on 27 Jul 1997
(FN 51: 1025, 1997). Selway River 64 km west of Lolo Pass: 1 with 8+ Vaux’s Swifts
on 30 Jul 1993. Confluence of Lochsa and Selway rivers: mouth of Pete King Creek:
1 foraging low with Vaux’s Swifts during stormy weather on 17 Jun 1929; Johnson
Bar: 1 with 10 Vaux’s Swifts on 28 Jul 1993.

Latilong 7 — Idaho Co. Joseph Plain along Billy Creek Road (about T29N & T30N
R1W): 1 on 15 Jul 1989 (AB 43:1344, 1989).

Latilong 8 — Idaho Co. Warren, Burgdorf BBS (IDA-208): 4 on 24 Jun 1989.

Latilong 10 — Although Stephen and Sturts (1998) indicated a migration record, no
data confirm it, and this is most likely a typographical error.

Latilong 11 — Valley Co. Bear Basin, McCall: 2 on 12 Jun 2000 (NAB 54:402,

2000 ).

Latilong 13 — Custer Co. Spar Canyon, 25 km south of Challis: 1 with a few
White-throated Swifts flying around a 120-m east-oriented cliff on a south-facing
slope at 1850 m elevation 8 Jul 1984.

Latilong 17 — Canyon Co. Deer Flat NWR: 1 flew under low clouds and over the
New York Canal at Lake Lowell on 5 Sep 1992 (AB 47:122, 1993). Ada Co. Lucky
Peak Bird Obseiwatory (T3N R3E Sec. 11): 30 to 35 on 25 Sep 1997 (FN 52:95,
1998); 3 on 10 Sep 2001. Boise: 3 on 4 Jun 1999 (NAB 53:412, 1999); 2 on 5 Sep
2000 (NAB 55:76, 2001). Owyhee Co. Near C.J. Strike Dam: 1 on 13 Oct 2000
(erroneously published as Elmore Co. in NAB 55:76, 2001).

Latilong 19 — Blaine Co. Hailey: 1 about 8 m above the ground in a mixed flock
of swallows at dusk on 2 May 1998 (erroneously published as 24 May in FN 52:361,
1998).

Latilong 23 — Owyhee Co. Owyhee River: 2 on 1 Jun 1984.

227

NOTES

DETECTIONS OF CALIFORNIA BLACK RAILS IN
THE COLORADO RIVER DELTA, MEXICO

OSVEL HINOJOSA-HUERTA and WILLIAM W. SHAW, 104 Biological Sciences
East, School of Renewable Natural Resources, University of Arizona, Tucson, Arizona
85721

STEPHEN DeSTEFANO, U. S. Geological Survey, Massachusetts Cooperative Fish
and Wildlife Research Unit, Holdsworth Natural Resource Center, University of
Massachusetts, Amherst, Massachusetts 01003

Populations of California Black Rails ( Laterallus jamaicensis coturniculus ) have
been drastically reduced in western North America over the last several decades
(Repking and Ohmart 1977, Evens et al. 1991). The California Black Rail is listed as
threatened by the California Department of Fish and Game and is considered a
“species of concern” by the U.S. Fish and Wildlife Service (www.dfg.ca.gov/endan-
gered/birds.html). In Mexico, the California Black Rail is listed as endangered (Diario
Oficial de la Federation 2000). Current management of the lower Colorado River,
including the difficulty maintaining shallow and stable water levels at potentially
suitable wetlands, is the critical factor limiting the distribution of Black Rails inland
(Eddleman et al. 1994). Black Rails were first detected in the Colorado River delta in
1998, at the Cienega de Santa Clara (Piest and Campoy 1999), despite rail surveys
having been conducted there in the 1980s and early 1990s (Abarca et al. 1993,
Eddleman et al 1994). Evens et al. (1991) speculated that Black Rails were absent
from these wetlands because of massive habitat degradation. The purpose of our study
was to assess the presence or absence of Black Rails in the remnant wetlands of the
Colorado River delta, Baja California and Sonora, Mexico.

Our surveys were focused in the Cienega de Santa Clara, at about 5800 ha the
largest marsh in the delta. This wetland lies within the Upper Gulf of California and
Colorado River Delta Biosphere Reserve. Other surveyed areas were Hardy River, El
Mayor River, Pescaderos River, Riito Drain, Cucapa Complex, El Indio Lagoon, El
Doctor wetlands, and Eastern Drains (Figure 1). The surveyed wetlands included
emergent marshes fed by agricultural runoff and natural springs. Vegetation was
dominated mostly by cattail ( Typha domingensis), with common reed (Phragmites
australis ), bulrush ( Scirpus spp.), saltcedar ( Tamarix ramosissima), and salt grasses
( Distichlis spp.) present also. Glenn et al. (2001) described each wetland.

We conducted call-response surveys from March to June 2000 during Yuma
Clapper Rail ( Rallus longirostris yumanensis ) surveys (Hinojosa-Huerta et al. 2001).
After completing the Yuma Clapper Rail survey protocol, we played taped vocaliza-
tions of California Black Rails for 2 minutes, followed by a silent period of 2 minutes
in which we recorded all responding individuals. The tape included two types of calls
(starting with kickee-doo, followed by grunt vocalization) arranged in a 1-minute loop.
Surveys started at sunrise and continued no later than 1030. Survey stations were
circular plots (30-m radius) located at least 200 m apart and grouped into routes. We
visited each station once during the early breeding season (11-17 March) and again
during late breeding season (18-22 May). We selected the location of the routes in the
Cienega de Santa Clara randomly (16 routes, 173 stations, covering about 9% of the
total area of the cienega). Other wetlands considered potential habitat were much
smaller, and we placed routes in them nonrandomly to maximize coverage of these
areas (8 routes, 55 stations).

228

Western Birds 32:228-232, 2001

NOTES

Key to Features

Colorado River

Handy River

El Mayor River

Laguna del Indio

Cienega de Santa Clara

El Doctor

•

Detections of Black Rails

f\J Streams

/\,

' Levee

] Wetland areas

Wetlands

1 - Riparian corridor

2 - Hardy - El Mayor

3 - Floodplain

4 - Laguna del Indio - Eastern Drains

5 - Cienega de Santa Clara - El Doctor

Figure 1. Wetland areas where California Black Rails were detected in the Colorado
River delta, Baja California and Sonora, Mexico.

We detected a total of 19 Black Rails at 18 survey stations (3.94 % of the surveyed
stations) during the two survey periods (Figure 2). Most were located in the Cienega de
Santa Clara, where we detected 10 Black Rails at nine stations (5.20% of the surveyed
stations) during early breeding season and six at six stations (3.46% of the surveyed
stations) during late breeding season. All of the detections in the late breeding season
were >500 m away from any detection in the early breeding season (Figure 2). Cattail
was the dominant vegetation (>50% of vegetation cover) at all stations where Black
Rails were detected in the cienega. Bulrush was an important vegetation feature

229

NOTES

^ Detections of black rails

during early breeding season

# Detections of black rails

during late breeding season

Open water

Marsh

Figure 2. Survey stations where California Black Rails were detected in the Cienega
de Santa Clara, Sonora, Mexico during 2000.

(>15% of the vegetation coverage) at five of these stations, saltcedar only at two.

We detected three Black Rails at other wetlands in the delta during March (early
breeding season) (present at 5.45% of the surveyed stations). One individual was along
El Mayor River in a shallow (12-30 cm) agricultural drain dominated by cattail. A
second Black Rail was at El Doctor wetlands in Sonora, which are maintained by
natural springs. This area has constant shallow water throughout the year, and its
vegetation is dominated by bulrush. The third individual was at El Indio Lagoon, Baja
California, a recently restored wetland supported by agricultural drainage water,
dominated by saltcedar but with substantial cattail. We detected no Black Rails at

230

NOTES

Hardy River, Pescaderos River, Riito Drain, Cucapa Complex, or Eastern Drains. This
absence may be related to the dominance of saltcedar and the lack of a constant
source of water at these wetlands (Hinojosa-Huerta 2000).

California Black Rails were scarce and located at only a few sites in the Colorado
River delta during our surveys in 2000. However, these detections document
California Black Rails occurring in these wetlands during the breeding season. These
sites should be monitored for changes in the population, with a survey design specific
for the subspecies, to avoid potential disruption caused by other procedures (e.g.,
eliciting taped calls of Yuma Clapper Rails). An optimum protocol to survey California
Black Rails should follow recommendations by Spear et al. (1999), although further
research is needed. The sequence of calls in the survey tape should be reassessed, as
the kickee-doo call may interfere with the grunt vocalization (M. Legare pers. comm.).

The subspecies should be included in management plans for the biosphere reserve,
with specific practices to enhance or restore Black Rail habitat. Our results indicate
that there is potential in agricultural drainage water and remnant wetlands in the delta
for the conservation of the subspecies. This information should be considered in the
development of conservation and recovery plans for inland populations.

This research was funded by the U.S. Fish and Wildlife Service, Region 2,
(agreement number 1448-20181-98-G942), through the Arizona Cooperative Fish
and Wildlife Research Unit. We thank Lin Piest, Jose Campoy, and Martha Roman for
their continuous help throughout the project. Jules Evens, Robert A. Hamilton,
Michael Legare, and Philip Unitt made helpful comments on an earlier draft.

LITERATURE CITED

Abarca, F. J,, Ingraldi, M. F., and Varela-Romero, A. 1993. Observations on the
desert pupfish (Cyprinodon macutarius), Yuma Clapper Rail (Ratlus iongirostris
yumanensis), and shorebird communities in the Cienega de Santa Clara,
Sonora, Mexico. Nongame and Endangered Wildlife Program Tech. Rep., Ariz.
Game and Fish Dept., 2221 West Greenway Road, Phoenix, AZ 85023-4312.

Diario Oficial de la Federacion. 2000. PROY-NOM-059-ECOL-2000 16/OCT/
2000 Protection ambiental — Especies de flora y fauna silvestres de Mexico. —
Categorias de riesgo y especificaciones para su inclusion, exclusion o cambio. —
Lista de especies en riesgo. Secretaria de Gobernacion, Mexico, D.F.

Eddleman, W. R,, Flores, R. E., and Legare, M. L. 1994. Black Rail ( Laterallus
jamaicensis), in The Birds of North America (A. Poole and F. Gill, eds.), no 123.
Acad. Nat. Sen, Philadelphia.

Evens, J. G., Page, G. W., Laymon, S. A., and Stallcup, R. W. 1991. Distribution,
relative abundance, and status of the California Black Rail in western North
America. Condor 93:952-966.

Flores, R. E., and Eddleman, W. R. 1995. California Black Rail use of habitat in
southwestern Arizona. J. Wildlife Mgmt. 59:357-363.

Glenn, E. P., Zamora- Arroyo, F., Nagler, P. L., Briggs, M., Shaw, W., and Flessa, K.
2001. Ecology and conservation biology of the Colorado River delta, Mexico. J.
Arid Env. 49:5-15.

Hinojosa-Huerta, O. 2000. Distribution, abundance, and habitat use of the Yuma
Clapper Rail ( Rallus Iongirostris yumanensis ) in the Colorado River delta,
Mexico. M.S. thesis, Univ. of Ariz., Tucson.

Hinojosa-Huerta, O., DeStefano, S., and Shaw, W. 2001. Abundance and distribu-
tion of the Yuma Clapper Rail (Rallus Iongirostris yumanensis) in the Colorado
River delta, Mexico. J. Arid Env. 49:171-182.

231

NOTES

Piest, L., and Campoy, J. 1999. Report of Yuma Clapper Rail surveys at the Cienega
de Santa Clara, Sonora, 1998. Ariz. Game and Fish Dept., Yuma Regional
Office, 9140 E. County IOV 2 St., Yuma, AZ 85365.

Repking, C. F., and Ohmart, R. D. 1977. Distribution and density of Black Rail
populations along the lower Colorado River. Condor 79:486-489.

Spear, L. B., Terrill, S. B., Lenihan, C., and Delevoryas, P. 1999. Effects of temporal
and environmental factors on the probability of detecting California Black Rails.
J. Field Ornithol. 70:465-480.

Accepted 27 September 2001

232

BOOK REVIEWS

Birds of North America, Western Region, by Fred J. Alsop, III. Smithsonian
Handbooks, DK Publishing, New York. Paperback, $24.95. ISBN 0-7894-7157-4.

“Until now, no tool for identifying birds has also provided access to information on
behavior, nesting, flight patterns, and similar birds in a compact and user-friendly
format.” So proclaims the introduction to Birds of North America, Western Region
(hereafter BNAW), and that this book is written for novices and for experienced
birders. How does it uphold these claims?

The subject matter of BNAW is birds recorded west of the 100th meridian, north of
Mexico. A brief introduction explains how to use the book (e.g., the numerous icons),
including sections on watching birds and conservation. The introduction is not free of
miscues: the “Ruby-throated Hummingbird” photo (p. 13) is of a Plain-capped
Starthroat, and in the abundance and distribution terms (pp. 24-25) the European
Starling is “abundant,” while the Cattle Egret is “exotic,” and the Antillean Nighthawk
(unknown in the West) is “rare.” Single-page accounts follow for 696 species, in the
latest AOU sequence. Each has one or two color photos (or paintings), a small color
map, and various other information conveyed by text (song, behavior, breeding,
nesting, population) or icons (flight pattern, nest identification, habitat). A small box
covers similar species. The book concludes with a list of 80 “accidental” species, a
glossary, and an index.

I have yet to see an identification guide that works well for all levels. In regard to
BNAW, I doubt a beginner wants to wade through many pages of species he will never
see in an attempt to identify a bird in his yard. Advanced birders will be frustrated (or
amused) by the concept and execution: e.g., criteria for which species are addressed
in accounts appear purely whimsical: included are the Streaked (but not Manx)
Shearwater, Red-tailed (but not Red-billed) Tropicbird, Great Knot (but not Ruff!), and
so on. Illustrations are the crux of any identification guide, yet one full-color photo of
a Red-throated Loon or Sanderling in breeding plumage is unlikely to help beginners
identify these species during most of the year. Photos generally have been trimmed to
the bird’s outline, but some retain an unappealing and distracting color outline (e.g.,
the Great Egret and Baird’s Sandpiper), and many are of birds in poses unhelpful for
identification. The paintings appear to have come from “professional” design people
unfamiliar with avian anatomy or live birds. I didn’t search for misidentified photos but
the female “Rufous” Hummingbird is a Lucifer, and the White Wagtail is not of the
Alaskan subspecies ocularis.

The text is of little substantive value for field identification. For other topics (such as
behavior and nesting) it contains much that is accurate, but little reflects first-hand
experience. An eastern bias is pervasive, and the editing is poor. Equally good or
better life-history summaries can be found in The Birder’s Handbook by Paul Ehrlich
et al, (Simon and Schuster, 1988, whence much information in BNAW appears to
have been copied directly) or Kenn Kaufman’s Lives of North American Birds
(Houghton Mifflin, 1986). For field-identification use the Sibley, National Geographic
Society, or Kaufman guides, which are all excellent, well-conceived, and together
cater to the full spectrum of birders. You’d be unlikely to take BNAW afield (it’s heavy,
at 8.5" x 5.5" x 1.75”), so having two or more useful books at home would be better
than having this one.

BNAW appears to be a well-intentioned but poorly executed attempt to combine
life-history information with identification. Usually I donate review copies to a library,
but in this case I’ll recycle my copy when this review is finished.

Steve N. G. Howell

Western Birds 32:233-236, 2001

233

BOOK REVIEWS

Isles of Refuge, by Mark J. Rauzon. 2001 . University of Hawaii Press, Honolulu.
206 pp., 97 color and 46 black-and-white photos, 21 illustrations, 11 maps.
Paperback, $29.95. ISBN 0-8248-2330-3.

You are on a May pelagic trip off Bodega Bay. You reach the continental shelf, and
suddenly the chummed-in fray is joined by one, two, 25, 50, perhaps even 500
incoming bombers: majestic, graceful Black-footed Albatrosses splay their feet and
eagerly scatter the screeching gulls in search of a morsel of popcorn or suet. Some of
them have bleached heads, some are in fresh plumage, some have begun their molt,
others have tattered wings. A few wear metal or color bands around one or both legs.
You wonder whence they have traveled that day or that week. As was discovered
recently through satellite transmitters, the answer is quite astounding: the bleach-
headed birds are tending chicks over 5000 km away in the northwestern Hawaiian
Islands. They have ridden the winds on a quick grocery run to the California coast. You
wonder what kind of place can produce such marvels of the sea.

Aptly named, Isles of Refuge takes you on a sun-drenched cruise through the atolls
and pinnacles of the Black-footed Albatross and many other tropical seabirds.
Although making up less than 0. 1% of Hawaii’s land area, the northwestern Hawaiian
Islands span a distance of more than 1600 km, over twice that of the populated or
“main” Hawaiian Islands. As the Pacific plate moves over Hawaii’s volcanic hotspot,
lands are created, eroded, submerged, maintained by surface-reaching coral, and
finally extinguished as they reach “Darwin’s Line” at 29° N. The northwestern islands
consist of five remnant rocky volcano tops (e.g., Nihoa, Laysan, and Gardner
Pinnacles) and six coral atolls (e.g., French Frigate Shoals, Midway, and Kure), the
latter graced with shifting snow-white sands, sparse native vegetation, and impossibly
blue lagoons. These remote islands have a rich and storied human history, culminating
in their protection as national fish and wildlife refuges and Hawaii state refuges. But
it is the stunning images and insights into the spectacular natural history of Isles of
Refuge that will be of interest to the readers of Western Birds.

The book is divided into 22 chapters. Those on each of the island groups are
interspersed with others covering the biology of keystone species (such as the
“goonies,” Monk Seal, and Green Sea Turtle), vertebrate and subtidal ecology,
conservation concerns and initiatives, personal stories, and human campaigns. The
last range the spectrum from a voyage of the native Hawaiian canoe Hokule’a to
Nihoa in search of sacred Polynesian sites to the battle of Midway. Being a writer,
photographer, and ornithologist, Rauzon shares with the reader a unique understand-
ing and perspective of this important biological reserve. You learn how it is to be a
biologist “stranded” for months at a time with little but the wind, waves, and seabirds
to keep you company: “It was OK when the goonies talked to you, but when you
understood what they said, it was time to leave.” You gain an appreciation for the
spiritual ways and poetic views of the kamaaina, or peoples of Hawaii. You contrast
this with the bungling, shipwrecking, murderous, warring, and ecologically apocalyp-
tic exploitations of the haoles and other foreign visitors of the nineteenth and early
twentieth centuries. Most important, you see hope in recent efforts to study the
resident species, eradicate alien flora and fauna, and restore the islands to their native
constituents.

Beautifully written, entertaining, and with few miscues (fans of Pink Floyd will
cringe at the reference to “Dark Side of the Sun”), I fully recommend Isles of Refuge
to those with an interest in the seabirds and ecology of the tropical Pacific.

Peter Pyle

234

BOOK REVIEWS

Bird Songs of Southeastern Arizona and Sonora, Mexico by Geoffrey A.
Keller. 2001. Library of Natural Sounds, Cornell Laboratory of Ornithology. Set of 2
compact disks; $24.95. ISBN 0-938027-58-1.

This fine set of recordings appears to be part of a series from Cornell that, to date,
has covered Alaska (1999), the Rocky Mountain states and provinces (1999; reviewed
in W. Birds 31:64), and the lower Rio Grande valley and southwestern Texas (2000).
The compilation reviewed here contains vocalizations from 151 “Arizona species”
(those with “at least one confirmed breeding record in the state” — although, appar-
ently, a nest with two eggs of the Rufous-capped Warbler [Rosenberg and Witzeman
1999. W. Birds 30:94-120] does not qualify) and a further 51 “Sonora species,”
including some that stray rarely to southeastern Arizona (e.g., the Plain-capped
Starthroat and Yellow Grosbeak). As with other works in this series, the selection of
species is somewhat eclectic with no stated reason for inclusion or omission. For
example, included are the Sharp-shinned Hawk but not the Red-tailed, the Eastern
Meadowlark but not the Western. Nonetheless, apparently all of the “southeastern
Arizona specialties” are included, which may be the main focus for most potential
buyers. Species are arranged in AOU (1998 checklist) sequence, but the 42nd
checklist supplement (2000) was not followed, e.g., the Arizona Woodpecker ( P.
arizonae ) remains as Strickland’s Woodpecker ( P. stricklandi). An accompanying
booklet provides context for most vocalizations and also gives the location of each
recording (at the state level only, see below). The booklet includes many written
transcriptions and often articulates helpful pointers for distinguishing vocalizations of
similar-sounding species. Regional or subspecific variation in song is mentioned for
some taxa, e.g., the Southwestern Willow Flycatcher ( E . t. extimus) and Eastern
Meadowlark (S. m. lilianae), but not for others, e.g., the Northern Pygmy-Owl or
White-breasted Nuthatch.

The recordings are, almost without exception, of superb quality which, ironically,
makes some sound “unnatural,” because ambient noise we usually hear in the field is
lacking. Among many possibilities, one can make useful comparisons of the songs of
the Bendire’s, Curve-billed, Crissal, and Le Conte’s thrashers, or of the calls of the
Ladder-backed, Hairy, and Arizona/Strickland’s woodpeckers. The three southwest-
ern Myiarchus flycatchers are included, as is the Nutting’s Flycatcher from Sonora,
and other notable species included are the White-throated and Pine flycatchers and
Black-capped Gnatcatcher. Other species are sometimes audible in the background
but, although not identified, are unlikely to be confused with the featured species.

The following observations are intended as constructive comments to be consid-
ered for future editions and other works in this series and, I acknowledge, are for the
most part niggling relative to the overall scope and quality of this undertaking. My
main complaint is that the date and location are not provided for each cut, although,
according to the booklet’s introductory material, such information can be requested.
Nonetheless, in an age when appreciation of geographic variation with respect to
subspecies (or even local dialects) is growing, the addition of date and location data
should be mandatory and, with forethought, would not take up much space in the
booklet. Instead, locations are given only at the state or province level, and without
date. More than one subspecies can breed in a state, however, and subspecies not
breeding in a region can sing during migration. Related to this, 25% of the “Arizona”
species were recorded outside that state, as were many additional cuts for other
species. Consequently the title is somewhat misleading and might more accurately
read “Songs and calls of birds that occur in southeastern Arizona....” Surely there are
recordings from Arizona of the Common Raven or Brown Creeper? The flight call of
the male Brown-headed Cowbird is renowned for its geographic variation (the cut
included is from Oregon), and the vocalizations of Berylline Hummingbird (from
Chiapas, southern Mexico) pertain to a very different subspecies and are unlikely to be
of much help in Arizona.

235

BOOK REVIEWS

I recognize that the vocal repertoires of very few species are completely known, let
alone represented by recordings. In particular, this might pertain to the Mexican
species on these CDs — and can highlight where field work needs to be directed — but
for other species I would hope that fuller ranges of sounds could be found, and of the
relevant subspecies. For example, no drum is included for the Ladder-backed
Woodpecker, and the peek call of the Hairy Woodpecker is from an Oregon
subspecies. Some calls I hear commonly from several species are not included in the
cuts, e.g,, the chup call of a Hermit Thmsh or the Berylline Hummingbird’s diagnostic
buzz call. Several vocalizations sound as if birds were agitated (perhaps by playback or
near the nest?), e.g., the unusually persistent (and “atypical”) Flame-colored Tanager
calls. If birds were responding to playback this could be noted; the resulting vocaliza-
tions are still “natural” but may not be those heard under most field conditions.

The distinction between a “song” and a “call” is, of course, rather anthropomor-
phic and often somewhat subjective, but the Gray-collared Becard’s so-called “song”
sounds like an infrequently heard “agitation call,” while the second cut is an attenuated
version of this species’ typical “territorial song.” Users should also be aware that the
booklet’s text sometimes compares non-analogous vocalizations. This could lead to
mistaken beliefs that some species’ calls are quite different, e.g., the calls provided for
Northern Cardinal (from Honda) and Pyrrhuloxia. Alternatively, the Eared Trogon’s
voice is reportedly “very different from that of the Elegant Trogon.” True enough, but
the relevant cuts compare Elegant Trogon “songs” with non-analogous “calls” of the
Eared.

My final observation, having been involved in some of the in-progress review work,
is that the completed CDs and booklet appear not to have been subjected to final
review — an important step not to overlook. Thus, although I am credited with
reviewing the Mexican species for authenticity I was surprised to see the inclusion of
the Maroon-fronted Parrot (endemic to northeast Mexico!) under the Thick-billed
Parrot (the Nuevo Leon cut). Also note the “Common Black Hawk” from “Costa Rica:
Puntarenas,” which, on geographic grounds, seems more likely to have been a
Mangrove Black Hawk (split by the AOU if not by Middle American authorities, e.g.,
see Stiles and Skutch, 1989, A Guide to the Birds of Costa Rica). The booklet also
could have benefited from a copy-editing check for grammar, but, all in all, my
comments and complaints are minor set against the fine resource that Geoff Keller
and Cornell have produced. Anyone interested in the songs and calls of North
American and Mexican birds should own these CDs and, if possible, help fill in gaps
to make future editions more comprehensive.

Steve N. G. Howell

236

FEATURED PHOTO

AN UNUSUAL PLUMAGE VARIANT
OF THE HEERMANN’S GULL

KIMBALL L. GARRETT, Section of Vertebrates, Natural History Museum of Los
Angeles County, 900 Exposition Blvd., Los Angeles, California 90007

Minor individual plumage variation in gulls is one of many factors confounding field
identification of this notoriously difficult group. Plumage variation can sometimes take
the form of more extreme anomalies such as leucism and albinism (Grant 1986). A
well-known variant of the Heermann’s Gull, Larus heermarmi, shows patches of
white on the greater primary-coverts (Hubbs and Bartholomew 1951), as depicted,
for example, by Sibley (2000); some individuals have additional white on other wing
coverts, scapulars, or remiges (pers. obs.). White primary-covert patches occur in
0.01% (Hubbs and Bartholomew 1951) to 0.5% (Sibley 2000) of Heermann’s Gulls.
I photographed a different Heermann’s Gull variant in Santa Barbara, Santa Barbara
County, California, on 16 January 2000 (see back cover).

Typical of leucistic or albinistic gulls (Grant 1986), the Santa Barbara bird shows
bare parts (bright red basal four-fifths of bill and thin red orbital ring) that are normally
pigmented and in this case suggest that the bird was an adult in definitive plumage.
The normal dark grays of the body plumage have been replaced by paler gray (many
upperwing coverts and scapulars) or creamy white (underparts, center of back, greater
secondary coverts, and tertials). Other photographs not reproduced here show pale
gray underwing coverts and confirm that the normally blackish areas of the remiges
and rectrices were dusky brown (secondaries, incoming inner two primaries, dark
areas of rectrices) to pale brown (outer eight primaries, which are presumably faded).
Active primary molt in Heermann’s Gulls generally commences in May (S. N. G.
Howell pers. comm.), so this individual is anomalous in this regard, as well as in its
pigmentation. The pure white head indicates definitive alternate plumage, which is
typically acquired between November and January (S. N. G. Howell pers. comm.,
contra Dwight 1925).

The bird is at least 2.5 to 3.5 years old and thus may have survived into adulthood
in this leucistic plumage; alternatively, it bore normal subadult plumages and exhibited
leucism only in its first (or a subsequent) definitive plumage. In this case a suite of
characters including size, shape, and, most importantly, bare-part coloration makes
the identification of this unusual variant simple. However, varying degrees of leucism
shown by other gulls, in particular the large white-headed gulls of the northern
hemisphere, can lead to difficult or intractable field-identification problems.

I thank Steve N. G. Howell and Philip Unitt for comments that improved the
manuscript.

LITERATURE CITED

Dwight, J. 1925. The gulls (Laridae) of the world; their plumages, moults, variations,
relationships and distribution. Bull. Am. Mus. Nat. Hist. 52:63-401.

Grant. P. J. 1986. Gulls, A Guide to Identification, 2nd ed. Buteo Books, Vermillion,
■SD.

Hubbs, C. L., and Bartholomew, G. A., Jr. 1951. Persistence of a rare color
aberration in the Heermann Gull. Condor 53:221-227.

Sibley, D. A. 2000. The Sibley Guide to Birds. Knopf, New York.

Western Birds 32:237, 2001

237

PRESIDENT S MESSAGE

At our annual meeting in Reno last fall your WFO board of directors made several
important decisions aimed at improving the quality of our journal, increasing our
appeal to a broader range of field ornithologists and ensuring the continued financial
health of your organization, Western Birds has and always will be the primary focus
of WFO, and we continue to work for its improvement. The publication fund we
established about a year ago is the primary tool for this objective, and to that end we
have substantially increased the amount in the fund. In the most recent issue of
Western Birds we appealed for donations to the publication fund, and you have been
both quick to respond and generous with your gifts. For those of you who have already
responded we are pleased and very grateful. If you have not yet sent us your
contribution please consider doing so. The recent WFO-sponsored trip to Yucatan,
Mexico, led by Steve Howell and David Yee was a great success, and the tour
participants also contributed generously to the publication fund. Because of your
generosity we expect in the near future to publish more color photographs in the
journal and continue our series of monographs. Thank you all for your support!

Since its inception 31 years ago the WFO board of directors has been made up of
nine members. Both to improve the balance of the board and to increase our appeal
to a broader constituency we changed the WFO by-laws to increase the membership
to 12. The board is currently well represented by top field ornithologists and experts
from wildlife agencies. While maintaining our focus on field ornithology, we hope to
improve the board by filling the new positions with members who have experience
and expertise in the areas of law, marketing, and fund raising. If any of you have some
of these qualifications I invite you to join the board. If you are interested you should
submit your name and biography to the nominations committee, chaired by Dave
Krueper, or to Dave Shuford or Gjon Hazard who also serve on the committee.

In the past few months there have been several changes among key positions in
WFO. For nearly nine years Dori Myers has served as your treasurer and membership
chair. This is a very important responsibility in WFO, and Dori has served us very well
for all those years. It was with great reluctance that we accepted her resignation at the
last board meeting. Fortunately, Robbie Fisher has stepped in as her replacement, and
recently the transition from Dori to Robbie was completed in a smooth and timely
manner. At about the same time Lucie Clark resigned as recording secretary, but we
were very fortunate that Kei Sochi has stepped forward to fill that position. To
represent the Great Basin region better the newest member elected to the Board is
Ted Floyd from the Great Basin Bird Observatory, who replaces Mark Sogge from
Arizona. Thanks to all who have served us so well, and welcome to the new officers
and board members.

The annual WFO meetings continue to improve and grow in appeal to our
membership. The upcoming meeting in Orange County should prove to be no
exception. Under the fast-paced and very capable leadership of Catherine Waters
from Sea and Sage Audubon, our co-sponsor, the meeting is shaping up to be one of
the best ever. It will include a Friday evening barbecue and feature the great seabird
expert Bob Pitman as our banquet speaker. The field trips should appeal to every level
of interest among birders and include a wide variety of destinations. For the meeting,
we have booked a first-class facility, the Ayers Country Inn and Suites in Costa Mesa,
so mark your calendars for 10-13 October 2002.

Look for details on our web site, www.wfo-cbrc.org. We hope to see you there.

Mike San Miguel
President, WFO

27th ANNUAL MEETING
OF WESTERN FIELD ORNITHOLOGISTS

will be held 10-13 October 2002 at the San Joaquin Wildlife Sanctuary in
Irvine, California, and at Ayres Country Inn in nearby Costa Mesa. The
meeting is hosted and co-sponsored by the Sea and Sage Audubon Society.

Our featured speaker on Saturday evening, 12 October, will be famed
marine biologist Robert L. Pitman, addressing the seabirds of the eastern
Pacific. Well enjoy also day and evening field trips, a pelagic field trip,
afternoon scientific research presentations, and break-out sessions focusing
on documentation for the California Bird Records Committee, an update by
Philip Unitt on the surprises revealed by the San Diego County Bird Atlas,
and social activities.

Membership in Western Field Ornithologists, subscription to Western
Birds, and the afternoon sessions are included in the meeting registration
fee. For details see the WFO website (www.wfo-cbrc.org) or the Sea and
Sage Audubon website (www.seaandsageaudubon.org) or contact
Catherine Waters at robcatwaters@earthlink.net or 562-869-671 8.

Call for Papers

Oral and poster presentations should reflect original research, or summa-
rize existing unpublished information, and be presented in a manner that will
be of interest to serious amateur field ornithologists. We welcome talks on a
wide variety of topics relevant to the ornithology of western North America,
such as distribution, migration, identification, geographic variation, behav-
ior, ecology, conservation, and field techniques. Plan on 20 minutes per oral
presentation, which should include 5 minutes for questions and discussion.
Slide and overhead projectors will be available. Should you wish to make a
presentation by means of Power Point, you must bring the equipment
necessary and test it before your presentation. Posters should fit within a
width of 6 feet.

An abstract of your talk in the following format should be submitted no
later than 20 June to Philip Unitt at birds@sdnhm.org or San Diego Natural
History Museum, P. O. Box 121390, San Diego, CA 92112-1390.

LAST NAME, FIRST NAME. Your affiliation (if any), complete mailing
address, and (optional) e-mail address. Title of Your Talk. Brief (300-word
maximum) summary of the goals, results, and conclusions of your study.

Procedures for submission can also be downloaded from the Sea and Sage
Audubon website (www.seaandsageaudubon.org) or the WFO website
(www.wfo-cbrc.org), or contact Catherine Waters at 562-869-6718 or
robcatwaters@earthlink.net.

239

WESTERN BIRDS, INDEX, VOLUME 32, 2001

Compiled by Philip Unitt

Accipiter stria tus, 101, 107
Acevedo, Marcos, see Arnaud, G.
Actitis macularia, 108, 150, 152, 155
Aegolius acadicus, 110
Aimophila cassinii, 33
Aix sponsa, 105
Ajaia ajaja, 53
Albatross, Laysan, 72
Short-tailed, 14, 16
Shy, 13

Amador, Edgar, see Arnaud, G.
Amazilia beryllina, 59, 65
Ammodramus sauannarum , 115
Amphispiza bilineata, 115
Anas cyanoptera, 105
discors, 105
falcata, 13, 35, 44
penelope, 68, 105
platyrhynchos, 105
querquedula, 18
rubripes, 35

Ani, Groove-billed, 26, 59, 65, 109
Anser albifrons , 103, 105
erythropus, 13, 35
Anthus cervinus, 67
hodgsoni, 13, 32
spragueii, 32

Aphelocoma californica, 186-187
coerulescens , 186
insular is, 186
Aphriza virgata, 151
Archilochus alexandri, 26, 127, 132
colubris, 14, 26, 36, 132
Ardea cinerea, 88-90
herodias, 88, 89, 104
Ardeola bacchus, 89
Arenaria interpres, 151

melanocephala , 149, 151, 152,
153, 154, 155, 157
Arnaud, Gustavo, Edgar Amador, and
Marcos Acevedo, A potential threat
to Bald Eagles in Baja California
Sur, Mexico, 136
Asio otus, 110
Athene cunicularia, 73
Avocet, American, 1-12, 150
Aythya ferina, 14, 18, 20
mania, 105

Barrowclough, George F., see Sweet, P. R.
Bartramia longicauda, 56

Basileuterus rufifrons, 50, 62
Bishop, Orange, 81-82
Bittern, Least, 103, 104
Blackbird, Brewer’s, 41
Rusty, 63

Black-Hawk, Common, 107
Bluebird, Eastern, 13
Bobolink, 103, 116
Bobwhite, Northern, 13
Bombycilla garrulus, 61, 114
Booby, Blue-footed, 17, 34, 135
Brown, 17-18, 20, 41, 134, 135
Masked, 17
Nazca, 17

Red-footed, 17-18, 20
Brachyramphus perdix , 14, 26
Brant, 11, 53
Branta bernicla, 11, 53
leucopsis, 13, 41

Brown, Nikolle L„, see LaRue, C. T.
Bubo uirginianus, 72-73
Bubulcus ibis, 101, 104
Bucephala albeola , 106
clangula, 101, 106
islandica, 106
Bufflehead, 106
Bulweria buluierii, 13, 16
fallax, 16

Bunting, McKay’s, 13, 40
Painted, 14, 34, 41, 42-44
Snow, 34
Varied, 40-41

Burton, Kenneth M., and Sean D,
Smith, First report of the Gray
Heron in the United States, 88-90
Buteo albicaudatus, 64
albonotatus, 18, 35, 107
brachyurus, 50, 55
Iineatus, 53, 55, 64, 68, 107
nitidus, 55

platypterus , 55, 64, 68
Buteogallus anthracinus, 107

Calcarius lapponicus, 63, 68
pictus, 40

Calidris alba, 103, 108, 145, 151,
152, 153, 153, 155, 157, 159
alpina, 148, 149, 151, 152, 153,
154, 155, 156, 157, 160, 161
canutus, 151, 152, 155
fuscicollis, 36

240

Western Birds 32:240-248, 2001

INDEX

mauri, 151, 152, 153, 156, 157,
160, 161
minuta, 36

minutilla , 149, 151, 152, 153,

154, 155, 156, 157
pusilla, 108
ruficoHis , 14, 35-36
Callipepla douglasii, 64
Calonectris leucomelas, 34
Calothorax lucifer, 59
Calypte anna, 73, 91, 101, 110, 127,
131-133
costae, 110, 132

Campylorhynchus brunneicapillus,
112

Caprimulgus ridgwayi, 65
vociferus, 65, 110
Caracara, Crested, 44
Caracara cheriway, 44
Cardellina rubrifrons, 33
Cardinalis sinuatus , 41-42
Carduelis sinica, 44
Carpodacus mexicanus, 74
purpureu s, 68

Catbird, Gray, 14, 15, 29-30, 31
Catharus fuscescens, 14, 29, 38, 66
guttatus, 113
minimus, 29, 30
ustulatus, 71, 73

Catoptrophorus semipalmatus, 150,
152, 153, 154, 155, 157, 161
Centrocercus urophasianus, 64
Cervantes-Sanchez, Juan, and Eric
Mellink, Nesting of Brandt’s
Cormorants in the northern Gulf of
California, 134-135
Charadrius alexandrinus, 150, 152,
154, 161
mongolus, 14, 19
semipalmatus, 149, 150, 152,

153, 154, 155, 157
vociferus, 150, 152, 153, 154, 157
l vilsonia, 14, 19, 21
Chen rossii , 53, 101, 103, 105
Chlidonias niger, 189-217
Clangula hyemalis, 106
Coccyzus americanus, 109
erythropthalmus, 50, 59, 65
Cogswell, Howard L., Book review:

The California Condor, 173-141
Colaptes auratus, 71, 73, 74-79
Colinus virginianus , 13
Columbfna irtca, 109
minuta , 26, 36

passerina, 109
talpacoti, 26, 36

Colwell, Mark A., Tamar Danufsky,
Ryan L. Mathis, and Stanley W.
Harris, Historical changes in the
abundance and distribution of the
American Avocet at the northern
limit of its winter range, 1-12
Condor, California, 137-140
Contopus pertinax, 26, 36-37, 38
sordid ulus, 26

virens, 14, 26-27 , 37, 50, 59
Cormorant. Brandt’s, 72, 134-135,
177-178

Double-crested, 101, 104, 134, 177
Neotropic, 14, 18
Pelagic, 177

Coturnicops noveboracensis, 19, 35
Cowbird, Brown-headed, 168, 175
Crossbill, Red, 116
Crotophaga sulcirostris, 26, 59, 65,
109

Cuckoo, Black-billed, 50, 59, 65
Yellow-billed, 109
Curlew, Bristle-thighed, 13, 21, 35
Long-billed, 150

Cyanocitta cristata, 60, 103, 112
Cygnus buccinator, 18, 35, 44, 103,
105

cygnus, 14, 18
C'ynanthus latirostris, 26
Cypseloides niger, 50, 218-227

Danufsky, Tamar, see Colwell, M. A.
Dendroica castanea, 39, 62
discolor, 50, 57, 62, 103, 114
dominica, 32, 62
fusca, 61, 67
graciae, 32
magnolia, 61
pinus , 32, 39, 62
striata, 39, 62
tigrina, 61
virens, 61, 67

DeStefano, Stephen, see Hinojosa-H.,

°.

Dickson, Lara L., see LaRue, C. T.
Dolichonyx oryzivorus, 103, 116
Dove, Common Ground, 109
Inca, 109
Mourning, 72
Plain-breasted Ground, 26
Ruddy Ground, 26, 36
White-winged, 101, 103, 108-109

241

INDEX

Dowitcher sp., 151, 152, 153, 156,
157, 160

Duck, American Black, 35
Falcated, 13, 35, 44
Long-tailed, 106
Wood, 105

Dumetella carolinensis, 14, 15, 29-
30, 31

Dumroese, R. Kasten, Mark R.

Mousseaux, Shirley Horning Sturts,
Daniel A. Stephens, and Paul A.
Holick, Idaho Black Swifts: Nesting
habitat and a spatial analysis of
records, 218-227
Dunlin, 148, 149, 151, 152, 153,

154, 155, 156, 157, 160, 161
Dunn, Jon L,, and Kimball L, Garrett,
Featured photo: Parapatry in
Woodhouse’s and California Scrub-
Jays revisited, 186-187
Dunnock, 91

Eagle, Bald, 136

Earnheart-Gold, Sasha, and Peter Pyle,
Occurrence patterns of Peregrine
Falcons on Southeast Farallon
Island, California, by subspecies,
age, and sex, 119-126
Eider, King, 18, 35
Egret, Cattle, 101, 104
Reddish, 18, 52
Egretto rufescens, 18, 52
tricolor, 18

Elanoides forficatus, 50
Empidonax alnorum, 37, 39, 43, 171
difficilis, 27
flaviventris, 27, 65
hammondii. 111
minimus, 59, 65
oberholseri, 111, 171
occidentals, 171

traillii, 37, 39, 43, 110, 167-172,
174

virescens, 27
wrightii, 111

Erickson, Richard A., and Hamilton,
Robert A., Report of the California
Bird Records Committee: 1998
records, 13-49

Escalante-Pliego, Patricia, see Sweet, P. R.
Eudocimus albus, 44, 52, 64
Eugenes fulgens, 59
Euphagus carolinus, 63
cyanocephalus, 41

Euplectes franciscanus, 81-82
Euptilotis neoxenus, 59, 65
Euthlypis lachrymosa, 50, 62

Falco fernoralis, 64

peregrinus, 107, 119-126
rusticolus, 14, 19
sparuerius, 72
Falcon, Aplomado, 64
Peregrine, 107, 119-126
Finch, House, 74
Purple, 68

Finlay, J. Cam, see Scarfe, A.

Flicker, Northern, 71, 73, 74-79
Flycatcher, Acadian, 27
Alder, 37, 39, 43, 171
Brown-crested, 27, 101, 111
Cordilleran, 171
Dusky, 111, 171
Dusky-capped, 14, 27
Fork- tailed, 67
Gray, 111

Gray Silky, 13-14, 44, 67
Great Crested, 27, 65
Hammond’s, 111
Least, 59, 65

Nutting’s, 50, 55, 59-60, 65
Scissor-tailed, 103, 111
Streaked, 28
Sulphur-bellied, 14, 28
Vermilion, 111
Western, 27

Willow, 37, 39, 43, 110, 167-172,
174

Yellow-bellied, 27, 65

Gallinago gallinago, 151
Gallinula chloropus, 107
Gallinule, Purple, 68
Gardali, Thomas, and Alvaro Jaramillo,
Further evidence for a population
decline in the Western Warbling
Vireo, 173-176
Garganey, 18

Garrett, Kimball L., Featured photo: An
unusual plumage variant of the
Heermann’s Gull, 237; see also
Dunn, J. L.

Gatz, Thomas A, , Orange Bishops breed-
ing in Phoenix, Arizona, 81-82
Gavia adamsii, 16
immer, 103-104
pacifica, 104
stellata, 51, 63

242

INDEX

Geothlypis trie has, 40, 114
Gnatcatcher, Black-capped, 50, 51,

56, 60, 66
Black-tailed, 60, 66
Blue-gray, 113
Godwit, Bar-tailed, 22
Marbled, 145, 151, 152, 153, 155,
157, 159

Goldeneye, Barrow’s, 106
Common, 101, 106
Golden-Plover, American, 55-56, 64,
68, 150, 179
European, 179-181
Pacific, 50, 53, 56, 150, 152, 154,
179, 180

Golet, Gregory H., Book review: The
Riparian Bird Conservation Plan,
184-185

Goose, Barnacle, 13, 41

Greater White-fronted, 103, 105
Lesser White-fronted, 13, 35
Ross’, 53, 101, 103, 105
Grackle, Common, 14, 34. 41, 63,

68, 101, 103, 116
Great-tailed, 41, 141-143
Grebe, Horned, 104
Least, 34, 51, 63
Greenfinch, Oriental, 44
Grosbeak, Pine, 68
Ground-Dove, Common, 109
Plain-breasted, 26, 36
Ruddy, 26, 36
Grouse, Sage, 64
Gull, Black-headed, 22
Glaucous, 58
Glaucous-winged, 177
Heermann’s, 237
Iceland, 13, 15, 22-24, 36
Laughing, 58

Lesser Black-backed, 14, 23, 24-25
Little, 22
Mew, 58
Ross’, 13, 36
■ Slaty-backed, 13
Thayer’s, 23
Western, 65, 72, 177
Yellow-footed, 50, 54, 58, 64-65
Gutierrez, R, J., see Zimmerman,

G. S.’

Gymnogyps ca/ifornianus, 137-140
Gyrfalcon, 14, 19

Haematopus palliatus, 21
Haliaeetus leucocephalus, 136

Hamilton, Robert A., Book review: The
Sibley Guide to Birds, 95-96; see
also Erickson, R. A.

Harris, Stanley W., see Colwell, M. A.
Hawk, Broad-winged, 55, 64, 68
Common Black, 107
Gray, 55

Harris’, 13, 15, 19, 21
Red-shouldered, 53, 55, 64, 68,

107

Sharp-shinned, 101, 107
Short-tailed, 50, 55
White-tailed, 64
Zone-tailed, 19, 35, 107
Heliomaster constantii, 59
Helmitheros vermiuorus, 33, 39-40, 67
Heron, Black-crowned Night, 89
Chinese Pond, 89
Gray, 88-90
Great Blue, 88, 89, 104
Tricolored, 18

Yellow-crowned Night, 18, 64
Heteroscelus breuipes, 35
irtcanus, 50, 56

Hinojosa-Huerta, Osvel, William W.
Shaw, and Stephen DeStefano,
Detections of California Black Rails
in the Colorado River delta,

Mexico, 228-232

Holick, Paul A., see Dumroese, R. K.
Howell, Steve N. G., Book review:

Birds of North America, 93-94;
Featured photo: Field identification
of female Allen’s and Rufous
Hummingbirds, 97-98; Book
review: United States Shorebird
Conservation Plan, 182-183;

Book review: Birds of North
America, Western Region, 233;
Book review: Bird Songs of
Southeastern Arizona and Sonora,
Mexico, 235-236

Hummingbird, Allen’s, 91-92, 97-98,
132

Anna’s, 73, 91, 101, 110, 127,
131-133
Berylline, 59, 65
Black-chinned, 26, 127, 132
Broad-billed, 26
Broad-tailed, 132
Calliope, 127-130
Costa’s, 110, 132
Lucifer, 59
Magnificent, 59

243

INDEX

Ruby- throated, 14, 26, 36, 132
Rufous, 91, 97-98, 132
Humphrey, Joan M., see Shuford, W. D.
Hylocichla mustelina, 29, 61, 66

Ibis, Glossy, 13
Sacred, 64
White, 44, 52, 64
Icterus bullockii, 63
cucullatus, 71, 74
galbula , 63, 68
pustulatus, 63, 103, 116
spurius, 63, 68
Ictinia mississippiensis, 19
Ixobrychus exilis, 103, 104

Jagana, Northern, 54, 56
Jacana spinosa, 54, 56
Jaeger, Parasitic, 56, 58
Pornarine, 50, 56
Jaramillo, Alvaro, see Gardali, T.

Jay, Blue, 60, 103, 112
Florida Scrub, 186
Island Scrub, 186
Western Scrub, 186-187
Junco, Dark-eyed, 40
Guadalupe, 73-74
Junco hyemalis, 40
insu laris, 73-74

Kelly, John P, Distribution and

abundance of winter shorebirds on
Tomales Bay, California: Implica-
tions for conservation, 145-166
Kestrel, American, 72
Killdeer, 150, 152, 153, 154, 157
Kingbird, Eastern, 111
Thick-billed, 28
Kiskadee, Great, 66
Kite, Mississippi, 19
Swallow-tailed, 50
Kittiwake, Black-legged, 59
Klicka, John T., see Sweet, P. R.

Knot, Red, 151, 152, 155
Koronkiewicz, Thomas J., see Sogge,
M. K.

LaHave, William S., see Zimmerman,
G, S.

Langridge, Suzanne M., see Sogge, M.
K.

Lanius excubiior, 111-112
LaRue, Charles T., Lara L. Dickson,
Nikolle L. Brown, John R. Spence,

and Lawrence E. Stevens, Recent
bird records from the Grand
Canyon region, 1974-2000, 101-
118

Larus atricilla, 58
canus, 58

fuscus, 14, 23, 24-25
glaucescens, 177
glaucoides, 13, 15, 22-24, 36
heermanni , 237
hyperboreus, 58
livens, 50, 54, 58, 64—65
minutus, 22

occidentalis, 65, 72, 177
ridibundus, 22
schistisagus, 13
thayeri, 23

Laterallus jamaicensis, 228-232
Leonard, Janet L., Cloacal inspection
of pecking in Allen’s Hummingbird,
91-92

Limnodromus sp., 151, 152, 153,

156, 157, 160

Limosa fedoa, 145, 151, 152, 153,
155, 157, 159
lapponica, 22
Longspur, Lapland, 63, 68
Smith’s, 40

Loon, Common, 103-104
Pacific, 104
Red-throated, 51, 63
Yellow-billed, 16
Lophodytes cucullatus, 106
Loxia curvirostra, 116
Lymnocryptes minimus, 36

Mallard, 105

Mathis, Ryan L., see Colwell, M. A.
Meadowlark, Western, 71, 74
Melanerpes erythrocephalus, 59
Melanitta fusca, 53, 106
nigra, 53

perspicillata, 105-106
Melanotis caerulescens, 66-67
Mellink, Eric, see Cervantes-Sanchez, J.
Melospiza georgiana, 115
lincolnii, 115
Merganser, Hooded, 106
Red-breasted, 107
Mergus senator, 107
Mimus polygiottos, 73, 113
Mockingbird, Blue, 66-67
Northern, 73, 113
Molothrus ater , 168, 175

244

INDEX

Montanez-Godoy, Liliana, see Sweet, P. R.
Moorhen, Common, 107
Motacilla alba , 15, 30-32
lugens, 15, 30-32

Mousseaux, Mark R., see Dumroese, R. K.
Murrelet, Long-billed, 14, 26
Myiarchus crinitus, 27, 65
nuttingi , 50, 55, 59-60, 65
tuberculifer , 14, 27
tyrannulus, 27, 101, 111
Myioborus miniatus, 67
pictus, 67, 114

Myiodynastes luieiventris, 14, 28
maculatus, 28

Night-Heron, Black-crowned, 89
Yellow-crowned, 18, 64
Nightjar, Buff-collared, 65
Numenius americanus, 150
phaeopus , 150
tahitiensis, 13, 21, 35
Nur, Nadav, see Shuford, W. D.
Nyctanassa violacea, 18, 64
Nycticorax nycticorax, 89

Oceanodroma leucorhoa, 50, 52, 64
melania, 50, 52, 64
microsoma, 50, 52
tethys, 44
Opororrtis agilis, 40
formosus, 62, 67
Philadelphia, 33, 40, 62, 67
Oreoscoptes montanus , 113
Oriole, Baltimore, 63, 68
Bullock’s, 63
Hooded, 71, 74
Orchard, 63, 68
Streak-backed, 63, 103, 116
Osprey, 107, 136
Otus flammeolus, 109-110
Owen, Jennifer C., see Sogge, M. K.
Owl, Barn, 71, 72-73
Burrowing, 73
Flammulated, 109-110
Great Horned, 72-73
Long-eared, 110
Northern Saw-whet, 110
Spotted, 83-87
Oystercatcher, American, 21

Pandion haliaetus, 107, 136
Parabuteo unicinctus, 13, 15, 19, 21
Parula, Northern, 103, 114
Parula americana, 103, 114

Passerella iliaca, 115
Passerina ciris, 14, 34, 41, 42-44
versicolor , 40

Paxton, Eben H., see Sogge, M. K.
Pelecanus erythrorhynchos, 104
occidentalis, 104
Pelican, American White, 104
Brown, 104

Petrel, Black Storm, 50, 52, 64
Bulwer’s, 13, 16
Jouanin’s, 16
Leach’s Storm, 50, 52, 64
Least Storm, 50, 52
Wedge-rumped Storm, 44
Pewee, Eastern Wood, 14, 26-27, 37,
50, 59

Greater, 26, 37, 38
Western Wood, 26-27
Phaethon rubricauda, 34
Phalacrocorax auritus, 101, 104,

134, 177

brasilianus, 14, 18
pelagicus, 177

penicillatus, 72, 134-135, 177-178
Phalaenoptilus nuttallii, 110
Phalarope, Red, 151
Red-necked, 151
Phalaropus fulicaria, 151
lobatus, 151

Phoebastria albatrus, 14, 16
immutabilis, 72
Phoebe, Black, 101, 111
Eastern, 103, 111
Pinicola enucleator, 68
Pipit, Olive-backed, 13, 32
Red-throated, 67
Sprague’s, 32
Piranga bidentata, 63
erythrocephala , 67-68
ludouiciana, 63
ohvacea, 33, 40, 62-63, 67
rubra, 101, 114-115
Pitangus sulphuratus, 66
Plectrophenax hyperboreus, 13, 40
nivalis, 34

Plegadis falcinellus, 13
Plover, American Golden, 55-56, 64,
68, 150, 179

Black-bellied, 150, 152, 153, 154,
155, 157

European Golden, 179-181
Mongolian, 14, 19
Pacific Golden, 50, 53, 56, 150,
152, 154, 179, 1890

245

INDEX

Semipalmated, 149, 150, 152, 153,

154, 155, 157
Snowy, 150, 152, 154, 161
Wilson’s, 14, 19, 21

Pluuialis dominica , 55-56, 64, 68, 150
fulva, 50, 53, 56, 150, 152, 154
squatarola, 150, 152, 153, 154,

155, 157

Pochard, Common, 14, 18, 20
Podiceps auritus, 104
Polioptila caerulea, 113
meianura, 60, 66
nigriceps, 50, 51, 56, 60, 66
Pond-Heron, Chinese, 89
Pooecetes gramineus, 40
Poorwill, Common, 110
Porphgrula martinica, 68
Porzona Carolina, 107
Protonotaria citrea, 103, 114
Prunella modularis, 91
Ptilogongs cinereus, 13-14, 44, 67
Puffinus pacificus, 14, 16-17
puffinus , 17, 34
Pyle, Peter, Book review: Isles of
Refuge, 234; see also Earnheart-
Gold, S.

Pyrocephalus rubinus, 111
Pyrrhuloxia, 41-42

Quail, Elegant, 64

Quiscalus mexicanus, 41, 141-143
quiscula , 14, 34, 63, 68, 101, 103,

116

Rail, Black, 228-232
Clapper, 228, 231
Virginia, 107
Yellow, 19, 35
Rallus Iimicola, 107
lorigirostris, 228, 231
Recurvirostra americana, 1-12, 150
Redstart, American, 114
Painted, 67, 114
Slate-throated, 67
Rhodostethia rosea, 13, 36
Rissa tridactyla, 59
Robin, Rufous-backed, 61, 66
Rosenberg, Gary H., Arizona Bird
Committee report: 1996-1999
records, 50-70

Salpinctes obsoletus, 73
Sanderling, 103, 108, 145, 151, 152,
153, 155, 157, 159

Sandpiper, Least, 149, 151, 152, 153,
154, 155, 156, 157
Semipalmated, 108
Solitary, 108

Spotted, 108, 150, 152, 155
Upland, 56

Western, 151, 152, 153, 156, 157,
160, 161
White-rumped. 36

San Miguel, Mike, President’s message,
238

Sapsucker, Yellow-bellied, 103, 110
Sagornis nigricans , 101, 111
phoebe, 103, 111

Scarfe, Ann, and J. Cam Finlay, Rapid
second nesting by Anna’s Hum-
mingbird near its northern breeding
limits, 131-133
Scaup, Greater, 105
Scolopax minor, 13, 22
Scoter, Black, 53
Surf, 105-106
White- winged, 53, 106
Scrub-Jay, Florida, 186
Island, 186
Western, 186-187
Seiurus motacilla, 62
Selasphorus platgcercus, 132
rufus, 91, 97-98, 132
sasin, 91-92, 97-98, 132
Setophaga ruticilla, 114
Shaw, William W., see Hinojosa-H., O.
Shearwater, Manx, 17, 34
Streaked, 34
Wedge-tailed, 14, 16-17
Shrike, Northern, 111-112
Shuford, W. David, Joan M.

Humphrey, and Nadav Nur,
Breeding status of the Black Tern in
California, 189-217
Sialia sialis, 13

Silky-flycatcher, Gray 13-14, 44, 67
Smith, Sean D., see Burton, K. M.
Snipe, Common, 151
Jack, 36

Sogge, Mark K., Jennifer C. Owen,
Eben H. Paxton, Suzanne M,
Langridge, and Thomas J.
Koronkiewicz, A targeted mist net
capture technique for the Willow
Flycatcher, 167-172
Somateria spectabilis , 18, 35
Sora, 107

Sparrow, American Tree, 68

246

INDEX

Black-throated, 115
Brewer’s, 115
Cassin’s, 33
Chipping, 115
Clay-colored, 115
Field, 14, 33, 50, 63, 68
Fox, 115

Golden-crowned, 116
Grasshopper, 115
Lincoln’s, 115
Swamp, 115
Vesper, 40

White-throated , 115-116
Spence, John R., see LaRue, C. T.
Sphyrapicus varius, 103, 110
Spizella arborea, 68
breweri, 115
pallida, 115
passer ina, 115
pusilla , 14, 33, 50, 63, 68
Spoonbill, Roseate, 53
Starling, European, 71, 73, 113-114
Starthroat, Plain-capped, 59
Stelgidopteryx serripennis , 112
Stellula calliope, 127-130
Stephens, Daniel A., see Dumroese, R. K.
Stercorarius parasiticus, 56, 58
pomarinus, 50, 56
Sterna anaethetus, 13, 25
caspia, 103, 108
fuscata, 14, 26
lunata, 25
paradisaea, 59

Stevens, Lawrence E., see LaRue, C. T.
Stint, Little, 36
Red-necked, 14, 35-36
Storm-Petrel, Black, 50, 52, 64
Leach’s, 50, 52, 64
Least, 50, 52
Wedge-rumped, 44
Strix occidentals, 83-87
Sturnella neglecta, 71, 74
Sturnus vulgaris, 71, 73, 113-114
Sturts, Shirley Horning, see Dumroese,
R. K.

Su/o dactylatra, 17
grand, 17

leucogaster, 17-18, 20, 41, 134,
135

nebouxii, 17, 34, 135
sula, 17-18, 20
Surfbird, 151

Swallow, Northern Rough-winged, 112
Tree, 112

Swan, Trumpeter, 18, 35, 44, 103,
105

Whooper, 14, 18
Sweet, Paul R., George F.

Barrowclough, John T. Klicka,
Liliana Montanez-Godoy, and
Patricia Escalante-Pliego,
Recolonization of the flicker and
other notes from Isla Guadalupe,
Mexico, 71-80
Swift, Black, 50, 218-227

Tachybaptus dominicus, 34, 51, 63
Tachycineta bicolor, 112
Tanager, Flame-colored, 63
Red-headed, 67
Scarlet, 33, 40, 62-63, 67
Summer, 101, 114-115
Western, 63
Tattler, Gray-tailed, 35
Wandering, 50, 56
Teal, Blue-winged, 105
Cinnamon, 105
Tern, Arctic, 59
Black, 189-217
Bridled, 13, 25
Caspian, 103, 108
Gray-backed, 25, 25
Sooty, 14, 26
Thalassarche cauta, 13
Thrasher, Crissal, 101, 113
Sage, 113

Threskiornis aethiopicus, 64
Thrush, Gray-cheeked, 29, 30
Hermit, 113
Swainson’s, 71, 73
Wood, 29, 61, 66
Thryothorus ludovicianus, 50, 60
Toxostoma crissale, 101, 103
Tringa melanoleuca, 150, 152, 154
solitaria, 108

Troglodytes aedon, 112-113
troglodytes , 50, 60, 113
Trogon, Eared, 59, 65
Tropicbird, Red-tailed, 34
Turdus rufopatliatus, 61, 66
Turnstone, Black, 149, 151, 152, 153,
154, 155, 157
Ruddy, 151

Tyrannus crassirostris, 28
forficatus, 103, 111
saoana, 66
tyrannus, 111
Tyto alba, 71, 72-73

247

INDEX

Veery, 14, 29, 38, 66
Vermiuora celata, 114
chrysoptera, 32, 61
peregrina, 61, 67, 68
pinus, 32, 38-39, 50, 57, 61, 67
Vireo, Bell’s, 60, 101, 112

Blue-headed, 14, 25, 28-29, 37,
50, 66

Cassin’s, 25, 28, 112
Hutton’s, 103, 112
Philadelphia, 14, 28-29, 38, 60
Red-eyed, 38, 60, 66, 112
Warbling, 29, 173-176
White-eyed, 28, 60, 66
Yellow-green, 29, 38, 60, 66
Yellow-throated, 28, 66
Vireo bellii , 60, 101, 112
cassinii, 25, 28, 112
flavifrons, 28, 66
flavoviridis, 29, 38, 60, 66
gilvu s, 29, 173-176
griseus , 28, 60, 66
huttoni, 103, 112
oliuaceus, 38, 60, 66, 112
philadelphicus, 14, 28-29, 38, 60
s olitarius, 14, 25, 28, 37, 50, 66

Wagtail, Black-backed, 15, 30-32
White, 15, 30-32

Wahl, Terence R., Brandt’s Cormorant
sinks at sea, 177-178
Warbler, Bay-breasted, 39, 62
Blackburnian, 61, 67
Blackpoll, 39, 62
Black-throated Green, 61, 67
Blue-winged, 32, 38-39, 50, 57,
61, 67

Cape May, 61
Connecticut, 40
Fan-tailed, 50, 62
Golden-winged, 32, 61
Grace’s, 32
Kentucky, 62, 67
Magnolia, 61
Mourning, 33, 40, 62, 67
Orange-crowned, 114

Pine, 33, 39, 62
Prairie, 50, 57, 62, 103, 114
Prothonotary, 103, 114
Red-faced, 33
Rufous-capped, 50, 62
Tennessee, 61, 67, 68
Worm-eating, 33, 39-40, 67
Yellow-throated, 32, 62
Waterthrush, Louisiana, 62
Waxwing, Bohemian, 61, 114
Wehtje, Walter, Featured photo: Range
expansion of the Great-tailed
Grackle in western North America,
141-143
Whimbrel, 150
Whip-poor-will, 65, 110
Wigeon, Eurasian, 68, 105
Willet, 150, 152, 153, 154, 155, 157,
161

Williams, Brian D. C., Low-elevation
nesting by Calliope Hummingbirds
in the western Sierra Nevada
foothills, 127-130
Woodcock, American, 13, 22
Woodpecker, Red-headed, 59
Wood-Pewee, Eastern, 14, 26-27, 37,
50, 59

Western, 26-27
Wren, Cactus, 112
Carolina, 50, 60
House, 112-113
Rock, 73

Winter, 50, 60, 113

Yellowlegs, Greater, 150, 152, 154
Yellowthroat, Common, 40, 114

Zenaida asiatiea, 101, 103, 108-109
macroura, 72

Zimmerman, Guthrie S., William S.
LaHaye, and R. J. Gutierrez,
Breeding-season home ranges of
Spotted Owls in the San Bernar-
dino Mountains, California, 83-87
Zonotrichia albicollis , 115-116
atricapilla , 116

248

World Wide Web site:

WESTERN BIRDS www.wfo-cbrc.org

Quarterly Journal of Western Field Ornithologists

President: Mike San Miguel, 2132 Highland Oaks Dr., Arcadia, CA 91006;
sanmigbird@aol.com

Vice-President: Daniel D. Gibson, University of Alaska Museum, 907 Yukon
Dr., Fairbanks, AK 99775-6960

Treasurer/Membership Secretary: Dori Myers, 6011 Saddletree Lane, Yorba
Linda, CA 92886

Recording Secretary: Lucie Clark, 9889 Tahoe Blvd., #56, Incline Village, NV
89451

Directors: Kimball Garrett, Daniel D. Gibson, Bob Gill, Gjon Hazard, Dave
Krueper, Mike San Miguel, W. David Shuford, Mark K. Sogge, David Yee

Editor.- Philip Unitt, San Diego Natural History Museum, P.0. Box 121390, San
Diego, CA 92112-1390; birds@sdnhm.org

Associate Editors: Daniel D. Gibson, Robert A. Hamilton, Ronald R. LeValley,
Tim Manolis, Kathy Molina, Mark K. Sogge

Graphics Manager: Virginia P. Johnson, 4637 Del Mar Ave., San Diego, CA 92107

Photo Editor: Peter La Tourrette, 1019 Loma Prieta Ct., Los Altos, CA 94024

Featured Photo: Robert A. Hamilton, 34 Rivo Alto Canal, Long Beach, CA 90803

Book Reuiews: Steve N.G. Howell, Point Reyes Bird Observatory, 4990 Shoreline
Highway, Stinson Beach, CA 94970

Secretary, California Bird Records Committee: Guy McCaskie, P.O. Box 275,
Imperial Beach, CA 91933-0275; guymcc@pacbell.net

Chairman, California Bird Records Committee: Richard A. Erickson, LSA Associates,
1 Park Plaza, Suite 500, Irvine, CA 92614; richard.erickson@lsa-assoc.com

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Birds: Patron, $1000.00; Life, $400.00 (payable in four equal annual installments);
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Published March 15, 2002

ISSN 0045-3897

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