It

Volume 27, Number 1, 1996

Eighteenth Report of the California Bird Records Committee: 1992

Records Matthew T. Heindel and Michael A. Patten 1

Breeding Distribution of Vaux’s Swift in California John Sterling

and Peter W. C. Paton . . . . 30

The Prince of Wales Spruce Grouse: A New Subspecies from
Southeastern Alaska Robert W. Dickerman and
Jack Gustafson 41

Fall Migration of Turkey Vultures and Raptors Through the Southern
Sierra Nevada, California Sean P. Rowe and Terri Gallion ... 48

NOTES

A Winter Record of the Gray Vireo from San Luis Potosi,

Mexico Adam J. Fry, Octavio R. Rojas-Soto, and Aldolfo G.
Navarro S 54

Cover photo by © Jack Wilburn of Rescue, California: Great Gray
Owl (Strix nebulosa), Yellowstone National Park, October, 1995.

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WESTERN BIRDS

Volume 27, Number 1, 1996

EIGHTEENTH REPORT OF THE CALIFORNIA BIRD
RECORDS COMMITTEE: 1992 RECORDS

MATTHEW T. HEINDEL, 4891 Royce Road, Irvine, California 92715

MICHAEL A. PATTEN, Secretary, California Bird Records Committee, P. O. Box
51959, Riverside, California 92517-2959

In this article we report the results of the recent review of 253 records of
96 species by the California Bird Records Committee (hereafter the Com-
mittee or CBRC). Of these records, 219 were accepted, for an acceptance
rate of 86.6%. This rate is higher than in recent reports, primarily the result
of an unusually large number of accepted records of passerines normally
associated with the southeastern United States during the spring of 1992.
This report contains records from 1954 through 1993, although the great
majority are from 1992.

Three species newly added to the California state list are included in this
report: the Great Frigatebird ( Fregata minor), Black-tailed Gull ( Larus
crassirostris), and Fork-tailed Flycatcher ( Tyrannus sauana). The list now
stands at 587. The earliest accepted records of two species already on the
California list are published here: the Mississippi Kite ( Ictinia mississip-
piensis ) and Gray Catbird (Dumetella carolinensis).

All records reviewed by the CBRC are archived at the Western Foundation
of Vertebrate Zoology, 439 Calle San Pablo, Camarillo, California 93012.
All written documentation, photographs, voice recordings, and videotapes
are housed there, catalogued, organized by CBRC record number, and are
available for public review. The CBRC solicits information on all occur-
rences in California of species on its Review List (see Roberson 1993), as
well as species unrecorded in California, and requests that documentation be
sent to Michael A. Patten, CBRC Secretary, at the address above. For
further reading on how the Committee functions, see Heindel and Garrett
(1995) and Patten et al. (1995).

The format closely follows that of recent reports (e.g,, Patten and
Erickson 1994, Heindel and Garrett 1995). In general, records are listed
chronologically by first date of occurrence. Included with each record is the
location, county abbreviation (see below), and date span. The date span

Western Birds 27:1-29, 1996

1

CALIFORNIA BIRD RECORDS

generally follows that published in American Birds. 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 the record, if known, are
followed by a semicolon, then the initials of additional observers submitting
documentation, then the CBRC record number. Ail records are sight records
unless otherwise noted. Initials followed by a dagger (f) indicate the observer
supplied an identifiable photograph. Similarly, (f) designates videotape, (§),
a voice recording. A indicates a specimen record, and is followed by the
acronym (see below) of the institution housing the specimen and the
institution's specimen number.

An asterisk (*) prior to a species name indicates that it is no longer on the
Review List. The number in parentheses following the species’ name is the
number of records accepted by the CBRC through this reporting period.
Two asterisks (**) after this number indicate that the number of accepted
records is limited to a restricted review period or includes records accepted
for statistical purposes only (see Roberson 1986 for more information).

When an individual bird returns to a locality after an absence (for example,
in consecutive winters), or remains for multiple years, each subsequent
occurrence is reviewed as a new record. The Committee judges, by a
majority vote, whether or not the same individual is involved. If a majority of
the Committee considers it the same bird, that information is included in the
comments, and the total number of records remains unchanged.

Although the Committee does not formally resolve identification issues
below the species level, comments on age, sex, or subspecies are often
included. The authors of this report assume responsibility for all such
comments, although they are usually based on input provided by Committee
members during circulation of the record.

The Committee uses the following codes for California counties: ALA,
Alameda; ALP, Alpine; AMA, Amador; BUT, Butte; CLV, Calaveras: COL,
Colusa; CC, Contra Costa; DN, Del Norte: Eb, El Dorado; FRE, Fresno;
HUM, Humboldt; IMP, Imperial; INY, Inyo; KER, Kern; KIN, Kings; LAK,
Lake; LAS, Lassen; LA, Los Angeles: MAD, Madera; MRN, Marin; MRP,
Mariposa; MEN, Mendocino; MER, Merced; MOD, Modoc; MNO, Mono;
MTY, Monterey; NAP, Napa; NEV, Nevada; ORA, Orange: PLA, Placer;
PLU, Plumas; RIV, Riverside; SAC, Sacramento; SBT, San Benito; 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; SHA, Shasta; SIE, Sierra; SIS, Siskiyou; SOL, Solano;
SON. Sonoma; $TA, Stanislaus; SUT, Sutter; TEH, Tehama; TRI, Trinity;
TUL, Tulare; TUO, Tuolumne; VEN, Ventura; YOL, Yolo; YUB, Yuba.

Museums that have allowed Committee members access to specimens,
have provided information, or house specimens are cited below are as
follows: CAS. California Academy of Sciences, San Francisco; CMN,
Canadian Museum of Nature, Ottawa, Canada; FM, Field Museum of
Natural History, Chicago; LACM, Natural History Museum of Los Angeles
County, Los Angeles; LSUMZ, Museum of Zoology at Louisiana State
University; ROM, Royal Ontario Museum, Toronto; SBCM, San Bernardino
County Museum, Redlands; SDNHM, San Diego Natural History Museum;
UMMZ, University of Michigan Museum of Zoology, Ann Arbor; and WFVZ,

2

CALIFORNIA BIRD RECORDS

Western Foundation of Vertebrate Zoology, Camarillo. Other abbreviations
used are AFB, Air Force Base; I., island; L., lake; mt., mountain; n. miles,
nautical miles; NM, National Museum; NWR, national wildlife refuge; Pt.,
point; R., river; SB, state beach; and SP, state park.

RECORDS ACCEPTED

YELLOW-BILLED LOON Gavia adamsii (55). Single individuals were seen at
Whiskeytown Reservoir, SHA, 30 Dec 1991-17 Feb 1992 (DLR: FG, SBT; 31-

1992) , Morro Bay, SLO, 10 Dec 1992 (TME, CMt ; 304-1992), Santa Barbara,
SBA, 11 Dec 92 (J&PC; SEFt, PEL; 12-1993), and in San Francisco Bay, SF, off
Alameda Creek and then off San Lorenzo Creek 20-24 Dec 92 (DRi; RJR; 124-

1993) .

All of these records appear to pertain to first-year birds, which account for most
California records. The Shasta record is of particular interest in being inland.
Disappointingly, however, the documentation was rather brief, given the significance
of inland reports. A number of observers failed to submit any supporting details. We
encourage all observers to send in their notes to document these records fully. The
Santa Barbara record, one day later than and 100 miles south of that at Morro Bay,
could possibly pertain to the same individual, but these two were considered as
different.

MOTTLED PETREL Pterodroma inexpectata (53). One was 109 n. miles west of
Pt. Arguello, SBA, 11 Feb 92 (PP; 76-1992), and another was 71 n. miles west of Pt.
Arguello, SBA, on the same date (PP; 77-1992). Although the first bird was
photographed, no detail was discernible in the pictures, and so the record is listed as
a sight record. Although not annual, this species is occasionally seen in late winter/
early spring well off the coast of California.

STEJNEGER'S PETREL Pterodroma lorigirostris (6). One was 153 n. miles SW
of San Nicolas I., VEN, 4 Jul 1992 (PP; 203-1992), and another was 189 n. miles
WSW of San Nicolas I., VEN, 10 Jul 1992 (PP; 204-1992). Both records are
significant because they are the first for summer off our coast; the previous records
have been for late fall. A third bird was seen on 10 Jul 1992, 209 n. miles from the
island, outside of our region of coverage, so was not reviewed. In comments, Pyle
relayed that Patrick Gould (pers. comm.) found Stejneger's the most common
Pterodroma in the south-central Gulf of Alaska in summer. Presumably, these Alaska
birds account for our fall records (as they move south), but perhaps some Stejneger’s
also spend the summer with Cook’s Petrels (P cookii) far offshore. Pyle noted large
numbers of Cook's (up to 200/day) in the same area during early July 1992.

RED-TAILED TROPICBIRD Phaethon rubricauda (8). Immatures were 129 n.
miles WSW of Pt. Sur. MTY, 8 Aug 1992 (JLD, PPt; 227-1992). and 87 n. miles
WSW of Pt. Piedras Blancas, SLO, 19 Aug 1992 (Figure 1; SFB, RAE, DRf; 229-
1992). These well-documented records provide increasing evidence that this species
probably occurs with some regularity at this season. The descriptions and photos
show a large, robust tropicbird with a large blackish bill, nearly all-white wings and a
small eye patch. There was fine barring on the upperparts and a slender and stiff tail
streamer.

MASKED BOOBY Sula dactylatra (5). An adult was at the Salinas R. mouth,
MTY, 18, 20, and 22 Jun 1992 (Figure 2; JB, RD; SFBf. RC, JM, DRf; 174-1992).
An adult booby reported (but not reviewed by the Committee) at Capitola Pier, SCZ,
on 8 Jun could have been the same bird. Another adult flew by Mugu Rock, VEN, 20
Jun 1992 (DDe, BH; 209-1992). An immature was off Newport Pier, ORA, 30 Jun

3

CALIFORNIA BIRD RECORDS

1992 (DRW, BED; 210-1992). With only two prior California records, this "invasion”
was unexpected.

BROWN BOOBY Sula leucogaster (40). An immature frequented SE Farallon I.,
SF, 25 May-24 Nov 1992 (PPt; FG; 162-1992). An adult (or near-adult) was over
Mountain View, in San Francisco Bay, SCL, 29 Aug 1992 (MMa; 243-1992). The
Farallon L bird was absent from 16 Sep to 7 Oct, but returned to finish its stay on the
same perch. Pyle noted that it fed on juvenile Pacific Sardines ( Sardinis sagax ), the first
of these noted around the island in 40 years. The record from inside San Francisco Bay
is most unusual, but unfortunately the bird did not remain for others to see.

RED-FOOTED BOOBY Sula sula (10). An immature was approximately 166 n.
miles WSW of San Nicolas I., VEN, 1 Feb 1992 (PPt; 73-1992). Photographs show
a fairly uniform brown body with bright pinkish-red feet. The bill was mixed dull blue
and pinkish, with a dusky tip. The soft-part colors are diagnostic for this species.

NEOTROPIC CORMORANT Phalacrocorax brasilianus (4). An adult was photo-
graphed at Imperial Dam, IMP, 1 2 Sep 1992 (Figure 3; JTat; 15-1993). The date and
location fit the species' limited pattern of occurrence. The photograph shows a
cormorant with a small body, short bill, and relatively long tail, all excellent marks for
the Neotropic.

GREAT FRIGATEBIRD Fregata minor (1). A female, apparently adult or near-
adult, was at SE Farallon I., SF. 14 Mar 1992 (PPt; EE; 12T1992); a photograph was
published in Am. Birds (46:500). Most of the Committee had to take a crash course
in frigatebird identification, as we normally see just one species, the Magnificent (F.
magnificens). Pyle immediately suspected that this bird was a Great, from his
experience with that species in Hawaii, among other places. Fortunately, the bird

Figure 1. Red-tailed Tropicbird, Phaethon rubricauda , 19 August 1992 (229-1992),
well off Pt. Piedras Blancas, SLO. Diagnostic features visible in this photograph are
the extensively white wings, small eye patch, large bill, and fine barring on the
upperparts. The bird also appears rather large for this genus.

Photo by Don Roberson

4

CALIFORNIA BIRD RECORDS

came back after distant views and flew overhead, allowing the pictures to be taken.
The combination of a dark head and gray throat is unmatched in F, magnificens. A
small amount of rufous was present at the sides of the nape, a mark indicative of F.
minor. There are also subtle differences in the pattern of black and white on the breast
(see Howell 1995 for a thorough discussion of this difficult problem).

The CBRC was also concerned about eliminating the next most likely species, the
Lesser Frigatebird (F. ariel ). The bird in question was too large for a Lesser (as assessed
in direct comparison with a Western Gull, Larus occidental is) and had dark axillars,
whereas a Lesser would show a distinct white spur.

This record points out the need for all frigatebirds seen in California, particularly
those out of season, to be critically reviewed. The majority of our records for the
Magnificent are from the Salton Sea and coastal southern California from late June to
September.

TRICOLORED HERON Egretta tricolor (7**). An adult was at the south end of the
Salton Sea, IMP, 4-11 Jul 1992 (GMcC, MAPt; 178-1992). An immature was near
Santa Rosa, SON, 7-19 Nov 1992 (LLf, JM, BDP; 284-1992). An immature was at
the Tijuana R. mouth, SD, 24 Oct 1992-18 Jan 1993 (TC, GMcC; 16-1993). The
Sonoma bird was the second to be recorded from northern California (the first was at
Honey Lake, LAS, 24 Aug-26 Sep 1971; Manolis 1972).

REDDISH EGRET Egretta rufescens (62). An adult was at Pt. Mugu, VEN, 28 Mar
1992 (HC, AS; 105-1992). Another was in Anaheim Bay, ORA, 12-14 Apr 1992
(SM; BED, RAE; 133-1992). An immature was on San Diego Bay, SD, 17 Apr-19

Figure 2. This adult Masked Booby, Sula dactylatra, was seen on 18. 20, and 22
June 1992 (174-1992) at the Salinas R. mouth, MTY.

Photo by Stephen F. Bailey

5

CALIFORNIA BIRD RECORDS

Jun 1992 (GMcC; 138-1992). An adult, easily recognized by a deformity on its bill,
returned to San Diego, SD. for its eleventh year, 14 Aug-13 Sep 1992 (JLD, PEL;
263-1992). See Heindel and Garrett (1995) and Patten and Erickson (1994) for a
complete date span. An immature was at Bolsa Chica, ORA. 18 Oct 1992-3 Jan
1993 (SC, BED, MTHt. CMt. MAP, TG; 288-1992).

YELLOW-CROWNED NIGHT-HERON Nyctanassa violaceo (16). The adult that
has resided at La Jolla, SD, since 1981 was in La Jolla 11 Jan-25 Jul 1992 (GMcC;
FHt, PEL; 84-1992). It attempted to nest with a Black-crowned Night-Heron
( Nycticorax nycticorax) as it has done in past years.

BLACK-BELLIED WHISTLING-DUCK Dendrocygna autumnalis (9). One was at
the south end of the Salton Sea. IMP. 6 Jul 1992 (WRR; 236-1992). and one was at
the north end of the Salton Sea. RIV, 10 Jul 1992 (NDH; 226-1992). There was
considerable discussion over whether these records pertained to the same individual;
given the species' rarity, lumping these two records together might be justified. The
birds were seen more than 30 miles apart, however, and there are enough records of
Black-bellied Whistling-Ducks wandering north to justify acceptance of two individuals.

TRUMPETER SWAN Cygnus buccinator (20). Two were at White L., Lower
Klamath NWR, SIS, 30 Nov 1991 (DRf; 210-1991). A family group of three were in
Sierra Valley, PLU, 28 Feb 1992 (LJ; 91-1992). Records of this species have been
scrutinized closely, because of the difficulty of distinguishing the Trumpeter from its
more common congener, the Tundra Swan (C. columbianus). In both of these cases,

Figure 3. Although the detail is somewhat difficult to discern, the picture shows a
smaller cormorant, with a long tail and white border to the throat. This Neotropic
Cormorant. Phalacrocorax oliuaceus. was photographed at Imperial Dam, IMP, 12
September 1992 (15-1993).

6

Photo by Jim Taylor

CALIFORNIA BIRD RECORDS

the birds were well described, including in the latter the sharply pointed L ‘V” on the
forehead, one of the best marks for separating adults. In addition, the diagnostic call,
a low double "honk,” was heard.

GARGANEY Anas querquedula (15). One of undetermined age/sex was in
Mountain View, SCL, 22 Aug-22 Sep 1992 (PJM; WGB, GMcC, SEF, JM, MMR,
SBT, JSh, AWf: 241-1992). This bird was generally regarded as a female by most
observers, although the descriptions led some committee members to leave this
question unresolved. Some of these age/sex determinations must always be left
tentative. Jackson (1992) covered the identification of female and eclipse-plumage
Garganeys well.

COMMON POCHARD Aythya ferina (1). An adult male returned to Silver Lakes,
SBE, 14 Jan-8 Feb 1992 (CM; 106-1992) and again 26-29 Nov 1992 (MAP;
GMcC; 287-1992). This bird was first seen 11-17 Feb 1989 but was missed the
following winter Its recurrence in subsequent years, including 18 Jan-23 Feb 1991,
suggests the bird was probably somewhere in the area during the winter of 1989-
1990. For full details, see Patten (1993).

KING EIDER Somateria spectabilis (32), A female was in Humboldt Bay, HUM, 6
Jan-1 Feb 1992 (BBA; FB, SWH, GSL; 109-1992). What was believed to be the
same bird was in Humboldt Bay, HUM, 12 Nov 1992-30 Jan 1993 (SWH. GSL. JM,
DR; 40-1993). The dates are consistent with most other records for California.

MISSISSIPPI KITE Ictinia mississippiensis (25). An immature collected at Goleta,
SBA, 18 Jun 1933 (FM 156760; 58-1994) was the first for California (Willett 1933;
see also Roberson 1993). One was at Furnace Creek Ranch, INY. 17 May 1992
(THf: GMcC. MAPt; 131-1992). One was flying over the South Fork of the Kern R.
near Weldon, KER, 5 Jun 1992 (JCS; 148-1992). One was in Norwalk, LA, 1 Jul
1992 (JSc; 175-1992). One was in Rancho Palos Verdes. LA. 26 Sep 1992 (JLA;
42-1993).

The four spring records were of subaduits. like most Mississippi Kites reaching
California. The Kern record was the first for that county. The Norwalk record was
accompanied by extensive details and impressive sketches. The Rancho Palos Verdes
record was exceptional in being for fall. The bird appeared to be a subadult retaining
some juvenal secondaries and tail feathers; Wheeler and Clark (1995) discussed this
plumage.

ZONE-TAILED HAWK Buteo albonotatus (32). An adult near the San Diego Wild
Animal Park at San Pasqual. east of Escondido, SD. 12 Jan 1992 (CR; 126-1992)
was judged to be a returning individual, seen previously in Escondido on 30 Dec 1989
and 4 Feb-10 Mar 1991 (Heindel and Garrett 1995). An adult was at L. Murray. San
Diego, SD, 14 Dec 1992 (JiM ; 78-1993). What was believed to be the same individual
was in Santee. SD, 29 Jan-5 Feb 1993 (EA, JWo; 79-1993). The L. Murray and
Santee records were thought to pertain to the same individual seen in this area in
previous years (Heindel and Garrett 1995. Patten et al. 1995).

YELLOW RAIL Coturnicops noueboracensis (64). One was at Tomales Bay.
MRN, 22 Nov 1992 (RS: 36-1993), during a high tide in an area that has yielded a
few other recent records. A previously unreviewed specimen was located by Michel
Gosselin. at the Canadian Museum of Nature in Ottawa. Canada, It had been taken at
Pt. Reyes, MRN. 30 Oct 1905 (CMN 9065; 127 1994).

MONGOLIAN PLOVER Charadrius mongolus (5). A juvenile was at Moss
Landing SB, MTY. 16-20 Sep 1992 (Figure 4; RC, JMDt. SEF, FGt, JMLf. TDM.
GMcC, JM, BDP. DRt. MMTt. SBTt; 250-1992), a photo appeared in Am, Birds
47: 166. Many observers were careful to separate this species from the Greater Sand
Plover (C. leschenaultii). Although there are no American records for the latter, it is

7

CALIFORNIA BIRD RECORDS

Figure 4. This juvenile Mongolian Plover, Charadrius mongolus, was at Moss
Landing SB, MTY, 16-20 September 1992 (250-1992). The small bill, tarsus length,
and overall size are key to distinguishing the Mongolian from the Greater Sand Plover,
C. leschenaultii.

Photo by Monte Taylor

Figure 5. This juvenile Wilson’s Plover, Charadrius wilsonia , one of two in this
report, was photographed in Santa Barbara, SBA, 1 1 August 1992 (212-1992). The
relatively massive bill separates Wilson's Plover from its more common relatives.

Photo by Shawneen Finnegan

8

CALIFORNIA BIRD RECORDS

a long-distance migrant. Some of the pictures seemed to show a long-legged bird that
looked too big for the Mongolian (also called Lesser Sand Plover in the Old World). In
addition, at least one photo showed the legs to be a paler greenish gray, a mark more
typical of the Greater Sand. Other pictures (for example, Figure 4), however, showed
a leg length and color, as well as overall size, typical of the Mongolian Plover. The small
bill, in particular, eliminates the Greater Sand Plover.

WILSON’S PLOVER Charadrius wilsortia (7). A juvenile was in Santa Barbara,
SBA, 11 Aug 1992, (Figure 5; FS; NBB, RC, KFC, SEF+, PEL, MAP; 212-1992).
One was at Moss Landing SB, MTY, 15 Sep 1992- 1 Jan 1993 (DEG; RC, JLD,
JRGt, EG+, JMLt, GMcC, JM, CAM+, BDP, DR+, BS, SBT+, AWt, BW; 256-1992).
These are the first records of this species in fall.

The Moss Landing bird was unique in its extended stay as well as in being the first
for northern California. From the wear shown by many of the wing coverts, etc.,
many observers felt this bird was an adult. Others noted that some juvenal lesser
coverts may have been retained, however, and because a southern shorebird may
breed much earlier in the year than its arctic congeners, its plumage cycle may differ.
We leave the age of this bird unresolved. See Marchant et al. (1986) for further
discussion of age determination in Wilson’s Plover.

EURASIAN DOTTEREL Charadrius morinellus (5). One was at Pt. Reyes, MRN,
17 Oct-21 Nov 1992 (LL; HG, PEL, GMcC, JM, BDP, MAPt; 272-1992). Again,
the age of this bird was unclear. It was widely referred to as a juvenile, but some
observers noted a feather pattern consistent with either an adult or a first-year bird in
basic plumage. As suspected by some observers, the bird may have been molting from
juvenal into first basic plumage.

Figure 6. This Little Stint, Calidris minuta , in Irvine, ORA. 25 July 1992 (205-1992),
was the first adult to be accepted in fall. The orange face and throat, white chin, and
breast pattern are all excellent marks for this species.

Photo by Herb Clarke

9

CALIFORNIA BIRD RECORDS

BAR-TAILED GODWIT Limosa lapponico (14). A juvenile was at Pt. Reyes, MRN,
20 Aug-24 Sep 1992 (RSt; EG+, JM, BDP, MAP, JWr; 231-1992). Another was in
Bodega Harbor, SON, 26 Oct 1992 (GHF; DNt; 278-1992). Both birds showed the
characteristics of baueri, the expected race of this vagrant to our area. The one at
Bodega was particularly worn, as might be expected on this date.

LITTLE STINT Calidris minuta (5). An adult was in Irvine, ORA, 25-28 Jul 1992
(Figure 6; HCt, BED, JRG+, DK|, MH+, GMcC, MAP; 205-1992), constituting the
first accepted record of a fall adult for California. This bird was in bright alternate
plumage, showing substantial orange in the face and throat but a white chin, as is
typical of this species. The streaks did not quite meet at the center of the breast, and
the tertials were quite dark with rufous edges, all excellent marks for distinguishing this
species from the Rufous-necked Stint (C. ruficollis).

WHITE-RUMPED SANDPIPER Calidris fuscicollis (12). An aliernate-plumaged
bird was near the Wister Unit, Imperial Wildlife Area, south end of the Salton Sea,
IMP, 30-31 May 1992 (MAPI; GMcC; 137-1992). This is the ninth spring record,
with the others falling between 17 May and 16 June.

LITTLE GULL Larus minutus (46). An adult frequented the Santa Maria-Oso
Flaco Lake area, SBA/SLO, 23 Mar-22 May 1992 (JMC; TME, DWQt, JSR; 111-
1992). A first-summer bird was at the north end of the Salton Sea, RIV, 10 May-4 Jul
1992 (GMcC; MAP; 123-1992). A first-year bird at Playa del Rey, LA, 21 Mar 1992
(MH; 185-1992) was judged to be the same individual seen in San Pedro, LA, 26
Apr-1 May 1992 (MHt; NBB, KLG; 186-1992).

COMMON BLACK-HEADED GULL Larus ridibundus (15). A first-winter bird
was in Santa Barbara, SBA, 21 Nov-21 Dec 1992 (SEFt; DDf, PEL, CMt, GMcC,
ASt; 292-1992). On this individual, the pale base of the bill, usually obvious on a
Black-headed Gull, was not always evident even with binoculars. Similarly, the
undenting pattern, with the diagnostic dusky inner primaries contrasting with the two
outer white primaries, was less easily visible than in most individuals of this species.

BLACK-TAILED GULL Larus crassirostris (1). An adult was collected on San
Diego Bay. SD, 28 Nov 1954 (UMMZ 136176; 143-1977) and published by Monroe
(1955). In its 3rd report (Luther et al. 1979). and again in its 9th (Roberson 1986), the
CBRC rejected this record, questioning whether the occurrence was natural. There
were also two votes to reject on the basis of identification, as the evidence supporting
that identification was not circulated. Stephen F. Bailey analyzed the specimen (thanks
to Robert W. Storer and C. Sims of the University of Michigan Museum of Zoology)
and supplied photographs which established its identity beyond question.

The argument against this bird's natural occurrence is based on the concept that
the Black-tailed Gull is generally restricted to coastal areas, without an extensive
pattern of vagrancy. Since the species occurs in Korea, and the specimen was
collected shortly after the Korean War, near a naval shipyard, the probability that the
bird reached San Diego on a ship seemed higher than a unique instance of vagrancy.
Over the past 10 years, however, knowledge of the Black-tailed Gull’s distribution has
increased, and a pattern has emerged, with records of vagrants from Australia and
Thailand. Closer to California, there are now at least seven records from Alaska, one
from Manitoba, and one from Maryland. Among these is a bird photographed at
Ketchikan, Alaska, 22 Aug-8 Oct 1992 (Am. Birds 47:166). In fall, where would this
bird be going? Movement south from Alaska may account for a west-coast record.
Whether Alaska records suggest a pattern relevant to California is debatable, but they
certainly do not hurt the argument that the species could reach this state naturally. As
we go to press, a number of Black-tailed Gulls have been reported in 1995, from
Alaska and the Atlantic states.

10

CALIFORNIA BIRD RECORDS

Figure 7. This Fork-tailed Flycatcher. Tyrannus sauana , photographed 4 September
1992 (240-1992) in Bridgehaven. SON. was the first confirmed in California.

Photo by Nancy T. Conzett

Figure 8. For many species typical of the southeastern U.S.. 1992 was a memorable
year, but at 36 the number of Kentucky Warblers. Oporornis formosus. is one of the
more impressive tallies. This bird, one of eleven found in the area, was in the upper
Santa Ynez R. drainage. SBA. 29 May 1992 (200 1992).

Photo by James M. Greaves

11

CALIFORNIA BIRD RECORDS

Figure 9. A Red-faced Warbler, Cardellina rubrifrons , was at SE Farallon L, SF, 25
August 1992 (253-1992). Both the date and location are unprecedented.

Photo by Peter Pyle

Figure 10. This Field Sparrow. Spizello pusilla. photographed 16 October 1992
(271-1992) at Furnace Creek Ranch. 1NY. shows the small pink bill and eye ring
expected of this species. The rather pale underparts indicate the western subspecies.
S. p. arenacea.

Photo by Jon L. Dunn

12

CALIFORNIA BIRD RECORDS

THICK-BILLED MURRE Uria lomvia (27). One was on Humboldt Bay, HUM, 16
Dec 1992 (DF: BBA, TL; 26-1993). The description was quite complete, mentioning
the dark head and neck, typical of this species at this season. In addition, the pattern
of white extending up into the neck in a “V" (rather than in a rounder “U” shape, as
in the Common Murre, U. aalge ) was noted, as was the thicker, more heavily curved
culmen. The white tomium stripe was not seen, but it may be faint or absent on the
Thick-billed.

PARAKEET AUKLET Cglorrhgnchus psittacuia (42). One was seen about 140 n.
miles SW of San Nicolas L, SBA, 1 Feb 1992 (PP; 74-1992). Five were seen
approximately 193 n. miles west of San Miguel I., SBA, 10 Feb 1992 (PP; 75-1992).
A specimen found dead at the mouth of San Simeon Creek, SLO, 6 Feb 1955, is in
the Royal Ontario Museum in Toronto (ROM 81724; 70-1994). This record,
published by Munro (1957), was on List A of the appendix of the CBRC’s 14th report
(Roberson 1993), of records based on specimens believed lost. We thank Stephen F.
Bailey for obtaining this skin for our evaluation.

RUDDY GROUND-DOVE Columbina talpacoti (53). A male wintered in
Ridgecrest, KER, 5 Feb-4 Apr 1992 (DVB, MOCf; 127-1992). Three birds at
Furnace Creek Ranch, 1NY, 17 May-21 Jul 1992 (GMcC, MAP; 132-1992) were
judged to be the same three that spent the previous winter there (Patten et al. 1995).
Sorting out the occasional fall “explosions” of this species at Furnace Creek Ranch is
often difficult. For the fall of 1992, up to 10 were accepted from 12 Sep 1992 to 4
Jun 1993 (JLDt, SEFf, JH, TH, PEL, GMcC, MAP; 257-1992). A male was at Iron
Mountain Pumping Plant, SBE, 9-16 Oct 1992 (GMcC; MAP; 262-1992). Another
male was in the Tijuana R. valley, SD, 23 Oct 1992 (EDG; 17-1993).

GROOVE-BILLED ANI Crotophaga sulcirostris (8). One was along the Colorado
R. 14 miles north of Blythe, RIV, 30 Sep-8 Oct 1992 (SClf; SFB, SEF, JLD, GMcC,
MAPI. DRt; 261-1992). Another in Baker, SBE. 22-23 Oct 1992 (PEL; SEFf,
SJMt; 291-1992) was the first for San Bernardino County. Another was near Desert
Center, RIV, 23 Oct 1992 (TB; 18-1993). One at El Monte and Pico Rivera, LA, 9
Nov-30 Dec 1992 (SC, BED, KLG, CM; 302-1992) was the first for Los Angeles
County.

This remarkable influx doubles the number of previous records for the state. P. Pyle
(in comments) noted that the grooves in the bill get deeper and more extensive with
age. In the photographs 2-4 shallow grooves are visible, indicating young birds. The
description of the individual in Los Angeles County, mentioning contrasting brown
and black feathers, also specifies an immature.

BROAD-BILLED HUMMINGBIRD Cgrtanthus Jatirostris (36). A first-year male
was in Lone Pine. INY, 12-14 Sep 1992 (MI; JH, THf; 299-1992). This is the first
record for Inyo County. Irwin, who was camping, had set out a feeder attracting
various hummingbirds, including this bird. Although the date is consistent with the
pattern of fall arrivals, the location is not, as this species is scarce in the interior and,
particularly, so far north.

VIOLET-CROWNED HUMMINGBIRD Amazilia violiceps (3). One was at
Kenwood, SON, 26-29 Mar 1992 (SFB, RC, JM, DN+, BDP, DRt; 110-1992). The
early date was some cause for concern, but the species is typically on the move in
Arizona at the time. Furthermore, the likelihood of escaped hummingbirds was not
felt to be high.

GREATER PEWEE Contopus pertinax (29). One was in the Tijuana R. valley, SD,
19 Dec 1992-3 Jan 1993 (GMcC; 4-1993). This record fits a well-established pattern
of late-fall and winter records of this species in coastal southern California.

13

CALIFORNIA BIRD RECORDS

ALDER FLYCATCHER Empidonax ahnorum (2). A singing individual at
Butterbredt Springs, KER, 30 May 1992 (MTH; DVB, MOC; 149-1992) followed
California’s first record, also of a singing bird, by only one year (Patten et al. 1995).
LInlike the first record, which was documented with voice recordings and sonograms,
this record included only written transcriptions of the song (and plumage descriptions),
so it met with some initial resistance. However, the descriptions of the song were
convincing, and the song was compared to that of nearby singing Willow Flycatchers
(E. traillii). The plumage characters (e.g., a thin eye ring) were consistent with the
Alder Flycatcher (although probably within the range of some Willows).

DUSKY-CAPPED FLYCATCHER Myiarchus tuberculifer (28). Nine were found
along the central and southern coast: along the Santa Ynez R. near Lompoc, SBA, 31
Jan-9 Feb 1992 (MAH; SEFf, PEL; 85-1992), at California State University at
Dominguez Hills, Carson, LA, 4-6 Nov 1992 (BED, KLG; 305-1992), at the Big Sur
R. mouth, MTY. 21 Nov-15 Dec 1992 (JND, CH; RC, DRt, RFT; 308-1992), at
Natural Bridge SP. SCZ, 21 Nov 1992-10 Jan 1993 (EL, JM, DLS; 314-1992). at
Pine Gulch Creek, Bolinas Lagoon, MRN, 7-11 Dec 1992 (RS; PPT. 34-1993), at
San Marino, LA. 13-19 Dec 1992 (KLGt; EM; 47-1993), at Pacific Grove, MTY. 23
Dec 1992-11 Jan 1993 (DRt; RC. SBTt, BJW; 313-1992), another at Pacific
Grove, MTY, 29 Dec 1992-3 Jan 1993 (DS: RC, DRt, JSot, SBTt , BJW; 5-1993),
and at Goleta, SBA, 29 Dec 1992-2 Mar 1993 (SEFt; PEL, CAM, GMcC; 6-1993).
A color photograph of one of the birds at Pacific Grove appeared in Am. Birds
47:321. All these records, in late fall and winter, fit the established pattern for the
species, but the appearance of eight in one season (the fall and early winter of 1992)
was unprecedented.

It was impossible to determine the age of many of these individuals, but those at
Bolinas Lagoon and Goleta, retaining juvenal rectrices, appeared to be in their first
winter (P. Pyle in comments). Although this rectrix retention is not well understood or
documented, it seems to explain the presence of rufous margins to the base of the
outer rectrices, a feature that adults lack (Pyle et al. 1987).

GREAT CRESTED FLYCATCHER Myiarchu s crinitus (37). One at Wilmington.
LA, 31 Oct-2 Nov 1990 (MHt; JKAt, KLG; 215-1990) stirred a lively debate, as the
possibility of Brown-crested Flycatcher (M tyrannulus ) was strongly considered by
some members. Much of the debate centered on several poor photographs taken in
harsh lighting, so that the throat and breast of the bird looked paler gray than in life
(K. L. Garrett in comments). Another point raised dealt with the description of the
tertials (the three innermost secondaries). The innermost tertial of the Great Crested
Flycatcher often shows a diagnostic pattern of a whitish fringe wide at the feather base
and tapering to a point toward the tip. The Brown-crested Flycatcher, by contrast,
shows a narrower whitish fringe of fairly equal width throughout the feather. However,
independent examinations of specimens by Garrett (LACM), Heindel (LSUMZ).
McCaskie (SDNHM), and Patten (LACM, WFVZ) led to the conclusion that whereas
the Brown-crested, apparently never shows a tapered fringe, the Great Crested can
have tertial fringes of fairly uniform width. After four full circulations, and discussions
at two different annual meetings, the record was eventually accepted on the strength
of a thorough written description and sketch by Garrett. The documentation included
mention of olive on the back and sides of the breast, a feature lacking on even fresh
Brown-crested Flycatchers of the northwestern (and expected) subspecies M. t.
magister , although potentially present on more southerly subspecies.

Less controversial was a first-fall bird near the Santa Maria R. mouth. SBA. 4 Oct
1992 (JMC, DWQt; 265-1992), as it fit the seasonal pattern slightly better and the
single photograph, though also poor, shows a bird with a dark gray breast.

THICK-BILLED KINGBIRD Tyrannus crassirostris (10). An adult at Seal Beach.
ORA, 9 Oct 1992-20 Mar 1993 (TLW; GMcC, SBT; 7-1993) had returned for its

14

CALIFORNIA BIRD RECORDS

second winter at this location. It was also present 29 Oct 1991-14 Mar 1992 (Patten
et al. 1995).

SCISSOR-TAILED FLYCATCHER Tyronnus forficatus (83). Single individuals
were at Laguna Beach, ORA, 17-25 Mar 1992 (JEP; 37-1993) and at Ft. Dick. DN,
12 May 1992 (ADBf; 60-1993). A male was at Furnace Creek Ranch, 1NY, 24 May
1992 (GMcC; MAPI", SBTt; 136-1992). Individuals were found at the Cactus City
Rest Area along Interstate 10, 10 miles NE of Mecca, RIV, 25 May 1992 (JBo; 217-
1992) and Olema, MRN, 28-30 Jun 1992 (SPJ; LLt; 228-1992). An adult, probably
a female, was at China L. NWC, KER, 7 Aug 1992 (DVB; 20-1993). A probable
female was at Cerro Noroeste, KER, 6 Sep 1992 (R&DS; 21-1993). One was near
the Big Sur R. mouth, MTY 16-19 Oct 1992 (SFB, RC, DR; 273-1992). An
immature was at San Dieguito Co. Park, SD, 4 Dec 1992 (PAG; 76-1993). An
immature female was in El Monte, LA, 6 Dec 1992-9 Jan 1993 (JG; KLG, CAM,
MSM; 48-1993). An adult female/immature male was in Goleta, SBA, 1 1 Dec 1992-
5 Mar 1993 (DDf. PELt, CAMf, GMcC; 8-1993); a photograph was published in
Am. Birds 47:301. This species has become one of the more “routine” rarities
reviewed by the Committee, with records spanning all seasons.

FORK-TAILED FLYCATCHER Tyrannus savana (1). A first-fall bird was at
Bridgehaven, SON, 4-8 Sep 1992 (Figure 7; SFBf, WGB, RC, NTCt, SEFt, FGt,
EDGt, CHK, THK, JML, LL, CAMt. GMcC, JM, DWNt, BDP, MAPt, DEQ, DRt,
MMR, RSt, BvSf, SBTf; 240-1992). A color photograph was published on the cover
of vol. 25, no. 3 of Western Birds, and a black-and-white print appeared in Am. Birds
47.146. Although the subspecies could not be positively determined without a
specimen and comparison with a series, the bird appeared to be of the nominate
subspecies, the one apparently accounting for most records for the United States and
Canada (McCaskie and Patten 1994). This record is one of only three confirmed for
western North America, the others being from Alberta 1 Jun 1 988 (Wedgwood 1 988)
and Idaho 25 Aug-7 Sep 1991 (Trost 1991). There is, however, a report from Santa
Monica, LA, in “late summer” 1883 (Toppan 1884). The alleged specimen support-
ing this record cannot be found, and the record was questioned by Grinnell (1915); it
has not been considered by the CBRC. See Monroe and Barron (1980) and McCaskie
and Patten (1994) for summaries of this species' status and distribution in the United
States and Canada, and the latter for information on subspecies and age determina-
tion.

NORTHERN WFIEATEAR Oenanthe oenanthe (5). One of unknown age/sex (but
possibly an adult male from its sharply defined black mask and uniform tawny
coloration) was at SE Farallon l., SF. 26 Sep 1992 (PP; 293-1992), the site of two
previous records. Aside from the first California record, of a bird taken at SE Farallon
1., 11 Jun 1971 (Manuwal and Lewis 1972, Dunn 1988; CAS 68566), all California
records have been in fall between mid-September and mid-November.

GRAY-CHEEKED THRUSH Cathorus minimus (15). One was at Pt. Reyes NS
(fish docks), MRN, 13-15 Oct 1992 (RS; JM; 312-1992). The descriptions appeared
to eliminate the possibility of Bicknells Thrush, C. bickneUi (Ouellet 1993), a species
unrecorded (and unlikely) in California. See McLaren (1995) and Curson (1994) for
some sobering identification problems with this species-pair. This record fits the Gray-
cheeked Thrush’s pattern of occurrence in California: 13 of the 15 records fall
between 12 September and 31 October (the other two are for spring).

WOOD THRUSH Hylocichla mustelina (10). A singing male was at Dechambeau
Creek, Mono L., MNO. 2-7 Jun 1992 (DP§ ; DWS; 220-1992). One banded and
photographed in hand at Palomarin, MRN, 18-19 Jun 1977 (Luther 1980) consti-
tutes the only previously accepted spring record for California.

15

CALIFORNIA BIRD RECORDS

RUFOUS-BACKED ROBIN Turdus rufopalliatus (7). An apparent female was at
Snow Creek Village, RIV, 1-20 Mar 1992 (TJG; KLG, GMcC, MAP, TLW; 78-1992).
Aside from two birds in Newport Beach, ORA, during the winter of 1982/1983
(Roberson 1986), all Rufous-backed Robins in California, like this one, have been
found in the desert in the southeastern portion of the state,

GRAY CATBIRD DumeteUa carolinensis (65). One collected on SEFarallon 1., SF,
4 Sep 1884 (USNM 100202; 51-1994) was the first for California (Townsend 1885),
Single individuals were at Pt, Reyes NS (lighthouse), MRN, 25 Jun 1992 (RSt; WSf;
29-1993). at Huntington Beach, ORA. 12-31 Oct 1992 (JEP; JRGt- SRG, MAP;
266-1992), and at Onck, HUM, 12 Dec 1992-31 Jan 1993 (GSLf, DR; 41-1993).
A photograph of the Huntington Beach bird appeared in Am. Birds 47; 149, and a
photograph of the Orick bird was published in Am. Birds 47:298.

CURVE-BILLED THRASHER Toxostoma curuirostre (14). One showing the
characters of the western subspecies T. c, palmeri was along the Colorado R. at Sue
Clark’s ranch 14 mi. north of Blythe, RIV, 8-22 Oct 1992 (SFB, JLD|. SEFt, CAM,
GMcC, MAPf, DRf; 260-1992). It represents the first acceptable record for Califor-
nia outside of Imperial County, although given the habitat in the lower Colorado River
Valley and the seven Colorado River records for Imperial County, it was hardly
unexpected.

YELLOW WAGTAIL Motacilla flava (10). A first-fall bird, probably a female, was
at San Joaquin Marsh, ORA, 19-20 Sep 1992 (BED, MTHt, MAPI; 246-1992). As
noted by Patten et al. (1995), all California records of this species fall in the narrow
window of 4 to 21 September, and all are from coastal locations. This record,
however, was only the second for southern California, following a bird photographed
at Malibu Lagoon, LA, 6 Sep 1987 (Pyle and McCaskie 1992).

WHITE-EYED VIREO Vireo griseus (27). A remarkable total of eleven individuals
was found during the spring and summer of 1992, almost doubling the number of
California records. This unprecedented invasion took place simultaneously with that
of the Yellow-throated Vireo (V flavifrons; 9 birds; see below). Northern Parula
(j Parula americana ; 138 birds), Yellow-throated Warbler (Dertdroica dominica ; 6
birds; see below), Worm-eating Warbler ( Helmitheros uermiuorus; 8 birds; see
below), Kentucky Warbler ( Oporornis formosus ; 36 birds; see below), and Hooded
Warbler (Wi/sonia citrina ; 76 birds). This massive incursion of species breeding
predominantly in the southeastern United States was discussed by Terrill et al. (1992);
more complete details will be published elsewhere.

Spring and summer records: Singing males at Upper Newport Bay, ORA, 10 May
1992 (JEP, DRW; 81-1993), Butterbredt Springs, KER, 14-17 May 1992 (MTH;
150-1992), South Fork Kern R. Presen/e, KER, 24-27 Mav 1992 (MDH; 18-1994),
Wilmington, LA, 25 May 1992 (MHt; NBB; 179-1992), Deep Springs, 1NY, 31 May
1992 (JH. TH; 187-1992), upper Arrastre Creek, San Bernardino Mis., SBE, 23-24
Jun 1992 (GH§; 237-1992), San Juan Capistrano, ORA, 26-28 Jun 1992 (BED;
GMcC; 188-1992), China Ranch, near Tecopa, INY, 9-11 Jul 1992 (JT§; 207-
1992), along the Santa Margarita R. near the confluence of De Luz Creek on Camp
Pendleton, SD, 12-17 Jul 1992 (PAG; GMcC; 189-1992), and at Mono L., MNO,
13-14 Aug 1992 (E$t; 286-1992).

An immature was at Pt. Loma, SD, 25 Oct 1992 (PAG; GMcC; 279-1992), and
one of unknown age and sex was measured and banded at SE Farallon I, SF, 28 Oct
1992 (PPt; 297-1992).

YELLOW-THROATED VIREO Vireo flavifrons (49). Nine were located during the
spring and summer of 1992, giving California its largest incursion on record. Single
individuals were at Anaheim, ORA, 9 May 1992 (DPu; 238-1992), Redondo Beach,

16

CALIFORNIA BIRD RECORDS

LA, 9-10 May 1992 (JKAt; 91-1993), Pt. Reyes NS (fish docks), MRN. 16 May
1992 (RS; SC, LL ; 182-1992), and Pt. Loma, SD, 17 May 1992 (GLR; 190-1992).
Singing males were at Ogilvy Ranch along Mono Creek, SBA, 23 May 1992 (JMGt;
173-1992), at Huntington Beach, ORA, 28-30 May 1992 (JEP; 38-1993), at
Descanso Gardens, La Canada-Flintridge, LA, 9 Jun-9 Jul 1992 (RAE; KLG; 146-
1992), and at Centerville Beach, HUM, 25 Jun 1992 (BBAf; GSL; 224-1992). One
at Mono Creek Campground, SBA. 26 Jun-1 Jul 1992 (HR; SEF; 211-1992) was
judged to be an individual different from the bird at Ogilvy Ranch, a location 6 km (4
mi) upstream. A fall vagrant was at Stinson Beach, MRN, 11-18 Oct 1992 (KH, JM,
BDP, SBT; 275-1992).

PHILADELPHIA VIREO Vireo philadelphicus (85). One was at Galileo Hill Park.
KER, 10 Oct 1992 (AS; JLD; 280-1992). One at Goleta, SBA, 14 Fet^l7 Mar 1992
(SEFt; DDt. PEL, GMcC; 87-1992) was perhaps the first to winter anywhere in the
United States; a color photograph of it was published in Am. Birds 46:333. It was
certainly the first to winter unequivocally because two previous winter-season individu-
als in California, at Harbor L., LA, 30 Dec 1978-12 Jan 1979 (Luther et al. 1983)
and Huntington Beach, ORA, 26 Nov 1982-1 Jan 1983 (Morlan 1985), appeared to
be attempting to winter, but may also have been lingering fall vagrants.

YELLOW-GREEN VIREO Vireo flauoviridis (33). An immature was at SE Farallon
I., SF, 30 Sep 1992 (JK, PPf ; 294-1992). Aside from a bird collected at Harper Dry
L., SBE, 2 Oct 1988 (Patten and Erickson 1994; SBCM 52625), all California
records have been for the coast between 8 September and 30 October.

BLUE-WINGED WARBLER Vermiuora pirws (15). An apparent female was at
Mojave, KER, 22 May 1992 (DVB; MTH, SBT; 151-1992), a male was at SE Farallon
I., SF, 24-25 May 1992 (PP; 163-1992), and a probable male was at Pt. Reyes NS
(lighthouse), MRN, 19 Sep 1992 (SC, BDP; 248-1992). This species tends to be
recorded slightly more frequently in spring than in fall.

GOLDEN-WINGED WARBLER Vermiuora chrysoptera (48). A female in Alpers
Canyon, MNO, 15 Jul 1992 (DWS; 221-1992) was remarkable for its date and
perhaps was summering, although it may have been a late spring vagrant. A male was
at El Capitan SB. SBA, 19-20 Sep 1992 (RHt. PELt; 264-1992), and a female was
at Stinson Beach, MRN, 10-12 Oct 1992 (KH; JM. SBT; 311-1992). A male at
Whiting Ranch Regional Park, ORA, 19 Feb- 14 Mar 1992 (MTH. GMcC; 1 OS-
1992) was the first to winter in California, although there are two prior December
records of likely late-fall vagrants: a male found dead in Claremont. LA, 18 Dec 1972
(Patten and Erickson 1994) and a female in the Tijuana R. valley, SD, 15 Dec 1990
(Heindel and Garrett 1995).

YELLOW-THROATED WARBLER Dendroica dominica (70). A singing male was
near Lopez Pt., MTY, 24 May 1992 (SFB; 147-1992). A singing male at Pt. Loma,
SD, 8-10 May 1992 (GMcC; 122-1992), a probable female at Pt. Reyes NS
(Mendoza Ranch), MRN, 30-31 May 1992 (RSt; JM, SBT; 159-1992). one at Pt.
Reyes NS (Nunes Ranch), MRN. 2-3 Jun 1992 (JM; 230-1992), a singina male at
Areata, HUM, 3 Jul 1992 (FB; BBAt, GSL; 225-1992). and a male at Pt. Reyes NS
(Mendoza), MRN, 18 Sep 1992 (RSt; 44-1993) all showed the characters of the
subspecies D. d. albilora , the race that accounts for the vast majority of California
records. The six records in spring/summer of 1992 tied the previous high for that
season, as that number was reached in both 1981 and 1982 (Binford 1985, Morlan
1985, Roberson 1986, Dunn 1988, Bevier 1990, Langham 1991).

GRACE'S WARBLER Dendroica graciae (28). A singing male was at Clark Mt..
SBE, 23 May 1992 (RJR; 141-1992). Only one of two singing males claimed was
accepted; see Roberson (1993) for a discussion of this issue. Males of this species have

17

CALIFORNIA BIRD RECORDS

been recorded on Clark Mountain in 1977 (Luther 1980). 1981 (Roberson 1993),
and 1986 (Bevier 1990); reports from additional years (e.g.. Johnson 1995) have
either not been reviewed or not been accepted by the CBRC (see Roberson 1993).

PINE WARBLER Dendroica pinus (48). An immature male was at Ft. Loma, SD,

6 Jan-12 Apr 1992 (PAG, GMcC, MAPt. 30-1992). An immature male at Furnace
Creek Ranch, 1NY, 21 Oct 1992 (JLD, CAM; SEFt. TH. PEL. GMcC; 281-1992)
provided only the second interior fall record for California, the first being of a female
collected near Westmorland, IMP, 13 Oct 1991 (Patten et al. 1995; SDNHM 47864).
A male at Pt. Loma, SD, 25 Oc.t-10 Nov 1992 (GMcC; 306-1992) was judged to be
probably different from the male present the previous winter (record 30-1992 above).
The frequency of California records continues to increase at an impressive rate; see
Patten and Erickson (1994) for a discussion,

CERULEAN WARBLER Dendroica cerulea (13). A singing male was at Pt. Loma,
SD. 6 Jun 1992 (REW; 191-1992). This species remains very scarce in California in
comparison to many other wood-warblers primarily of eastern North America. Only
three were recorded in spring prior to this bird: a female at Oasis, MNO, 27 May 1974
(Luther et al. 1979), a female at Pt. Loma, SD, 26-27 May 1979 (Luther et al. 1983),
and a male at California City, KER, 17 May 1985 (Dunn 1988).

WORM-EATING WARBLER Helmitheros vermiuorus (68). Single individuals
were at Huntington Beach, ORA, 7 May 1992 (DP; 239-1992) and SE Farallon I., SF,

7 May 1992 (PRBO; 164-1992). A singing male was along Baker Creek near Big
Pine. INY, 19 May 1992 (JH, THi; 193-1992). A female was at Butterbredt Springs,
KER, 24 May 1992 (HB. MOC, MTH; 142-1992). A singing male was at Pt. Reyes
NS (fish docks), MRN, 31 May-2 Jun 1992 (JM; 183-1992). A first-spring bird was
at SE Farallon I., SF. 6-7 Jun 1992 (PPt; 165-1992). One measured and banded at
Coyote Creek Riparian Station, SCL, 17 Jun-6 Sep 1992 (KSt, SBT; 69-1993) was
the first certain to have oversummered in California. One was at Montana de Oro SP,
SLO, 28 Jun 1992 (BSc; 222-1992). The eight individuals found during the spring
and summer of 1992 made easily California’s largest influx of Worm-eating Warblers
on record.

LOUISIANA WATERTHRUSH Seiurus motacilla (6). A sinqing male was at
Huntington Beach, ORA, 3-6 May 1992 (BED; RAE, MTHt. MHt, GMcC, MAP;
119-1992); a photograph of it was published in Am. Birds 46:482. California had
but one record until the mid-1980s, but five have accumulated since that time,

"KENTUCKY WARBLER Oporornis formosus (101). Although Kentucky War-
blers have made impressive showings in other recent springs and summers, such as 8
in 1985 (Dunn 1988, Bevier 1990, Roberson 1993) and 13 in 1987 (Langham
1991, Roberson 1993), the 36 found in spring and summer of 1992 were astound-
ing, representing a number 10 times that of the most recent 10-year average for the
season (Terrill et al. 1992). This year also furnished the first definite summering
records for the species, although breeding was never proven.

Southeast Farallon Island, SF, has hosted more Kentucky Warblers (21 accepted
records prior to this report) than any other location in California, Six more were added
to its tally in 1992: an adult male 4-25 May (PPt; 166-1992), a first -spring female
14-15 May (PRBO; 167-1992), a first-spring male 15-16 May (PRBO, WJSt; 168-
1992), a first-spring female 16 May (PRBO, WJSt; 169-1992), an adult female 1-2
Jun (PPt; 170-1992), and a first-spring female 6-7 Jun (PPt; 171-1992).

On the heels of Southeast Farallon Island for Kentucky Warbler records is Kern
County, which yielded eight in spring 1992: a female at Galileo Hill Park, 9-10 May
(V&AH; MTH, SBT; 152-1992), one at California City, 20 May (RAE; 145-1992),
a singing male at the South Fork Kern R. Preserve, 22 May (MBSt; 195-1992), a
singing male at Butterbredt Springs, 24 May (JMC; MTH; 196-1992), one of

18

CALIFORNIA BIRD RECORDS

unknown age/sex at Butterbredt Springs, 26 May (SBT; 232-1992), another singing
male at Butterbredt Springs, 31 May (RC, MTH, DRo; 140-1992), a singing male at
Mojave, 4 Jun (MTH; 153-1992), and one of unknown age/sex at Butterbredt
Springs 6-7 Jun (MOC: 197-1992)

A singing male was at Los Osos, SLO, 9 May 1992 (JSR; 194-1992). A male
struck a window in Petaluma, SON, 15-16 May 1992 (CNt, DWNf; 62-1993).
Singing males were at Carpinteria Creek, SBA, 16 May 1992 (BBA; SEK PEL; 156-
1992), at Donner Pass, NEV, 24 May-27 Jun 1992 (LJEt; 161-1992), at Furnace
Creek Ranch, Death Valley NP, INY. 25 May 1992 (RST; EH; 154-1992), at Wildrose
Canyon, Glass Mtn.. MNO. 31 May 1992 (PJM; 63-1993). at Mountain Home
Village. SBE, 5-15 Jun 1992 (JDG§; RJH; 267-1992), in Noble Canyon 2.5 miles
north of Pine Valley, SD, 8 Jun 1992 (BC; 198-1992), at Blue Jay in the San
Bernardino Mts., SBE, 12 Jun 1992 (DG; 25-1993), and at Pacific Grove, MTY, 14-
21 Jun 1992 (SFB; RC, DR§, JSot; 157-1992). A female was along Sandia Creek
near Fallbrook, SD, 19-20 Jun 1992 (GMcC: 201-1992).

An amazing total of eleven (and perhaps more) individuals was found in the upper
Santa Ynez River drainage. SBA, between 24 May and 11 Aug 1992, Many of these
birds were banded and photographed in hand, and the efforts of James M. Greaves
were essential in getting a handle on the number of individuals present. Specific
records are as follows: one was along Cameusa Creek near Gibraltar Reservoir. 24
May (JMGt; 200-1992). Three males were found near P-Bar Campground, 28-29
May (Figure 8; JMGt; 200-1992); a color photograph of one was published in Am.
Birds 46:50 1 . Three were at Juncal Campground, 10 Jun-1 1 Aug (JMGt; SEF. PEL,
CAM; 200-1992). One was at Mono Adobe along Mono Creek, 1 1 Jun (JMGt; 200-
1992). Two were at P-Bar Campground, 15 Jun-3 Aug (JMGt: PEL. CAM; 200-
1992). One was at Mono Creek Campground, 22 Jun (JMGt; 200-1992). Voice
recordings of one or two singing males at Juncal Campground on 18 Jun 1992
(CAM§) and of one singing male at P-Bar Campground on 18 Jun 1992 (CAM§) were
deposited at the Library of Natural Sounds. Cornell University, Ithaca, New York.

After the massive showinq in spring and summer of 1992, only two appeared in
fall: at Gaviota SP, SBA, 3 Sep 1992 (BH; 290-1992) and at Galileo Hill Park, KER,
25 Oct 1992 (HBt; 276-1992),

Records of this species are no longer reviewed.

CONNECTICUT WARBLER Oporornis agilis (68). An immature was at SE
Farallon L t SF, 18 Sep 1992 (JKf; 9-1993). Another immature, probably a female,
was at Bodega Harbor. SON, 3-4 Oct 1992 (RAR: DRMt, JM, DWNt, BDP; 269-
1992). Only one observed 22 Oct 1978 at Santa Cruz, SCZ (Luther et al. 1983) was
later in fall than one at SE Farallon I,, SF, 18 Oct 1992 (PPt; 296-1992). As in
previous years. Southeast Farallon Island remains the primary location in California
for this species.

MOURNING WARBLER Oporornis Philadelphia (84). A female was at Mojave,
KER, 22 May 1992 (MTH; 155-1992), an immature male was at SE Farallon I., SF,
30-31 Aug 1992 (PPt; 252-1992), a probable immature male was at Pt. Reyes NS
(Fish Docks), MRN, 20 Sep 1992 (GMcC; SEF; 255-1992), and an immature,
probably a female, was at Furnace Creek Ranch, [NY, 5 Oct 1992 (JLD, GMcC; 270-
1992) Only 12 of California’s prior 80 Mourning Warblers occurred in spring, so the
Mojave bird was noteworthy in that regard. The bird at Furnace Creek Ranch was only
the second found in the interior in fall, following one collected at Baker, SBE, 10 Nov
1979 (Roberson 1993; SBCM 30529).

RED-FACED WARBLER Cardellina rubrifrons (9). An immature, probably a
male, at SE Farallon I,, SF, 25 Aug 1992 (Figure 9; PPt; 253-1992) provided the first
record for northern California; a photograph appeared in Am. Birds 47:147.

19

CALIFORNIA BIRD RECORDS

SCARLET TANAGER Piranga olivacea (83). A female was at Pt. Loma, SD, 24
Oct 1992 (CGE; TC; 23-1993). An immature male at Oceano Campground, Pismo
SB, SLO, 27 Nov-7 Dec 1992 (JMC; TME, KAH. CAM; 303-1992) was quite late,
the only later record being of one at San Luis Obispo, SLO, 27 Nov-13 Dec 1976
(Luther et al. 1979).

PAINTED BUNTING Passerina ciris (41). One was at Goleta, SBA. 2 Sep 1992
(SEF+; 289-1992), and first-fall birds were at SE Farallon I., SF, 5 Oct 1992 (PPf;
295-1992) and Mojave. HER. 6-7 Oct 1992 (GH: MOC, JLD ; 282-1992). Virtually
all accepted California records are of fall birds in female or immature “supplemental”
plumage; all three of these birds fit that pattern well.

FIELD SPARROW Spizeila pusilla (3). One at Furnace Creek Ranch, [NY, 16-17
Oct 1992 (Figure 10; JLDf; THt, GMcC, MAP; 271-1992) appeared to be of the
western subspecies S. p. arenacea. The only previous records were of a bird banded
and photographed in hand at SE Farallon I., SF. 17 Jun-9 Jul 1969 (Robert 1971,
Roberson 1986) and one photographed at Irvine Regional Park, ORA, 25 Nov
1989-6 Jan 1990 (Patten and Erickson 1994).

LE CONTE'S SPARROW Ammodramus leconteii (24). A juvenile was at SE
Farallon I., SF, 18-19 Sep 1992 (JKt; 10-1993). One at Malibu Creek SP, LA, 20
Dec 1992-17 Jan 1993 (SH. KLGf; JBr, JLD, CAM+, GMcC, JM, SS. SBT; 11-
1993), the first for Los Angeles County, was only the third to winter in California,
following others at China L., KER, 27 Nov 1988-2 Jan 1989 and along the Smith
River near Ft. Dick, DN. 5 Jan-11 Feb 1989 (Pyle and McCaskie 1992), The bird on
Southeast Farallon Island was more typical, as aside from the three winter records and
two spring records (Luther 1980, Binford 1985), all Le Conte's Sparrows in
California have occurred in fall between 11 September and 16 November.

SNOW BUNTING Plectrophenax nivalis (52). One was at SE Farallon I., SF, 18
Nov 1992 (LG; 298-1992). One at Bear Valley Ridge. HUM, 22 Nov 1992 was
joined by a second bird on 25 Nov 1992 (MM, AME; 105-1993). Most California
Snow Buntings have occurred from late October through November.

COMMON GRACKLE Quiscalus quiscula (31). A male at Big Pine, INY, 16 Feb-
14 Mar 1992 (THt; DLD+, GMcC, MAP; 93-1992), one at Pt. Loma, SD. 23 Apr
1992 (VPJ, BJ; 202-1992), a different male at Big Pine. INY, 7 Nov 1992 (TH; 300-
1992), and an immature male at Stovepipe Wells, Death Valley NP, INY, 29 Nov
1992 (RSt; LL; 35-1993) all appeared to be Bronzed Crackles, Q. q. versicolor, the
only subspecies recorded in California.

RECORDS NOT ACCEPTED, identification questionable

YELLOW-BILLED LOON Gauia adamsii. The description of one in Carmel Bay,
MTY, 20 Jan 1992 (67-1992) mentioned a pale yellow bill but did not go into any
detail on the distribution of paleness on the bill or some of the other marks expected
on this species.

STREAKED SHEARWATER Calonectris leucomelas. One was reported near
shore at La Jolla, SD, 18 Nov 1992 (83-1993). This record failed to get any support
for a variety of reasons, including the location, late date, and incomplete description.
In addition, the bill was described as pink with a black tip, whereas the vast majority
of Streaked Shearwaters have a pale grayish bill with dusky on the tip of only the
mandible.

20

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification questionable, Cont.

BAND-RUMPED STORM-PETREL Oceanodroma castro. A storm-petrel well
studied and well described bird off San Francisco, west of the Gumdrop Seamount, SF,
2 May 1992 (158-1992) may have been this species. Understanding of the criteria for
distinguishing Band-rumped and Leach’s (O. leucorhoa) storm-petrels in the field,
however, is still evolving. The flight behavior and amount and pattern of white on the
under tail coverts of Leach s vary tremendously. There is a difference in tail length and
the depth of the fork in the tail, but these can be very difficult to assess in the field. One
Committee member, from a drawing of the tail, felt this identification was incorrect,
demonstrating the importance most of us place on this field mark. Also, the Band-
rumped is a warm-water species, and the waters off San Francisco at the time of this
observation were quite cold. As mentioned in previous reports (e.g., Heindel and
Garrett 1995), we have accepted only one record for California (McCaskie 1990), and
given the complexities, it is being re-reviewed.

TRUMPETER SWAN Cygnus buccinator. A photograph of five swans from
Areata Bottoms. HLJM, 2-6 Jan 1991 (Figure 11; 58-1991) demonstrates the
difficulty in identifying them, particularly when vocal clues are not available. After
three circulations of this record, there is still no consensus; a majority of the
Committee felt these birds were most likely Tundra Swans (C. coiumbianus). The
variation in interpretation of these photographs supports the tough scrutiny records of
the Trumpeter have received lately. An immature at White L., Lower Klamath NWR,
SIS, 18 Jan 1992 (104-1992) was identified only by direct size comparison with
nearby Tundra Swans. See Patten and Heindel (1994) for pitfalls in the identification
of immature Trumpeter and Tundra swans.

Figure 1 1 . This group of five swans on 5 January 1991 , at Areata Bottoms, HUM (58-
1991) illustrates how difficult the identification of Trumpeter (C. buccinator ) and
Tundra (C. coiumbianus ) Swans can be. Though a majority of the Committee
concluded that this was a group of Tundra Swans, a consensus could not be reached.

Photo by Michael Hughes

21

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification questionable, Cont.

TUFTED DUCK Ay thyafuligu la. Reports of males at Novato, MRN, 12 Feb 1988
(69-1991) and at Pyramid L... LA, 14 Jan-7 Feb 1991 (102-1992) lacked convincing,
contemporary documentation, although each was felt to be likely correct by a majority
of Committee members. Indeed, the Pyramid Lake bird may have been a previously
accepted male returning for its second winter (see Patten and Erickson 1994).

ZONE-TAILED HAWK Buteo albonotatus. Although this species has become
annual in winter in southern California, the description of one at Irvine Regional Park,
ORA, 20 Dec 1992 (122-1993) was very brief, and owing to lighting and quick views,
too weak to garner support.

GRAY-TAILED TATTLER Heteroscelus brevipes. A tattler, photographed and
seen next to a Wandering Tattler (H. incanus ) on Southeast Farallon I., SF, 9 Oct
1992 (53T993), had whiter sides, looked a touch paler, and had wingtips falling just
short of the tail. In addition, a call that reminded the observer of a golden-plover’s
(Pluuialis dominica,/fu!ua) was heard near the tattlers. Dennis Paulson reviewed the
photograph but considered the identification inconclusive, although the bird in
question definitely had paler sides. Some Committee members wondered whether a
Wandering Tattler could be that pale, or if it could drop its wings enough to cover some
of the gray that typically shows on the flanks. The calls are generally believed to be the
most diagnostic character. The typical call of the Gray-tailed is a two-noted upslurred
whistle, quite different from the repeated monotone whistle of the Wandering. Less
frequently, the Gray-tailed gives a three-noted whistle, still upslurred, as was the case
with the call in question. The uncertainty over whether the vocalization came from a
tattler was a significant factor in most members' letting this one go. Finally, a juvenile
Gray-tailed should show extensive spotting on the upperparts, somewhat reminiscent
of that of the smaller sandpipers of the genus Tringa (e.g., the Solitary, T. solitaria,
or Wood, T. glareola). The general consensus was that this may very well have been
a “good one that got away.” Excellent reading on the identification of this species pair
has been published recently (Paulson 1993, Hirst and Proctor 1995).

CURLEW SANDPIPER Calidris ferruginea. It was apparent that the description
of one at Princeton Harbor, SM, 8 Aug 1992 (51-1993) was written well after the
observers consulted many references. We discourage this practice to the extent
possible, as it may influence subtle details that were not observed, even with the best
of intentions on behalf of the observer. In this case, the main concern was that the
observer, stating it was molting to basic from either adult or juvenal plumage, was not
certain of the bird's age. We feel that if a shorebird cannot be aged with certainty,
certainty of its identification is not likely. Also, the peach color ascribed to this bird's
underparts is far more appropriate for the Red Knot (C. canutus). Some members felt
that this bird could have been a molting adult Red Knot, perhaps with more droop to
the bill than most. '

UPLAND SANDPIPER Bartramia longicauda. One at Crescent City, DN, 8 Sep
1992 (49-1993) proved difficult for the Committee. Much of the description was good
and the date certainly fits the Upland Sandpiper's pattern in fall. There were some
weaknesses in the description, however, and a local observer added uncertainty.
Given the rarity of this species in California, only one member supported the record.

LITTLE/RUFOUS-NECKED STINT Calidris rninuta/ruficollis. A juvenile peep
reported to be one of these species was seen at Elkhorn Slough, MTY, 8 Sep 1992
(13-1993). The basis for the report was a perceived lack of vestigial webs and bright
plumage. We cannot overemphasize the need for caution is assessing whether these
webs are present or absent. Often, seeing the webs in the field is almost impossible.

22

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification questionable, Cont.

Another major pitfall in this identification is seeing a juvenile Least Sandpiper (C.
minutilla) with basic-plumaged adults. The juvenile looks bright in comparison, and
the leg color is often obscured by mud. Finally, the range of brightness of juvenile
Semipalmated Sandpipers (C. pusilla ) is an underappreciated identification problem.
The detail on critical feathers provided in this report failed to address these concerns
adequately.

LONG TOED STINT Catidris subminuta. One reported at the Salinas R. mouth,
MTV, 17 Sep 1992 (268-1992) was photographed, but the images were too distant
to be of any value. Some parts of the description were intriguing, but others were
deficient, and some did not seem right. The observer compared this individual to an
adult he photographed in Alaska, saying it matched that bird very well. Although in the
Long-toed the juvenile arguably looks more like the adult than do those of other
Calidris sandpipers, it is still quite distinct, and a comparison is not really appropriate.

SOOTY TERN Sterna fuscata. We considered two older reports that had not
previously been reviewed by the Committee. One was from San Clemente, ORA. 13
Aug 1968 (1 19-1994), the other from Venice Beach, LA, 27 Jul 1969 (120-1994).
Both records received only four votes to accept, as the majority felt the documentation
supplied did not have enough detail. These records’ being reviewed now is related to
the recent appearance of tropical terns. As noted by Heindel and Garrett (1995) there
have been recent reports from Bolsa Chica, ORA, where in the summer of 1995, a
Sooty Tern was photographed and seen over a prolonged period.

VIOLET-CROWNED HUMMINGBIRD Amazilia violiceps. Shortly after the sight-
ing of one in Kenwood, SON. 28-30 Mar 1992 (see under Records Accepted, 1 10A-
1992), there was a report from Tiburon, MRN, 2-7 Apr 1992 (HOB-1992).
Members felt the locations were too far apart to involve the same individual, so each
record needed to stand on its own. Given the rarity of the Violet-crowned Humming-
bird anywhere in California, especially this far north, the description should be
complete and the bird should have been seen at length in good light. In this case, the
entire bird was not viewed and lighting was poor, leaving most of us uncertain of the
identification.

BLUE-THROATED HUMMINGBIRD Lampornis clemenciae. A female was re-
ported from Morongo Valley, SBE, 25 Apr 1992 (139-1992). This record failed to
get any support on its first circulation. With only one record for the state, all reports
of this species receive exceptional scrutiny. In this case, the bird was described as 1.25
to 1.5 times the size of a Costa’s Hummingbird ( Calypte costae ). Although linear
measurements support the latter comparison, all members noted that the difference
in volume is much greater, making the Blue-throated appear in the field to dwarf
Costa's. Furthermore, the eyestripe and other facial details were not well described,
making many of us suspect an Anna’s Hummingbird (C. anna ) may have been
misidentified. Anna s are quite numerous at Morongo Valley (Patten pers. obs.), and
a juvenile female Anna's matches the described bird very well.

THREE-TOED WOODPECKER Picoides tridactplus. One was reported from
Dixie Mt., PLU, 26 Jun 1992 (245-1992). The Committee was impressed with the
honest write-up and many felt the species claimed may indeed have been present. But
with only one accepted record for California (Trochet et al. 1988), a report of the
Three-toed Woodpecker must meet a high standard, [n this case, there was no
mention of the number of toes and the facial pattern seemed to have a bit too much
white. Furthermore, acceptance of this record would imply either unprecedented
wandering or an unknown population over 100 miles from the previous record.
Although everyone concedes that such wandering it possible, a more certain record is

23

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification questionable, Cent.

necessary to establish it. The most likely source of confusion is with a juvenile Hairy
Woodpecker (P oillosus), Kaufman (1993) covered this problem well. The Committee
appreciates the observer's understanding of the need for caution.

GREATER PEWEE Contopus pertinax. One was reported at the Big Sur R.
mouth, MTY, 19 Sep 1992 (307-1992), but the early date, incomplete description,
and after-the-fact identification led to caution among the Committee. Only two
Greater Pewees, in Huntington Beach, ORA, 11 Sep 1991 and Newport Beach,
ORA, 14 Sep 1991 (Patten et al 1995), have occurred earlier in the fall.

NORTHERN WHEATEAR Oenanthe oenanthe. One at San Rafael, MRN, 12
Dec 1992 (70-1993) was supported by details suggesting a wheatear but also not
eliminating a number of other species such as the Loggerhead Shrike ( Lanius
ludovicianus).

VEERY Catharus fuscescens. One reported at Galileo Hill Park, KER, 25 Oct
1992 (277-1992) was described as being rather olive throughout the upperparts.
Despite the misleading illustration in the National Geographic Society’s (1987) Field
Guide to the Birds of North America, even the westernmost subspecies C. /.
saltcico/us is fairly rufous above. See Phillips (1991) for an appreciation of the range
of variation in this species, but Patten’s examination of the specimen itself (WFVZ
50311) suggests the putative specimen of salicicolus in the color photograph facing
page 104 is instead a Gray-cheeked Thrush (C. minimus).

GRAY-CHEEKED THRUSH Catharus minimus. One at the Smith R. mouth. DN,
6 Jun 1992 (242-1992) may well have been this species, as the observer is
experienced. Nevertheless, the brief views and somewhat incomplete description led
to a caution with a species so difficult to identify in the field.

YELLOW WAGTAIL Motacilla flava. Individuals reported at Black Butte Dam,
TEH, 26 Sep 1992 (283-1992) and Novato, MRN, 4 Dec 1992 (58-1993) were
supported by details suggesting other species were in fact involved.

WHITE WAGTAIL Motacilla alba. Although a male White Wagtail had wintered
near Saticoy and Oxnard in three of the previous four winters (Pyle and McCaskie
1992, Patten and Erickson 1994), the report of a male at Saticoy, VEN, 8 Feb 1992
(86-1992) was too brief to add another year to its occurrence.

WHITE/BLACK-BACKED WAGTAIL Motacilla alba/lugens. One reported at
Coyote Creek Riparian Station, SCL, 15 Dec 1991 (219-1992) was not thoroughly
described; indeed, it was not even clear that a wagtail was seen. Given the extreme
difficulty in the identification of these sister species, a complete description of any
suspected wagtail is essential for the review process to be worthwhile.

RED-THROATED PIPIT Anthus ceruinus. A heara-only fly-over was reported by
a reliable observer at Bolinas, MRN, 22 Oct 1991 (157-1991). As noted by Patten et
ai. (1995), the Committee's standards have changed somewhat in recent years, so
that records of Red-throated Pipits heard only are now often found unacceptable,
lacking a necessary level of documentation that simply cannot be provided given the
nature of the records.

SPRAGUE S PIPIT Anthus spragueii. The description of two birds reported 6
miles NE of Coalinga, FRE, 15 May 1992 (160-1992) suggested that they were in fact
juvenile Horned Larks (Eremophila alpestris). This record is not the first of juvenile
Horned Larks being misidentified at Sprague’s Pipits. Observers should note carefully
the behavior, calls, and face, back, and tail patterns of any purported Sprague’s Pipits
before reporting this species.

24

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification questionable, Cont.

PHILADELPHIA VIREO Vireo philadelphicus. Although perhaps correct, the
identification of a bird at Big Sur R. mouth, MTY, 3 Oct 1992 (309-1992) was
questioned because the observation was brief and the details were sparse.

MOURNING WARBLER Oporornis Philadelphia. Photographs and detailed
descriptions from two experienced observers suggested that a bird reported at Galileo
Hill Park, KER, 9 Oct 1992 (22-1993) may have been an immature MacGillivray’s
Warbler (O. tolmiei ) with a yellowish wash to the throat. The rather bold eye-arcs,
distinct breast-band, yellowish flanks, and grayish head supported the identification of
this bird as a MacGillivray's, but the call note and, perhaps, the throat color suggested
a Mourning. The possibility of a hybrid cannot be dismissed, although this hybrid
combination is unproven in nature; instead, various factors "suggest that extreme
Oporornis specimens are not hybrids” (Pitocchelli 1993). More likely, the bird was a
MacGillivray’s Warbler showing an extreme amount of yellow on the throat, featured
by a small percentage of first-year MacGillivray’s. See Pitocchelli (1990, 1993) and
Pyle and Henderson (1990) for more information about variation and identification
pitfalls in this difficult species pair.

RED-FACED WARBLER Cardellina ruhrifrons. The brevity of observation and
the observer s not having binoculars led to a cautious approach for one reported at
Coyote Hills Regional Park, ALA, 30 Apr 1992 (184-1992), although the details
suggested that this species may indeed have been involved.

EASTERN MEADOWLARK Sturnella magna. A bird photographed at SE Farallon
L, SF, 29 May 1992 (254-1992) was reported as S. m. lilianae , the pale southwest-
ern subspecies. Although field identification of this subspecies (versus Western
Meadowlark, S. neglecta ) may be possible (Zimmer 1984, 1985), the distance of the
observation precluded a detailed plumage description and large-image photographs.
The Committee tends to exercise extreme caution with potential first state records.

RECORDS NOT ACCEPTED, natural occurrence questionable
(identification accepted)

BAR-HEADED GOOSE Anser indicus. One was at Lake Merritt, ALA, 1 Jun
1992 (WVMt; 177-1992). The Committee appreciates the efforts to document this
record, and the photographs certainly do that. Because the Bar-headed Goose is
common in captivity, however, a pattern of records (from Alaska, for example) must
develop before a California record will be given serious consideration.

RUDDY SHELDUCK Tadorna ferruginea. One was at Tule Lake NWR. SIS, 8
Aug 1992 (ADDf;213-1992). Another was well described from Sacramento NWR,
GLE, 14 Nov 1992 (WM; 285-1992). The identification of this species is straightfor-
ward; it is common in captivity, however, and wild Ruddy Shelducks are not thought
to occur anywhere near California.

CONTRIBUTORS

Eva Aiken, Jonathan K. Alderfer, Brooks B. Allen, Jonathan L. Atwood, Stephen
F. Bailey, Alan D. Barron, Brian H. Bell, Tom Biller, David V. Blue, William G.
Bousman, Jeff Boyd (JBo), Jean Brandt (JBr), N. Bruce Broadbooks, Hank Brodkin,
Fred Broerman, June Buntin, Kurt F. Campbell, Rita Carratello, Jamie M. Chavez,

25

CALIFORNIA BIRD RECORDS

Mark O. Chichester, Sue Clark (SCI), Herb Clarke, Therese Clawson, Jim and Peggy
Connolly (J&PC), Nancy T. Conzett, Bart Cord, Scott Cox (SC), Brian E. Daniels, J.
Michael Danzenbaker, Deborah L. Davidson, Jeff N. Davis, Don Desjardins (DDe),
Ruth Doudiet, Aaron D. Drew, Jon L. Dunn, Thomas M. Edell, Leo J. Edson, Claude
G. Edwards, Elias Elias, Felipa M. Errecart, Alan M. Eisner, Aaron J. Fink, Shawneen
E. Finnegan, John Fitch, David Fix, James R, Gallagher, Sylvia R. Gallagher, Frank
Gardner, Kimball L. Garrett, Douglas E. George, Lucy Gilbert, Peter A. Ginsburg,
Joann Getze, Theodora J. Glenn, John D. Goodman, David Goodward, Edward D.
Greaves, James M. Greaves, Helen Green, Frangois Halligon, Murrelet D. Halterman,
Keith Hansen, Scott Harris, Stanley W. Harris, Ed Hase, Karen A. Havlena, Bob
Hefter, Jo Heindel, Matthew T. Heindel, Mitch Heindel, Tom Heindel, R. J. Higbie,
Brad Hines, Ron Flirst, Norman D. Hogg, Craig Hohenberger, Mark A. Holmgren,
Vernon and Andrew Howe (V&AH), Richard Irvin, Marge Irwin, Lin Jensen, Suzanne
P. Johnson, Virginia P. Johnson, Bernice Jones, Joe Kaplan, Christine H.
Koundakjian, Theodore H, Koundakjian, Jeri M. Langham, Earl Lebow, Paul E.
Lehman, Tom Leskiw, Gary S. Lester, Leslie Lieurance, Elaine MacPherson, Michael
Mammoser (MMa), Timothy D. Manolis, Curtis A. Marantz, Guy McCaskie (GMcC),
Peter J. Metropolus, Wayne Meyer, Steven Mlodinow, David R. Moore. Joseph
Morlan, Jim Morris (JiM), Michael Morris, Stephen J. Myers, Clyde Nelson, Dan W.
Nelson, Debby Parker (DP), Benjamin D. Parmeter, Michael A. Patten, James E. Pike,
Pt. Reyes Bird Observatory (PRBO), Nick Pulcinella, Dick Purvis (DPu), Peter Pyle,
David E. Quady, David W. Quesenberry, William R. Radke, Hugh Ranson. Daniel L.
Reinking, Craig Reiser, Robert J. Richmond, Dave Riensche (DRi), Karen Rippens,
Don Roberson (DR), Geoffrey L, Rogers, Michael M. Rogers, Jim S. Royer, Ruth A.
Rudesill, Florence Sanchez, Mike San Miguel, Barry Sauppe (BS), Brad Schram (BSc),
Kristin Shields, John Shipman, David W. Shuford, Daniel Singer, Arnold Small, John
Sorenson (JSo), Rich Stallcup, Willow Stallcup, John C. Sterling, Russell and Dorothy
Stone (R&DS), Mary Beth Stowe, Ernilie Strauss, David L. Suddjian, Sherman Suter,
William J. Sydeman, Jan Tarble (JT), Jim Taylor (JTa), Monte M. Taylor, Scott B.
Terrill, Ronald S. Thorn, Robert F. Tintle, William van Meter, Bill van Schaick, Alan
Walther, Jan Wasserman, Richard E. Webster, Brian J. Weed, Bette Wentzel, Janet
Wessel (JWe), Tom L. Williams, Douglas R, Willick, John C. Wilson, Jon Winter (JWr),
Joseph Worley (JWo).

ACKNOWLEDGMENTS

We thank J. V. Remsen, Jr., for information on age determination and subspecies
of the Fork-tailed Flycatcher. Robert W. Storer and C. Sims were of great assistance
in obtaining information about and loaning the specimen of the Black-tailed Gull from
the University of Michigan Museum of Zoology. Likewise, David Willard provided
photographs and information regarding the Mississippi Kite at the Field Museum, and
M. Ralph Browning and Don Roberson were instrumental in obtaining information
regarding the Gray Catbird at the U.S. National Museum. Dennis Paulson was helpful
with discussion on Gray-tailed Tattler identification.

Committee members who reviewed some or all of the records treated in this report
were Stephen F. Bailey, Jon L, Dunn. Richard A. Erickson, Shawneen E. Finnegan,
Kimball L. Garrett, Matthew T. Heindel, Paul E. Lehman, Gary S. Lester, Michael J.
Lippsmeyer, Guy McCaskie, Joseph Morlan, Michael A. Patten, Peter Pyle, Don
Roberson, and Scott B. Terrill.

26

CALIFORNIA BIRD RECORDS

LITERATURE CITED

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.

Curson, J, 1994. Identification forum: Separation of Bicknell’s and Grey-cheeked
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CALIFORNIA BIRD RECORDS

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CALIFORNIA BIRD RECORDS

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Accepted 17 November 1995

Kentucky Warbler

Sketch by Edward Rooks

29

BREEDING DISTRIBUTION OF VAUX’S SWIFT
IN CALIFORNIA

JOHN STERLING, Smithsonian Migratory Bird Center, National Zoological Park,
Washington, D.C. 20008

PETER W. C, PATON, U,S. Department of Agriculture Forest Service, Redwood
Science Laboratory, 1700 Bayview Drive, Areata, California 95521 (present address:
Department of Natural Resources Science, University of Rhode Island, Kingston,
Rhode Island 02881)

Vaux’s Swift ( Chaetura vauxi) is a migrant that breeds from the western
United States south to northern Venezuela and winters from central Mexico
to Venezuela (AOU 1983). In 1994, the California Department of Fish and
Game designated it a “species of special concern.” Its breeding biology and
habitat requirements are poorly known but are thought to be closely linked
to old-growth forests (Lundquist and Mariani 1991, Bull and Hohmann
1993). One of the most controversial topics facing biologists today is the
fragmentation of old-growth forests and its effects on bird distribution in the
western United States {Harris 1984, Thomas et al. 1990). The bulk of the
ornithological work addressing this topic focuses on the ecology of three
species, the Spotted Owl (Strix occidentalis) (Thomas et al. 1990), Marbled
Murrelet ( Brachyramphus marmoratus) (Carter and Morrison 1992), and
Pileated Woodpecker ( Dryocopus pileatus) (Mellen 1987). Other species
receive relatively little research emphasis (Carey 1989, Ralph et al. 1991,
Huff and Raley 1991).

Most published studies on Vaux’s Swift have concentrated on its use of
man-made chimneys as nest sites (Baldwin and Hunter 1963, Baldwin and
Zaczkowski 1963, Thompson 1977), although more recent work focuses
on forested ecosystems in northeastern Oregon (Bull and Cooper 1991,
Bull and Hohmann 1993, Bull and Beckwith 1993).

For California, Grinnell and Miller (1944) described the breeding distribu-
tion of Vaux’s Swift as extending in a “narrow northwest coast belt south
from the Oregon line in Del Norte County as far south as Santa Cruz, Santa
Cruz County.” The coastal breeding range of swifts in California generally
corresponds to the historical distribution of the Coast Redwood ( Sequoia
semperuirens) (Kuchler 1977). Less than 10% of the original old-growth
redwood forest remains (Fox 1989), the rest having been harvested (Green
1985) since the early ornithological surveys of California. Grinnell and Miller
(1944) also cited occasional breeding-season records from the Sierra Ne-
vada. We discuss here the current distribution of Vaux’s Swift in California
based on our recent survey work, U.S. Fish and Wildlife Service (FWS)
breeding-bird surveys, anecdotal observations, and a review of the literature.

METHODS

Vaux’s Swifts were censused from Del Norte to Sonoma County during
129 Marbled Murrelet surveys conducted in 1989 by Paton and Ralph
(1990), who provided details on the study areas and survey methods.

Western Birds 27:30-40, 1996

30

VAUX’S SWIFT BREEDING DISTRIBUTION

Biologists conducted surveys along transects, with 250 to 1000 m spacing
between stations and 8 to 12 stations per transect. They censused each
station for 10 minutes. The survey period extended from 45 minutes before
to 90 minutes after sunrise from mid-May through mid-August. They noted
swifts as present or absent at each station. Defining statistical significance as
alpha < 0.05, we compared swift use of old-growth versus second-growth
stands by means of a log-likelihood ratio-test statistic (G 2 ).

Fox (1989), using infrared aerial photographs, mapped and classified
redwood forest as old growth (> 200 yrs. old) or second growth (< 200 yrs.
old). Using these data, we designated each of our transects as old growth or
second growth.

J. Hunter and G. Hazard (unpublished data) conducted 4452 ten-minute
point counts in 274 randomly selected late mature (150-200 yrs. old) and
old-growth (> 200 yrs. old) stands from 17 April to 23 July 1995 in the Mad
River Ranger District of the Six Rivers National Forest. Their study area
extended north to Last Chance Ridge, south to the Yolla Bolly Wilderness,
west to approximately 30 miles from the coast, and east to 45 miles from the
coast at South Fork Mountain.

Sterling searched for Vaux’s Swifts during extensive bird surveys for the
U.S. Forest Service in Modoc, eastern Shasta, and northwestern Lassen
counties from April to September 1990 and 1991. These surveys included
30 transects each 1 km long and 200 meters wide as well as incidental
observations during active searching from all localities accessible by road.
The bulk of the effort was along Hat Creek, in the Warner Mountains, on the
Modoc Plateau, and in the Black’s Mountain region.

We searched American Birds files for all breeding-season records of
Vaux’s Swift in northern California. We also obtained data from the
Breeding Bird Survey Program (BBS) of the FWS as well as from numerous
birders and biologists.

We felt that swifts found from June to early August were probably not
migrants and represented breeding populations. We incorporated data from
mid May in the results only if swifts were also present at that site in June and
July. Apart from a few nesting records from chimneys in towns, conifers
provide nesting and roosting sites.

RESULTS

Swifts on Marbled Murrelet Surveys

Swifts were observed on 48 of the 129 surveys (37.2%). We plot the
locations in Figure 1 . There was a tendency for swifts to be detected more
often on old-growth transects: 29 of 65 old-growth transects (44.6%) and
19 of 64 second-growth transects (29.7%). However, using a log-likelihood
ratio test, we found the difference of P = 0.079 (G 2 = 3.09, df = 1) only
marginally significant statistically.

During murrelet surveys, we saw swifts in all four northwestern California
counties — Del Norte, Humboldt, Mendocino, and Sonoma (Figure 1). Areas
with the most stations where swifts were present included the large state and
national parks in Humboldt and Del Norte counties: Jedediah Smith Red-

31

VAUX’S SWIFT BREEDING DISTRIBUTION

Vaux's Old-growth

Swift Redwood

Figure 1. Current distribution of Vaux’s Swift and old-growth redwood in northwest-
ern California, based on Fox (1989). Open circles, no swifts detected on murrelet
transect; filled circles, swifts detected on murrelet transect; filled squares, probable
swift breeding site from Shuford (1993). Numbered polygons: (1) Jedediah Smith
Redwoods State Park, (2) Prairie Creek Redwoods State Park, (3) Redwood National
Park, (4) Pacific Lumber Company lands, (5) Humboldt Redwoods State Park, (6)
Miranda, (7) Russian Gulch/Van Damme state parks, (8) Standish Hickey State Park,
(9) Armstrong Redwoods State Park, (10) Samuel P. Taylor State Park.

32

VAUX’S SWIFT BREEDING DISTRIBUTION

woods State Park, Prairie Creek Redwoods State Park, Redwood National
Park, and Humboldt Redwoods State Park. Encounters with swifts extended
as far inland as 24 miles at Grizzly Creek Redwoods State Park, Humboldt
County, although this was the farthest inland that we conducted murrelet
surveys.

Point-Count Data from Six Rivers National Forest

Hunter and Hazard detected swifts on only three of 4452 point counts.
Two records were during the breeding season: in addition, a pair and a single
swift were at two locations in the study area (see Appendix A), These sites
are 35 to 45 miles inland.

Distribution Throughout California

In the northeast, pairs in courtship display were located at three widely
scattered areas along Hat Creek, at four localities in the Warner Mountains,
and in the town of Fort Bidwell. Swifts were not detected from over a large
area including the Black s Mountain region of the Lassen National Forest
and the Modoc Plateau (Sterling pers. obs.).

Of the 217 BBS routes conducted throughout California from 1968 to
1994, only 32 had swifts, primarily in the northwest and northeast (Figure
2). The routes within 25 miles of the north and central coast averaged 1.64
swifts per route per year for all survey years (n = 310). In contrast, routes in
the northeast averaged only 0.48 swifts (n = 169). Using a two-tailed t test,
we found the difference highly significant, with P < 0.000001.

We determined that the coastal breeding range extends from the north
coast of Del Norte County south to Santa Cruz County and, rarely, to Big
Sur, Monterey County. This matches the broad-scale range described by
Grinnell and Miller (1944). However, we speculate that forest fragmentation
alters the species’ distribution on a smaller scale, as we found the majority of
murrelet transects with swifts in parks (Figure 1). Future research should
focus on the effects of this fragmentation. Scattered inland records are from
western Siskiyou County and central Trinity County south through central
Mendocino County and eastern Sonoma County. Infrequently, a few pairs
have nested in chimneys in eastern Modoc, central Sonoma, central Contra
Costa, and Santa Clara counties. Further inland, a few swifts reside from
southeastern Siskiyou County south along the west slope of the Sierra
Nevada to Tulare County (most between 1500 and 4500 feet elevation) and
in eastern California from the Warner Mountains in Modoc County south to
Sierraville, Plumas County (Appendix; Figure 2) (BBS data, Am. Birds data,
Gaines 1992, Harris 1991, Roberson and Tenney 1993, Shuford 1993,
Sterling pers. obs.).

DISCUSSION

We view the results from several angles. First, Vaux’s Swift’s breeding
distribution may be closely linked to the availability of suitable nest sites,
namely, large, hollow live trees and snags and man-made chimneys (Bull and
Collins 1993). Second, we lack both quantitative and qualitative data on

33

VAUX’S SWIFT BREEDING DISTRIBUTION

nest-site selection in California. Third, we lack detailed knowledge of how far
Vaux’s Swifts range from their nests and how that distance may vary by
habitat, stage of the nesting cycle, or time of day.

A discussion of the species’ breeding range should consider the availability
of suitable nest sites; however, there is still relatively little known about the
breeding ecology of Vaux’s Swifts in California forests. In northeastern
Oregon, all 21 nests found by Bull and Cooper (1991) were in Grand Firs
( Abies grand is) decayed and hollowed out by Indian paint fungus
( Echinodontium tinctorium) and excavated by Pileated Woodpeckers. In
California, the Grand Fir is restricted to the north coast forests, where it is

Figure 2. Current distribution of Vaux’s Swift in California during the breeding season.
Open circle, no detections on breeding-bird survey route; filled circle, swifts detected
on breeding-bird survey route; filled square, single or multiple detections from
American Birds files and unpublished sightings.

34

VAUX’S SWIFT BREEDING DISTRIBUTION

only minor component of the forest. However, evidence for a stronger
association between Pileated Woodpeckers and Vaux’s Swifts is the dose
correspondence of the two species’ ranges (Zeiner et al. 1990). The swift’s
only known nesting populations outside of the woodpecker’s range in
California, in Modoc, Contra Costa, Santa Clara, and Monterey counties,
are small. Interestingly, many of the records of swifts nesting in man-made
chimneys are from these localities.

It is difficult to assess the effects of forest fragmentation on the coastal
range of Vaux’s Swift properly because we lack quantitative and qualitative
data on potential nest trees. This makes conclusions of habitat requirements
based on census results speculative. Bull and Hohmann (1993) positively
associated swifts with mature and old-growth forests, which contain a higher
density of suitable nest trees than logged stands. However, we are unsure if
these findings from northeastern Oregon are relevant to coastal popula-
tions, especially in the redwood zone. We did not conduct detailed vegeta-
tion studies along our Marbled Murrelet survey transects. Potential nest trees
may have existed in both the old-growth and second-growth stands that we
surveyed, explaining why we found only slight differences in the swift’s
frequency in these two forest-age classes. It is possible that the lack of
significant difference is due to the definition of the two classes. Bull (pers.
comm.) believes that in northeastern Oregon mature stands (>150 years)
offer a suitable forest structure and nest sites. Perhaps if we had defined the
age classes as second-growth (<150 years) and mature to old-growth (>150
years) we would have found a significant difference in the survey results.

Bull and Hohmann (1993) reported limited use of residual snags in
second-growth forest. Dawson (1923) and egg collectors such as Clay (from
egg-set data cards at Humboldt State University) described nests in residual
snags on old burns and clear-cuts. There is a great need for studies that
determine the extent of residual snags in logged stands, the length of time
these snags remain standing after the logging of adjacent forest, and the time
needed for their regeneration in different areas.

The results of our censuses may reflect the early-morning foraging by
swifts in second-growth stands away from their nest trees in old-growth
forests. Bull and Beckwith (1993) found swifts foraging more than 40 meters
from their nests 47% of the time. To our knowledge, no one has quantified
the activity patterns of swifts in California. We need observations of known
nest sites and their occupants’ foraging to enable us to interpret census
results properly. At this point in our knowledge, the best method for
assessing the swift’s population is censuses of nest sites.

Our study of Vaux’s Swift distribution in California has supported and
somewhat extended the range described by Grinnell and Miller (1944). The
BBS data demonstrate the restriction of highest densities in the state to the
narrow coast belt of northern and central California, the redwood zone. The
study in Six Rivers National Forest indicates that swifts fall to very low density
only 30 to 45 miles inland and in apparently suitable forest, namely, mature
and old-growth Douglas Fir ( Pseudotsuga menziesii). This low density is
seemingly representative of the swift population throughout the bulk of its
range in California. It is difficult to know whether the species’ range in
California has recently extended into the northeast. Early explorers possibly

35

VAUX’S SWIFT BREEDING DISTRIBUTION

overlooked it. In the Sierra Nevada, apart from one nest, suspected breeding
remains undocumented. Amazingly, there are only a few reports of nests in
the entire state since Grinnell and Miller (1944). Of these, all but one, to our
knowledge, are from chimneys, including the first documented nest for
Marin County in 1995 (Appendix).

SUMMARY

In California, Vaux’s Swifts live mostly in the narrow redwood-forested
coastal zone from Del Norte to Santa Cruz counties. At the time of Grinnell
and Miller (1944), there were a few scattered breeding-season records from
the Sierra Nevada and no nesting records outside the narrow belt along the
north coast. Since then, our knowledge has changed little. There are still
only a few records from scattered localities in the Sierra Nevada, and these
probably reflect the species’ true status rather than our lack of data. The lack
of swifts over large areas illustrates how local this distribution is; for example,
Jim Steele (pers. comm.) reports an absence of June and July records for the
Yuba Pass and Sierra Valley area since 1976. Since the swift nests primarily
in hollow snags, the presence of nest sites probably limits its distribution. In
northeastern Oregon, suitable nest trees had Pileated Woodpecker cavities,
and in California, Vaux’s Swift and this woodpecker have nearly coinciding
ranges. Their relationship merits more research. In California, ornitholo-
gists and birders contribute principally to the understanding of Vaux’s Swifts
by expanding the number of known summer localities through northeastern
California and the Sierra Nevada. Unfortunately, the knowledge of the
species in California does not extend much beyond the description of its
general range.

ACKNOWLEDGMENTS

We thank William Laudenslayer for his support throughout the project, for
Sterling’s support during bird surveys in Modoc and Lassen National Forests, and for
comments that greatly improved early drafts. Bruce Peterjohn graciously supplied
BBS data. Betty Burridge compiled and sent us nesting records from Sonoma County.
David Graber furnished data from Kings Canyon and Sequoia national parks. Mike
Robbins, Nancy Naslund, and Ron LeValley supplied unpublished sightings. John
Hunter and Gjon Hazard, Six Rivers National Forest, generously provided unpub-
lished data from point counts. We thank C. J. Ralph, Redwood Sciences Laboratory,
for access to swift survey data from coastal California. David Craig, Brian O’Donnell,
and Bud Widdowson helped collect field data during Forest Service Marbled Murrelet
surveys. Evelyn Bull, C. J. Ralph, and Philip Unitt kindly reviewed the manuscript and
suggested many improvements.

LITERATURE CITED

American Ornithologists’ Union. 1983. Check-list of North American Birds, 6th ed.
Allen Press, Lawrence, KS.

Baldwin, P. H., and Hunter, W. F. 1963. Nesting and nest visitors of the Vaux’s Swift
in Montana Auk 80:81-85.

36

VAUX’S SWIFT BREEDING DISTRIBUTION

Baldwin, P. H., and Zaczkowski . N. K. 1963. Breeding biology of the Vaux Swift.
Condor 65:400-406.

Bull, E. L. 1991 . Summer roosts and roosting behavior of Vaux’s Swifts in old-growth
forests. Northwest. Naturalist 72:78-82.

Bull, E. L., and Beckwith, R. C. 1993. Diet and foraging behavior of Vaux's Swifts in
northeastern Oregon. Condor 95:1016-1023.

Bull, E. L., and Collins, C. T. 1993. Vaux’s Swift (Chaetura uauxi ), in The Birds of
North America (A. Poole and F. Gill, eds.), No. 77. Acad. Nat. Sri., Philadelphia.

Bull, E. L., and Cooper, J. D. 1991. Vaux’s Swift nests in hollow trees. W. Birds
22:85-91.

Bull, E. L., and Hohmann, J. E. 1993. The association between Vaux’s Swifts and old-
growth forests in northeastern Oregon. W. Birds 24:38-42.

Burridge, B. (ed.) 1995. Sonoma County Breeding Bird Atlas. Madrone Audubon
Soc., Santa Rosa, CA.

Carey, A. B. 1989. Wildlife associated with old-growth forests in the Pacific North-
west. Nat. Areas J. 9:151-162.

Carter, H. R., and Morrison, M. L. (eds). 1992. Status and conservation of the
Marbled Murrelet in North America. Proc. West. Found. Vert. Zool. 5:1-133.

Dawson, W. L. 1923. The Birds of California. South Moulton Co., San Diego.

Fox, L. 1989. A classification, map, and volume estimate for the coast redwood forest
in California. Forest Rangelands Resources Assessment Program, Calif. Dept.
Forestry and Fire Protection, Sacramento, CA.

Gaines, D, 1992. Birds of Yosemite and the East Slope. Artemisia Press, Lee Vining,
CA.

Green, K. 1985. The old growth redwood resource: A historical review of harvesting
and preservation. Hammon, Jensen, Wallen and Associates, 8407 Edgewater
Dr., Oakland, CA 94621.

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

Harris, L. D. 1984. The Fragmented Forest: Island Biogeography Theory and the
Preservation of Biotic Diversity. Univ. Chicago Press, Chicago.

Harris, S.W. 1991. Northwestern California Birds. Humboldt State Univ. Press,
Areata, CA.

Huff, M. H., and Raley, C. M. 1991. Regional patterns of diurnal breeding bird
communities in Oregon and Washington, in Wildlife and vegetation communities
of unmanaged Douglas-fir forests (L. F. Ruggiero, K. B. Aubry, A. B. Carey, and
M. H. Huff, eds.), pp, 177-206. U.S. Forest Serv. Gen. Tech. Rep. PNW-GTR-
285.

Kuchler, A. W. 1977. Natural vegetation of California. William and Heintz Map
Corp., Washington, D.C. 20027.

Lundquist, R. W., and Mariani, J. M. 1991. Nesting habitat and abundance of snag-
dependent birds in the southern Washington Cascade range, in Wildlife and
vegetation communities of unmanaged Douglas-fir forests (L. F. Ruggiero, K. B.
Aubry, A. B. Carey, and M. H. Huff, eds.), pp. 221-240. U. S. Forest Serv. Gen.
Tech. Rep. PNW-GTR-285.

Mellen, T. K. 1987. Home range and habitat use of Pileated Woodpeckers, western
Oregon. M. S. thesis, Ore. State Univ., Corvallis.

37

VAUX’S SWIFT BREEDING DISTRIBUTION

Paton, P. W., and Ralph, C. J. 1990. Distribution of the Marbled Murrelet at inland
sites in California. Northwest. Naturalist 71:72-84.

Ralph, C. J., Paton, P. W., and Taylor, C. A. 1991. Habitat association patterns of
breeding birds and small mammals in Douglas-fir/hardwood stands in northwest-
ern California and southwestern Oregon, in Wildlife and vegetation communities
of unmanaged Douglas-fir forests (L. F. Ruggiero, K, B. Aubry, A. B. Carey, and
M. H. Huff, eds.), pp. 379-394. U.S. Forest Serv. Gen. Tech. Rep. PNW-GTR-
285.

Roberson, D., and Tenney, C. (eds.). 1993. Atlas of the Breeding Birds of Monterey
County, California. Monterey Peninsula Audubon Soc., Carmel, CA.

Shuford, D. 1993. Marin County Breeding Bird Atlas. Bushtit Press, Bolinas, CA.

Thomas, J. W. , Forsman, E. D., Lint, J. B., Meslow, E. C., Noon, B. R., and Verner,
J. 1990. A conservation strategy for the northern Spotted Owl. 1990-791-171/
20026, U.S. Govt. Printing Office, Washington, D.C.

Thompson, B. C. 1977. Behavior of Vaux’s Swifts nesting and roosting in a chimney.
Murrelet 58:73-77.

Zeiner, D., Laudenslayer, W. F., Mayer, K., and White, M. (eds.). 1990. California’s
Wildlife, vol. 2. Calif. Dept. Fish and Game, Sacramento.

APPENDIX. Records of Vaux’s Swift in California during the breeding
season, from American Birds files and unpublished data. Organized by
county, location, date, and observer; if the birds were noted using a
chimney, this is specified. Abbreviations: cyn., canyon; ft., fort; mt., moun-
tain; PRBO, Point Reyes Bird Observatory; r., river; res., reservoir; S, P,
state park.

Butte Co.: Butte Meadows?, Jun-Jul 1973 (D. Gaines)

Contra Costa Co.: Walnut Creek, 12 Jun 1972 (W. Purcell); Alamo, 17 Jun 1981
(J. Richmond)

Del Norte Co.: Crescent City, 8 Jul 1982 (J. Hornstein); Yurok, Klamath R., 6 Jun
1990 (G. Lester), 18 Jun 1990 (A. Barron), 7 Jul 1990 (G. Lester)

El Dorado Co.: Wright’s Lake, 17 Jul 1955 (W. Minturn), 14 Jul 1956 (A. Craig);
China Flat, 9 Jun 1962 (F. Evenden); Union Valley Res., 6 Jun 1987 (E. Harper);
Kyburz, 21 May 1993 (M. Johnson)

Fresno Co.: Kinsh Flat, 29 Jun 1975 (R. Hansen); Teakettle, 1 Jun 1990, 7 Jun
1990 (K. Purcell); Markwood, 18 Jun 1990 (K. Purcell)

Humboldt Co.: Orleans, 30 May 1988 (M. Robbins); Areata and Eureka, each
summer (many observers), in chimneys

Lassen Co.: South Eagle Lake, mid Jun 1974 (S. Laymon); 12 mi. W Susanville, 7
Jul 1979 (M. Mans); Manzanita Lake, 30 Jul 1979 (B. & C. Yutzy); Johnstonville, 4
Jun 1980 (B. Deuel); Crater Lake, 7 Jul 1984 (P. Metropulos); near Westwood, 13 Jul
1985 (J. Hornstein); Blue Lake, S. Warner Mts., 20 Jun 1990 (J. Sterling)

Marin Co.: Lake Lagunitas, 15 Jul 1970 (A. L. Carl); Alpine Lake, 22 Jun 1971
(W. Purcell); Palomarin, 16 Jun-7 Jul 1979, 3 Jun 1977, 23 Jun 1982 (PRBO); Five
Brooks, 31 May 1980 (J. Evens), 17 Jun 1977 (B. Sorrie); Bolinas Lagoon, 14 Jun
1980 (J. Evens), 30 Jul 1995 (K. Hansen), in chimney; Novato, 16 Jul 1980 (D.
Shuford); Kent Lake, 18 Jul 1981 (D, Shuford); Terralinda, 30 May 1982 (B. Lenarz);
Carson Ridge, 5 Jun 1982 (D. Shuford); Garden Club Cyn., 4 Jul 1982 (D. Shuford);

38

VAUX’S SWIFT BREEDING DISTRIBUTION

Galloway Cyn., all Jun 1983 (D. DeSante), 1 Jun 1985 (PRBO); Bolinas Ridge, 30
Jun 1985 (D. Holway); Bolinas, 27 Jul 1985 (A. Edwards); Las Gallinas pond, 13 Jul
1988 (D. Holway)

Mariposa Co.: Yosemite, 17 Jun 1969 (A. Baldridge), 13 Jun 1971 (T. Chandik);
Tamarack Flat, 25 Jul 1983 (W. Bousman); Vernal Falls, 20 Jul 1984, Chisholm;
North Dome Trail, 11 Jun 1985 (R. Marlowe)

Modoc Co.: Buck Creek, 18 Jun 1975 (D. Winkler); Lassen Creek, 21 Jun 1975
(D. Winkler); Day, 8 Jun 1980 (S. Laymon); Whitehorse Flat R., 3 Jun 1985 (M.
Robbins); Thoms Creek at Highway 299, 5 Jun 1985 (J. Greenhouse); Clear Lake,
15 Jul 1985 (D. Shuford); Soup Creek, S. Warner Mts., 20 Jun 1990 (J. Sterling); Ft.
Bidwell, 11 Aug 1988, Jun-Jul 1990, Jun-Jul 1991 (J. Sterling), in chimney; near
Eagleville, 15 Jul 1990 (J. Sterling); Cedar Pass, Jun-Jul 1991 (J. Sterling); S. Warner
Mts., 6 Jul 1991 (A. Barron)

Mono Co.: Paha Campground, 20 Jul 1985 (H. Green)

Monterey Co.: Torres and Grimes Creek, 5 Aug 1984 (D. Roberson); Big Sur R.
mouth, 8 Jun 1985 (D. Roberson); Partington Cyn., 29 Jun 1991 (D. Roberson)

Nevada Co.: Boca Res., 16 Jul 1959 (G. McCaskie); Sagehen Creek, 19 Jul 1966
(H. Cogswell)

Placer Co.: Tahoe City, 16 Jul 1959 (G. McCaskie), 16 Jun 1962 (P. DeBenedictis),
20 Jun 1982 (D. Yee); French Meadows, 27 Jun 1982 (T. Chandik)

Plumas Co.: Buck’s Lake, 9 Aug 1973 (R. Stallcup); Butterfly, 2 Jul 1974 (P.
Metropulos); Chester, 5 Jul 1984 (H. Green); L. Almanor, 22 Jul 1987 (H. Green)

San Mateo Co.: Skyline Ridge, 16 Jun 1981 (D. Houk), 11 Jun 1988 (W.
Bousman); Skyline Ranch, 29 Jun 1986, 13 Jul 1986 (P. Noble); Pescadero, Jun-Jul
1987 (H. Green); Gazos Creek, 1 Jul 1987, 8 Jun 1988 (H. Green); Ano Nuevo, 6
Jul 1988 (P. Metropulos)

Santa Clara Co.: Los Gatos, 16 Jul 1957 (E, Smith), in chimney, 28 Jun 1991 (J.
DuBois), in chimney; Saratoga, 18 Jun 1959 (E. Smith), in chimney, 7 Jul 1987 (W.
Bousman); Rancho San Antonio, 4 Jul 1986 (A. Edwards); Coyote Creek, 6 Jun
1987 (D. Roberson); Vasona Res., 6 Jun 1987 (W. Bousman); Fremont Older Open
Space Preserve, 22 Jun 1987 (W. Bousman)

Santa Cruz Co.: Santa Cruz Swamp, 17 Jul 1955 (A. Craig); Aptos, 21 Jul 1985
(B. LaBar), in chimney; Ben Lomond, 6 Jun 1987 (N. Naslund), in chimney; Summit
Meadows, 16 Jun 1987 (D. Suddjian); Univ. Calif., Santa Cruz, 17 Jun 1987 (D.
Suddjian); Big Basin S. R, 20 Jun 1987, 30 Jun 1987 (D. Suddjian); 1 1 Jun 1989 (P.
Paton); Soquel, 26 Jun 1987 (D. Suddjian); Brookdale, 3 Jul 1987, 12 Jul 1988 (N.
Naslund), in chimney; Henry Cowell S. R, 15 Jul 1987 (D. Suddjian); San Lorenzo R.,
24 Jul 1987, 25 Jun 1988 (D. Suddjian); Sycamore Grove, 5 Jun 1988 (D. Suddjian);
Scott’s Valley, 25 Jul 1988 (N, Naslund), in chimney; Blooms Creek Campground, 27
Jun 1989 (N. Naslund)

Shasta Co.: Ft. Cook, 2 Jun 1971 {T. Manolis); Burney Falls, 10 Jul 1979 (B. & C.
Yutzy), Jun-Jul 1990, Jun-Jul 1991 (J. Sterling); Hat Creek town, Jun-Jul 1990 (J.
Sterling); Hat Creek at Pit R., Jun-Jul 1990, Jun-Jul 1991 (J. Sterling)

Sierra Co.: Chapman Creek, 20 Jul 1962 (F. Evenden)

Siskiyou Co.: Bull Mt., 18 Jun 1980 (S. Laymon); Cedar Lake, 22 Jun 1980 (B. &
C. Yutzy); Butler Creek, 2 Jun 1985 (M. Robbins); Crepo Creek, 1 Jun 1986 (M.
Robbins); Thompson Creek, 27 May 1987 (M. Robbins); Somes Bar, 30 May 1988
(M. Robbins); Seiad, 3 Jun 1989 (M. Robbins)

39

VAUX’S SWIFT BREEDING DISTRIBUTION

Sonoma Co.: Gualala, 16 Jun 1956 (W. Pursell), 11 Jul 1982 (T. Gates), 1 Jun
1991 (M. Parmeter); Timber Hill, 17 Jul 1956 (G. Bolander); Duncan Mills, 25 May
1956{J. Kelly); Santa Rosa, 10 Jul 1962 (N. Mestechin); Sonoma, nested in 1961,
1963 (N. Mestechin), 11 Jul 1979 (L. Binford), in chimney; Austin Creek, 27 Jul
1983 (D. Beall); Two Rock, 13 Jul 1986 {R. Marlowe); Healdsburg, 22 Jul 1986 (J.
Smith), 20 Jul 1990 (M. McCulley); Duncan's Landing, 17 Jun 1989 (R. Rudesilt), in
chimney; Monte Rio, 24 Jun 1989 (D. Willard); Stewart's Point, 25 May 1990 (B.
Lenarz), in chimney; Dry Creek, 2 Jul 1990 (Bird Rescue Center), nestlings

Tehama Co.: Chico Meadows, 13 Jul 1962 (T. Rodgers); Elan Creek Campground,
15 Jul 1962 (E. Hodnette)

Trinity Co.: Waterman Ridge, 20 Jul 1982 (K. Rosenberg); Hayfork, 20 Jun 1995
(G. Hazard); Hyampom, 6 Jul-25 Aug 1995 (G. Hazard)

Tulare Co.: Colby Meadow, 7 Jul 1952 (P. Raven); Hogietown Picnic Area, 7 Jul
1973 (A. Baldridge); Log Meadow, 6 Jul 1974 (D. DeSante), nest in tree, 9 Jul 1979
(L. Norris), 11 Jul 1985 (J. Boone): near Badger, 19 Jun 1975 (R. Hansen); Park
Ridge Lookout, 18 Jun 1980 (L. Norris); Big Stump, 2 Aug 1982, 3 Jun-30 Jul
1985, 4-11 Jun 1986, 19 Jul 1987 (J. Warner); Potwisha Campground, 10 Jun-1
Aug 1984, 31 Jul 1985 (J. Boone); Wolverton area, 12 Jun 1984 (J. Boone);
Crescent Meadow, 26 Jun 1984 (G. San Miguel), 25 Jul 1986 (D. Graber); Moro
Rock, 4 Jul 1984 (J. Boone); Ash Mountain, 17 Jun 1985 (L. Norris); Grant Grove,
28 Jun 1985, 16 Jul 1987, 14 Jul 1988 (G. San Miguel); Lodgepole, 30 Jun 1985
(J, Boone); Pine Camp, 30 Jun 1985 (G, San Miguel); Big Baldy Trail, 7 Jul 1985 (G.
San Miguel); Wolverton Meadow, 18 Jun 1986 (J. Boone), 2 Aug 1988 (J. Warner),
24 Jun 1989 (G. San Miguel); Redwood Saddle, 10-11 Jun 1988 (G. San Miguel);
South Fork Campground, 12 Jun-6 Aug 1988 (T. Jeffrey); Dorst Creek, 6 Jun 1990
(G. San Miguel)

Tuolumne Co.: Crane Rat, Jun-Jul 1971, 8 Jul 1973 (M. Mans), 1 Jul 1974 (no
observer), 9-28 Jul 1985 (J. Lovio), 9 Jun 1986 (P. Metropulos), 20 Jun 1986, 26
Jun 1987 (D. Suddjian); Hodgdon Meadow, 27 Jun 1982 (Keeler); Harden Flat, 21
Jul 1988 (R. Erickson)

Yuba Co.: W of Yuba Pass, 16 Jun 1973 (no observer); Yuba Summit, 12 Jun 1976
(J. Richmond)

Accepted 5 September 1995

40

THE PRINCE OF WALES SPRUCE GROUSE: A NEW
SUBSPECIES FROM SOUTHEASTERN ALASKA

ROBERT W. DICKERMAN, American Museum of Natural History, Central Park West
at 79th St., New York, New York 10024 (current address: Museum of Southwestern
Biology, University of New Mexico, Albuquerque, New Mexico 87131)

JACK GUSTAFSON. Alaska Department of Fish and Game, Ketchikan, Alaska
99901

The Spruce Grouse ( Falcipennis canadensis ; see below for use of generic
name) consists of two groups of subspecies, those with white-tipped upper
tail coverts and lacking a chestnut tail band (the franklinii group) and those
without white tipping but with a chestnut tail band (the canadensis group,
see Figure 1). The first group, up to now composed of only the subspecies
franklinii, was until recently represented from Alaska by only a single
museum specimen, an adult female taken by Wilfred H. Osgood on Prince
of Wales Island in the Alexander Archipelago on 27 May 1903 (unpublished
data in Smithsonian Institution archives). A second specimen, a male, was
taken on the island by Paul Coffey on 14 September 1982.

In 1993 Gustafson, with the help of other biologists, assembled a series of
five additional specimens. These included an adult female struck by a car on
Prince of Wales Island on 22 June 1993, a subadult male collected there on
12 June 1993, an adult female collected on Heceta Island on 9 June 1993,
and two males, one adult and one subadult, taken by a hunter on adjacent
Kosciusko Island in the spring of 1990. The last were retrieved from a
taxidermy shop in Ketchikan, Alaska.

These five specimens were prepared at the American Museum of Natural
History, New York, three as round skins and two as “shmoos” and full
skeletons. These five, plus the two earlier specimens, Dickerman compared
with a small series of recently taken males (1958 to 1984) from elsewhere
in the range of franklinii and large series of both sexes taken 1900-1923.
This study revealed the archipelago birds to be a distinctive but unnamed
form. Before describing it, we must digress to discuss the species’ nomencla-
ture and foxing.

NOMENCLATURE

We strongly agree with Yamashina (1939), Parkes (1952), Stepanyan
(1962), Potapov (1986, not seen in the original), and Boag and Schroeder
(1992) that the Spruce Grouse, long placed in its own genus, Canachites, is
not congeneric with the Blue Grouse ( Dendragapus obscurus), contra
Short (1967), who was followed by the A, O. U. (1983). Yamashina (1939)
made a strong argument, most of which was cited by Short (1967), that the
Spruce Grouse is, instead, congeneric with the Siberian or Sharp-winged
Grouse ( Falcipennis falcipennis). The name Falcipennis Elliot, 1864, has
priority over Canachites Stejneger, 1885. Short discussed the distinctness
of the downy young of the Spruce Grouse with respect to those of the Blue
Grouse and mentioned, but did not consider important, the difference in the

Western Birds 27:41-47, 1996

41

PRINCE OF WALES SPRUCE GROUSE

number of rectrices (16 in Falcipennis and Canachite s vs. 18 in
Dendragapus) or absence of inflatable esophageal sacs in Falcipennis and
Canachites. We fully agree with Bendell and Zwickle (1984), cited by
Zwickle (1992), that the Spruce and Siberian Grouse are forest-adapted
members of the smaller-sized forest-grouse complex, which lacks esoph-

Figure 1. Range of the Spruce Grouse in western Canada and Alaska, showing range
of Falcipennis canadensis isleibi and zone of intergradation between the canadensis
and franklinii subspecies groups (inset). Solid dot, specimen record; open dot, sight
record; triangle, bones; square, nest.

42

PRINCE OF WALES SPRUCE GROUSE

ageal air sacs for booming, while the Blue Grouse is a forest-adapted
representative of the prairie/scrubland Tympanuchus complex, whose
members are larger and have esophageal air sacs. Recent studies of grouse
relationships using mitochondrial DNA confirmed the distinctness of
canadensis and obscurus and placed the former in a clade with the Ruffed
Grouse ( Bonasa umbellus ); however, grouse with esophageal air sacs did
not form a monophyletic clade (Ellsworth et al. 1995).

FOXING

Postmortem plumage-color change, or foxing, is extensive in males of F.
canadensis (insufficient females were seen for the extent of foxing among
them to be assessed). Three 1981-1987 males of F. c. franklinii were
compared with a large series taken from 1897 to 1914, and to three from
the period 1958-1964. The older series is dramatically browner, in both the
grays and the blacks, than the most recently taken birds, while even the
1958-1964 birds have foxed sufficiently that they differ consistently from
the 1981-1987 series. Thus only the latter series was used in the color
diagnosis. No recently taken females of franklinii were available. However,
the three females from the Alexander Archipelago, all spring birds, are not
consistently separable by color from a large series of older fall-taken
franklinii.

DESCRIPTION

The Alexander Archipelago population may now be described as

Falcipennis canadensis isleibi new subspecies

Holotype. Adult male, American Museum of Natural History no. 830558;
collected by Paul Coffey on 15 September 1982, near Little Naukati Bay,
Prince of Wales Island (55° 52' N, 133° 13' W), southeastern Alaska;
prepared by Daniel D. Gibson (DDG 819). Formerly no. 4282, University of
Alaska Museum.

Diagnosis. Most similar to F. c. franklinii, but with shorter wings and
longer tail (Table 1). Males darker, more olive, less clear gray on the dorsum
and flanks; top of head darker, more sooty. White tips of the long upper tail
coverts dramatically narrower than in franklinii (<5 mm wide vs. 6-1 1 mm,
see Figure 2). Available females do not differ consistently from franklinii
except in size. Other subspecies of the Spruce Grouse lack white on the
upper tail coverts and have a chestnut band at the tip of the tail (Figure 1).

Etymology. This subspecies is named in honor of the late Malcolm E.
(Pete) Isleib, outstanding birdwatcher, collector, contributor to our knowl-
edge of the Alaskan avifauna, and friend to the Alaskan ornithological
community. We suggest as a common name “Prince of Wales Spruce
Grouse,” to reflect much of the known range of the new taxon.

Discussion. One female is distinctly darker and more richly ochraceous
than any fall female franklinii examined, but the other two females are more
worn and faded and match mainland birds. Two females, taken 9 and 22

43

PRINCE OF WALES SPRUCE GROUSE

June 1993, were both molting heavily on the brood patch. Thus the
characteristics of fresh-plumaged females of isleibi await determination. An
immature male (white tipping on several rectrices) taken 12 June was in non-
breeding condition, with testes measuring only 2x3 mm, and was in light
body molt.

All four males (both adults and first-year birds) have traces of chestnut in
the tips of the outer rectrices (Figure 2). Thus in this character and in the
narrowness of the white tips of the upper tail coverts isleibi resembles
Spruce Grouse found elsewhere only in the zone of intergradation between
canadensis and franklinii.

In view of the abundance of taxa endemic to the area of the Queen
Charlotte Islands and the Alexander Archipelago, it is surprising the Spruce
Grouse population, known since 1903, has not been described previously.
Four minor anecdotal accounts (Osgood 1903, 1905, Swarth 1911,
Gabrielson and Lincoln 1959) refer to the occurrence of the species in the
archipelago on Warren and Zarembo islands as well as on Prince of Wales
Island.

The Spruce Grouse is absent from the Queen Charlotte Islands of British
Columbia to the south and from most, if not all, of the adjacent mainland to
the east (Swarth 1911, Boag and Schroeder 1992).

In 1992 Gustafson began efforts to document the range of this popula-
tion. He compiled information on recent sight records on Prince of Wales
Island and obtained the birds from Kosciusko and Heceta islands. On
Suemez Island, beneath a Northern Goshawk ( Accipiter gentilis) nest, he
found avian keels that were identified as Spruce Grouse remains (D. D.
Gibson pers. comm.). On Suemez Island, a nesting female Spruce Grouse
with six eggs was found by foresters on 11 May 1993, in an area of
proposed logging. Peter J. Walsh (pers. comm.) saw a Spruce Grouse on
Mitkof Island on 17 December 1989. The species probably occurs on other
islands in the southern portion of the Alexander Archipelago.

Table 1 Wing Chord and Tail Lengths (mm) of Two Subspecies of the Spruce
Grouse, Falcipennis c. franklinii and F. c. isleibi

Males

Females

Wing chord

Tail

Wing Chord

Tail

F. c. franklinii 0
Adults

183.6 ± 3.1 (11)

113.4 ± 3.6(11)

179.5 ± 4.4(8)

94.7 + 2.3 (8)

Immatures

179.5 ± 4.1 (11)

102.0 ± 1.6(4)

168.2 ± 6.6 (5)

89.3 ± 4.5 (5)

F. c. isleibi
Adults
Immatures
Age unknown

169 (type)
169

126, 128 (type)

114, 117

168, 169, 170

98, 105

“Mean ± standard error (sample size). Data from Boag and Schroeder (1992).

44

PRINCE OF WALES SPRUCE GROUSE

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Spruce Grouse are recognized as poor long-distance flyers. In the Great
Lakes, for example, there is no evidence the species has occurred on Isle
Royale or other islands more than a mile from the mainland. The islands on
which it is found, such as Drummond Island in Lake Huron, lie 1 mile or less
offshore (Ammann 1963).

Of the southeastern Alaska islands known to support F. c. isleibi, only
Warren and Mitkof are separated by more than 1 mile from Prince of Wales,
the apparent core of the population. Notably, Prince of Wales is larger than
Graham Island in the Queen Charlotte Archipelago, and it is in size second
only to Kodiak among the islands of Alaska. Except for its linkage to
Zarembo Island via a series of smaller islands, Prince of Wales Island is
isolated from the next nearest mainland connection by nearly 4 miles of salt
water while Zarembo is separated from other islands in the direction of the
mainland by 2 or more miles. The waters separating Zarembo and Prince of
Wales from the mainland are shallow, and a land bridge could have existed
during the Pleistocene. A femur of a bear, probably a Grizzly ( Ursus arctos),
dated to 35,365 ± 800 years before present and an incisor of a marmot
( Marmota sp.) dated to over 44,500 years before present have recently
been reported from Prince of Wales Island (Heaton 1995). These mammals
have been lacking from the island in historic times. Consequently, it is
possible that this relict population of F. canadensis has been isolated since
the late Pleistocene, and it might be that the unglaciated islands were the
refugium from which the species expanded to the mainland during periods
of low sea-water levels and from which paler franklinii, adapted to the drier
interior slopes, evolved.

SUMMARY

The Spruce Grouse of Prince of Wales and nearby islands in the Alexander
Archipelago in southeastern Alaska constitute a subspecies agreeing with F.
c. franklinii and differing from other subspecies of F. canadensis in its
having white-tipped upper tail coverts and lacking a chestnut tail band. The
new form, F. c. isleibi, differs from franklinii in its shorter wing and longer
tail; males differ by their darker, more olive upperparts and flanks and
narrower white tips on the upper tail coverts. Because of its 16 rather than
18 or 20 rectrices, lack of inflatable neck sacs, and different color pattern of
the downy young, the Spruce Grouse is better placed in Falcipermis than in
Dendragapus.

ACKNOWLEDGMENTS

We thank the curators of the following collections for the loan of specimens
examined: the Thomas Burke Memorial Washington State Museum, University of
Washington, Seattle (UWBM), the Charles R. Conner Museum, Washington State
University, Pullman, the National Museum of Natural History, Washington, D.C., and
the University of Alaska Museum, Fairbanks. Specimens in the American Museum of
Natural History (AMNH) and the Museum of Southwestern Biology, University of
New Mexico, Albuquerque (MSB), were also used. Additionally, we express gratitude
to Randall R. Jahnke of Southeastern Taxidermy, Ketchikan, Alaska, for the donation
of the Kosciusko Island birds. We especially thank Brina Kessel and Daniel D. Gibson

46

PRINCE OF WALES SPRUCE GROUSE

of the University of Alaska Museum, Fairbanks, for exchanging the adult male, our
type specimen, for an immature male and an adult female. Daniel D. Gibson. Kenneth
C. Parkes, and Paul A. Johnsgard provided useful comments during the development
of the manuscript. Dr. Parkes and Robin Panza provided data on specimens from the
zone of intergradation between canadensis and franklinii in the Carnegie Museum of
Natural History. Beth Dennis made the map.

LITERATURE CITED

Ammann, G. A. 1963. Status of the Spruce Grouse in Michigan. J. Wildlife Mgmt.
27:591-593.

American Ornithologists’ Union. 1983. Check-list of North American Birds, 6th ed.
Am. Ornithol. Union, Lawrence, KS.

Bendall, J. F., and Zwickle, F. C. 1984. A survey of the biology, ecology, abundance
and distribution of the Blue Grouse (genus Dendragapus). Int. Grouse Symp.,
World Pheasant Assoc.. Proc. 3:163-190.

Boag. D. A., and Schroeder, M. A. 1992. Spruce Grouse, in The Birds of North
America (A. Poole, P, Stettenheim, and F. Gill, eds.), no. 5. Acad. Nat. Sci.,
Philadelphia.

Ellsworth, D. L., Honeycutt, R. L., and Silvy, N. J. 1995. Phylogenetic relationships
among North American Grouse inferred from restriction endonuclease analysis
of mitochondrial DNA. Condor 97:492-502.

Gabrielson, 1. N., and Lincoln, F. C. 1959. Birds of Alaska. Wildlife Mgmt. Inst.,
Washington, D.C.

Heaton, T. H. 1995. Middle Wisconsin bear and rodent remains discovered from
Prince of Wales Island, Alaska. Current Research in the Pleistocene 12: in press.

Osgood, W. H. 1905. In Alaska’s rain belt. Condor 7:68-71.

Parkes, K. C. 1952. The birds of New York and their taxonomy. Ph. D. dissertation,
Cornell Univ., Ithaca, N. Y.

Potapov, R. L. 1985. Fauna of the USSR: Birds, vol. III. Order Galliformes, family
Tetraonidae. Science Inst., Leningrad (in Russian).

Short, L. L., Jr. 1962. A review of genera of grouse (Aves, Tetraoninae). Am. Mus.
Novitates 2289.

Stepanyan, L. S. 1962. [The systematic relationships between the Sharp-winged
Grouse and the Spruce Grouse.] Ornitologiya 5:368-371 (in Russian).

Swarth, H. S. 1911. Birds and mammals of the 1909 Alexander Alaska Expedition.
Univ. Calif. Publ. Zool. 7:9-172.

Yamashina, Y. 1939. Note sur le tetras falcipenne de Siberie. Oiseau Rev. Fr.
Ornithol., N. S., 9:3-9.

Zwickle, F. C. 1992. Blue Grouse, in The Birds of North America (A. Poole, P.
Stettenheim, and F. Gill, eds.), no. 15. Acad. Nat. Sci., Philadelphia.

Accepted 20 June 1995

47

FALL MIGRATION OF TURKEY VULTURES
AND RAPTORS THROUGH THE SOUTHERN
SIERRA NEVADA, CALIFORNIA

SEAN P. ROWE and TERRI GALLION, Kern River Research Center, P. O. Box 990,
Weldon, California 93283

The migration of Turkey Vultures ( Cathartes aura ) is not nearly as well
studied as that of many species of raptors. Raptor migration counts are
conducted annually at numerous locations throughout North America
(Kerlinger and Gauthreaux 1985, Heintzelman 1986, Kerlinger 1989).
Count sites are generally located along mountain ridges or coastlines where
migrating raptors congregate (Kerlinger and Gauthreaux 1985, Kerlinger
1989). Both raptors and vultures migrate by day, taking advantage of
thermal updrafts. However, sites that provide good conditions for migrating
raptors, or for raptor viewing, do not necessarily provide optimal conditions
for migrating vultures. Indeed, large flights of migrating vultures (i.e., >5000
individuals) are rarely recorded at hawk-watch sites.

In southern California, Turkey Vultures are known to migrate in large
numbers through the Mojave Desert during spring and fall (Jaeger 1981,
Rosenberg et al. 1991). Fall counts of Turkey Vultures migrating southeast
from Victorville, San Bernardino Co., have recorded in excess of 10,000
individuals per season (Watkins 1976, Yurkunas 1994). Spring counts
(February through April) at Victorville yielded only one tenth of this number
(Watkins 1976). A similar pattern appears to prevail in the Kern River Valley
(S. Laymon pers. comm.). Migration in spring appears to be more pro-
tracted and much lower in magnitude than in fall.

The migratory route of vultures has been mapped from the Mojave River
in the vicinity of Victorville to Blythe, Riverside Co., along the Colorado
River (Watkins 1976). However, little else is known of the magnitude of
Turkey Vulture migration in the western United States. Here we document
the largest known Turkey Vulture flyway north of Mexico and report
observations of migrating raptors during fall 1994.

STUDY SITE

Our count site is located 8 km (5 miles) south of Weldon, Kern Co.,
California, at the southern terminus of the Sierra Nevada. The site (elevation
900 in; 2950 feet) is just west of Kelso Creek on a low rise at a point where
the valley narrows in width to 1 km (0.6 mile) from 4 km (2.5 miles) at the
mouth. Kelso Creek runs southeast-northwest into the South Fork Kern
River (elevation 800 m; 2650 feet) and is bordered by two desert mountain
ranges, the Scodie Mountains on the east and the Piute Mountains on the
west. The South Fork Kern Valley is bisected by extensive cottonwood/
willow riparian forest bordering the South Fork Kern River. The forest is
surrounded by agricultural lands and desert mountains. The forest provides
roosting sites for a large percentage of the migrating Turkey Vultures that
pass the count site.

48

Western Birds 27:48-53, 1996

MIGRATION OF TURKEY VULTURES

METHODS

We conducted counts daily from 7 September through 26 October 1994
(except 9-10 September and 22-23 October), Observations commenced
between 08:30 and 10:00 PST and lasted from three to six hours depending
on the intensity of the vulture movement and availability of observers. From
7 to 30 September observations ended about 12:00 when migration activity
appeared to cease; however, on 1 October a second wave of activity was
observed in early afternoon. Subsequent observations (1 to 26 October)
were conducted until the afternoon wave ceased, generally between 14:00
and 15:00.

We made our counts from a single station. From the count site we had a
nearly 360-degree view of the surrounding desert and mountains. At least
two observers were present during all observations. Both observers actively
located and counted vultures, but only one observer recorded data. Observ-
ers frequently communicated the location, activity, and numbers of vultures
seen. Vultures were typically first spotted in kettles forming to the north of
the count site. We attempted to keep track of the kettles as they dispersed
and re-formed before recording them. Kettles were observed until individuals
began to “break out” and glide past the count site. Because vultures
frequently break out of kettles individually and in single file, it is often
possible to obtain exact counts. When kettles drifted past the count site or
when large numbers of individuals broke out simultaneously, passing in a
broad front, we estimated by groups of ten. In nearly all cases, all birds were
counted or estimated by both observers, who then agreed on the number to
be recorded. Time of passage was recorded for all individuals or groups.
Temperature, estimated wind speed, wind direction, and percent cloud
cover were recorded at the beginning and end of each observation period.

We recorded observations of raptors in the same manner as those of
vultures. We assessed whether individual raptors were residents or migrants
by noting flight behavior and direction. Only raptors that we considered
migrants were recorded.

RESULTS

We recorded 27,415 Turkey Vultures during 46 days (162.5 hours) of
observations, averaging 596 vultures/day (169 vultures /hour). A high count
of 4521 Turkey Vultures was recorded on 7 October following three days of
inclement weather, characterized by strong, gusty winds, high cloud cover,
light rain, and few vultures. The second highest count (3694 individuals) was
on 2 October immediately before the passage of this front. The median
migration date, calculated from daily vulture totals, was 1 October. Peak
activity occurred during the 7-day period from 29 September to 5 October
when 37% (10,228) of all vultures were recorded (Figure 1).

We recorded 328 raptors of 13 species and 12 unidentified individuals.
Red-tailed Hawks ( Buteo jamaicensis ) and Cooper’s Hawks ( Accipiter
cooperii ) were the most commonly observed migrants, accounting for 33%
(108) and 32% (105), respectively, of all raptors identified. Sharp-shinned
Hawks (Accipiter striatus) (9.5%; 31) and American Kestrels ( Falco

49

MIGRATION OF TURKEY VULTURES

sparuerius) (9%; 30) were the next most abundant. The remaining nine
species, accounting for 16% of the total, included the Northern Harrier
{ Circus cyaneus) (13 from 13 September to 17 October), Prairie Falcon
(j Falco mexicanus ) (11 from 2 to 26 October), Osprey ( Pandion haliaetus )
(9 from 19 September to 1 1 October), Ferruginous Hawk (Buteo regalis) (5
from 30 September to 24 October), Golden Eagle ( Aquila chrysaetos ) (5 on
8 October), Northern Goshawk ( Accipiter gentilis) (5 from 30 September
to 24 October), Swainson’s Hawk ( Buteo swainsoni ) (4 from 11 to 30
September), and a single Peregrine Falcon ( Falco peregrinus ) on 20
October. Notable species were the Northern Goshawk, previously undocu-
mented as a migrant in the region (S. Laymon pers. comm.), and a single
Zone-tailed Hawk (Buteo alhonotatus) on 3 October, only the second
reported for Kern County (M, Heindel pers. comm.; record currently being
considered by the California Bird Records Committee). Raptors averaged
2.0 per hour. We detected no seasonal peak in activity. However, raptors
tended to migrate in pulses; on 1 1 days no raptors were recorded, while on
four days 20 or more were recorded. Of the four most commonly recorded
species only the Sharp-shinned Hawk revealed a distinct seasonal trend,
increasing sharply in early to mid-October (Figure 2). High counts of raptors
were 26 (6 species) on 7 October and 24 (5 species) on 1 1 October.

DISCUSSION

Although the exact route used is unknown, anecdotal observations sug-
gest that large numbers of fall-migrant vultures in California follow the west
side of the Sierra Nevada (east side of the Central Valley) before passing
through the Mojave Desert. Published reports of migrating vultures in fall
include 2500 to 3000 counted in 30 minutes over Springville, Tulare Co.,
on 29 September 1965 (Chase 1966); 1000 at Chico, Butte Co., on 28

9/07 9/14 9/21 9/28 10/5 10/12 10/19 10/26

Figure 1 . Seasonal timing of Turkey Vulture migration through the Kern River Valley,
California, in fall 1994, expressed as mean number of vultures recorded per hour
(bars) and percent total (line) by 7-day period. Total number of hours of observation
per 7-day period is shown above bars.

50

MIGRATION OF TURKEY VULTURES

55
50
45
40
2 35

t 30
§ 25

t_

9/08- 9/15- 9/22-

9/14 9/21 9/28

■

□ AMH

□ss»-

9/29- 10/6- 10/13- 10/20-

10/5 10/12 10/19 10/26

Figure 2. Seasonal distribution of the four most commonly recorded raptors migrating
through the Kern River Valley, California, in fall 1994, expressed as percent total by
7-day period. COHA, Cooper's Hawk; RTHA, Red-tailed Hawk; AMKE, American
Kestrel; SSHA. Sharp-shinned Hawk.

September and hundreds in Fresno Co. on 3 and 4 October 1972 (DeSante
and Remsen 1973); and 100+ at various locations from Chico to Fresno Co.
from 15 September through 5 October 1973 (Remsen and Gaines 1974).
Flocks of up to 500 a day in late September and early October regularly
roost near Porterville, Tulare Co. (B. Barnes pers. comm.).

Once vultures reach the desert, known suitable nocturnal roost sites are
limited to riparian forests. The riparian forest along the South Fork Kern
River is the last large patch of suitable roosting habitat available to vultures
before they migrate out over the desert. The next known major roost site is
along the Mojave River, in the vicinity of Victorville, approximately 160 km
(100 mi) to the southeast (Watkins 1976, Jaeger 1981). The Kern River
Valley lies directly in the path of vultures as they migrate down the west side
of the Sierra Nevada toward the Mojave River. Once vultures have reached
the Kern River Valley the most direct route to the Mojave Desert is southeast
along Kelso Creek. The Scodie and Piute mountains appear to act as leading
lines, tunneling migrating vultures southeast along Kelso Creek toward the
Mojave River.

To our knowledge, the Turkey Vulture migration through the Kern River
Valley is the largest documented north of Mexico. We were able to locate
reports of only three sites in the United States and Canada that regularly
record more than 5000 Turkey Vultures per season. Observers at Michigan’s
Lake Erie Metro Park reported an 8-year average of 10,767 Turkey Vultures
per season and in 1993 recorded an all-time high of 21,720 vultures (Benoit
1994). Observers at Holiday Beach, Ontario, reported a 20-year high count
of 16,692 in 1991 (Latta 1994). In the western United States, the Mojave
Desert Raptor Watch has recorded a high of 12,238 Turkey Vultures
migrating over Apple Valley, near Victorville (Yurkunas 1994).

We believe that most of the vultures recorded at Apple Valley are those
that have previously passed through the Kern River Valley. The timing of

51

MIGRATION OF TURKEY VULTURES

peak numbers at the Mojave River roosts near the Apple Valley count site
coincides closely with peak movement past our site (Watkins 1976, Yurkunas
pers. comm ). These roost sites lie directly along the route vultures travel
when leaving the Kern River Valley. Watkins (1976) stated that fall migrants
follow the San Joaquin Valley then pass over the Tehachapi Mountains
before roosting along the Mojave River in the vicinity of Victorville. How-
ever, he was apparently unaware of the movement through the Kern River
Valley and did not observe fall migrants before they reached the Mojave
River roosts. Although some vultures certainly do continue south through
the Central Valley and around the southern end of the Sierra Nevada our
data suggest that the vast majority leave the Central Valley, crossing over the
west edge of the Sierra and into the Kern River Valley.

Our observations early in the season were limited to the morning hours;
hence it is likely that 5000 to 10,000 vultures may have passed unrecorded.
With more intensive coverage we believe as many as 40,000 vultures may be
recorded annually from this location. Additional count sites located in the
Central Valley and Transverse Ranges (e.g. , near Bakersfield and Tehachapi)
are necessary to determine the number of migrating vultures that continue
moving southward through the Central Valley, passing over the Tehachapi
Mountains instead of crossing into the Kern River Valley. The large number
of Turkey Vultures that pass through the Kern River Valley probably
represents a significant portion of the vulture population in the Pacific
Northwest, west of the Cascade-Sierra Nevada axis, making this a prime
location for monitoring long-term trends in vulture numbers in the West.

SUMMARY

Turkey Vultures and raptors use the valley of Kelso Creek, Kern County,
California, as a fall migration route, after roosting in the riparian forest along
the South Fork Kern River. From 7 September to 26 October 1994 we
counted 27,415 Turkey Vultures, the largest flight yet recorded in the United
States. The South Fork Kern River and Kelso Creek appear to lie along a
flyway leading from the east side of the Central Valley to the Mojave River
near Victorville, previously found to be a major roost site for migrating
vultures. The flyway is also used by raptors (328 of 13 species counted over
the same period as the vultures), including a few Northern Goshawks.

ACKNOWLEDGMENTS

We thank the many volunteers who participated in the project. We especially thank
Terri Middlemiss, who organized most of the volunteer effort and spent many days
counting vultures. Stephen Laymon and Pamela Williams generously allowed Rowe
time off from other duties and provided advice throughout the project. Bob Barnes,
Stephen Laymon, Amadeo Rea, Philip Unitt, and Pamela Williams provided helpful
comments on earlier drafts of this manuscript. This is Contribution No. 1 of the Kern
River Research Center.

52

MIGRATION OF TURKEY VULTURES

LITERATURE CITED

Benoit, D. 1994. Eastern Great Lakes Region. Hawk Migration Association of North
America. Hawk Migration Studies 20:46-49.

Chase, T., Jr. 1966. The fall migration. Middle Pacific Coast region. Audubon Field
Notes 20:88.

DeSante, D., and Rernsen, V. 1973. The fall migration. Middle Pacific Coast region.
Am. Birds 27:114.

Jaeger, E. C. 1981. Desert Wildlife. Stanford Univ, Press, Stanford, CA,

Heintzelman, D. S. 1986. The Migrations of Hawks. Indiana Univ. Press,
Bloomington.

Kerlinger, P. 1989. Flight Strategies of Migrating Hawks. Univ. of Chicago Press,
Chicago.

Kerlinger, P., and Gauthreaux, S. A., Jr. 1985. Flight behavior of raptors during
spring migration in south Texas studied with radar and visual observations. J.
Field Ornithol. 56:394-402.

Latta, W. C. 1994. Trends in abundance of fall migrating raptors at Holiday Beach
Migration Observatory, Essex County, Ontario, 1977-93. Hawk Migration
Association of North America. Hawk Migration Studies 20:7-11.

Rernsen, V., and Gaines, D. A. 1974. The fall migration. Middle Pacific Coast region.
Am. Birds 28:100.

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, Tuscon.

Watkins, T. J. 1976. Turkey Vulture migrations in the Mojave Desert of California.
M.S. Thesis, Calif. Polytechnic Univ., Pomona.

Yurkunas, V. G. 1994. Mojave Desert raptor watch. Hawk Migration Association of
North America. Hawk Migration Studies 20:11-12.

Accepted 18 September 1995

53

NOTES

A WINTER RECORD OF THE GRAY VIREO FROM
SAN LUIS POTOSI, MEXICO

ADAM J. FRY, Bell Museum of Natural History, 100 Ecology Building, University of
Minnesota, 1987 Upper Buford Circle, St. Paul, Minnesota 55108

OCTAVIO R. ROJAS-SOTO and ADOLFO G. NAVARRO S., Museo de Zoologia
"Alfonso L. Herrera," Facultad de Ciencias, Universidad Nacional Autonoma de
Mexico, Apdo. Postal 70-399, Mexico, D. F. 04510, Mexico

The Gray Vireo, Vireo uicinior. winters mainly in coastal Sonora (including Tiburon
and San Esteban islands) and sparsely in southern Baja California, southern Arizona
(mountains of Yuma and western Pima counties), the Big Bend region of western
Texas, and probably southwestern Coahuila (Phillips et al. 1964, Barlow and Wauer
1971. AOU 1983, Phillips 1991, Howell and Webb 1995). We report here a recent
record of the Gray Vireo from the state of San Luis Potosi, Mexico, and suggest that
the winter distribution of the Gray Vireo may be more widespread than is currently
recognized.

On 29 November 1994, along Mexico Highway 80, 30 km by road east-southeast
of El Huizache (approximately 22° 50' N, 100° 30' W), elevation 1220 m, we
collected an adult male Gray Vireo. The bird weighed 14.9 grams and had a wing
chord of 68 mm. The bird was in good condition with light fat and heavy molt on the
head and body; the skull was completely pneumatized. This specimen (catalog number
11999 MZFC) is housed at the Museo de Zoologia, Mexico City. The habitat was
typical Chihuahuan desert as described by Atwood (1988) and Toledo and Ordonez
(1993) and seemed to be suitable wintering habitat for the Gray Vireo (but see Bates
1992). This locality was a Black-tailed Gnatcatcher (Polioptila melanura) collecting
site of Atwood’s (1988), and we found that species here as well.

There exists a single Mexican specimen of the Gray Vireo from south or east of
Sonora, a bird (USNM 164057) taken at Inde, Durango, on 13 August 1898. An
additional specimen from Quelite, Sinaloa, collected 6 February 1934, was appar-
ently misidentified (Phillips 1991).

The San Luis Potosi specimen is thus the southernmost and easternmost of the
Gray Vireo for Mexico. This seemingly anomalous specimen may represent a broader,
though more local (Phillips 1991), winter distribution than is currently recognized. It
is possible that some eastern Gray Vireos breeding in the Chisos Mountains (Texas)
and Sierra Del Carmen (Coahuila, Mexico) may winter as far south as San Luis Potosi.
The sight record of a Gray Vireo in southwestern Coahuila on 22 November (cited in
Phillips 1991) may also represent this heretofore unknown winter range.

Suitable (see Bates 1992) arid and semiarid habitats on the central Mexican
plateau, particularly from Texas and New Mexico south to San Luis Potosi, Zacatecas,
and Durango (see discussion of habitats in Toledo and Ordonez 1993) should be
considered as a possible winter range extension for the Gray Vireo. Further documen-
tation with additional specimens is required.

Our field work was supported by National Science Foundation grant DEB9317945
to R. M. Zink and a Frank M. Chapman Memorial Fund award to Fry. John M. Bates,
Jon C. Barlow, and Steve N. G. Howell provided valuable comments.

Western Birds 27:54-55, 1996

54

NOTES

LITERATURE CITED

American Ornithologists’ Union. 1983. Checklist of North American Birds. Am.
Ornithol. Union, Lawrence, KS.

Atwood, J. L. 1988. Speciation and geographic variation in Black-tailed Gnatcatch-
ers. Ornithol. Monogr. 42.

Barlow. J. C., and Wauer, R. H. 1971. The Gray Vireo (Vireo uicinior Coues; Aves:
Vireonidae) wintering in the Big Bend region, west Texas. Can. J. Zool. 49:953-
955.

Bates. J. M. 1992. Frugivory on Bursera microphylla (Burseraceae) by wintering
Gray Vireos (Vireo uicinior , Vireonidae) in the coastal deserts of Sonora, Mexico.
Southwest. Nat. 37:252-258.

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

Phillips, A. R., Marshall, J. T., and Monson. G. 1964. The Birds of Arizona. Univ.
Ariz. Press, Tucson,

Phillips, A. R. 1991. The Known Birds of North and Middle America, part 2. A. R.
Phillips, Denver.

Toledo, V. M., and Ordonez, M. J. 1993. The biodiversity scenario of Mexico: A
review of terrestrial habitats, in Biological Diversity of Mexico: Origins and
Distribution (T. P. Ramamoorthy, R. Bye, A. Lot, and J. Fa, eds.), pp. 757-777.
Oxford Univ. Press, Oxford, England.

Accepted 10 October 1995

55

Wing Your Way to . . .

Western Field Ornithologists

21st Annual Meeting

with the

Colorado Field Ornithologists

ESTES PARK, COLORADO

14-16 June 1996

at the YMCA of the Rockies, adjacent to Rocky Mountain National Park

Field trip destinations on Friday and Sunday include Rocky
Mountain National Park and the Pawnee National Grassland in
northeastern Colorado.

Target species include the White-tailed Ptarmigan, Three-toed
Woodpecker, Mountain Plover, Chestnut-collared and
McCown’s Longspurs, and many others.

On Saturday, we will enjoy a papers session, evening banquet,
and the notorious identification panel.

For more information contact Steve Bouricius, 3412 C Road,
Grand Junction, Colorado 81526.

56

WESTERN BIRDS

Quarterly Journal of Western Field Ornithologists

President: Kimball L. Garrett, Natural History Museum of Los Angeles County, 900
Exposition Blvd., Los Angeles, CA 90007

Vice-President: Mike San Miguel, 2132 Highland Oaks Dr., Arcadia, CA 91006

Treasurer/Membership Secretary: Dorothy Myers, 6011 Saddletree Lane, Yorba
Linda, CA 92686

Recording Secretary: Jean-Marie Spoelman, 4629 Diaz Drive, Fremont, CA 94536

Directors: Kimball Garrett, Daniel D. Gibson, Tim Manolis, Guy McCaskie, Mike
San Miguel, W. David Shuford, David Stejskal, Bill Tweit, David Yee

Editor: Philip Unitt, San Diego Natural History Museum, P.O. Box 1390, San
Diego, CA 92112

Associate Editors: Cameron Barrows, Tim Manolis, Thomas W. Keeney
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

Secretary, California Bird Records Committee .-Michael A. Patten, P. 0. Box 51959,
Riverside, CA 92517-2959

Editorial Board: Robert Andrews, Alan Baldridge, Andrew J. Berger, Laurence C.
Binford, R. Wayne Campbell, David F. DeSante, Jon L. Dunn, Richard Erickson,
William T. Everett, Kimball L. Garrett, Joseph R. Jehl, Jr., Ned K. Johnson,
Virginia P. Johnson, Brina Kessel, Stephen A. Laymon, Paul Lehman, John S.
Luther, Guy McCaskie, Joseph Morlan, Harry B. Wehls, Dennis R. Paulson, Gary H.
Rosenberg, Oliver K. Scott, Ella Sorensen, Richard W. Stallcup, Charles Trost,
Terence R. Wahl, Bruce Webb

Membership dues, for individuals and institutions, including subscription to Western Birds:
Patron, $1000; Life, $350; Supporting, $50 annually; Contributing, $30 annually;
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Send membership dues, changes of address, correspondence regarding missing issues,
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Back issues of California Birds/Western Birds: $20 per volume, $5.00 for single issues.
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All postpaid.

Published January 15, 1996

ISSN 0045-3897

VoL 27, No. 2, 1996

Volume 27, Number 2, 1996

Identification at Sea of Cook’s, de Filippi’s, and Pycroft’s Petrels

Steve N. G, Howell, Sophie Webb, and Larry B. Spear 57

Winter Distribution of Hermit Thrush Subspecies in the Sierra de la
Laguna, Baja California Sur Philip Unitt and
Ricardo Rodriguez Estrella 65

The Breeding Colony of Laysan Albatrosses on Isla de Guadalupe,

Mexico Juan-Pablo Gallo-Reynoso and Ana-Luisa Figueroa-
Carranza 70

President’s Message Kimball L. Garrett 77

NOTES

Nesting Anna's Hummingbirds in Urban Tucson, Arizona Gloria J.
Maender, Katherine L, Hiett, and Scott Jay Bailey 78

Some Nesting Waterbirds From Southern San Jose Island and Adjacent
Islands, Gulf of California, Mexico Roberto Carmona, Saudiel
Ramirez, Bulmara Zarate, and Felipe Becerril 81

First Documented Breeding of the Eurasian Skylark in Alaska Paul. J.
Baicich, Steven C. Heinl, and Mike Toochin 86

A Record of the Roseate Spoonbill on the Pacific Coast of the Peninsula
of Baja California Edgar Amador and Juan Jose Ramirez .... 89

Cover photo by © Rich Stallcup of Inverness, California: Cactus
Wren (Campylorhynchus brunneicapillus ), Organ Pipe National
Monument, Arizona, March, 1988.

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, popula-
tion 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 Philip Unitt, San Diego Natural History Museum, P.O.
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Reprints can be ordered at author’s expense from the Editor when proof is
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western birds. Please send these, with captions, to Graphics Manager.

WESTERN BIRDS

Volume 27, Number 2, 1996

IDENTIFICATION AT SEA OF COOK S,

DE FILIPPFS, AND PYCROFTS PETRELS

STEVE N, G. HOWELL, SOPHIE WEBB, and LARRY B. SPEAR, Point Reyes Bird
Observatory, 4990 Shoreline Highway, Stinson Beach, California 94970

Petrels of the genus Pterodroma are notorious for being difficult to
identify at sea. Among the most problematic species are Cook’s (P. cooki),
de Filippi’s (P. defilippiana ) and Pycroft’s {P. pycrofti) petrels, the three
most similar of those small Pterodroma united in the subgenus Cookiiaria.
P. defilippiana has also been called Defilippe’s Petrel (Roberson and Bailey

1991) or Masatierra Petrel (Harrison 1983, 1987). “Defilippe’s” is an
anglicization of defilippiana, but as Giglioli and Salvadori (1869) named the
bird for Professor F. de Filippi, the correct English spelling should be “de
Filippi’s Petrel.”

Cook’s Petrel breeds from October to April on islands off New Zealand
and migrates to the northern and eastern Pacific, where nonbreeding birds
occur mostly from April to November in the Peru Current, the California
Current, and the North Pacific Convergence (Roberson and Bailey 1991,
Spear et al. 1992). De Filippi’s Petrel breeds from June to January on
islands off central Chile and ranges at sea in the nearby Peru Current, south
of the equator (Harrison 1987, Roberson and Bailey 1991, Spear et al.

1992) . Pycroft’s Petrel breeds from November to March on islands off New
Zealand (Dunnet 1985), and until recently its nonbreeding distribution was
unknown. It is now apparent that Pycroft’s Petrel disperses into the tropical
Pacific in waters of the Equatorial Countercurrent and South Equatorial
Current between longitudes 99° 29' W (July 1995; Howell) and 167° 45' W
at latitudes from 5° S to 18° N (Spear et al. 1992). Records to date are
mainly from April to June but also from October to December, so some
Pycroft’s Petrels probably occur in this area throughout the year. While the
occurrence in North American waters of de Filippi’s and Pycroft’s petrels
seems unlikely, this cannot be assumed, and, unless identification characters
are fully understood, the pelagic distributions of these forms will remain
incompletely known. All three of these Cookiiaria petrels share a gray

Western Birds 27:57-64, 1996

57

IDENTIFICATION OF PETRELS AT SEA

crown (concolorous with the back) and narrow black underwing margins.
The identification criteria in Harrison (1983, 1987) were refined by
Roberson and Bailey (1991), although the latter authors’ experience with de
Filippi’s and Pycroft’s petrels was limited to museum specimens. Spear et al.
(1992) added first-hand identification data, confirmed by collecting speci-
mens, and described these species’ molt schedules: Cook’s and Pycroft’s
molt their flight feathers from March to August, while de Filippi’s molts from
November to March. To the best of our knowledge these periods encompass
the molts of both immatures and adults. Thus, Cook’s and de Filippi’s petrels
molting their primaries can be identified readily to species, even in March,
when the molting periods overlap, as a few de Filippi’s Petrels are then
replacing their outermost primaries while a few Cook’s have dropped their
innermost primaries. Molting birds characteristically exhibit conspicuous
white patches, formed by exposed inner webs of the primaries, on the dorsal
surfaces of the wings (Spear et al. 1992, figure 10b). During recent cruises
in the eastern Pacific Ocean, Howell and Webb assessed the marks pro-
posed by these authors for Cook’s and de Filippi’s petrels. Here we
summarize our results and briefly discuss Pycroft’s Petrel.

METHODS

We studied Cook’s and de Filippi’s petrels during cruises between Califor-
nia and Chile in March and April 1994 (northbound; Webb; 50 Cook’s, 220
de Filippi’s), April and May 1995 (northbound; Howell, Webb; 430 Cook’s,
160 de Filippi’s), and July and August 1995 (southbound; Howell, Webb;
135 Cook’s, 40 de Filippi’s, 1 Pycroft’s). We did not observe Cook’s and de
Filippi’s petrels together but saw both species within a few days of one
another. Most birds were observed with 8-power binoculars at ranges of less
than 300 m from the ship, many within 100 m, and ample time usually was
available to double-check identification criteria. At ranges greater than 300
m, specific identification often was not possible without the aid of mounted
25 x 150 binoculars. Spear et al. (1992) summarized our cumulative
previous experience with these species.

RESULTS AND DISCUSSION

The characters we looked at when confronted with a Cook’s/de Filippi’s
Petrel were, as the bird approached, structure and flight manner, underwing
pattern, dorsal tail pattern, face and neck pattern, and bill size.

Structure and Flight Manner

We did not find the differences in wing length [1.7% greater in Cook’s,
from measurements of Roberson and Bailey (1991)] or tail length (7.8%
greater in de Filippi’s) useful in distinguishing these two species, contra
Roberson and Bailey (1991). At sea, variation due to molt, flight behavior,
and wind speed often masks such small differences. Also, differences in
proportion may evoke perceptions of the birds’ shapes different from those
implied by measurements alone.

58

IDENTIFICATION OF PETRELS AT SEA

Cook’s impressed us as having narrower wings and a narrower, more
rounded tail (Figure 1A) so that, relative to the narrow wings, the tail did not
look short. De Filippi’s looked broader-winged with a broader, wedge-
shaped tail (Figure 1B-D) and so did not appear long-tailed. In heavy wing
molt (April 1994, May 1995), Cook’s Petrels often appeared narrower
winged than usual such that the tail appeared long. Thus, on the first 1995
cruise we had the impression that Cook’s was longer tailed than de Filippi’s
[and compare figures 3 and 7 of Roberson and Bailey (1991)].

In moderate to strong winds, the wings of both species appeared narrower
and more pointed than in light winds or calm conditions, when they
appeared broader and blunter-tipped. Birds taking off from or landing on the
water, even in windy conditions, appeared broader-winged than during
active flight. That wing shape changes with behavior and wind speed is often
overlooked when slight structural differences are discussed in identification
papers.

When Howell and Webb saw their first de Filippi’s Petrels (in December
1992 off Valparaiso, Chile) they were struck by the birds’ thickset shape and
leisurely, buoyant flight, although they recognized the latter reflected a
rather low wind speed. However, further experience revealed that flight
manner is of little use for identification, the differences in flight between
strong and slack wind conditions being greater than between species. In
general, both species fly quickly in wheeling arcs in moderate to strong
winds; more buoyantly, with a more leisurely, weaving progression, in light
winds, and with bursts of fairly quick wingbeats and long, low, fairly level
glides in near-calm conditions. Furthermore, molting Cook’s (April) flew
quickly, with rapid wingbeats and bounding glides, suggesting a Sooty
Shearwater, but in similar wind conditions and in fresh plumage or with
primary molt all but completed (July), they flew notably more buoyantly, less
hurriedly.

While we agree with Roberson and Bailey (1991) that de Filippi’s does
appear relatively thickset, or “chunky” for a Cookilaria (contra Spear et al.

Figure 1. Shape and dorsal pattern of Cook's and de Filippi's Petrel tails. A, Cook’s,
narrower, more rounded, with black tip. B-D, de Filippi's, broader, more wedge-
shaped. B, rare variant (1/100 birds) with blackish tip. C, uncommon variant (5/100
birds) with dusky tip. D, typical pattern of all-gray tail.

Sketch by Steve N. G. Howell

59

IDENTIFICATION OF PETRELS AT SEA

1992), evaluating this at sea can be difficult without considerable experi-
ence. Assessing flight manner is highly subjective and generally unreliable for
specific identification.

Underwing Pattern

The width and extent of the black underwing margin was of no use for
separating Cook’s and de Filippi’s petrels at sea, as surmised by Roberson
and Bailey (1991). Because the human eye emphasizes contrast, at dis-
tances greater than 200 m the underwing margins often looked thicker than
at close range (Figure 2), especially in bright, sunny (when the underwings
were shadowed) and dull, overcast conditions. Then the black underwing
margins of both species appeared wider than on Stejneger’s Petrel [P
longirostris), even suggesting a Black-winged Petrel ( P. nigripennis), al-
though not as bold as the latter species. Therefore we urge caution in
distinguishing Black-Twinged and Cook’s petrels by apparent underwing
pattern alone. At distances of less than 200 m it was easier to see the true
underwing patterns. The black underwing margins of Cook’s Petrels in fresh
plumage (July) appeared bolder than the narrow and less distinct margins of
birds in wing molt (April).

Dorsal Tail Pattern

Tail pattern has been proposed as a character for separating Cook’s and
de Filippi’s petrels: Cook’s has black-tipped central rectrices; de Filippi’s has
all-gray central rectrices (Roberson and Bailey 1991, Spear et al. 1992). We
found this character not 100% reliable. While all Cook’s Petrels showed a
black tail tip (visible within 100 to 200 m, depending on light conditions;

Figure 2. Underwings of Cook’s and de Filippi’s petrels. A, narrow black margins
visible at close range (<150-200 m). B, illusion of thicker black margins sometimes
apparent at moderate range (200-300 m).

60

Sketch by Steve N. G. Howell

IDENTIFICATION OF PETRELS AT SEA

Figure 1A), five de Filippi’s Petrels in April and July 1995 (of 100 seen very
well) showed a slightly contrasting, dusky gray tail tip (Figure 1C), and one
(July 1995) showed a quite distinct blackish tail tip (Figure IB). All of these
atypical birds were studied at close range, often in direct comparison with
other de Filippi’s Petrels, and their overall structure, tail shape, diagnostic
face and neck pattern (see below), and thick bill were seen clearly, convinc-
ing us the birds were not Cook’s Petrels. However, from its black-tipped tail,
we initially identified one July bird as a Cook’s Petrel. The occasional darker
tail tip on de Filippi’s Petrel may be caused by wear.

The more extensive white in the outer rectrices of Cook’s Petrel (Roberson
and Bailey 1991) is of virtually no use in identification at sea under any but
the most favorable conditions. In our experience, Cook’s often held their
tails closed so that the white was not very obvious, whereas on the broader
tail of de Filippi’s, white sides were usually quite apparent (e.g., figure 7 of
Roberson and Bailey 1991). On a bird spreading its tail, when flushing from
or alighting on the water, Cook’s does show more extensive white in the tail
than de Filippi’s, although the moment is usually so brief that, unless
captured by a photograph, there would be no time to confirm one’s first
impression.

Thus, while an all-gray tail appears to be diagnostic of de Filippi’s Petrel,
this species can, at least rarely, show a dusky or dark tail tip suggesting
Cook’s Petrel. As noted by Roberson and Bailey (1991), birds with very
extensive white in their outer rectrices should be Cook’s, but the amount of
white is often difficult to ascertain at sea, and de Filippi’s shows distinct white
tail sides as often as Cook’s.

Face and Neck Pattern, Bill Size

In a bird seen well, we found face and neck pattern, in combination with
bill size, to be the best characters for separating Cook’s and de Filippi’s
petrels at sea. At ranges greater than 150-200 m, however, it was difficult
to distinguish these features without the aid of mounted 25-power binocu-
lars. Face and neck pattern were best evaluated with a bird viewed in profile
and/or from below but were also of use in dorsal views. Cook’s Petrels have
a gray cap whose contrast with the white lower face and neck sides varies,
being most distinct in worn and/or backlit birds [e.g., figure 2 of Roberson
and Bailey (1991)1 and least distinct in birds in fresh plumage and/or direct
sun. The eye always looked small and “beady” in the gray cap (with no
apparent surrounding black eye patch), and the small slender bill was not
striking (Figure 3A).

In contrast, de Filippi’s Petrels have a distinct gray collar on the sides of
the neck [suggesting a Black-winged Petrel; e.g., figure 8 of Roberson and
Bailey (1991)]. The eye of de Filippi’s appears large and set in a mascara-like
black smudge, and the bill is strikingly thick. Thus, de Filippi’s looks collared,
with the eye patch and thick bill appearing as two equally large and bold
black marks on the head (Figure 3B). Roberson and Bailey (1991) described
the face/neck pattern difference in terms of de Filippi’s having a white
“cheek” curving up behind the auriculars in a short “half-collar”; this
description is not inaccurate but may reflect specimen versus field experi-

61

IDENTIFICATION OF PETRELS AT SEA

ence. At sea, the gray neck collar stood out, not the white notch in the
auriculars.

We disagree with Roberson and Bailey (1991) that “separation of the gray
cap from the white lower face is not well-defined” in Cook’s Petrel. At sea
Cook’s often looked distinctly capped unless the birds were in fresh plumage
and the sun was behind the observers. Roberson and Bailey (1991) dis-
missed the larger eye patch of de Filippi’s, first suggested by Harrison
(1987), as a function of plumage wear, worn birds reportedly having smaller
eye patches. Even if so, the two species’ different molt schedules (Spear et
al. 1992; see above) could make eye-patch size a useful feature. However,
we saw no Cook’s Petrels (worn or fresh) with large black eye patches
approaching the pattern of de Filippi’s. Also, de Filippi’s Petrels in April,
and more so in July, were in worn plumage and so should have had small
black eye patches; this was not apparent in the field.

Pycroft’s Petrel

Spear et al. (1992) discussed features for separating Pycroft’s Petrel from
Stejneger’s and Cook’s petrels. They noted that Pycroft’s differs subtly from
Cook’s in size, flight profile, and flight behavior, criteria all somewhat
difficult to evaluate at sea. In July 1995, Howell saw one Pycroft’s Petrel and

Figure 3. Face and neck patterns, as viewed in profile from below, of A, Cook’s Petrel;
B, de Filippi’s Petrel; C, Pycroft’s Petrel. Note the flat gray cap, small “beady” black
eye of Cook’s, the gray collar mark and bold black bill and eye patch of de Filippi’s,
and the Stejneger’s-like cap of Pycroft’s.

Sketch by Steve N. G. Howell

62

IDENTIFICATION OF PETRELS AT SEA

noted its distinctive face/neck pattern (Figure 3C) which, when the bird was
backlit, initially led him to consider Stejneger’s Petrel (a problem discussed
by Spear et al. 1992).

The cap’s curving down on to the neck sides is a good character for
separating Stejneger’s from Cook s Petrel (Roberson and Bailey 1991,
Spear et al. 1992). While the similar face/neck patterns of Stejneger’s and
Pycroft’s petrels were illustrated and discussed by Spear et al. (1992, figure
9b), those authors inadvertently failed to mention this character in direct
reference to Pycroft’s versus Cook’s Petrel.

Spear’s experience with 100+ Pycroft’s Petrels and Howell’s experience
with four Pycroft’s (including a total of five birds collected; Spear et al. 1992)
suggest that the differences in face/neck pattern shown by Figure 3 may be
the most useful feature for separating this species at sea from Cook’s Petrel.
Presumably referring to the same character, Roberson and Bailey (1992)
noted that 60% of Pycroft’s Petrel specimens they examined showed a hint
of the white face extending up into the auriculars, compared with only 20%
of Cook’s Petrels. This difference from our conclusions may reflect speci-
men “make” and museum versus field experience, and we urge observers to
evaluate the face/neck pattern of known Pycroft’s Petrels at sea.

SUMMARY

We field-tested identification criteria proposed for separating Cook’s and
de Filippi’s petrels. Variation due to molt, behavior, and wind speed
frequently mask the slight differences in shape and flight manner between
the two species. Nonetheless, de Filippi’s often appears broader-winged and
more thickset than Cook’s, with a broader and more wedge-shaped (but not
obviously longer) tail.

Black-tipped central rectrices appear to be universal in Cook’s Petrel;
uniformly gray ones are usual in de Filippi’s. But a few de Filippi’s Petrels
show a dark tail tip. At ranges of less than 150-200 m, we found face and
neck pattern, in combination with bill size, to be the most useful characters
for separating the two species at sea: Cook’s Petrels show a “flat” gray cap,
a “beady” black eye, and a small, slender bill, de Filippi’s Petrels show a gray
collar (like that of Black-winged Petrel), a bold black eye patch, and a thick
black bill (Figure 3).

Pycroft’s Petrel typically shows a cap shaped like that of Stejneger’s Petrel
(and thus different from Cook’s Petrel; Figure 3), and we recommend critical
observations at sea to evaluate the reliability of this feature for separating
Pycroft’s from Cook’s Petrel.

Despite experience at sea with thousands of Cookilaria petrels, including
all species found in the eastern Pacific Ocean (Spear et al. 1992), we
frequently let birds go as unidentified to species at ranges greater than 200-
300 m, and we urge caution with this problematic group of birds.

ACKNOWLEDGMENTS

We thank David Ainley, Mike Force, and Denise Hardesty for help with observa-
tions on the cruises, and the officers and crew of the National Oceanic and

63

IDENTIFICATION OF PETRELS AT SEA

Atmospheric Administration vessel Surveyor and of the R/V Polar Duke for logistical
support. Our data collection was supported in part by National Science Foundation
grant OPP-9526435 to Spear and David Ainiey. The comments of Richard R. Veit,
Philip Unitt, and Peter Pyle improved the manuscript greatly. This is contribution
number 705 of the Point Reyes Bird Observatory.

LITERATURE CITED

Dunnet, G. M. 1985. Pycroft’s Petrel in the breeding season at Hen and Chicken
Islands. Notornis 32:5-21.

Giglioli, H. H., and Salvadori, T. 1869. On some new Procellariidae collected on a
voyage round the world in 1865-68 by H. I. M.’s “Magenta". Ibis 5:61-68.

Harrison, R 1983. Seabirds, an Identification Guide. Houghton Mifflin, Boston.

Harrison, P. 1987. Seabirds of the World, a Photographic Guide. Christopher Helm,
London.

Roberson, D., and Bailey, S. F. 1991. Cookilaria petrels in the eastern Pacific Ocean.
Am. Birds 45:1067-1081.

Spear, L. B., Howell, S. N. G., and Ainiey, D. G. 1992. Notes on the at-sea
identification of some Pacific gadfly petrels (genus: Pterodroma). Colonial
Waterbirds 15:202-218.

Accepted 25 January 1996

64

WINTER DISTRIBUTION OF HERMIT THRUSH
SUBSPECIES IN THE SIERRA DE LA LAGUNA,
BAJA CALIFORNIA SUR

PHILIP UNITT, San Diego Natural History Museum, P. O. Box 1390, San Diego,
California 92112

RICARDO RODRIGUEZ ESTRELLA, Centro de Investigaciones Biologicas del
Noroeste, Apdo. Postal 128, La Paz, Baja California Sur 23000, Mexico

The Hermit Thrush ( Catharus guttatus ) winters commonly in Baja
California Sur. Specimens we collected of this species in the Sierra de la
Laguna, however, reveal new details and clarify misunderstandings concern-
ing the distribution of its subspecies in this region.

STUDY AREA AND METHODS

In January 1990 we made a 2-week expedition across the Sierra de la
Laguna, the forested mountains of the Cape district of the peninsula of Baja
California and now a biosphere reserve. The sierra, consisting mainly of
Cretaceous granites, reaches altitudes of 2200 m. Ornithologists have
seldom visited these mountains in winter. We ascended the east slope of the
sierra, beginning from Santiago, then climbed the Canon de la Zorra,
paused at Palo Extrano and La Laguna, and finally descended to La Burrera
at the west base of the mountains.

This route enabled us to cover both vegetation zones of the sierra: tropical
deciduous woodland and oak-pine forest. The more diverse tropical decidu-
ous forest covers 170,500 ha at elevations between 300 and 1500 m and
is dominated by Pachycereus pecten, Ferocactus spp., Lysiloma divaricata,
Plumeria acutifolia, Euphorbia spp., Erythrina flabelliformis, Cassia
emarginata, Pithecellobium mexicanum, and Yucca spp. (Arriaga and
Leon 1989). The mean annual rainfall in this zone is 400 to 700 mm; the
mean monthly temperature, 23.3° C (Coria 1988). The oak-pine forest
covers 20,000 ha at elevations over 1500 m and is dominated by Quercus
deuia, Pinus lagurtae, Arbutus peninsularis , and Nolina beldingii (Leon
de la Luz and Dominguez 1989). The mean annual rainfall exceeds 700
mm, and the mean monthly temperature is 14.7° C. Late summer, mainly
August and September, is the rainy season, and the area is subject to
hurricanes.

We remained 2 days at most camp sites, observing and collecting birds via
mist nets at a wide range of elevations. Unitt prepared the specimens
collected as study skins, now stored at the Centro de Investigaciones
Biologicas del Noroeste, La Paz (CIB). In 1992 Rodriguez brought some of
the specimens to the San Diego Natural History Museum (SDNHM), where
we studied them.

Western Birds 27:65-69, 1996

65

HERMIT THRUSH SUBSPECIES

RESULTS

We collected nine specimens of the Hermit Thrush (Table 1), at elevations
ranging from 430 m (in Canon La Zorra) to 1650 m (at La Laguna). When
preparing the specimens, we were struck by their variation in body mass, the
largest being 45% heavier than the smallest, although none was fat and all
but one were males. Comparing them with each other and with the
substantial collection at SDNHM revealed that these differences in size
corresponded with differences in plumage color and pattern and that the
nine specimens represented at least three subspecies.

The four smaller specimens, weighing from 18 to 21 grams, all have the
breast lightly spotted, conforming to the subspecies s levin i and jewetti. The
specimen from La Burrera is slightly paler dorsally than the other three and
likely represents slevini, which breeds at least in the Coast Ranges of central
and northern California (possibly farther north). The other three match a
specimen identified by the late A. R. Phillips as jewetti, a slightly darker and
browner form that breeds from the Olympic Peninsula of Washington south
an undetermined distance (Phillips 1991). These two subspecies are very
similar, and Aldrich (1968) did not distinguish them. We have not seen fresh-
plumaged specimens from the breeding ranges of both so cannot confirm
their differences.

The four intermediate specimens, weighing from 22 to 24 grams, have
the moderately heavy breast spots and rather dark gray-brown upperparts
typical of Catharus g. guttatus. This form breeds in southwestern and
south-central Alaska (at least) and winters commonly in San Diego County,
Upper California, so an ample supply of suitable comparison specimens was
available to us in SDNHM. Two of the four specimens from the Sierra de la

Table 1 Hermit Thrushes Collected in the Sierra de la Laguna,
21-31 January 1990

Specimen

Sex

Locality

Eleva-

tion

(m)

Wing

Chord

(mm)

Bill

from

Nostril

(mm)

Weight

(g)

C. g. slevini/jewetti

A006

M

Canon de la Zorra

865

81.6

63.2

18.8

A031

M

La Burrera

500

88.2

67.8

19.7

A003

M

Canon de la Zorra

430

90.4

71.3

20.4

A009

M

Canon de la Zorra

1275

86.7

65.3

20.8

C. g. guttatus

A026

F

La Laguna

1650

86.8

66.4

22.3

A025

M

La Laguna

1650

86.8

67.9

22.3

A019

M

La Laguna

1650

89.2

68.5

23.0

AO 15

M

Palo Extrano

1625

89.9

68.5

23.2

C. g, auduboni/polionotus

A020

M

La Laguna

1650

101.6

75.2

27.3

66

HERMIT THRUSH SUBSPECIES

Laguna are completely typical of guttatus; two have slightly darker backs,
more as in uaccinius, but they lack the extensively dark gray flanks, deeper
buff background color on the breast, and very heavy breast spotting of the
latter subspecies.

The ninth specimen, from La Laguna, weighed 27.3 grams and much
exceeds the other specimens in linear measurements, too. These measure-
ments exclude any coastal subspecies of the Hermit Thrush and identify it as
either C. g. auduboni or polionotus, breeding in the Great Basin/Rocky
Mountain region. With its very large breast spots and upperparts paler and
grayer than in guttatus it conforms with auduboni in plumage as well as in
size. The subspecies auduboni and polionotus are very similar; neither
Phillips (1962) nor Aldrich (1968) recognized them as distinct, though in
1991 the former reversed his opinion. We have not seen specimens that
would allow us to distinguish them.

Our specimens of sleuini (sensu lato, including jewetti) differed strikingly
in elevation and habitat from those of guttatus and auduboni ( sensu lato,
including polionotus ). The four specimens of sleuini all came from eleva-
tions below 1300 meters in tropical deciduous woodland variously domi-
nated by Tecoma stans, Lysiloma divaricata, Dodonaea viscosa, Jatropha
uemicosa, and J. argentea. The five specimens of guttatus and auduboni
all came from elevations above 1600 meters in‘oak-pine woodland with an
understory of Helianthus similis, Lepechinia hastata, Mimosa xantii , and
Calliandra brandegeei. Both Catharus g. guttatus and sleuini have been
reported previously from the Cape region of Baja California Sur, but this
difference in elevation and habitat preference has not. The difference in
habitat, however, corresponds well to the subspecies’ known distributions.
Catharus g. guttatus winters mainly in woodland and chaparral in Upper
California, and the latitude of the Sierra de la Laguna is near the southern
extreme of its main winter range (AOU 1957, Phillips 1991), so it should be
expected there at higher elevations. Catharus g. sleuini, on the other hand,
winters mainly in northwestern mainland Mexico, extending north only
slightly across the international frontier. It occurs at low to moderate
elevations in Arizona (Monson and Phillips 1981) and apparently in Sonora
and Sinaloa as well, as far as can be inferred from the localities listed by van
Rossem (1945) and Miller et al. (1957). At 700 meters, Cumpas is the
highest locality listed by van Rossem (1945).

To the extent that elevations can be inferred from the often vague
localities on specimens from early collectors, the difference in elevations
occupied by the two subspecies is apparent in the previous literature
(Grinnell 1928, Miller et al. 1957). Apparently both forms may be found at
an elevation of about 1220 meters, the elevation of El Sauce, where C. C.
Lamb collected one sleuini and two guttatus in November and December
1928 (specimens in the Museum of Vertebrate Zoology, University of
California, Berkeley).

Although the AOU (1957) listed sleuini as occurring only “casually” in
Baja California Sur, that state is clearly part of its normal winter range, as
specified by Miller et al. (1957).

Catharus g. auduboni has been reported previously from Baja California
Sur only on the basis of six specimens collected in the Sierra de la Laguna by

67

HERMIT THRUSH SUBSPECIES

M. A. Frazar from 11 May to 8 June 1887 (Brewster 1902) and still in the
Museum of Comparative Zoology, Harvard University, Cambridge, Massa-
chusetts (R. A. Faynter, Jr., pers. comm.). Although Frazar found the Hermit
Thrush “not numerous, but . . . seen [and heard singing] almost daily,” no
subsequent observer has reported Hermit Thrushes in these mountains
during the breeding season, and the species has not been confirmed as
nesting anywhere in Mexico [summer sightings only in the Sierra San Pedro
Martir, Baja California (Norte); Howell and Webb 1992], The subspecies
auduboni and polionotus winter mainly in pine-oak forests in mainland
Mexico (Phillips 1991), so our specimen from La Laguna was in typical
habitat.

SUMMARY

At least two subspecies of the Hermit Thrush winter commonly in the
Cape region of Baja California, Catharus g. slevini/jewetti at lower
elevations (up to at least 1275 meters) in tropical deciduous forest, and C. g.
guttatus at higher elevations in oak-pine forest (down to at least 1200
meters). On the basis of one specimen, Catharus g. auduboni and/or
polionotus also winters at least rarely in montane oak-pine forest.

ACKNOWLEDGMENTS

We thank Elizabeth Braker and Thomas A. Scott for organizing our expedition and
the University of California, Riverside, and CIB for supporting it. We thank the
authorities of the institutions listed above for their responding to our inquiries and
accommodating our use of their collections. The Secretaria de Desarrollo Urbano y
Ecologia (now the Secretaria de Desarrollo Social) authorized our collecting. And we
thank Steve N. G. Howell, Ned K. Johnson, and Tim Manolis for their helpful
comments on the manuscript.

LITERATURE CITED

Aldrich, J. W. 1968. Population characteristics and nomenclature of the Hermit
Thrush. Proc. U. S. Natl. Mus. 124 (3637):l-33.

American Ornithologists’ Union. 1957. Check-List of North American Birds, 5th ed.
Am. Ornithol. Union, Baltimore.

Arriaga, L., and Leon, J. L. 1989. The Mexican tropical deciduous forest of Baja
California Sur: A floristic and structural approach. Vegetatio 84:45-52.

Brewster, W. 1902. Birds of the cape region of Lower California. Bull. Mus. Comp.
Zool. 41:1-241.

Coria, R. B. 1988. Climatologia, in La Sierra de la Laguna de Baja California Sur (L.
Arriaga and A. Ortega, eds.), pp. 45-52. CIB-Robles Hnos. y Asoc., Mexico.

Grinnell, J. 1928. A distributional summation of the ornithology of Lower California.
Univ. Calif. Publ. Zool. 32:1-300.

Howell, S. N. G., and Webb, S. 1992. Noteworthy bird observations from Baja
California, Mexico. W. Birds 23:153-163.

Leon de la Luz, J., and Dominguez, R. 1989. Flora of the Sierra de la Laguna, Baja
California Sur, Mexico. Madrono 36:61-83.

68

HERMIT THRUSH SUBSPECIES

Miller, A. H., Friedmann, H., Griscom, L., and Moore, R. T. 1957. Distributional
check-list of the birds of Mexico, part II. Pacific Coast Avifauna 33.

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

Phillips, A. R. 1962. Notas sistematicas sobre aves mexicanas. I. Anal. Inst. Biol.
Mex. 32:333-387.

Phillips, A. R. 1991. The Known Birds of North and Middle America, part II. A. R.
Phillips, Denver.

Van Rossem, A. J. 1945. A distributional survey of the birds of Sonora, Mexico. Occ.
Pap. Mus. Zool. La. State Univ. 21.

Accepted 20 March 1996

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69

THE BREEDING COLONY OF LAYSAN
ALBATROSSES ON ISLA DE GUADALUPE, MEXICO

JUAN-PABLO GALLO-REYNOSO and ANA-LUISA FIGUEROA-CARRANZA, A-
318 Natural Sciences 4, University of California, Santa Cruz, California 95064
(current address of Gallo: CIDESON-Guaymas, Miramar 63, planta alta, Col. Miramar,
Guaymas, Sonora 85450 Mexico; current address of Figueroa: Conservation Interna-
tional-Mexico, A. C., Programa Golfo de California. Miramar 63, planta alta, Col.
Miramar, Guaymas, Sonora 85450, Mexico)

Early accounts of the birds of Isla de Guadalupe and adjacent waters did
not mention the Laysan Albatross, Diomedea immutabilis (Jehl and Everett
1985), though Pitman (1986) and Jennings (1987) observed the species
around the island from 1974 to 1984. Dunlap (1988) first reported it
breeding on Isla de Guadalupe in May 1986, the first known breeding colony
for the species east of the Hawaiian Islands and a major range extension.
Howell and Webb (1992) noted additional new colonies established on Isla
San Benedicto (19° 19'N, 110° 49'W)andIslaClari6n(18° 22'N, 114° 44'
W) in the Revillagigedo Archipelago. The colony at Isla de Guadalupe has
been reported on subsequently by Oberbauer et al. (1989) and Howell and
Webb (1992). Here we summarize the growth and current status of this
colony on the basis of our observations in 1991 and 1992 and those of the
island’s military staff.

STUDY SITE AND METHODS

Isla de Guadalupe (29° 00' N, 118° 15' 30" W), a volcanic island, 240 km
off Baja California, lies within the California Current, in which nutrient-rich
cold upwelled water flows from north to south (Roden 1971, Lynn and
Simpson 1987).

We censused nesting albatrosses by ground counts, maintaining a distance
of 10 m to avoid disturbing the birds. The colony was divided into three study
areas, according to substrate, vegetation, and density. Nests were plotted on
a map of the colony (Figure 1). The area occupied by the colony was
estimated from marine charts of Isla de Guadalupe (H. 0. 1688, U.S. Navy).
We estimated the total population by adding the number of nesting pairs to
the number of nonbreeding birds. We estimated breeding success by
monitoring during the incubation period to assess hatching success (Febru-
ary 1991: two censuses of the colony; February 1992: three censuses), after
fledging to assess chick mortality (June 1991: two censuses, July 1991: two
censuses; June 1992: one census, July 1992: three censuses), and during
arrival for nesting (November-December 1991: two censuses; November
1992: two censuses).

RESULTS

The Laysan Albatross colony is located at the southern end of the main
island, on a man-made terrace known as the “weather station.” This plateau
is approximately 100 m above sea level and is exposed to the predominant

Western Birds 27:70-76, 1996

70

LAYSAN ALBATROSSES ON ISLA DE GUADALUPE

northwesterly (fall, winter, spring) and southeasterly (summer) winds
(Berdegue 1957). The terrace has been cleared of scattered lava rocks and
gravel and is the site of a meteorological observatory and a seismographic
station. Several pathways and a dirt road cross the terrace (Figure 1). Parts
of this terrace are covered by dirt, sand, low vegetation, and lichens.

Most albatrosses (in 1992, 41 of 45 nests, or 91%) nested in areas with
low brush and rocks (Figures 2 and 3). Only a few nested in areas with little
or no vegetation (4 nests, or 9%). Area 1 , the area most exposed to the wind,
is located on the steep slope toward Punta Sur, covering about 1000 m 2 with
a substrate composed of lava rocks, lava rubble, gravel, and abundant brush
( Franseria camphorata and Airiplex palmeri). This area supported the

Figure 1. Location of the Laysan Albatross breeding area at Punta Sur, Isla de
Guadalupe, just above the town. The arrow at upper left shows the direction of the
predominant winds. The circle in Area 2 is the meteorological radar dome, and the
rectangle in Area 1 is the seismological station.

71

LAYSAN ALBATROSSES ON ISLA DE GUADALUPE

Figure 2. Area 1 of the Laysan Albatross colony, Isla de Gualaupe. Slope sheltered
from the wind by rocks and brush (February 1992).

Photo by Juan-Pablo Gallo-R.

Figure 3. Area 1 of the Laysan Albatross colony, Isla de Guadalupe. Terrace with little
cover from the wind (February 1992).

Photo by Juan-Pablo Gallo-R.
72

LAYSAN ALBATROSSES ON ISLA DE GUADALUPE

highest density and number of birds with 79 individuals (60.8%) (Figures 2
and 3). Area 2, separated from Area 1 by a dirt road, is where the buildings
of the weather and seismography stations are located. It covers about 2000
m 2 , and is characterized by lava rocks, lava rubble, and sparse vegetation.
Nineteen individuals (14.6%) were found here. Area 3 is separated from
areas 1 and 2 by a dry creek bed, and is about 8 m lower than the terrace.
It covers about 3000 m 2 and is also composed of lava rocks, rubble, and
gravel with abundant low brush and few scattered areas of dirt. We counted
32 individuals (24.6%) here.

From 2 to 5 June 1983, Gallo visited Guadalupe for a pinniped survey.
Several portions of the island were explored, including the terrace where the
Laysan Albatrosses currently nest. We found no evidence of this species on
the island (including nests, bones, feathers, or eggshells) even though the
expedition was made before any albatross chicks would have fledged.

According to the island’s military staff, in November 1983 the first two
pairs of albatrosses landed in the terrace area, about 100 m above the naval
base. They attempted to nest but were not successful (Cruz-Bautista pers.
comm.). Later that winter, in January 1984, four pairs nested in the terrace
area (Cruz-Bautista pers. comm.). Four hatchlings were observed in Febru-
ary 1984, but no information concerning their fledging success is available.

In January 1985, five pairs attempted nesting (Cruz-Bautista pers. comm.),
and by May 1986, six molting chicks and five to six adults were observed
(Jennings 1987, Dunlap 1988).

On 26 January 1988, Howell and Webb (1992) estimated 35-40 adults,
12 of which were incubating single eggs. That year, however, military
personnel ate some eggs and some adults; as a result, the population was
almost exterminated. Although eating albatrosses by humans was stopped,
later in the same year, a dog from the naval base was observed killing and
eating a young chick. The dog was killed by military personnel (Cruz-Bautista
pers. comm.).

On 30 March 1989, Oberbauer et al. (1989) found only 10 adults, five
young and one nest with an egg.

By February 1990 the population consisted of 18 pairs with 18 chicks
(Cruz-Bautista pers. comm.). That year, R. Le Due found a dead adult
albatross near the colony that military personnel said a dog had killed (R. L.
Pitman in. litt).

On 18 and 19 February 1991 we counted 21 nesting pairs, 21 nestlings,
and six unpaired individuals. We censused the population again on 16 June,
and observed 12 young with their parents.

On 14 and 18 February 1992, we counted 45, nests and estimated a
population of about 130 birds. Unusually heavy rain (rainfall for 5-6
February was 75.5 mm) associated with 1992 El Nino was the probable
cause of death for three chicks killed by rock and mud slides. That summer,
we arrived on 26 June, and found 13 fledglings. Upon arriving we observed
a dead fledgling floating southeast of the island.

In fall 1992 the first albatross arrived on 2 November. When we left on 24
November the colony had 41 individuals, 32 of which were nesting birds.

Using the exponential model of growth, k = (In t - In t 0 )/t (where k = rate
of increase), we obtained an average rate of annual population increase of

73

LAYSAN ALBATROSSES ON ISLA DE GUADALUPE

29.9% over the last eight years (exponential regression: r 2 = 0.78, n = 8
years) (Figure 4). The finite rate of increase, the year-to-year increase of the
population (>.), of 13.5% was calculated from the expression X = e k (Poole
1974).

Laysan Albatrosses arrived on Isla de Guadalupe from early November to
mid-December, The egg-laying period over the two years of our study was
from 27 November to 12 February. Hatching extended from 23 December
1990 to at least 28 February 1991 (when we left the island, seven eggs had
not hatched), peaking around 27 January. Rice and Kenyon (1962) found
the species’ nestling period in Hawaii to be 165 days. We found an average
length of the nestling stage of 201.5 days for the two nesting seasons (21
nests in 1991 and 45 nests in 1992). The average nesting period started on
23 December and finished on 17 July.

In 1991, the chicks fledged between 12 June and July 17. Fledging
success in 1991 was likely near 100%, as we found no evidence of dead
young around the colony, or near caves which often shelter feral cats and
where carcasses of Xantus’ Murrelets (Synthliboramphus hypoleucus)
were seen. Albatrosses started arriving again on 14 November, and immedi-
ately began pair formation and courtship.

In 1992 the last chick fledged on 10 July, seven days earlier than the
previous year. In this year, 45 of the 41 chicks that hatched fledged, for a
fledging success of 91%.

DISCUSSION

Approximately 2.5 million individual Laysan Albatrosses breed on the
northwestern Hawaiian Islands. The density of the population is very high,
and new nesting areas were established and grew in the mid to late 1980s
(Harrison 1990). From the availability of nesting area at Isla de Guadalupe
and apparent reproductive success, it is probable that this population will
expand.

The Laysan Albatrosses nesting on the island today can not all be
descendants of the first four pairs found on Isla de Guadalupe in 1984
(Figure 4). The rate of population growth has been greater than intrinsically
possible, on the basis of an average age at first breeding of 5 to 7 years (Rice
and Kenyon 1962, Fisher 1972) and annual reproductive potential. Thus
we infer that recruitment to Isla de Guadalupe explains much of the
population increase.

The factors prompting the Laysan Albatross to colonize the islands off
Mexico can only be speculated on. Possibly significant are the continuing
increase of the Hawaiian population, now recovering from earlier exploita-
tion (Harrison 1990), and the massive development since 1980 of the drift-
net fishery in the North Pacific. The latter, though catching huge quantities
of the albatrosses’ prey species, also releases a tremendous quantity of waste
(squid offal) that the birds consume.

The conservation and growth of the Laysan Albatross colony on Isla de
Guadalupe will be achieved if ongoing efforts are continued. The presence of
biologists has had a significant impact on the authorities and fishermen by

74

LAYSAN ALBATROSSES ON ISLA DE GUADALUPE

helping them understand the importance of this species as a newcomer to
the Mexican avifauna. Efforts by Mexican authorities, especially the Mexican
Navy, to preserve this species at Isla de Guadalupe have been undertaken
and have been successful to date.

SUMMARY

The Laysan Albatrosses breeding on Isla de Guadalupe arrive from early
November to mid December and lay from late November to early February.
The chicks hatch from late December to late February and fledge from mid-
June to mid-July. From two seasons of study, the mean length of the nestling
stage is 201.5 days. From 4 pairs in 1984 the colony has grown to 131
individuals in 1992, an annual rate of increase of 13.5%. This colony was
established after the species’ population expansion in the Hawaiian Islands
and coincident with the development of the drift-net fishery.

r = 0.78

Figure 4. Growth of the Laysan Albatross population at Isla de Guadalupe. Nesting
adults include nesting pairs. Circles, total population; squares, nesting adults; tri-
angles, chicks; curve, derived rate of population increase ( k = 0.299). No data
available for 1987. The decrease observed in 1989 was due to exploitation of the eggs
by military personnel.

75

LAYSAN ALBATROSSES ON ISLA DE GUADALUPE

ACKNOWLEDGMENTS

We are indebted to the Secretaria de Marina, which provided transportation,
especially to Lt. Cruz-Bautista, Island Coordinator, and to fishermen of “Cooperativa
de langosteros y abuloneros de Ensenada,” which provided logistic support on the
island. These observations were conducted under permits 0596, 2538, and 4933 of
Secretaria de Desarrollo Urbano y Ecologia (SEDESOL), Mexico. We thank The
National Geographic Society for funding three of the expeditions and UC-MEXUS for
funding one expedition. Partial funding for this research was given to Gallo by the
Direccion General de Asuntos del Personal Academico Universidad Nacional
Autonoma de Mexico. The manuscript benefited from the comments of Philip Unitt,
Steve N. G. Howell, Robert L. Pitman, B. Tyler, and William Sydeman.

UTERATURE CITED

Berdegue, J. 1957. La Isla de Guadalupe, Contribucion al conocimiento de sus
recursos naturales renovables. Secretaria de Marina, Dir. Gral. Pesc. Indus.
Conex., Mexico, D.F.

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

Fisher, H. I. 1972. Sympatry of Laysan and Black-footed Albatrosses. Auk 89:81-
402.

Harrison, C. S. 1990. Seabirds of Hawaii: Natural history and conservation. Cornell
Univ. Press, Ithaca, N.Y.

Howell, S. N. G., and Webb, S. 1992. Changing status of the Laysan Albatross in
Mexico. Am. Birds. 46:220-223.

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

Jennings, G. Y. 1987. Guadalupe. Oceans 20(5):40-45.

Lynn, R. J., and Simpson, J. J. 1987. The California Current System: The seasonal
variability of its physical characteristics. J. Geophys. Res. 92(cl2): 12,947-
12,966.

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

Pitman, R. L. 1986. Atlas of seabird distribution and relative abundance in the Eastern
Tropical Pacific. Admin. Rep. LJ-86-02C, Natl. Marine Fisheries Serv., South-
west Fisheries Center, P. O. Box 271, La Jolla, CA 92038.

Poole, R. W. 1974. An Introduction to Quantitative Ecology. Mc.Graw-Hill
Kogakusha, Tokyo.

Rice, D. W., and Kenyon, K. W. 1962. Breeding cycles and behavior of Laysan and
Black-footed albatrosses. Auk 79:517-567.

Roden, G. 1. 197 1 . Large-scale upwelling off northwestern Mexico. J. Phys. Oceanogr.
2:184-189.

Accepted 30 January 1996

76

PRESIDENT’S MESSAGE

At a special meeting held on 1 August 1995, the Board of Directors of the Western
Field Ornithologists elected me to fill its presidency. I’ve been a member of this
organization for well over half of my life, all the while in awe of the “who’s who” of
western North American field ornithology who have worked hard to build WFO into
the premier organization of its kind. Being asked to fill the role of its president was an
honor, but not without its challenges.

Another important item of business at the August 1995 meeting was the replace-
ment of three retiring directors. Bruce Deuel, Peter Gent, and Steve Summers have
stepped down as directors; we thank them, for the organization has benefited greatly
from their input. Their departure, and the expiration of Bob McKernan’s term as
director, left four positions to be filled. Happily, we’ve brought ex-president Tim
Manolis back as a director, and have added three of the more active field workers in
the West: Dan Gibson from Fairbanks, Alaska, Dave Shuford from Stinson Beach,
California, and Mike San Miguel from Arcadia, California. Mike has further agreed to
step into the role of vice-president. I welcome all of these talented folks to the board
and look forward to working with them. Finally, I thank Bob McKernan for his years
of service as WFO president and look forward to his input as an ex-officio member of
the board.

What WFO does, it does well, Western Birds is perhaps the premier regional field
ornithology journal in North America. But this is a case where bigger is actually better,
and we are exploring means of raising additional revenues though advertising and
marketing that can be channeled directly into an even better Western Birds with more
papers, more pages, more photos, and more color. Other planned ventures include
the publication of new check-lists, a book (nearing completion in draft form) detailing
the decisions of the California Bird Records Committee, and a WFO presence on the
World Wide Web.

Is WFO a California organization that has a token extension into neighboring states
and provinces? I believe the answer is, and should be, no. But a California emphasis
is clearly reflected in our current membership. We need to build partnerships with
other state and regional field ornithology organizations, benefiting from each other’s
strengths. We must all work to increase our membership. With a hard-working Dori
Myers to run our membership, circulation, and treasury functions, it’s up to us to get
her some business!

Our 1996 meeting will be held jointly with the Colorado Field Ornithologists in
Estes Park, Colorado; Steve Bouricius of CFO is chairing the meeting, and Peter Gent
is acting as WFO liaison. The 14-16 June meeting dates are right before the
American Birding Association’s biennial convention in Park City, Utah. Plan to attend
both! The 1997 WFO meeting will be in California’s Imperial Valley; details are being
developed by Roger Higson. Finally, we owe our thanks to Bill Tweit and Russell
Rogers for organizing the successful Spokane meeting in June 1995.

I welcome any ideas from the members — this is your organization, after all. Write
me, or send me an e-mail message at garrett@bcf.usc.edu.

Kimball L. Garrett

Western Birds 27:77 , 1996

77

NOTES

NESTING ANNA’S HUMMINGBIRDS
IN URBAN TUCSON, ARIZONA

GLORIA J. MAENDER and KATHERINE L. HIETT, National Biological Service,
Cooperative Park Studies Unit, 125 Biological Sciences East, University of Arizona,
Tucson, Arizona 85721

SCOTT JAY BAILEY, 127 West 17th Street, Tucson, Arizona 85701

Anna’s Hummingbird (Calypte anna), formerly regarded as a California species
(Ridgway 1890), has extended its range in recent years. In Arizona, the species was
thought to be a fall and winter resident only, with no positive breeding records prior
to the mid-1960s (Phillips et al. 1964). Spring occurrences were not documented until
after 1964, and only rarely prior to the 1970s were the birds noted in summer
(Zimmerman 1973). The species first nested near Tucson in 1972; young fledged 14
March (Calder 1974). In Arizona, Anna’s Hummingbird’s breeding is confined mainly
to cities (Zimmerman 1973).

We followed the nesting of six (unmarked) female Anna’s Hummingbirds in Tucson
during 1993 and 1994. We provide information concerning nest-site characteristics,
interactions of females, and parental care of fledglings. We confirmed double
brooding (see Legg and Pitelka 1956) by two females.

Our study took place at the Western Archeological and Conservation Center on
1 . 19 ha of landscaped space in 4.2 ha of buildings and paved areas. Plants at this site
include nonnative ornamentals and native species. Tree species are the Sweet Acacia
(Acacia smallii), Honey Mesquite (Prosopis glutinosa), Blue Paloverde ( Cercidium
floridum), and Mexican Paloverde (Parkinsonia aculeata). We observed nesting
hummingbirds from February through July 1993 and November 1993 through early
July 1994. Nest height and straight-line distances between nests and from nests to
identified sources of paint flakes (used in nest construction) were measured. All trees
were mapped and identified, and female hummingbirds were named A through F. We
associated hummingbird nests with females (i.e., A-l refers to the first nest of female
A, A- 2 to the second of female A, etc.).

In 1993, females A and B nested simultaneously, each fledging young from two
broods (Appendix). The first pair of nests (A-l and R-l) were separated by approxi-
mately 70 m; the second pair (A-2 and B-2) were approximately 135 m apart. A
building separated the nests of female A from those of female B. Each female
communicated with a chip note when flying over the nest of the other (see Stiles
1982), but we did not observe these females contesting the vicinity of their nests. As
the young of B-2 were about to fledge, female C began to build her nest (C— 1) around
the corner of a building, approximately 37 m from B-2. After the failure of C-l,
female D (recognizable by distinctive markings) arrived on the study site and success-
fully nested (D-l) approximately 9 m from the site of C-l.

We observed females E and F on the southeast part of the study site as early as
November 1993. There were no visual barriers, such as man-made structures,
subdividing the area, and we observed many confrontations between the two birds.
Female E built her nest (E— 1) first. Female F often disturbed her at this nest by
approaching the nest and even perching on the side of it while female E occupied it.
Female E abandoned the nest four days after laying one egg and before laying a
second egg, although she did begin to incubate. Female E constructed a second nest
(E-2) in the same vicinity, with similar, persistent disturbance by female F; a predator
ultimately took the two nestlings. Female F began to construct her nest (F-l) while

78 Western Birds 27:78-80, 1996

NOTES

female E was feeding nestlings (E-2). Nests E-2 and F-l were located approximately
19 m apart with no intervening vegetation or other objects to obstruct view from one
nest to the other.

Three of the females (A, E, and F) frequently used prominent perches near their
nests, from which each chased intruding Anna’s Hummingbirds (and other bird
species) from the vicinity of their nests. Female A chased a male and female Anna’s
traveling together, and often chased Verdins (Auriparus flaviceps), Northern Mock-
ingbirds ( Mimus polyglottos), Curve-billed Thrashers ( Toxostoma curvirostre), House
Sparrows (Passer domesticus), and House Finches (Carpodacus mexicanus). While
building her nests and during incubation, female E chased female F on each occasion
they were observed together. After both nesting attempts of female E failed and
female F had begun her own nest, the role of aggressor reversed: female F began
chasing female E from her nest area.

Ambient temperatures increased during the advancing nesting seasons in 1993
and 1994. Later nests were built at greater heights (Appendix), with the exception of
the last nest of 1993 (D-l), which was shaded early in the afternoon by a building.

Hummingbirds added paint flakes of various colors to the outside of their nests with
the exception of female D, which added plant parts to the outside of D-l. Paint flakes
were collected from an adjacent building, a stationary trailer, and from buildings in the
neighboring area. Female A used only a few paint flakes, from a variety of sources, on
nest A-l, but covered A-2 profusely with flakes from a single source, about 100 m
northeast of her nest. We recorded paint-flake sources at distances ranging from
approximately 4 m to approximately 180 m from nests. We observed a female
feeding on flowers adjacent to the most distant paint-flake site.

Females A and B each raised a second brood after fledging of their first brood. They
nested simultaneously from mid-January through April 1993. Both females began
construction of second nests while still feeding fledglings from their first broods;
female A began to build her second nest the day after young from her first nest
fledged. Female A built nest A-2 38 m west of A-l, and female B built nest B-2 20
m north of B-l . We observed each female fly alternately to her new nest site and her
fledglings (for three days at start of A-2 and six days at B-2). Fledglings from the first
broods remained in the vicinity of their home nests until their mothers laid eggs and
began incubation. We observed female A feed her young from A-2 three days after it
fledged; female B was still feeding the second young to fledge from B-2 (distinguish-
able from her other fledgling by size) seven days after it fledged.

We observed female D, distinguishable by a crook in her bill, with her single young
24 to 27 days after it fledged. The young bird fledged between 9 and 12 July, and was
regularly seen being fed by its mother through 16 July. On 4 and 5 August, we saw
female D perched within a meter of presumably the same young bird.

We observed six nests built by four females in 1993 and three nests by two females
in 1994 (Appendix). In 1993, 91% of the eggs laid hatched and 73% of the eggs
fledged. One nest (C— 1) failed because of predation of nestlings; young fledged from
the other five nests. In 1994, only two of five eggs hatched and no nests were
successful.

There were few aggressive interactions in 1993 between nesting females. Birds A
and B acknowledged each other’s flights by vocal chips but did not chase; their nests
were visually separated by a building. Nesting of female C overlapped the second
nesting of females A and B; nesting of female D did not overlap other females’
nesting.

The insistent claim to the same area by females E and F in 1994, coupled with their
intolerance of each other in a shared area, may have contributed to nest failure for
both females. We do not know what caused E and F to select sites so close together
(19 m), but since 1994 was very dry and many food sources available in 1993 were
not in 1994, perhaps this area was critical.

79

NOTES

Our observations of female D and her young suggest that parental care of offspring
may be extended if the mother does not attempt additional broods. Female B was still
feeding one of her young from B-2 seven days after it fledged, the last day we saw
female B and her young on the site.

We thank Chris White, Joan Ford, Jim Reece, Blair Soles, and Lisa Gandara for
additional observations. Steve Russell provided additional information and encour-
aged production of this report.

LITERATURE CITED

Calder, W. A., Jr. 1974. The thermal and radiant environment of a winter humming-
bird nest. Condor 76:268-273.

Legg, K., and Pitelka, F. A. 1956. Ecologic overlap of Allen and Anna hummingbirds
nesting at Santa Cruz, California. Condor 58:393-405.

Phillips, A. R., Marshall, Jr., J. T., and Monson, G. 1964. The Birds of Arizona. Univ.
Ariz. Press, Tucson.

Ridgway, R. 1890. The Hummingbirds. Rep. U.S. Nat. Mus. 1889-1890, p. 336.

Stiles, F. G. 1982. Aggressive and courtship displays of the male Anna’s Humming-
bird. Condor 84:208-225.

Zimmerman, D. A. 1973. Range expansion of Anna’s Hummingbird. Am. Birds
27:827-835.

Appendix. Data on Six Anna’s Hummingbird Nests in Tucson, Arizona,

1993 and 1994.

Female A. Nest 1: In Acacia smallii, height 189 cm; 2 eggs laid before 4 Feb
1993; one hatched before 10 Feb, other hatching on 10 Feb; both young fledged
when inadvertently flushed from nest 4 Mar. Nest 2: In A. smallii, height 218 cm; 2
eggs laid 10 and 15 Mar; one hatched between 25 and 30 Mar; single young fledged
19 or 20 Apr.

Female B. Nest 1: In Cercidium floridum, height 205 cm; 2 eggs laid before 4 Feb
1993; first hatched on 4 or 5 Feb, second hatched between 5 and 8 Feb; both fledged
2 Mar. Nest 2: In C. floridum, height 251 .6 cm; 2 eggs laid between 5 and 8 Mar; first
fledged when flushed from nest 12 Apr, second on 15 or 16 Apr.

Female C: In Prosopis glandulosa, height 292.1 cm; 2 eggs laid before 27 Apr
1993; both hatched between 30 Apr and 3 May; nest and young destroyed,
presumably by predator, on 11 or 12 May.

Female D: In Prosopis glandulosa, height 175 cm; before 22 Jun 1993; hatched
before 22 Jun: fledged between 9 and 12 Jul.

Female E. Nest 1: In Cercidium floridum, height 166 cm; 1 egg laid 28 or 29 Jan
1994; nest abandoned before 2 Feb. Nest 2: In C. floridum, height 190 cm; 2 eggs,
one laid on 18 or 19 Feb, second between 19 and 21 Feb; first egg hatched on 7 or
8 Mar, second on 8 or 9 Mar; young destroyed, presumably by predator, between 17
and 19 Mar.

Female F: In Cercidium floridum, height 269 cm; 2 eggs, one laid on 23 or 24
Mar 1994, second on 25 or 26 Mar; eggs destroyed, presumably by predator, on 3 or
4 Apr.

Accepted 5 February 1996

80

NOTES

SOME NESTING WATERBIRDS FROM SOUTHERN
SAN JOSE ISLAND AND ADJACENT ISLANDS,
GULF OF CALIFORNIA, MEXICO

ROBERTO CARMONA, SAUDIEL RAMIREZ, BULMARA ZARATE, and FELIPE
BECERRIL, Universidad Autonoma de Baja California Sur, Apartado Postal 19-B, La
Paz, Baja California Sur 23080, Mexico

The Gulf of California is important for nesting seabirds (Anderson 1983), but the
low productivity of the southern portion causes the abundance of seabirds to decrease
with latitude (Cody et al. 1983, Carmona et al. 1994). Perhaps for this reason there
have been few recent ornithological studies of this area. San Jose Island, north of La
Paz Bay, is one of the areas for which very few records exist (Grinnell 1928, Wilbur
1987, Velarde and Anderson 1993). This paper presents a preliminary list of
waterbirds breeding in the southernmost portion of San Jose Island and on three
smaller adjacent islands.

The study area is located on the southeast side of the Baja California peninsula and
marks the northern limit of La Paz Bay (Figure 1). San Jose Island has a semidesert
climate with a mean annual temperature of 23° C (Garcia and Mosino 1969) and an
average annual precipitation of <250 mm (Jimenez 1989). It lies at the edges of two
major biogeographic areas: the California region and the Cortez province (Anderson
1983).

Off the southeast tip of San Jose Island are three important small islands: San
Francisquito, with an area of 3.8 km 2 , has 45-m cliffs along its east side and sandy
beaches elsewhere around its periphery; El Callo, with an area of 0.13 km 2 , is
surrounded by rocky beaches only; El Pardito, covering 0.12 km 2 , has no vegetation
and is inhabited year round by fishermen (Anonymous 1987).

In this area, we identified four nesting sites. Two are on San Francisquito Island: El
Arenal, a sandy beach 1 .5 km long, located on the northern portion of the island, and
Punta Colorada, a rocky beach 2 km long with a 5 m cliff, located west of El Arenal.
The third location, La Cocina, is a rocky beach 2 km long on the southwest side of San
Jose Island. Finally, El Callo has an elevated plain with vegetation dominated by cholla
cactus, Opuntia cholla, and surrounded by cliffs 20 m high.

We visited the area from 4 to 7 and 28 to 30 May 1995. On both visits, we
censused all four sites, counting nests, eggs, and chicks. We made the counts in the
shortest possible period of time, early in the morning and late afternoon, by walking
through every area. We found six species nesting.

Blue-footed Booby ( Sulci nebouxii). This species was observed nesting only at El
Callo. During the first visit, we found one nest with two eggs and an adult perching
nearby; during the second, three nests, two with one egg, the third with two (probably
the same recorded for the first visit), but neither chicks nor adults. Two nesting
colonies of S. nebouxii have been reported previously in La Paz Bay. One small
colony, at Gaviota Island, was used annually until the end of the 1970s. It was
abandoned because of the disturbance caused by the detonations when San Juan
Nepomuceno Island (approximately 800 m from Gaviota Island) was artificially joined
to the coast (Mendoza 1994). The other colony at La Lobera, (north of Espiritu Santo
Island) had one and two nests in 1988 and 1990, respectively (Carmona et al. 1994).

Brown Booby (S, leucogaster). Several individuals were observed perching at El
Callo, but only one adult was incubating during the first visit and no evidence of
nesting was observed during the second. The only nesting recorded within approxi-

Western Birds 27:81-85, 1996

81

NOTES

mately 40 km of the study area is of a small colony on La Gaviota Island, La Paz Bay,
that has since disappeared following the same disturbance that terminated the Blue-
footed Booby colony (Mendoza 1994). The paucity of nests of both booby species in
La Paz Bay and at El Callo may be attributable to the low productivity of the lower Gulf
of California.

Figure 1 . Southern San Jose Island, showing sites of waterbird colonies. EC, El Callo;
LC, La Cocina; EA, El Arenal; PC, Punta Colorada.

82

NOTES

Great Blue Heron ( Ardea herodias). We found four nests at El Callo. During the
first visit, one was empty, one had two eggs, and two had two chicks each. During the
second visit, one was empty, one had one egg, one had two eggs, and one had two
chicks. Two fledglings were also nearby. Nesting of this species has been widely
recorded in Baja California Sur (Becerril 1994, Carmona et al. 1994, Maldonado and
Sanchez 1994).

Heermann’s Gull (Larus heermanni). This species was observed nesting only at El
Callo. We counted 14 nests with 26 chicks and one egg during the first visit. During
the second visit only 1 1 chicks were observed, for a productivity of 0.78 fledglings per
nest. First- and second-winter immatures were also observed. This colony is very
recent; Carmona visited the area during the breeding seasons of 1986 and 1988,
finding no evidence of nesting by this species. The colony was surrounded by about
25-30 Yellow-footed Gull nests. Predation by the Yellow-footed Gull may explain the
apparent losses of Heermann’s chicks between the first and second visits (e.g.,
Velarde 1992). There is one previous report of nesting for this species in La Paz Bay,
of two solitary nests in 1990 (Carmona et al. 1994).

Yellow-footed Gull (L. livens). Nesting was observed at all four localities. At El Callo
there were 25-30 nests, with a total of 73 and 68 chicks observed during the first and
second visits, respectively. At La Cocina 22 nests, 13 chicks, and 27 eggs were
recorded on the first visit, 37 chicks and 3 eggs on the second. During both the first
and second visits to El Arenal, five nests and 10 chicks were observed. On the second
visit an additional six nests were seen about 500 m west of El Arenal. At Punta
Colorada the gulls’ nesting was more advanced than at the other localities. During the
first visit, 14 nests, 24 chicks, and one nest with two eggs were observed. During the
last visit we found 25 chicks and no eggs.

Interestingly, the Yellow-footed Gull’s nesting in this area, both within and between
colonies, is asynchronous. During the first visit to Punta Colorada, there was only one
egg, and most of the chicks were more than 15 days old; in contrast, at La Cocina
eggs predominated, though chicks older than 15 days were also found. Several factors
may cause this asynchrony: the colonies consisted of a mix of young and old pairs;
asynchrony diminishes competition for food at the most critical stage of the reproduc-
tive cycle; egg predation by fishermen induced renesting. Testing of these hypotheses
requires further studies.

The smallness of these colonies may be attributable to the characteristics of the
substrate and the thermoregulatory requirements of the chicks (Hand 1980, Hand et
al. 1981) and/or egging by fishermen, since smaller colonies are harder to spot (Spear
and Anderson 1989).

Osprey ( Pandion haliaetus). A pair was bringing new material to a nest atop an
abandoned lighthouse during our first visit to La Cocina, but they were absent during
our second visit.

Only six nesting species were recorded in this study area, compared to 21 for the
better-studied La Paz Bay (Carmona et al. 1994). However, San Jose Island has
several mangrove areas that we did not survey during our study. It is likely that some
species of the families Ardeidae and Rallidae nest in these mangroves. Furthermore,
remains of nests observed in crevices on San Francisquito Island suggest nesting of
storm-petrels ( Oceanodroma sp.). More detailed investigations will likely turn up
additional nesting waterbirds. Still, these colonies, like those in La Paz Bay, are
marginal in comparison to the much larger colonies farther north in the Gulf of
California. Further information is needed for the monitoring of the stress and
potential impacts of egg collection by local fishermen, as well as to help the design and
implementation of a future management program for this area.

83

NOTES

We thank Rafael Riosmena, Carlos Villavicencio, and Leticia Morales for their
logistical support, Javier Gaytan and Rafael De Luna for their support and encourage-
ment to continue ornithological work, the Cuevas family, residents of the fishery camp
El Pardito, and Philip Unitt and Rernie Tershy for their suggestions that improved this
paper substantially. This work was done as part of the program “Estudio Integral de
Isla San Jose” of the Universidad Autonoma de Baja California Sur.

LITERATURE CITED

Anderson, D.W. 1983. The seabirds, in Island Biogeography in the Sea of Cortez (T.
J. Case and M. L. Cody, eds.), pp. 246-264. Univ. Calif. Press, Berkeley.

Anonymous, 1987. Islas Mexicanas. Regimen Juridico y Catalogo. Secretaria de
Marina y Gobernacion, Mexico, D. F.

Beeerril, M. F. 1994. Reparto de los recursos temporal, espacial y trofico por parte de
los ardeidos anidantes en el manglar “El Conchalito,” Baja California Sur,
Mexico, durante las temporadas reproductivas de 1992 y 1993. Thesis, Univ.
Autonoma B.C.S., La Paz.

Carmona, R., and Zarate, B. 1992. Biologia reproductiva de la gaviota de patas
amarillas (Larus livens) en Isla Gaviota, B.C.S., Mexico. Rev. Inv. Cient. 3
( 1 ): 11 - 22 .

Carmona, R., Guzman, J., Ramirez, S., and Fernandez, G. 1994. Breeding waterbirds
of La Paz Bay, Baja California Sur, Mexico. W. Birds 25:151-157.

Cody, M., Moran, R., and Thompson, H. 1983. The plants, in Island Biogeography
in the Sea of Cortez (T. J. Case and M. L. Cody, eds.), pp. 49-97. Univ. Calif.
Press, Berkeley.

Garcia, E., and Mosino, P. A. 1969. Los climas de Baja California. Inst. Geofis. Univ.
Nacl. Autonoma Mex. Memorias (1966-1967).

Grinnell, J. 1928. A distributional summation of the ornithology of Lower California.
Univ. Calif. Publ. Zool. 32:1-300.

Hand, J. L. 1980. Human disturbance in Western Gull Larus occidentaiis livens
colonies and possible amplification by intraspecific predation. Biol. Conserv.
18:59-63.

Hand, J. L., Hunt, G. L., and Warner, M. 1981. Thermal stress and predation:
Influences on the structure of gull colony and possibly on breeding distributions.
Condor 83:193-203.

Jimenez, C. C. 1989. Habitos alimenticios, requerimiento energetico y consumo
alimenticio del pelicano cafe ( Pelecanus occidentaiis ) en La Bahia de La Paz, B.
C. S,, Mexico. Thesis, Univ. Autonoma B. C. S, La Paz.

Maldonado, D., and Sanchez, M. L. 1994. Estrategia reproductiva de Nycii corax
viotaceus bancrofti (Huey, 1927) (Aves: Ardeidae) en el manglar “El Conchalito,”
Ensenada de la Paz, B. C. S. Thesis, Univ. Autonoma B. C. S., La Paz.

Mendoza, S. R. 1994. Anidacion del gallito marino californiano ( Sterna antillarum
browni) y manejo de una de sus areas de reproduction en el region de La Paz, B.
C. S. Master’s thesis, CICIMAR, Inst. Politecnico Nacl., Mexico.

Spear, L. B., and Anderson, D. W. 1989. Nest-site selection by Yellow-footed Gulls.
Condor 91:91-99.

Velarde, E. 1992. Predation of Heermann’s Gull ( Larus heermanni ) chicks by Yellow-
footed gulls (Larus livens) in dense and scattered nesting sites. Colonial Waterbirds
15:8-13.

84

NOTES

Velarde, E., and Anderson, D. W. 1994. Conservation and management of seabird
islands in the Gulf of California: Setbacks and successes. Int. Council Bird
Preserv. Tech. Publ. 721-767.

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

Zarate, B. 1995. Biologia reproductiva de la gaviota de patas amarillas Larus livens
en Isla Gaviota y evaluation de su estado reproductive en la Bahia de La Paz, B.
C. S., durante 1990. Thesis, Univ. Autonoma B. C. S., La Paz.

Accepted 6 February 1 996

Blue-footed Boobies Sketch by Tim Manolis

85

NOTES

FIRST DOCUMENTED BREEDING OF
THE EURASIAN SKYLARK IN ALASKA

PAUL J. BAICICH, P.O. Box 404, Oxon Hill, Maryland 20750-0404

STEVEN C. HEINL, P.O. Box 23101 Ketchikan, Alaska 99901

MIKE TOOCHIN, #13 10460 #3 RD, Richmond, British Columbia V7A 4W5

Introduced, resident populations of the Eurasian Skylark, nominate Alauda arvensis
arvensis, breed locally on southern Vancouver Island, British Columbia, and the San
Juan Islands, Washington. (AOU 1983: 488). In Alaska, the species occurs naturally
as an annual rare migrant and casual summer visitant to the western Aleutian Islands
(Near Islands group) and a casual migrant and summer visitant to St. Lawrence Island
and the Pribilof Islands, in the Bering Sea (Kessel and Gibson 1978; Byrd et al. 1978;
Gibson 1981). All Alaska specimens are of the northeast Asiatic form A. a.
pekinensis, which breeds as far east as the Koryak Highlands, Kamchatka, and the
Kurile Islands (fide D. D. Gibson, University of Alaska Museum; Vaurie 1959;
Portenko 1963). Breeding has been suspected in Alaska (twelve birds, including a
singing male, at St. Paul Island, 1-9 July 1970; Kessel and Gibson 1978), but there
has been no solid evidence of breeding, and no skylarks have previously been
identified as females in the field. Here we report the first evidence of breeding by the
Eurasian Skylark in Alaska and the first evidence of breeding by non-introduced
skylarks in North America.

On 22 May 1995 we were leading a bird tour group of 20+ people at St. Paul
Island, Pribilof Islands, Alaska, when Toochin heard the song of a Eurasian Skylark.
Upon locating the bird he discovered that there were several birds singing over an
open grassy area along the road 0.5 km north of the St. Paul airport. It was a clear
day, and our group watched the birds perform dramatic flight songs and chase each
other about for an hour, often at very close range. We soon determined that there
were three singing males and another bird whose behavior suggested a female. The
presumed female skylark gathered dead grass at one location, then flew 20 m and
deposited the material at another location. This circuit, from the gathering spot to the
depositing spot, was repeated many times as we watched. One male skylark stayed
very close to the female, following her back and forth on this circuit. The male did not
gather any nest material; instead, he sang while hovering over the female as she
collected material and sang from a raised mound near the depositing site. The other
male skylarks occasionally approached too near the female during their display flights,
and the attending male immediately drove them away, then returned to the female.
We assumed that the female was building a nest. We returned to the location several
times during the ensuing three days, sometimes finding singing males, sometimes
finding no skylarks, but we did not again find the female.

Shortly before departing the island on 26 May, we returned to the site again and
found the nest with four eggs 20 m west of the road (Figure 1). The eggs were dark
olive-green and completely covered with fine dark brown specks, heaviest on the
larger end. The nest was a deep cup built on the ground in a tussock of tall grass, and
it was constructed of coarse stalks with a lining of finer grass woven into the lower
portions. Although the nest was in a clump of tall grass, its top was not hidden, and
it was open to a southern exposure. We lacked instruments, so were unable to
measure the nest or eggs. Several people with the tour photographed and videotaped
the nest (photos on file at the University of Alaska Museum). Both birds were in
attendance, the male singing and displaying the entire time, and as we departed the
area the female flew to the nest, presumably to incubate the eggs. Our findings concur
with the details of skylark nesting habits detailed by Cramp (1988).

86

Western Birds 27:86-88, 1996

NOTES

We reported the skylark nest to Sean D. Smith, tourism director of St. Paul Tours,
and he monitored the nest for several days after 26 May. Unfortunately he found no
sign of eggs or egg shells at the nest on 30 May. It is highly likely that the eggs fell prey
to Arctic Foxes ( Alopex lagopus), which are common on the island. The skylarks
continued to be seen, and on 16 June M. Danzenbacker (pers. comm.) found another
nest in the same area only 1 m from the road. This nest contained three nestlings
approximately one week old. Two adult skylarks were seen in the vicinity of the nest.
Both were carrying food and were quite agitated by the observer’s presence. No
nestlings were found at or near this nest on 19 June. Although skylarks leave the nest
within 7 to 11 days of hatching (Cramp 1988), it is likely that this nest also fell prey
to Arctic Foxes, as the adults and juveniles should have been nearby. Sklylarks were
last seen around the St. Paul airport on 22 June.

We thank Sean D. Smith for following up and sharing his observations of the
skylark nests after our tour departed St. Paul Island. We also thank Mike Danzenbaker
for sharing his observations of the second skylark nest. We thank Daniel D. Gibson
and an anonymous reviewer for making useful suggestions to the text.

LITERATURE CITED

American Ornithologists' Union. 1983. Checklist of North American Birds, 6th ed.
Am. Ornithol. Union, Lawrence, KS.

Byrd, G. V., Trapp, J. L., and Gibson, D. D. 1978. New information on Asiatic birds
in the Aleutian Islands, Alaska. 1978. Condor 80:309-315.

Figure 1. Eurasian Skylark nest on St. Paul Island, Alaska, May 1995.

Photo by Mike Toochin

87

NOTES

Cramp, S. (ed.). 1988. The Birds of the Western Falearctic, Vol. 5. Oxford Univ.
Press, Oxford, England.

Gibson, D. D. 1981. Migrant birds at Shemya Island, Aleutian Islands, Alaska.
Condor 83:65-77.

Kessel, B., and Gibson, D. D. 1978. Status and distribution of Alaska birds. Studies
Avian Biol. 1.

Portenko, L. A. 1963. The ornithogeography of the Koryak Highlands (U.S.S.R.).
Proc. XIII Int. Ornithol. Congr. (1962):! 140-1 146.

Vaurie, C. 1959. The Birds of the Palearctic fauna, Vol. 1, Passeriformes. H. F. & G.
Witherby, London.

Accepted 25 March 1 996

88

NOTES

A RECORD OF THE ROSEATE SPOONBILL
ON THE PACIFIC COAST OF THE PENINSULA
OF BAJA CALIFORNIA

EDGAR AMADOR and JUAN JOSE RAMIREZ, Centro de Investigaciones Biologicas
del Noroeste, S. C., Division de Biologia Marina, Apdo. Postal 128, La Paz, Baja
California Sur 23000, Mexico

On 18 March 1994, we observed and photographed a single Roseate Spoonbill
( Ajaia ajaja ) at Estero de Rancho Bueno (29° 19'N, 111° 29' W), Baja California Sur,
Mexico. The bird was in breeding plumage and was roosting in the mangroves near
the head of the estero. The photograph, on file at the Centro de Investigaciones
Biologicas, La Paz, shows the spatulate bill, pale pink body plumage, and contrastingly
bright pink shoulders, but the image is too small to be reproduced well for publication.
Located at the southern end of the Bahia Magdalena-Bahia Almejas complex on the
Pacific coast, the Estero de Rancho Bueno is a coastal lagoon, 11 km long and
averaging 300 m wide, fringed by mangroves ( Rhizophora mangle, Laguncularia
racemosa, and Avicennia germinans ).

On the Pacific coast of mainland Mexico the Roseate Spoonbill is resident from
extreme southern Sonora (Knoder et al, 1980, Peterson and Chalif 1973, E. Palacios
and E. Mellink pers. comm.) to Chiapas (A.O.U. 1983). In Baja California Grinnell
(1928) described this species as a sporadic postbreeding summer visitor to the delta of
the Colorado River, although there are no recent records for this area (Wilbur 1987).
The only other record of the Roseate Spoonbill for the peninsula is for the east coast
of Baja California Sur, where Fernandez et al. (1993) observed a single individual in
first fall plumage in the Ensenada de La Paz (24° 06' N, 110° 23’ W) on 7 December
1992. Therefore our observation represents the second sight record of the Roseate
Spoonbill in Baja California Sur and the first for the Pacific coast of the peninsula.

During our surveys of Estero de Rancho Bueno, from November 1993 to June
1994, this was our only observation of a Roseate Spoonbill, so we presume the bird
was a vagrant. Outside of its usual distribution the species has been recorded
irregularly north to central California, U.S.A., mainly in late summer and early fall
(Small 1994).

We thank Eduardo Palacios and Leopoldo A. Moreno-Matiela for improving this
note.

LITERATURE CITED

American Ornithologists’ Union. 1983. Check-list of North American Birds, 6th ed.
Allen Press, Lawrence, KS.

Fernandez, G., Carmona, R., and Brabata, G. 1993. Primer registro de Ajaia ajaja
(Threskiornithidae) en la Peninsula de Baja California, Mexico. Rev. Inv. Cient.
4:111-113.

Grinnell, J. 1928. A distributional summation of the ornithology of Lower California.
Univ. Calif. Publ. Zool. 32:1-300.

Knoder, E., Plaza, P, and Sprunt, A. 1980. Status and distribution of the Jabiru Stork
and other water birds in western Mexico, in The Birds of Mexico: Their Ecology
and Conservation (P. Schaeffer and S. Ehlers, eds.). Proc. Natl. Audubon Soc.
Symp.

Peterson, R. T., and Chalif, E. L. 1973. A Field Guide to Mexican Birds. Houghton
Mifflin, Boston.

Western Birds 27:89-90, 1996

89

NOTES

Small, A. 1994. California Birds: Their Status and Distribution. Ibis, Vista, CA.
Wilbur, S. R. 1987. Birds of Baja California. Univ. Calif. Press, Berkeley.

Accepted 25 November 1995

90

Wing Your Way to . . .
Western Field Ornithologists

21st Annual Meeting

Colorado Field Ornithologists

ESTES PARK, COLORADO

14-16 June 1996

1996 JOINT CONVENTION

OF THE COLORADO FIELD ORNITHOLOGISTS

AND WESTERN FIELD ORNITHOLOGISTS

Headquarters: YMCA of the Rockies, Estes Park Conference Center,
Estes Park, Colorado 80511; phone 800-777-9622.

You are cordially invited to attend this very special convention in Estes Park,
Colorado, bringing together birders from across western North America. This will be
the 34th annual CFO convention and the 21st annual meeting of WFO. Members of
the newly formed Estes Park Bird Club are assisting with program arrangements. The
event is well timed, immediately preceding the American Birding Association conven-
tion in Park City, Utah, which runs from 17 to 23 June.

Tentative schedule:

Friday, 14 June 1996

5:30 AM Field trip: Wild Basin, south Rocky Mountain National Park; meet at
YMCA, bring your own lunch.

6:00 AM Field trip: Pawnee National Grassland; meet at Crow Valley Camp-
ground, a 2-hour drive from Estes Park. Bring your own lunch.

91

3:00 PM Check-in: YMCA, Estes Park. Dinner on your own, available at the YMCA.
6:00 PM Bird art show preview, YMCA.

6:30 PM Six-shot slide show, best of members’ works. Bring your best bird photos! YMCA.
7:30 PM WFO and CFO board of directors’ meetings, YMCA.

Saturday,

5:00 AM

11:30 AM
12:30 PM
1:00 PM
4:30 PM

4:45 PM

5:00 PM
7:00 PM

15 June 1996

Field trip: Continental Divide and Endo Valley, Rocky Mountain National
Park; sack breakfast provided.

Lunch, YMCA, Estes Park.

Bird art show opens, YMCA.

Convention papers session, YMCA.

California Bird Records Committee, discussion of selected records deci-
sions, YMCA.

Colorado Bird Records Committee, discussion of selected records deci-
sions, YMCA.

WFO bird identification panel, YMCA.

Banquet and speaker, Park Village Playhouse, 900 Moraine Ave., Estes Park.

Sunday, 16 June 1996

5:00 AM Field trips: Wild Basin, Sylvandale Ranch, Continental Divide, and Endo
Valley, Rocky Mountain National Park; (possible repeat) Pawnee National
Grassland. Sack breakfast and lunch provided.

Rocky Mountain National Park: A wilderness of some of the most spectacular
mountain scenery in the world, offering an abundance of birds in a variety of habitats.
Target species will include the White-tailed Ptarmigan, Three-toed Woodpecker, and
Brown-capped Rosy Finch. Also expected are the Red-naped and Williamson’s
Sapsuckers, American Pipit, Hammond’s, Dusky, Willow, and Olive-sided Flycatch-
ers, Broad-tailed Hummingbird, Pine Grosbeak Cassin’s Finch, and American Dipper.
Other possibilities include the Northern Goshawk, Blue Grouse, and Boreal Owl.

Pawnee National Grassland: This picturesque short-grass prairie of northeast-
ern Colorado is favored by many, not only for the special breeding birds found there,
but also because eastern vagrants are often discovered in the isolated wooded areas
and water sources. We should see the Mountain Plover, Chestnut-collared and
McCown’s Longspurs, and possibly Long-billed Curlew. Also to be found are the
Brown Thrasher, Lark Bunting, Brewer’s, Vesper, Cassin’s, and Grasshopper Spar-
rows, and Eastern and Western Kingbirds.

92

WESTERN BIRDS

Quarterly Journal of Western Field Ornithologists

President: Kimball L. Garrett, Natural History Museum of Los Angeles County, 900
Exposition Blvd., Los Angeles, CA 90007

Vice-President: Mike San Miguel, 2132 Highland Oaks Dr., Arcadia, CA 91006

Treasurer/Membership Secretary: Dorothy Myers, 6011 Saddletree Lane, Yorba
Linda, CA 92686

Recording Secretary: Jean-Marie Spoelman, 4629 Diaz Drive, Fremont, CA 94536

Directors: Kimball Garrett, Daniel D. Gibson, Tim Manolis, Guy McCaskie, Mike
San Miguel, W. David Shuford, David Stejskal, Bill Tweit, David Yee

Editor: Philip Unitt, San Diego Natural History Museum, P.O. Box 1390, San
Diego, CA 92112

Associate Editors: Cameron Barrows, Tim Manolis, Thomas W. Keeney

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

Secretary , California Bird Records Committee: Michael A. Patten, P. O. Box 51959,
Riverside, CA 92517-2959

Editorial Board: Robert Andrews, Alan Baldridge, Andrew J. Berger, Laurence C.
Binford, R. Wayne Campbell, David F. DeSante, Jon L. Dunn, Richard Erickson,
William T. Everett, Kimball L. Garrett, Joseph R. Jehl, Jr., Ned K. Johnson,
Virginia P. Johnson, Brina Kessel, Stephen A. Laymon, Paul Lehman, John S.
Luther, Guy McCaskie, Joseph Morian, Harry B. Nehls, Dennis R. Paulson, Gary H.
Rosenberg, Oliver K. Scott, Ella Sorensen, Richard W. Stallcup, Charles Trost,
Terence R. Wahl, Bruce Webb

Membership dues, for individuals and institutions, including subscription to Western Birds:
Patron, $1000; Life, $350; Supporting, $50 annually; Contributing, $30 annually;
Family, $22; Regular, U.S., $18 for one year, $35 for two years, $50 for three years;
outside U.S., $23 for one year, $45 for two years, $65 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 California Birds/Westem Birds: $20 per volume, $5.00 for single issues.
Xerox copies of out of print issues (Vol. 1, No. 1; Vol. 2, Nos. 1 and 4; Vol. 6, No. 2):
$5.50 each. Ten-column Field List of California Birds: $1.00 each, 10 to 39 $0.80
each, 40 or more $0.70 each. Checklist of the Birds of California: $2.00 each, 10 or
more $1.50 each. Pelagic Birds of Monterey Bay, California: $2.50 each, 10 or more
$2.00 each, 40 or more $1.50 each.

All postpaid.

Published April 15, 1996

ISSN 0045-3897

I

I

Vol. 27, No. 3, 1996

Volume 27, Number 3, 1996

Nineteenth Report of the California Bird Records Committee:

1993 Records Richard A. Erickson and Scott B. Terrill 93

The Black Skimmer in California: An Overview

Charles T. Collins and Kimball L. Garrett 127

Overwintering of Black Skimmers in California: Site Fidelity

and Inter-site Movements Kathleen T. Gazzaniga 136

Population Status and Breeding Biology of Black Skimmers at

the Salton Sea, California Kathy C. Molina 143

NOTES

First Nesting of Black Skimmers on San Francisco Bay Valerie L.
Layne, Robert J. Richmond, and Peter J. Metropulos * 159

Night Feeding of Black Skimmers at Estero Punta Banda,

Baja California, Mexico Horacio De la Cueva and

Guillermo Fern&ndez 162

Establishment of a New Black Skimmer Breeding Colony in Southern
California Adam W. Whelchel, Kathy M. Keane,
and Michael N. Josselyn 164

The Name of the Craveri Brothers’ Murrelet Storrs L. Olson . . 167

Cover photo by © Alan Walther of San Jose, California: Black
Skimmer (Rhynchops niger ), Charleston Slough, Mountain
View, California, August, 1995.

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, popula-
tion 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 Philip Unitt, San Diego Natural History Museum, P.O.
Box 1390, San Diego, CA 92112. 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 27, Number 3, 1996

NINETEENTH REPORT OF THE CALIFORNIA BIRD
RECORDS COMMITTEE: 1993 RECORDS

RICHARD A. ERICKSON, LSA Associates, One Park Plaza, Suite 500, Irvine,
California 92714

SCOTT B. TERRILL, H. T. Harvey & Associates, P. O. Box 1 180, Alviso, California
95002

This report covers 180 records of 69 species submitted by 174 observers
and evaluated by the California Bird Records Committee (hereafter the
Committee or CBRC). Of these, 145 records were accepted, for an
acceptance rate of 81%. Records from 1979 to 1994 are included, but the
great majority are from 1993. Top honors among the counties go to San
Diego with 15 accepted records, followed closely by San Francisco (14, all
from SE Farallon I.), Santa Barbara (14), Monterey (13), Inyo (13), Orange
(12), Los Angeles (12), and Marin (11).

One species, the Manx Shearwater ( Puffinus puffinus), is added to the
California state list, and one species, the Greater Shearwater (P gravis), is
removed following reconsideration of a previously accepted record. The list
of native species thus stands at 582 (following AOU 1995); an additional
eight nonnative species with well-established populations are also included
on the California list maintained by the Committee. Other highlights from
1993 include two Red-tailed Tropicbirds ( Phaethon rubricauda) in winter,
one Gyrfalcon ( Falco rusticolus ), one Little Curlew ( Numenius minutus),
one Groove-billed Ani ( Crotophaga sulcirostris ), three Sulphur-bellied
Flycatchers ( Myiodynastes luteiventris), one Dusky Warbler (Phylloscopus
fuscatus), one Rustic Bunting ( Emberiza rustica), far northern records of
the Broad-billed Hummingbird ( Cynanthus latirostris) and Dusky-capped
Flycatcher (Myiarchus tuberculifer), a wintering Blue-winged Warbler
(Vermiuora pinus ), and record numbers of Zone-tailed Hawks ( Buteo
albonotatus; 11), and Philadelphia Vireos (Vireo philadelphicus; 10).
Potential first state records of the Dark-rumped Petrel ( Pterodroma
phaeopygia), Common Greenshank ( Tringa nebularia), Bridled/Gray-

Western Birds 27:93-126,1996

93

CALIFORNIA BIRD RECORDS

backed Tern ( Sterna anaethetus/lunata), and Common Chaffinch ( Fringilla
coelebs) were not accepted.

Committee News. A new bylaw was adopted at the January 1996
meeting in Camarillo. Records not accepted by the Committee that were
formerly categorized as “identification questionable” will now be labeled
“identification not established.” This more accurately states the Committee’s
position on most of these records, where the identification may well have
been correct, but the documentation was insufficient to substantiate the
record. This situation unfortunately occurs more often than it should.
Detailed notes and drawings made at the time of observation, supplemented
by photos, video, or tape recordings greatly enhance the documentation of
a record. Taking detailed notes is a great exercise in and of itself, and it
enhances details of the observation for the observer and increases the
learning curve. Readers should refer to Dittmann and Lasley (1992) for a
more complete discussion of this issue.

At recent meetings, many Committee members have expressed their
desire to evaluate records of taxa below the species level that are generally
considered identifiable in the field. Some of these taxa will likely be
considered species in the future. Recognizing the many complications of
such an endeavor, the Committee will move deliberately. At this time, we
wish to announce our interest in the matter and to solicit documentation of
taxa below the species level that meet the Committee’s general “rarity
guideline” for species (i.e., an average of four or fewer records per year).
Evaluation and publication of such records may follow a different path than
species-level records, with interested Committee members, or others, taking
the lead on any particular taxon. For starters, we request descriptions and/
or photographs of any of the following taxa seen in California, now or in the
past; reports of all have been “published” in one form or another.

Bewick’s Swan ( Cygrius columbianus bewickii )

American Brant ( Branta bernicla hrota )

Eurasian Whimbrel ( Numenius phaeopus phaeopus/variegatus)
Siberian Common Tern (Sterna hirundo Jongipennis )

Long-billed Murrelet ( Brachyrhamphus marmoratus perdix)

Eastern Winter Wren ( Troglodytes troglodytes hiemalis/pullus)

Eastern Hermit Thrush (Catharus guttatus faxoni)

“Japanese” Pipit (Anthus rubescens japonicus)

Eastern Bell’s Vireo (Vireo bellii belli/medius )

Blue-headed Vireo ( Vireo s. solitarius/alticola )

Yellow Palm Warbler ( Dendroica palmarum hypochrysea)
White-winged Junco (Junco hyemalis aikeni)

Eastern Purple Finch ( Carpodacus p. purpureus)

At the 1995 and 1996 meetings, plans were discussed for a book to
summarize all of the Committee’s deliberations since its inception in 1970.
Preparation is now underway, and a publication date within about a year has
been targeted. Also, it was decided to initiate a numbering system for
publications prepared by the Committee or based primarily upon the
Committee’s archives. The numbering will be retroactive, to include all

94

CALIFORNIA BIRD RECORDS

previous publications. This report, therefore, is CBRC Contribution 37;
previous publications will be listed in the Committee’s book.

Records currently under review by the Committee include potential first
state records of the Light-mantled Albatross ( Phoebetria palpebrata) off
Marin Co., Bulwer's Petrel ( Bulweria bu/werii) at the Salton Sea, Black
Vultures ( Coragyps at rat us) from Butte and Humboldt counties. Crested
Caracaras ( Caracara plancus) from Imperial and San Diego counties, Red-
legged Kittiwake ( Rissa breuirostris) from Orange Co., Swallow-tailed Gull
( Creagrus furcatus ) off San Francisco Co., Ivory Gull (Pagophila eburnea)
from Orange Co., Lanceolated Warbler ( Locustella lanceolata) from SE
Farallon L, and Arctic Warbler ( Phylloscopus borealis ) from Monterey Co.
Also under review are recent records of Harris' Hawks ( Parabuteo
unicinctus) from southern California, with the welcome potential of remov-
ing the ‘‘extirpated’’ symbol that currently follows the species' name on the
state list (Binford 1986, CBRC 1991). Recent taxonomic decisions by the
AOU (1995) still have not rescued the CBRC from its Iceland Gull ( Larus
glaucoides) dilemma (see Heindel and Garrett 1995). Note also that there
are no documented claims in California of Bicknell’s Thrush ( Catharus
bicknetli ), Eastern Towhee ( Pipilo erythrophthalmus ), or Saltmarsh Sharp-
tailed Sparrow ( Ammodramus caudacutus), newly recognized as species.

The Committee's membership at the close of the 1996 meeting was
Michael A. Patten (Secretary), Matthew T. Fleindel (Vice-Secretary), Kimball
L. Garrett, Steve N. G. Howell, Guy McCaskie, Joseph Morlan, Peter Pyle,
Mike San Miguel, Daniel S. Singer, and Terrill.

CBRC Functions. All records reviewed by the CBRC are archived at the
Western Foundation of Vertebrate Zoology, 439 Calle San Pablo, Camarillo,
CA 93012. All written documentation, photographs, voice recordings, and
videotapes are housed there, catalogued, organized by CBRC record num-
ber, and are available for public review. The CBRC solicits information on all
occurrences in California of species on its Review List (see Roberson
1993a), as well as species unrecorded in California, and requests that
documentation be sent to Michael A. Patten, CBRC Secretary, P. O. Box
51959, Riverside, CA 92517-2959. Documentation concerning the poten-
tial establishment of exotic species not currently on the state list is also
sought. Heindel and Garrett (1995) and Patten et al. (1995) provided further
details on the Committee’s functions.

Format and Abbreviations: The format of these reports is now largely
standardized. In general, records are listed either geographically, from north
to south, or chronologically by first date of occurrence. Included with each
record is the location, county abbreviation (see below), and date span. The
date span generally follows that published in American Birds/National
Audubon Society Field Notes (NASFN). If the CBRC accepts a date span
that differs from that in a published source, the differing dates are italicized.
Initials of the observer(s) responsible for the record, if known, are followed by
a semicolon, then the initials of additional observers submitting documenta-
tion, then the CBRC record number. All records are sight records unless
otherwise noted. Initials followed by a dagger (t) indicate the observer
supplied an identifiable photograph. Similarly, (f) is used to designate
videotape, and (§) for voice recording. The symbol indicates a specimen

95

CALIFORNIA BIRD RECORDS

record, and is followed by the acronym (see below) of the institution housing
the specimen and the specimen number.

An asterisk (*) prior to a species name indicates that it is no longer on the
Review List. The number in parentheses following the species’ name is the
number of records accepted by the CBRC through this reporting period.
Two asterisks (**) after this number indicate that the number of accepted
records is limited to a restricted review period or includes records accepted
for statistical purposes only (see Roberson 1986 for more information).

When an individual bird returns to a locality after an absence (for example,
in consecutive winters), or is continuously present for multiple years, each
subsequent occurrence, or presence in a new calendar year, is reviewed as a
new record. The Committee judges, by a majority vote, whether or not the
same individual is involved. If a majority of the Committee considers it to be
the same bird, that information is included in the comments, and the total
number of records remains unchanged.

Although the Committee does not formally resolve identification issues
below the species level, comments on age, sex, or subspecies are often
included. The authors of this report assume responsibility for all such
comments, although they are usually based on input provided by Committee
members during circulation of the record and the draft Committee report.

The Committee uses the following codes for California counties: ALA,
Alameda; ALP, Alpine; AMA, Amador; BUT, Butte; CLV, Calaveras; COL,
Colusa; CC, Contra Costa; DN, Del Norte; ED, El Dorado; FRE, Fresno;
HUM, Humboldt; IMP, Imperial; INY, Inyo; KER, Kern; KIN, Kings; LAK,
Lake; LAS, Lassen; LA, Los Angeles; MAD, Madera; MRN, Marin; MRP,
Mariposa; MEN, Mendocino; MER, Merced; MOD, Modoc; MNO, Mono;
MTY, Monterey; NAP, Napa; NEV, Nevada; ORA, Orange; PLA, Placer;
PLU, Plumas; RIV, Riverside; SAC, Sacramento; SBT, San Benito; 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; SHA, Shasta; SIE, Sierra; SIS, Siskiyou; SOL, Solano;
SON, Sonoma; STA, Stanislaus; SUT, Sutter; TEH, Tehama; TRI, Trinity;
TUL, Tulare; TUO, Tuolumne; VEN, Ventura; YOL, Yolo; YUB, Yuba.

Museums that have allowed Committee members access to specimens or
that have provided information or house specimens cited herein are as
follows: MVZ, Museum of Vertebrate Zoology, University of California,
Berkeley; SBCM, San Bernardino County Museum, Redlands. Other muse-
ums used regularly by Committee members include the California Academy
of Sciences in San Francisco, the Natural History Museum of Los Angeles
County, and the San Diego Natural History Museum.

Other abbreviations used are AFB, Air Force Base; I., island; L,, lake; Mt.,
mountain; NP, National Park; n. miles, nautical miles; NWR, National
Wildlife Refuge; Pt, point; Reg., Regional; R., river; SB, State Beach; and
SP, State Park.

Seabirds. With the addition and deletion to the state list mentioned above,
and with several other records of extreme rarities discussed in both the
“Accepted” and “Not Accepted” sections below, this group of birds is well
represented in this report. Therefore, a few general comments are war-
ranted.

96

CALIFORNIA BIRD RECORDS

Because of the difficulty of access to much of offshore California,
especially very deep waters, a large percentage of seabird observations are
from research vessels. Given the often difficult conditions at sea, the quality
of seabird observations is sometimes marginal. In addition, individuals are
often busy collecting data, which can reduce opportunities to document a
rare bird. As a result, seabird records are probably accepted at a lower rate
than in other groups of birds. Exacerbating this problem may be the fact that
identification criteria are still rudimentary in some groups. Finally, some
observations may not be submitted because of a lack of understanding of the
200-nautical-mile U.S. fishery limit that the Committee follows (Roberson
1993b). This boundary extends well into waters west of northern Mexico
(Figure 1). Communication between the CBRC and researchers has been
somewhat lacking and, thus, record submittal and documentation of rare
seabirds has been rather erratic. We are currently taking steps to increase
communication with seabird researchers, and hope this effort will be
productive for California ornithology.

125 '

120 ‘

Figure 1 . The 200-nautical-mile U.S. fisheries conservation zone and CBRC coverage
area off southern California.

97

CALIFORNIA BIRD RECORDS

RECORDS ACCEPTED

MANX SHEARWATER Puffinus puffinus (4). This Atlantic seabird was added to
the California list on the basis of multiple accepted reports in 1993; even more
individuals were seen in 1994 ( NASFN 49:96, 100; CBRC unpubl. data). In the
Monterey Bay area, MTY, single birds were on Monterey Bay 25 July 1993 (JMDf;
81-1994; photo in Roberson 1996), 2 miles W of Pt. Joe 29 Aug 1993 (Figures 2 and
3; JMDt, JL+, RNt; 132-1993; color photo in Am. Birds 48:161, additional photos
in Roberson 1996), 8 miles W of Moss Landing 5 Sep 1993 (LLt; 16-1994), and 1 .5
miles W of Cypress Pt. 22 Sep 1993 (JLD, DJA, RAB; 15-1994). At SE Farallon L,
SF, a single bird was seen on 31 Aug 1993 (PP, SNGH; 138-1993). Another record
from Monterey Bay was not accepted (see Records Not Accepted, Identification Not
Established), and several additional reports (Am. Birds 48:147) have not been
submitted. The actual number of birds involved in this relatively small area is unknown,
but the Committee considers the accepted records to represent at least four birds: one
at SE Farallon I., and three in Monterey Bay. The state of molt assisted in the
evaluation of the birds photographed off Monterey. The extent of black spotting on
the longest axillars in the photographs and videotapes suggests that first-year or
possibly second-year birds were involved (Baker 1993; Pyle in comments); the August
Monterey bird was molting remiges, indicating it was at least a year old.

Reports of small white-vented shearwaters off California have accumulated since at
least 1970 (Am. Birds 25:100, Garrett and Dunn 1981), and the debate over such
birds has often been contentious. Roberson (1996) summarized recent records of
known and probable Manx Shearwaters in the Pacific Ocean suggesting a significant
range expansion. The majority of the 1993 birds were first identified as other shear-
waters (Black-vented, P. opisthomelas , Townsend’s, P a. auricularis, or Newell’s,
P. a. newelli ), however, demonstrating the rapid evolution of identification criteria for
small dark-and-white shearwaters in the North Pacific: compare also comments by
Roberson (1980, 1985, 1986), Dunn (1988), Langham (1991), Yee et al. (1994),
and Heindel and Garrett (1995) on previous records of this and similar species not
accepted by the Committee. Prepublication drafts of recent identification articles by
Howell et al. (1994) and Roberson (1996) circulated with these records, helping to
ease the minds of reluctant Committee members. Nevertheless, several members
expressed nagging concerns that California birds are not completely typical of
Atlantic Manx Shearwaters and might even represent some unknown taxon (skeptics
should consider the recent description of P. atrodorsalis by Shirihai et al. 1995). In
particular, California birds were initially perceived as having too extensive white flank
patches, a notion discussed and dismissed by Roberson (1996) and others (CBRC
members in comments). Figures 2 and 3, of the same bird, clearly show that the extent
of these patches is subject to feather placement; a fuller understanding of this issue is
desired.

Critical for the review of this species were a number of exceptional photographs,
first examined and correctly identified by Roberson, Morlan, and others. Mike
Danzenbaker especially is to be commended. He has returned to sea time and time
again to amass an important series of photographs of many species.

A problem associated with these records also needs mentioning. Of the first three
Monterey records, none included a written description. That two boat-loads of birders
could fail to submit a single description of a species not even on the state list (the first
bird was actually passed over as a Black-vented Shearwater and the subsequent birds
were initially identified as Townsend’s Shearwaters) is a disappointment to the
Committee (see also comments by Yee et al. 1994). Boat trip participants, regardless
of their level of experience, are strongly encouraged to document any rarities
encountered on organized boat trips. The documentation submitted by an individual
may be all that is received on a given sighting.

98

CALIFORNIA BIRD RECORDS

Figure 2. Manx Shearwater off Monterey, 29 August 1993 (132-1993). The species
was added to the state list in 1993.

Photo by J. Michael Danzenbaker

Figure 3. Manx Shearwater off Monterey, 29 August 1993 (132-1993). Note the
change in flank pattern on this individual depending upon its position.

Photo by J. Michael Danzenbaker

99

CALIFORNIA BIRD RECORDS

WEDGE-RUMPED STORM-PETREL Oceanodroma tethys (6). One was approxi-
mately 52 n. miles SSW of San Miguel I„ SBA (ca. 33° 26' N, 121° 22’ W), on 5 Oct

1992 (RRV; 29-1994). Accepted records are now evenly divided between the
Monterey Bay area and waters off the Channel Islands. Except for the first, of a storm-
driven waif picked up in Carmel, MTY, 21 Jan 1969 (Yadon 1970, Luther 1980), all
records are from 23 Jul to 9 Oct.

RED-TAILED TROPICBIRD Phaethon rubricauda (10). A subadult was approxi-
mately 130 n. miles SW of San Nicolas I., VEN (ca. 31° 18'N, 120°40'W), on 14 Jan

1993 (PP; 30-1993; photos included generally not considered adequate to document
the record), and an adult was approximately 16 1 n miles WSW of San Nicolas I. , VEN
(ca. 31° 28' N, 122° 06' W) on 16 Jan 1993 (PPt; 31-1993). These represent the first
winter records for California, although the maps by Gould et al. (1974) have long
suggested the possibility of such occurrences. All previous records were in the three-
month period from 3 Jul to 8 Oct.

BLUE-FOOTED BOOBY Sula nebouxii (74**). One was at the north end of the
Salton Sea, RIV, 25 July 1993 (RLM; 139-1993). Nearly all previous incursions at the
Salton Sea have been of multiple birds (McCaskie 1970, Garrett and Dunn 1981). To
the east, however, one was found in northern Arizona near Cameron on 27 Jul 1993
(Am. Birds 47:1133).

The crumbling of California booby dogma, noted by Patten and Campbell (1992),
has continued. In the early 1970s, the Masked (S. dactylatra ) and Red-footed (S. sula)
boobies remained unrecorded in the state, and the Blue-footed Booby was not even
on the CBRC review list. In contrast, accepted records since 1985 total Brown 17,
Red-footed 8, Blue-footed 6, and Masked 4, Additional Masked Boobies were
observed off northern Baja California at Islas Los Coronados 23 April 1988 (Everett
and Teresa 1988) and at Isla Guadalupe 20 Jan-9 Apr 1994 (Pyle et al. 1994, Guillen-
H. et al. 1995).

BROWN BOOBY Sula leucogaster (42). An adult was at Santa Cruz, SCZ, 26 Sep

1991 (IA, EF; 177-1991), a juvenile was ca. 3 miles S of Pt. Vicente, LA, 18 Oct

1992 (KLGf; 14-1993), and an adult female seen intermittently at SE Farallon I., SF,
16 Aug-18 Oct 1993 (PPt; 203-1993) had been present at the same location 25
May-24 Nov 1992, when still an immature of unknown sex (162-1992; Heindel and
Patten 1996). See comments concerning the changing status of this and other
boobies under the Blue-footed Booby, above.

The first two records were controversial and required multiple circulations. Given
age and geographic variation, and the fact that at least some of these tropical species
may breed at almost any time of year (thus, all age classes and plumages are possible
at any time of year), booby identification is often not as straightforward as the standard
references suggest. Several Committee members called for the preparation of a
detailed identification treatise on the group.

Descriptions of the Santa Cruz bird were contradictory, with one observer describ-
ing a “white throat.” This was sufficient cause for some to believe that the possibility
of the bird being a juvenile Masked Booby was too high. In the end, most members
were willing to overlook details in the one description and rely primarily upon the
other description, more thorough and deliberate.

The Los Angeles record generated a truer debate of identification criteria, as there
was no question of what the bird actually looked like in the field. Concerns revolved
primarily around the lack of an obvious breast/belly contrast and the possibility that
the bird was actually a Red-footed Booby. Through three circulations it became well
established that juvenile Brown Boobies can appear essentially uniform brown below
for the first few months of life. On such birds, other characters of use in distinguishing
them from the Red-footed Booby include heavier bill, yellowish legs and feet, white on

100

CALIFORNIA BIRD RECORDS

the flanks and underwing coverts and axillars, and, of less importance, the deeper
intensity of brown above and larger size.

TRICOLORED HERON Egretta tricolor (11**). On the coast, an adult at the
Tijuana R. estuary, SD, 22 Jan-5 Feb 1993 (GMcC; 74-1993) was followed by an
immature at the same location 18 Dec 1993-19 Feb 1994 (GLR, MBSf; GMcC,
PEL, SBTf; 49-1994), and what was judged to be the same immature on 23 May
1994 (MBSf; 112-1994). At the Salton Sea, immatures were south of the Salton Sea
NWR headquarters, IMP, 15 Aug 1993 (AME; 127-1993) and at the Whitewater R.
mouth, RIV, 1 Oct 1993 (RWH; 21-1994). These four birds represent the highest
annual total since the species was added to the review list in 1990.

REDDISH EGRET Egretta rufescens (63). A returning adult with a deformed bill
at the south end of San Diego Bay, SD, 10 Sep-27 Oct 1993 (GMcC; 32-1994) has
been featured in almost every Committee report since its debut a decade ago
(Roberson 1986; covering the bird s initial visit Dec 1982-Mar 1983). The Commit-
tee appreciates the persistence of observers documenting this bird year after year.
This bird was an adult when first seen in 1982 (Am, Birds 37:337). Thus, when seen
in the fall of 1993, it approximated the maximum known age of 12 years, 3 months
reported for this species (Clapp et al. 1982).

An immature near Oasis Station, north end of the Salton Sea, RIV, 19 Dec 1993-
20 Mar 1994 (PEL, CAMf, GMcC, MAP; 46-1994) makes only the fifth accepted
record from the Salton Sea.

YELLOW-CROWNED NIGHT-HERON Nyctanassa uiolacea (16). Another Com-
mittee staple: the adult in the night-heron rookery at La Jolla, SD, 26 Dec 1992-23
Jan 1993 (PEL, GMcC; 28-1993) and later at San Elijo Lagoon, SD, 14 May 1993
(NASFN 47 :453) has been seen annually since it was first reported as an adult in
October 1981 (Binford 1985). The maximum known age for this species reported by
Klimkiewicz and Futcher (1989) is only 6 years, 3 months, but the similar Black-
crowned Night-Heron ( Nycticorax nycticorax) is known to have reached 21 years, 1
month (Clapp et al. 1982).

TRUMPETER SWAN Cygnus buccinator (21). Two adults were in the Siskiyou
County portion of Tule Lake NWR 27 Nou 1993 (Figure 4; RE; 3-1994). The
locations of accepted records are generally well scattered, but this is the seventh
record from the Klamath Basin since 1984, representing more records than from any
other location. It seems likely that some records involve returning individuals, but the
possibility has not yet been seriously considered by the Committee.

KING EIDER Somateria spectabilis (33). A female at Aho Nuevo State Reserve,
SM, 28 Mar-4 Apr 1993 (RST+; 96-1993) fit the unusual pattern of distribution of
this largely arctic species. The majority of records (20) are from central California
(here defined as Sonoma through Monterey counties), and there are more records
from southern California (7) than from northern (6).

ZONE-TAILED HAWK Buteo albonotatus (44). This species is currently increas-
ing in California; 1993 produced more sightings than ever with 1 1 records accepted:
an adult at Furnace Creek Ranch, Death Valley NP, INY, 11 Apr 1993 (DW; 106-

1993) ; one in Santa Barbara, SBA, 28 Dec 1993-10 Jan 1994 (SEFf, PEL; 10-

1994) ; an adult male at Ojai, VEN, 6 Sep 1993 (RS; 194-1993), considered the same
as one there 28 Feb-8 Mar 1994 (BSt, BES; 71-1994; photo in NASFN 48:247);
an adult at Malibu Creek SP, LA, 25 Apr 1993 (KFC, JN; 72-1993); an adult at Irvine
Reg. Park, ORA, 26 Nov 1993 (BED; 182-1993), where one had been reported but
not accepted the previous winter (122-1993; Heindel and Patten 1996); an adult in
Lake Forest, ORA, 13 Nov-19 Dec 1993 (JEP; CB, BED, VL; 35-1994); an adult
male in Mission Viejo, ORA, 18 Dec 1993-13 Mar 1994 (KPL; RAE, RAH, CAM,

101

CALIFORNIA BIRD RECORDS

GMcC; 8-1994); an adult female in Laguna Beach, ORA, 15 Aug 1993-mid January
1994 (Figure 5; GStt; AAS; 135-1993), considered probably not the same as one in
Laguna Beach 22-30 Oct 1988 (70-1989; Pyle and McCaskie 1992); an adult over
Pines Park, Dana Point, ORA, 1 1 Jan 1993 (JEP; 39-1993); a returning adult at Hot
Springs Mt., SD, 26 Jun 1993 (GMcC, TC; 143-1993); and a returning adult at
Santee Lakes Reg. Park, SD, 6 Nov 1993-9 Feb 1994 (WEH; 33-1994). The Santa
Barbara, Ventura, and Los Angeles county records are the first to be accepted for the
coastal slope north of Orange County.

In previous years, an adult in the vicinity of Whelan L., Oceanside, SD, 22 Dec
1990 (GMcC; 2-1991) was considered probably different from previous records in the
area, an adult was at Santee Lakes Reg. Park, SD, 2-3 Nov 1991 (TC; GD; 34A-
1992), and an immature was at the same location 15 Jan-3 Feb 1992 (TC; GMcC,
JR; 34B-1992).

GYRFALCON Falco rusticolus (7). A gray-morph immature in the Smith R.
bottoms near Fort Dick, DN, 23 Dec 1993-20 Feb 1994 (RAE, SEF, DF, GSLf; 62-

Figure 4. Trumpeter Swans at Tule Lake National Wildlife Refuge, 27 November
1993(3-1994).

Trumpeter 5wam$ (tivo)
November Z7 1995

(

Sketch by Ray Ekstrom

102

CALIFORNIA BIRD RECORDS

1994) is believed to be the same as one seen at nearby L. Earl, DN, 31 Oct-1 Nov
1993 (in documentation; NASFN 48:245). Gyrfalcons have been recorded on the
Oregon coast south to Curry County (Schmidt 1989, Gilligan et al. 1994), but all
previous California records have been for the interior, including four for the Klamath
Basin.

YELLOW RAIL Coturnicops noveboracensis (66**)- Like most recently recorded
Yellow Rails, one at Palo Alto Baylands, SCL, 12 Dec 1993 (SFB, DEQ; 6-1994) was
seen during an extreme high tide.

AMERICAN OYSTERCATCHER Haematopus paHiatus (12). An adult and a
juvenile were at Middle Anacapa I., VEN, 4 Sep 1993 (KLG+, MH, KGLf; 36-1994).
These birds appeared typical of the west Mexican subspecies frazari but were never
scored using Jehl’s (1985) system (Table 1); see the discussion below under Records
Not Accepted, Identification Not Established. Observers are encouraged to use this
system as much as possible in describing potential American Oystercatchers.

UPLAND SANDPIPER Bartramia longicauda (13). One at Independence, INY,
13 Jun 1993 (AKt; 109-1993) was the fifth to be found in that county; all five have
been in spring. Previous accepted records were nearly evenly divided between spring
(five records 15-28 May, all but one inland) and fall (seven records 22 Aug-21 Sep,
all but one coastal).

LITTLE CURLEW Numenius minutus (3). An adult at the Santa Maria R. estuary,
SBA/SLO, and the ocean beach up to 2 miles south, 4-20 Aug 1993 (Figure 6;
BHit; SEFf, MHf, PEL, MM, MSM, MMTt, SBT; 125-1993; color photo in Am.

Figure 5. Adult female Zone-tailed Hawk in Laguna Beach, 29 August 1993 (135-
1993), one of a record 11 individuals documented in California in 1993.

Photo by Greg Stewart
103

CALIFORNIA BIRD RECORDS

Table 1 System for Assessing the Intermediacy o
Oystercatchers 0

Character state Score

Upper tail coverts

Black, as in bach man i 0

Black, a few white mottlings 1

Nearly equally black and white 2

White, a few black mottlings 3

White, as in palliatus 4

Tail

Black, as in bachmani 0

Mainly black, trace of white at base of vanes 1

Basal quarter of rectrices white 2

Basal third of rectrices white 3

Basal half of rectrices white, as in palliatus 4

Chest

Black, with black chest band extending smoothly onto midbelly, as in bachmani 0

Black chest band extending onto upper third of belly 1

Black chest band extending onto upper quarter of belly 2

Black chest band bordered by ragged edge on upper breast 3

Black chest band sharply delimited from white of upper chest, as in palliatus 4

Belly

Blackish, as in bachmani 0

Blackish, with traces of white on a few feathers 1

Blackish, white area around crissum 2

Three quarters black, one quarter white 3

Nearly equally black and white 4

Three quarters white, one quarter black 5

Entirely white, as in palliatus 6

Under tail coverts

Entirely black, as in bachmani 0

Mainly black with slight white mottling 1

Nearly equally black and white 2

Mainly white 3

Entirely white, as in palliatus 4

Thighs

Entirely black, as in bachmani 0

Black with grayish underdown, not noticable externally 1

Puffs of grayish down noticeable 2

Mainly white 3

Entirely white, as in palliatus 4

Greater secondary coverts (width of white edging in folded wing)

White lacking, as in bachmani 0

Less than 2 mm 1

2-5 mm 2

6-15 mm 3

More than 15 mm 4

Extent of white wing stripe

Lacking, as in bachmani 0

White markings confined to inner half of secondaries 1

White markings extend to outer secondaries but not to primaries 2

White present on some or all of inner five primaries 3

White present on at least one of primaries 6-10 4

104

CALIFORNIA BIRD RECORDS

Table 1 ( Cont .)

Underwing coverts

Entirely black, as in bachmani 0

Mainly black, some white mottling 1

Nearly equally black and white ■ 2

Mainly white 3

White, as in palliatus 4

Axillars

Black, as in bachmani 0

Mainly black, some white mottling 1

Nearly equally black and white 2

Mainly white 3

White, as in palliatus 4

“From Jehi (1985, Table 1). Jehl considered birds with total scores (all characters added together)
from 0 to 9 to be Black Oystercatchers, from 10 to 29 to be hybrids, and from 30 to 38 to be
American Oystercatchers.

Birds 48:159) was considered only possibly the same individual as was seen in
agricultural fields upstream in the lower Santa Maria Valley 16 Sep-14 Oct 1984
(Lehman and Dunn 1985, Roberson 1986) and 23-24 Sep 1988 (Patten and
Erickson 1994); Lehman (1994) also summarized all these records. The only other
well-established New World record of this species is of one collected on St. Lawrence
L, Alaska, 7-8 Jun 1989 (Gibson and Kessel 1992).

Figure 6. Adult Little Curlew with a Long-billed Curlew at the Santa Maria River
mouth, 10 August 1993 (125-1993).

Photo bp Monte M. Taplor

105

CALIFORNIA BIRD RECORDS

HUDSONIAN GODWIT Limosa haemastica (12). A juvenile near Drake’s Estero,
Pt. Reyes, MRN, 8-9 Aug 1993 (RSf; PPt; 131-1993) was the first for that popular
birding county. It just preceded the date span of the seven previous fall records, 9
Aug-3 Oct. Four spring records range from 9 to 22 May.

BAR-TAILED GODWIT Limosa lapponica (15). A juvenile at the Mad R, estuary,
HUM, 5-6 Sep 1993 (TEf; DF; 202-1993) was possibly the same bird seen in
Crescent City, DN, 28 Aug 1993 (Am. Birds 48:149; unreviewed by CBRC).
Northern California’s records of this species now outnumber southern California’s
4:1. All of the records are of fall migrants (11 Jul-30 Nov) except for one at Culver
City, LA, 1 1 Feb-2 Mar 1976 (Luther et al. 1979) and one at Crescent City 3-5 Jun
1984 (Dunn 1988).

LITTLE GULL Larus minutus (49). Three first-winter birds were all in the interior:
near Gustine, MER, 20 Nov 1993 (RJR; 7-1994); Piute Ponds, Edwards AFB, LA, 28
Nov 1993 (JHaf, GSH; 193-1993); and near Oasis Station, north end of the Salton
Sea, RIV, 14 Dec 1993 (possibly late November)-8 Jan 1994 (GMcC, MMo, MAPf,
HY; 200-1993). Most previous records have been coastal, but the Salton Sea
continues to generate sightings. There are now eight records there, including the
state’s first near Mecca, RIV, 16-21 Nov 1968 (Dunn 1988). The Gustine Little Gull
was the first for Merced County.

BLACK-HEADED GULL Larus ridibundus (17). A first-winter bird at Areata,
HUM, 24 Jan-7 Feb 1993 (BBA, BEDe, TWLf, JM; 52-1993) was seen later at the
Mad R. estuary, HUM, 12 Mar-5 Apr 1993 (Lester, in comments), and an adult at
Alviso, SCL, 15 Nov 1993 (SCR; 181-1993) was seen later at Sunnyvale, SCL, 23
Jan-9 Feb 1994 (JLf, MM, JM, BDP, MMRt, SCR; 50-1994). A second-winter bird
on the beach at Santa Barbara, SBA. 29 Nov 1993-5 Feb 1994 (SEFf, PEL, GMcC,
SBTt; 192-1993) had been present at the same location as a first-year bird 21 Nov-
21 Dec 1992 (Heindel and Patten 1996); in addition to behaving like the previous
winter’s bird, it showed the relatively dull leg color indicative of some second-year birds
(Grant 1986). Three in one calendar year is the highest total since four were seen in
1980 and three were seen in 1981 (Binford 1985, Morlan 1985).

THICK-BILLED MURRE Uria lomvia (30). Single individuals were off Cannery
Row, Monterey, MTY, 19-28 Sep 1993 (JMat; RC, HG, GH, JLf, DRf, DSSf; 150-
1993), 1.8 miles W of Cypress Pt., MTY, 22 Sep 1993 (JLDf; 19-1994), and 3-4
miles offPt. Bonita, MRN, 24 Oct 1993 (SBT; 213-1993). The last was only the third
California record away from Monterey Bay.

PARAKEET AUKLET Cyciorrhynchus psittacula (65). There were two record-
setting reports in 1993, of one approximately 158 n miles SW of San Nicolas L, VEN
(ca. 31° 03' N, 121° 12'W)on 14 Jan 1993 (PPt; 32-1993) and 18 (in groups of 1-
3; plus 7 probables) 61-72 n. miles W of Pt. Arguello, SBA, on 25 Jan 1993 (PPt;
33-1993). The first bird was farther south than the previous record of three birds
found dead on the beach north of La Jolla, SD, 28 Jan 1937 (Kenyon 1937,
Roberson 1993a); the species remains unrecorded in Mexican waters (Howell and
Webb 1995). The second record (actually considered as 18 of the 65 total accepted
records) involved more individuals than any other; 12 collected on Monterey Bay,
MTY, 13 Jan 1908 (Beck 1910, Roberson 1986) constitute the only other report in
double digits.

RUDDY GROUND-DOVE Columbina talpacoti (59). Five were found at Furnace
Creek Ranch, Death Valley NP, INY, in 1993: a female 4-24 Oct 1993 (TH; GMcC,
KLGt; 156-1993); a male 10-24 Oct 1993 (MAP, KFC; KLGt; 149-1993); a male
(adult?) 24 Oct 1993 (KLG; 166-1993); and two females 17 Nov 1993 (TH; 199-
1993). Elsewhere, a singing male was on the Colorado R. 14 miles N of Blythe, RIV,

106

CALIFORNIA BIRD RECORDS

25-31 May 1993 (RJ; 108-1993), a female was at Deep Springs, INY, 12 Oct 1993
(TH; 189-1993), and a female was along San Juan Cr., Dana Point, ORA, 4-5 Nov
1993 (BED; 183-1993). The last bird is the first to be accepted from Orange County.

GROOVE-BILLED ANI Crotophaga sulcirostris (9). One in Goleta, SBA, 13 Apr-
8 June 1993 (Figure 7; KL, RM; SEFt. DDt, PEL, GMcC; 85-1993) may have
arrived the previous fall during a record influx of four anis into the state (Heindel and
Patten 1996). Previous state records have all been from fall (13 Sep-30 Dec).

BROAD-BILLED HUMMINGBIRD Cynanthus latirostris (43). An immature male
was in Los Angeles, LA, on 3 Jan 1993 (KLG; 75-1993). An influx of this species in
fall 1993 resulted in five birds being found along the southern California coast, one in
northern California. An immature male was in Goleta, SBA, 6-22 Sep 1993 (SEFt;
PEL, GMcC; 159-1993). An adult male at a feeder in Camarillo, VEN, 12 Nov-19
Dec 1993 (JWf, HW; EMcCt; 197-1993) was joined by a female 23 Nov- 19 Dec
1993 (JWf; 198-1993). Another male (KLG, MK, CAM; 54A-1994) and female
(KLG, MHf. MK, CAM, SBTf; 54B-1994) were at the South Coast Botanic Garden,
Rolling H tils Estates, LA, from 2 Dec 1993 and 24 Oct 1993, respectively, through
February 1994. An immature male at Fairhaven, HUM, 8-14 Oct 1993 (SH; GSL,

Figure 7. Groove-billed Ani in Goleta, 28 May 1993 (85-1993).

Photo by Don Desjardins

107

CALIFORNIA BIRD RECORDS

TWLt; 63-1994; photo in Am. Birds 48: 149.) furnished the northernmost record on
the Pacific Coast (Yee et al. 1994).

DUSKY-CAPPED FLYCATCHER Myiarchus tuberculifer (30). One at Trinidad,
HUM, 9-11 Nov 1993 (GSc, KS; GSLf; 64-1994) represents the northernmost
record for this species in California (there is now a record for Oregon — Oregon Birds
22:21). Another was at Gazos Creek, SM, 20-21 Nov 1993 (MF; AME, RST; 195-
1993). After a banner year in 1992, when a record eight individuals were found in late
fall and winter (Heindel and Patten 1996), two Dusky-capped Flycatchers is more
typical. This species has occurred in the state on nearly an annual basis since 1980
(missing only 1982 and 1986) after only a single record in the 1960s (first recorded
in California on 23 Nov 1968; Suffel 1970, Roberson 1986) and two records during
the 1970s (both in the winter of 1975-76; Luther et al. 1979).

GREAT CRESTED FLYCATCHER Myiarchu s crinitus (38). One was at Gaviota
SP, SBA, on 3 Oct 1993 (BHif; 191-1993). Photos, one of which was published in
Am. Birds 48:152, clearly show a dark gray breast and the whitish fringe on the
innermost tertial tapering toward a point at the tip of the feather, features that rule out
the Brown-crested Flycatcher (M. tyrannulus). See Heindel and Patten (1996) for a
recent discussion of the identification of these two species.

SULPHUR-BELLIED FLYCATCHER Myiodynastes luteiuentris (1 1). One was at
Baywood Park, SLO, 20 Oct 1993 (VPJ, RAP: 39-1994). Remarkable were two in
Marin County within ten days of each other: one at Pt. Reyes 25 Sep 1993 (Figure 8;
WSKt, KLsf, JM, DSSt; 169-1993) and one at Bolinas 6-10 Oct 1993 (Figure 9;
KHt; GHF, EDGf, MM, JM, BDP, DEQt, SBTt; 155-1993; photo in Am. Birds
48:149).

Differences between the Marin birds included (JM in description) the Pt. Reyes
bird’s having more pink on the bill, a solidly rufous tail, white spotting on the inner
webs of the coverts forming conspicuous wingbars, and no noticeable yellow on the
crown, and the Bolinas bird’s having more dark on the bill, coverts narrowly tipped
with white forming inconspicuous wingbars, and conspicuous yellow on the crown.
These characteristics may indicate that the Bolinas bird was an adult and the Pt. Reyes
bird was an immature (Pyle, in comments).

Perhaps generally underestimated is the difficulty in separating this species from
the similar Streaked Flycatcher (M. maculatus), which has a mostly whitish chin, thin
malar stripes, and a pale yellowish supercilium and moustachial stripe, in contrast to
the more extensive blacker malar stripe and chin and whitish supercilium and
moustachial stripe of the Sulphur-bellied Flycatcher (Howell and Webb 1995). Like
the Sulphur-bellied Flycatcher, the Streaked Flycatcher is migratory, but its breeding
distribution is restricted to eastern Mexico, whereas the Sulphur-bellied extends into
southeastern Arizona. Although much less likely to occur in California, the Streaked
Flycatcher is a possible vagrant and should be eliminated when reports of the Sulphur-
bellied Flycatcher are evaluated.

THICK-BILLED KINGBIRD Tyrannus crassirostris (12). A bird first noted in
Pomona, LA, 3-8 Mar 1993 returned on 19 Oct 1993 and stayed until at least 4 Mar
1994 (CMB§; MAP; 57-1994). It made only the second record for Los Angeles
County. Another individual was near Rickey L., about 7 miles E of Chula Vista, SD,
on 3 Nov 1993 (ERL; 40-1994). All but one record of this species have come from
southern California, the exception being a bird in San Francisco, SF. 27 Oct-19 Dec
1974 (Luther et al. 1979).

SCISSGR-TAILED FLYCATCHER Tyrannus forficata (88). One at Solana Beach,
SD, 27-28 Mar 1993 (BM; PAG; 112-1993) was judged to be the same as one seen
nearby on 4 Dec 1992 (Heindel and Patten 1996). An adult was on San Nicolas I.,
VEN, on 9 Jun 1993 (GM; 145-1993), and individuals were photographed near

108

CALIFORNIA BIRD RECORDS

Figure 8. Sulphur-bellied Flycatcher (apparently an immature) on Pt. Reyes, 25
September 1993 (169-1993), the first record for northern California.

Photo by William S. Kossack

Figure 9. Sulphur-bellied Flycatcher (possibly an adult) in Bolinas, 10 October 1993
(155-1993).

Photo by David E. Quady

109

CALIFORNIA BIRD RECORDS

Norco, RIV, 11-30 Mar 1993 (HEC; GMcC, MAPf; 59-1993), at Panamint Springs,
INY. 30 May 1993 (LST+, SBT; GMcC; 92-1993), at Owens L., INY, 8 Jun 1993
(JHt, TH ; 113-1993), and near Nicasio, MRN, 25 Sej>-24 Oct 1993 (JM; JLD,
EDGt, MM, BDP, SBTf; 154-1993; photo in Am. Birds 48:150).

DUSKY WARBLER Phylloscopus fuscatus (4). One was in Goleta, SBA, 22-23
Oct 1993 (SEF; PEL, BSc; 160-1993). The discoverer was familiar with the
distinctive call, a flat note similar to that of a junco ( Junco sp.) or Lincoln’s Sparrow
(Melospiza lincolnii ), often given loudly and repeatedly by the Dusky Warbler. The
description and field sketch were quite detailed, and the record passed unanimously
on the first round. This bird was on private land with limited access, so rather few
observers were able to see it.

The Dusky Warbler represents the only accepted species of Phyltoscopus in
California, although an Arctic Warbler [P. borealis) banded and photographed in the
hand at the Big Sur R. mouth, MTY, in fall 1995 is currently being reviewed by the
Committee. There are now four records for the state (with a fifth from fall 1995
currently under review) and two records for Baja California (Erickson et al. in press),
a remarkable total considering the North American status of this species (five records
for Alaska are the only records outside California or Baja California).

Several species of Phylloscopus breed in eastern Asia, are long-distance migrants,
and are prone to vagrancy. Therefore, while some species are much more likely to
occur than others, members of this genus found in California should not be assumed
to be a “likely” species (i.e., the Arctic or Dusky warblers) on the basis of range or
previous records. In fact, as the Europeans have learned, each individual must be
documented meticulously in order to rule out conclusively the many similar-looking
contenders that may stray well out of range. Unlike the Dusky Warbler, most
Phylloscopus are distinctly greenish above and show at least one wingbar. Highly
migratory species that breed in Siberia, lack wingbars, and may approach the
appearance of the Dusky Warbler include Radde’s Warbler (P. schwarzi), Chiffchaff ( P.
collybita), and Willow Warbler [P. trochilus). Another similar-looking species, the
Yellow-streaked Warbler (P. armandii), breeds in northeastern and central China,
winters in Laos, Burma, and Thailand, and thus seems unlikely to occur as a vagrant
in North America, although it has been considered a possible vagrant to the western
Palearctic (Parmenter and Byers 1991). Of the more likely candidates, Radde’s
resembles the Dusky most closely (e.g., see Lewington et al. 1991, Parmenter and
Byers 1991) and offers the most difficulty in identification.

Radde’s Warbler, like the Dusky, breeds in Siberia (although not as far east) and
migrates long distances to southern China and southeast Asia; both species occur as
vagrants to western Europe. Identification criteria for these two species, as outlined by
Lewington et al. (1991), Jonsson (1993), Leader (1995), and others, include leg color
(flesh colored in the Dusky, pale yellowish or grayish pink in Radde’s), bill shape
(relatively short and thick in Radde’s, thinner in the Dusky); supercilium coloration
(whiter behind the eye than in front in Radde’s, evenly white or whiter in front of the
eye than behind it in the Dusky) and shape (tapered to a point in front of the eye in the
Dusky, more even in thickness in front of the eye in Radde’s), and call (a short chek
in the Dusky, a lower pitched tuk or tuk tch in Radde’s). A description and sketch of
the Goleta bird indicated that the lores were dark and the supraorbital region was
whitish and tapered anteriorly. In addition, Finnegan recognized the call almost
immediately, from two recent trips to China during which she had seen both the
Dusky (numerous) and Radde's warblers.

WOOD THRUSH H\;locich!a mustelina (11). A singing bird in Wilmington, LA,
18 Jun 1993 (MSM; 95-1993) represents the third accepted spring record for the
state and the first for southern California. This species remains remarkably rare in
California.

110

CALIFORNIA BIRD RECORDS

*RED-THROATED PIPIT Anthus ceruinus (104). Three on SE Farallon I., SF, 5
Oct 1991 (PP; 156- 1991) occurred during a record-breaking year for this species
(Patten et al. 1995).

WHITE-EYED VIREO Vireo griseus (30). Following a record ten birds reported in
spring and summer 1992, during an unprecedented year for southeastern vagrants,
four White-eyed Vireos during the same period in 1993 is still well above average [0.6
birds per year from April to July over the previous ten years; see Terrill et al, (1992),
Heindel and Patten (1996), Patten and Marantz (in press)]. Singing males were at
Huntington Beach, ORA, 8 May 1993 (PS; BED, RAE, DRW; 82-1993), Indian Wells
Canyon, KER, 23 May 1993 (HB§, PB; 93-1993), Huntington Beach, ORA, 31 May
1993 (BED; 94-1993), and Goleta. SBA, 6 June 1993 (PEL; SEF 87-1993).

YELLOW-THROATED VIREO Vireo flauifrons (53). One was at Pt. Reyes, MRN,
17-19 May 1993 (RS; JM; 90-1993), and singing males were at Huntington Beach,
ORA, 23 May 1993 (JEP; 136-1993) and Goleta, SBA. 1 Jun 1993 (PEL; 86-1993).

PHILADELPHIA VIREO Vireo philadelphicus (95). An unprecedented 10 indi-
viduals were recorded in September and October 1993 (the vast majority of California
records are from this two-month period). Single individuals were at the following
coastal locations: Big Sur R. mouth, MTY, 18-21 Sep 1993 (Figure 10; NL; JNDf
151-1993); Pescadero, SM. 30 Sep-17 Oct 1993 (RST; NL, JM; 174-1993); SE
Farallon I., SF, 6 Oct 1993 (PPf; 204-1993); Bolinas, MRN, 7-16 Oct 1993 (KH;
JM, SBT ; 179-1993); Carmel R. mouth, MTY, 7-14 Oct 1993 (DEG; RC, DR ; 164-
1993); Big Sur R. mouth, MTY, 9 Oct 1993 (CHo; 201-1993); Huntington Beach,
ORA. 11-14 Oct 1993 (SMI; BED, RAE; 172-1993); Los Osos, SLO, 10-15 Oct
1993 (JSR; 41-1994); and SE Farallon I., SF, 9 Nov 1993(PPt; 205-1993). One was
in the eastern desert at Stovepipe Wells, Death Valley NP, INY, on 14 Oct 1993 (JH,
THf; 187-1993).

Deletion of this species from the Review List was most recently discussed at the
1996 annual meeting. However, owing to a history of identification problems, the
Committee felt that the species should be retained.

YELLOW-GREEN VIREO Vireo flavoviridis (36). One was at Bolinas, MRN, 16-
22 Oct 1993 (JK, KH; GHF. MMcCt, JM; 177-1993), one was on SE Farallon I., SF,
26 Oct 1993 (PP; 206-1993), and one was at Pt. Reyes, MRN, 28 Oct 1993 (RS;
185-1993).

The Yellow-green and Red-eyed (V oliuaceus) vireos vary a fair amount individually
and can resemble each other more closely than may be widely appreciated. Red-eyed
Vireos can show relatively indistinct dark borders to the supercilium, bright yellow on
the undertail coverts, sides, and flanks, and their upperparts can be virtually identical
in color to those of the Yellow-green Vireo. Diagnostic for the Yellow-green is the
extension of yellow up past the shoulder onto the sides of the head behind the
auriculars and the edgings to the remiges and rectrices, which are yellow rather than
olive or greenish-gray in the Red-eyed (Terrill and Terrill 1981).

BLUE-WINGED WARBLER Vermiuora pinus (18). This species remains one of
the rarest of eastern wood warblers in California. However, three individuals were
found each year in 1992 and 1993. Records in 1993 are of a wintering bird at
Ferndale, HUM, 2 Jan-7 Mar 1993 (Figure 11; DF; RAE, SWH, SMcAf, JM, DRf,
DSS; 27-1993), and two fall vagrants: 14 Sep 1993 at the Big Sur R. mouth, MTY
(JNDf; RC, DR; 152-1993), and 27-28 Sep 1993 at the Carmel R. mouth, MTY
(RS; SFB, DR; 153-1993). Although until recently this species has been generally
more numerous in spring (Heindel and Patten 1996), records are now evenly divided
between spring and fall. Fall records span a relatively narrow period (13 Sep-2 Oct).

This species and the Golden-winged Warbler (V. chrysoptera) are closely related.
Although there were only two California records of each before 1970, there are now

111

CALIFORNIA BIRD RECORDS

Figure 10. Philadelphia Vireo at the Big Sur River mouth, 21 September 1993 (151-
1993). A record ten individuals were documented in California in 1993.

Photo by Jeff N. Davis

112

CALIFORNIA BIRD RECORDS

Figure 11. Blue-winged Warbler in Ferndale, 23 January 1993 (27-1993), first winter
record for California.

Photo by Sean McAlister

Figure 12. Rustic Bunting near Cantil, 9 November 1993 (162-1993), southernmost
record in the New World.

Photo by Matthew T. Heindel

113

CALIFORNIA BIRD RECORDS

nearly 50 records of the Golden-winged compared to 18 of the Blue-winged. Average
annual numbers of the Blue-winged have increased in the late 1980s and early 1990s
and now approach those of the Golden-winged. This increase parallels evidence that
Blue-winged Warbler populations are rapidly increasing and expanding (e.g.,
McCracken 1994), replacing the Golden-winged Warbler in some areas.

YELLOW-THROATED WARBLER Dendroica dominica (73). A singing male was
along Gazos Creek, SM, 19 May 1993 (RST; 97-1993), and a second-spring bird was
at Torrance, LA, 6 June 1993 (KGLt; 116-1993). The single 1993 fall record was
from Santa Barbara, SBA, on 24 Oct 1993 (GG, RG; 1990-1993).

GRACE’S WARBLER Dendroica graciae (29). One at Pismo SB, SLO, 3-6 Oct
1993 (KR; 77-1994) represents the northernmost record of this species on the coast.

PINE WARBLER Dendroica pinus (50). Two occurred on the same date, 24 Oct
1993: one at the Big Sur R. mouth, MTV (REM, RFT; RC, DR; 165-1993), and one
at Pt. Loma, SD (GMcC; 157-1993), This species is much rarer in northern California
than in southern; this represents the first record for Monterey County. The Pt. Loma
bird was believed by some observers to have been the same as an individual that
wintered at the same location 6 Jan-12 Apr 1992 and a bird seen there 25 Oct-10
Nov 1992 (Heindel and Patten 1996). However, the bird was accepted as a new
individual, as a majority of Committee members were swayed by the lack of
observations after early November 1992 and the fact that the bird under discussion
was seen only on 24 Oct 1993. In addition, one member raised the issue of difficulty
in ageing males at this time of year and believed that the description fit an adult or an
immature male equally well.

WORM-EATING WARBLER Helmintheros uermiuorus (70). One was at L.
Palmdale, LA, 21 Aug 1993 (KLG, JA; 128-1993), and another was at Carpinteria,
SBA, 16 Aug 1993 (BHn ; 129-1993).

*KENTUCKY WARBLER Oporornis formosus (105). After a record-breaking 40
Kentucky Warblers were recorded in the state in 1992 (Terrill et al. 1992, Heindel and
Patten 1996, Patten and Marantz in press), seven individuals in 1993 was closer to
the average. In contrast to spring/summer 1992, when 10 times the mean number of
Kentucky Warblers occurred, there were only two spring/summer records in 1993.
This rapid return to normal supports the hypothesis that the 1992 invasion of this and
other southeastern vagrants was probably due to a persistent unusual weather pattern
over the Gulf of Mexico in spring 1992 (Terrill et al. 1992).

The following 1993 Kentucky Warbler records were accepted: Green Valley,
Encinitas, SD, 30 Jun-2 Jul 1993 (BED; TC, GMcC; 147-1993); Wyman Canyon,
INY, 16-18 Jul 1993 (TH, JH ; 148-1993); Goleta, SBA, 12 Sep 1993 (DPH; SEF,
PEL; 161-1993); SE Farallon I., SF, 13 Sep 1993 (JK; 207-1993); Pt. Loma, SD. 21
Sept 1993 (DWA; 42-1994); Galileo Hill Park, KER, 10 Oct 1993 (HB, PB; 173-
1993); and Arcadia, LA, 18-19 Dec 1993 (HBo, BC, CHa ; JF, KGLf; 79-1994).

CONNECTICUT WARBLER Oporornis agilis (72). All four records were for fall:
SE Farallon L, SF, where the majority of California’s Connecticut Warblers have
occurred, 15 Sep 1993 (JKf; 208-1993) and 4-6 Oct 1993 (PPt; 209-1993);
Carmel R. mouth, MTY, 27 Sep 1993 (JCS; RFT; 163-1993); and Big Sur R. mouth,
MTY, 2 Oct 1993 (CHot, JND; 171-1993).

MOURNING WARBLER Oporornis Philadelphia (87). Three out of four 1993
birds were on SE Farallon 1., SF, where over half of the state’s records have been: 1
Oct 1993 (RAE, PPt; 210-1993), 4-5 Oct 1993 (PPt; 211-1993), and 6-7 Oct
1993 (PPt; 212-1993). The remaining record was from nearby Rodeo Lagoon,
MRN, 2 Oct 1993 (JM ; 180-1993).

114

CALIFORNIA BIRD RECORDS

SCARLET TANAGER Piranga oliuacea (86). An immature male was at Granada
Hills, LA, 17 Oct 1993 (TEW; 44-1994); another, probably an immature female, was
near Imperial Beach, SD, 21 Oct 1993 (DWA; TC, GMcC; 158-1993 ); and a third,
initially identified as a male, but thought to have been a female when the Committee
viewed the videotape, was at Pt. Reyes, MRN, 23 Oct 1993 (JM; EDGt, LLf; 178-

1993) .

Scarlet Tanagers have occurred annually since 1967. Three records is about
average for a given year. This species occurs about three times as frequently in the fall
as in spring/summer.

PAINTED BUNTING Passe rina ciris (43). One was at Huntington Beach, ORA,
18 Sep 1993 (SM; BED; 184-1993), and a first-year bird was at Furnace Creek
Ranch, Death Valley NP, INY, 11 Sept 1993 (MAPf; 134-1993).

CASSIN’S SPARROW Aimophila cassinii (36). Up to three (contra Am. Birds
47:455) singing males were in the Lanfair Valley, SBE, 8-30 May 1993 (REW§;
GMcC, MAP, SBTf; #54313 SBCM; 77-1993). A first fall record for the interior was
one at Death Valley Junction, INY, 14-16 Aug 1993 (REW; JH, TH; 188-1993).

LE CONTE’S SPARROW Ammodramus leconteii (25). One at Upper Newport
Bay, ORA, 14 Dec 1993-11 Jan 1994 (JEP, JSB, KAC; MTHf, CAM, GMcC; 9-

1994) was the third to have wintered in the state.

RUSTIC BUNTING Emberiza rustica (3). The third for California and the first for
southern California and the interior was near Cantil, KER, 7-10 Nov 1993 (Figure
12; MTHf; KFC, MOC, GMcC, MAP; 162-1993). This record is the southernmost
for North America.

This bird, photographed and described in detail, was probably a first-year male;
however, Svensson (1992) cautioned against ageing and sexing this species in
autumn. The Rustic Bunting is a regular straggler to western Alaska and is accidental
in British Columbia (two records), Washington (one record), and Oregon (one record).
In addition, one or two Rustic Buntings wintered at Hoopa, HUM, in 1995-96 (under
CBRC review).

SNOW BUNTING Plectrophenax nivalis (55). One was at SE Farallon I., SF, 22
Oct 1991 (SAf; 10-1992), one was at Crescent City harbor, DN, 27 Dec 1993-16
Jan 1994 (SEFt, GSLt; 65-1994), and one was in the interior at Sierra Valley, PLU,
15 Jan 1993 (LJ ; 167-1993).

RECORDS NOT ACCEPTED, identification not established

Note that several of the seabird records discussed below may have been
from beyond the CBRC’s 200-nautical-mile review area. All of these records
received full consideration, however; none gained Committee acceptance
with respect to identification.

YELLOW-BILLED LOON Gavia adamsii. One was reported at Rodeo Beach,
Golden Gate National Recreation Area, MRN, 24 Feb 1993 (66-1993; Am. Birds
47:296). An increase in the number of reports of this species across the continent
suggests an increased understanding of loon identification, but in California Yellow-
billed Loon reports have received a rather low acceptance rate of approximately 58%.

SHORT-TAILED ALBATROSS Diomedea albatrus. An adult was reported ap-
proximately 212 n. miles SW of San Nicolas I., VEN (ca. 32° 02' N, 123° 57' W), on
4 Oct 1992 (22-1994), and an immature was reported approximately 47 n. miles NW
of Pt. Arguello, SBA (ca. 34° 45' N, 121° 33' W), on 9 Oct 1992 (23-1994). There
remain only four accepted records of this species in California this century.

115

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification not established, Cont.

DARK-RUMPED PETREL Pterodroma phaeopygia. One reported near 31° 59'
N, 124° 01' W on 8 Apr 1993 (24-1994) was probably just over 200 n. miles SW of
San Miguel I., SBA. Pyle et al. (1993) recently reported two observations of this
species at similar distances off the coasts of Oregon and California, but one reported
SW of Pt. Reyes, MRN, 3 May 1992 (under review) and one photographed off
Monterey Co. 26 June 1994 (to be published as accepted in the next Committee
report) are the first reports within “California waters.’

GREATER SHEARWATER Puffin us gravis. One reported by five participants on
an organized boat trip on Monterey Bay, MTY, 24 Feb 1979 (17-1979) was
previously accepted by the Committee (Luther et al. 1983) and thus has been widely
treated in the ornithological literature as the sole record of this species in the North
Pacific (e.g., AOU 1983, Harrison 1983, Marchant and Higgins 1990). A few
individuals had always questioned this record, and the number of doubters gradually
grew until reaching critical mass early this decade. The Committee’s decision in 1993
to reevaluate the record on the basis of “new and substantial information,” however,
was so contentious that this former requirement for reconsideration was dropped a
year later. Now, any record can be reconsidered if a majority votes to do so at an
annual meeting. To overturn a formerly accepted record, a majority of the Committee
must vote against the record. This record went through three full circulations for all
viewpoints to be considered carefully and received the necessary majority vote to
overturn on each round.

The record still has its supporters (there were four accept votes in the final
circulation) and thus continues to be controversial. Two highly qualified observers,
long-serving members of this Committee and current members of the ABA Checklist
Committee, were the primary observers involved and neither has ever wavered in his
support of the record. One has since seen the most similar-looking gadfly petrel, the
Juan Fernandez Petrel [Pterodroma externa ), and insists the bird was not that
species. Obviously, many believe the descriptions best fit the Greater Shearwater.

Members voting against the record emphasized the uniqueness of the sighting: not
only was this the first record for the North Pacific, but it was also most unexpected in
the Northern Hemisphere in winter. Accordingly, these members insisted on unassail-
able documentation, no matter the observers. For them, it was not enough to ask what
the bird could have been if not a Greater Shearwater. The bird was well seen, but note
these shortcomings of the documentation: the obvious scaled pattern of the upper-
parts of Greater Shearwater was not noted by anyone — indeed, one observer
described a Pterodroma- like “M” pattern across the mantle; a dark belly patch
(although often difficult to see) was not seen by anyone, and the bird was consistently
described as immaculate white below; no dark markings were seen on the underwings;
the high arching flight of the bird was so distinctive (compared to other shearwaters
seen that day) that the bird was considered to have been a Pterodroma until the boat
was back in port; no whitish collar was seen, although some Greater Shearwaters lack
this mark; forehead and bare-part colors were poorly noted; the bird was not
consistently described as large as expected; the sighting was made at a time when only
one Pterodroma, the Mottled Petrel (P. inexpectata), had been recorded in California
(and never alive at sea) and almost none of the observers had seen a gadfly petrel or
fully understood the potential for members of the genus to reach California; and
although the Greater Shearwater was considered during the observation, the final
identification was not made until later, when critical marks could not be rechecked.

Ironically, near the end of this record’s second round through the Committee, a
Greater Shearwater was much better documented on Monterey Bay 1-2 Oct 1994
{ NASFN 49:95; CBRC unpubl. data). None of those global reference works will have

116

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification not established, Cont.

to be reprinted after all! Details of the CBRC review of the 1994 record will appear in
the next Committee report.

WEDGE-TAILED SHEARWATER Puffinus pad ficus. Organized boat trips gener-
ated reports of one ca. 7 n. miles W of the Pajaro R. mouth, MTY/SCZ, 24 Oct 1992
(3-1993; photo in Am. Birds 47:144) and two approximately 40 n. miles SW of Pt.
Arguello, SBA, on 17 Apr 1993: one dark morph (120-1993) and one light morph
(121-1993).

The 1992 Monterey report is especially interesting. It received minority support,
based only on the published photograph, on its first circulation. All support collapsed
in subsequent rounds as additional photographs submitted appear to depict only a
Sooty Shearwater ( P. griseus). Rumors continue to circulate that two birds were
actually involved and that important additional photographs exist. The Committee
encourages the submission of any additional documentation and will certainly recon-
sider the record as needed.

Despite its distinctive shape — small head, broad-based wings, and long tail — and
plumage (Harrison 1983, 1987; Stallcup et al. 1988), this species has been over-
reported in California. One light morph on Monterey Bay, MTY, 31 Aug 1986
(Stallcup et al. 1988, Bevier 1990) and one dark morph at the north end of the Salton
Sea, RIV, 31 Jul 1988 (McCaskie and Webster 1990, Pyle and McCaskie 1992)
remain the only accepted records, yet eight reports have now failed to gain Commit-
tee approval.

MANX SHEARWATER Puffinus puffinus. A bird seen on Monterey Bay, MTY, in
early September 1985 (168-1994) and one reported 8-10 miles W of Moss Landing,
MTY, on 24 Oct 1993 (67-1994; Am. Birds 48:147) showed several characters
typical of this species but were judged insufficiently documented. See Records
Accepted for a discussion of the first accepted records of this species in California.

BAND-RLJMPED STORM-PETREL Oceanodroma castro. Eight were reported by
seabird researchers in 1993: four approximately 212-225 n. miles SW of San Miguel
I., SBA, 20 Aug 1993 (26-1994); two approximately 140-145 n. miles SSW of San
Nicolas I., VEN, 10 Oct 1993 (27-1994); and two somewhere between 175 and 245
n. miles SW of San Nicolas 1., VEN, 13 Oct 1993 (28-1994).

The 1989 records reported by Small (1994) were not accepted by the Committee
(Heindel and Garrett 1995); Heindel and Patten (1996) discussed additional recent
records not accepted by the Committee. The only record ever accepted for California
(one off San Diego 12 Sep 1970; Luther et al. 1983, McCaskie 1990) is currently
being reconsidered by the Committee. There remains no specimen or photographic
record of this warm-water species in the northeastern Pacific.

RED-FOOTED BOOBY Sula sula. One was reported at La Jolla, SD, 13 Aug
1993 (31-1994; Am. Birds 48:151).

REDDISH EGRET Egretta rufescens. One reported in “mottled” plumage at Seal
Beach NWR, ORA, 2 Jan 1993 (123-1993) was described as having “whitish
immature feathers remaining.” Birds in northwestern Mexico (£. r, die kepi, presum-
ably responsible for all California records) are dark in all plumages, so the description
was not well received. An immature Reddish Egret was known to be present in the
area at the time (see Corrigenda below), however, so some members felt this was
merely a poor description of a known bird.

GARGANEY Anas querquedula. One reported in San Rafael, MRN, 16 Jan 1993
(54-1993; Am. Birds 47:297) was seen by many and described by three observers.
Most Committee members agreed that this was likely a Garganey but that the

117

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification not established, Cont.

documentation was insufficient to confirm a record of so rare a species outside of the
expected migratory periods. Incomplete descriptions of the wing pattern were of
particular concern.

ZONE-TAILED HAWK Buteo albonotatus. Single individuals were reported at
Butterbredt Spring, KRN, 8 May 1993 (17-1994) and Fort Piute, SBE, 16 May 1993
(107-1993; Am. Birds 47:451).

AMERICAN OYSTERCATCHER Haematopus palliatus. One on Pt. Loma, SD,
11 Mar-7 May 1992 (Figure 13; 120-1992; Am. Birds 46:480) was considered an
American x Black ( H . bachmani) Oystercatcher hybrid, whereas the identity of 12+
reported at Sausalito, MRN, 18 Feb 1993 (89-1993) was not established.

The hybrid determination of the Pt. Loma bird was based on the character-scoring
system devised by Jehl (1985; reproduced in Table 1). Committee members Patten
and McCaskie each evaluated the bird, generating total scores of 22-27 and 24-31,
respectively. To complicate matters, a specimen from Santa Barbara I., SBA (2 Jun
1863, MVZ# 4489), scored at 26-29 by Jehl and two others, was accepted by the
Committee, largely on the recommendation of Jehl himself (Roberson 1993a). The
scores for some of the other accepted records likely also fall below 30, the threshold
specified by Jehl for an unhybridized American Oystercater. Clearly the Committee
has an unresolved issue on its hands; it is inappropriate that similar-looking birds be
found among accepted and not accepted records. For the sake of consistency, a
reanalysis of all records is planned, with one goal to determine how best to evaluate
intermediate birds.

Figure 13. Oystercatcher on Pt. Loma, 28 March 1992, judged to be a hybrid
American x Black (120-1992). Note the dark uppertail coverts.

Photo by Michael A. Patten

118

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification not established, Cont.

COMMON GREENSHANK Tringa nebularia. A bird at the Chico oxidation
ponds, BUT, 1 Dec 1993 (4-1995) was described as like a Greater Yellowlegs (T.
melanoleuca) but with “yellow-greenish legs’’ and “a white wedge 1/2 to 2/3 of the
way up its back. " The description was interesting, but the shape of the bird (especially
the bill) did not match this species, and this potential first state record received no
support.

BAR-TAILED GODWIT Limosa lappontca. One was reported at Alameda, ALA,
8 Mar 1993 (88-1993).

RED-NECKED STINT Caiidris ruficollis. One reported at the San Diego R.
estuary, SD, 12 Aug 1993 (37-1994) was rather superficially described (for a “peep”)
by the single observer. The Committee has struggled over well-photographed birds (as
have other committees, e g., Round 1996), so records of all but the most obvious
alternate-plumaged stints require meticulous documentation.

LITTLE STINT Caiidris minuta. A juvenile was reported near Stratford, KIN, 28
Aug 1993 (170-1993). As with the previous record, this single-observer description
lacked the detail needed for adequate documentation. There are now as many rejected
records of this species in California as accepted ones, at five apiece.

BRIDLED/GRAY- BACKED TERN Sterna anaethetus/lunata . An adult tern seen
for several minutes near the massive tern colony at Bolsa Chica, ORA, 12 Jun 1993
^144-1993) was documented by all three observers. It was described as having a black
cap, whitish nape, gray back, and dark wings and tail except for the outermost rectrix,
which was “thinly edged with white near the tip. Other relevant features noted
included a white forehead patch that narrowed on either side and extended back to
end in a point above and behind each eye and a narrow black eyeline that boldly
separated the white supercilium from the whitish face. The underparts were entirely
white.

The bird was submitted as a Bridled or Gray-backed tern, two species of the tropical
Pacific still unrecorded in California. Committee members were allowed to vote for
either species, and the response was quite mixed: one voted to accept as the Bridled,
one voted to accept as the Gray-backed, four felt the bird was “almost certainly” one
or the other, and four were unwilling to endorse the record in any specific way, some
believing the possibility of confusion with the Sooty Tern (S. fuscata ) was too great.
After the one-day reports of a Sooty /Bridled Tern 5 Aug 1990 (Heindel and Garrett
1995), this record, and a Sooty Tern 30 July 1994 ( NASFN 48:989; CBRC unpubl.
data) — all at Bolsa Chica — frustrated birders were gladdened by the appearance of a
long-staying Sooty Tern there in 1995 ( NASFN 49:980; under CBRC review).

RUDDY GROLJND-DOVE Columbina talpacoti. One reported at Hidden Valley
Wildlife Area, Norco, RIV, 29 May 1993 (110-1993) would have been the first spring
record for the coastal slope of California.

ALDER FLYCATCHER Empidonax alnorum. Two birds together were reported
from Butterbredt Spring, KER, 28 May 1993 (1 1 1-1993). At this time, there are only
two accepted records for this species in California. The first (185-1991) was of a
singing bird tape-recorded at the South Fork of the Kern R., KER, on 11 Jul 1991.
Sonograms were analyzed by experts on the species, and the identification was
confirmed (Patten et al. 1995). The second record involved a bird repeatedly heard
calling and singing, described in great detail, also at Butterbredt Spring on 30 May
1992 (149-1992; Heindel and Patten 1996).

The identification of Alder and Willow (E. traillii ) flycatchers is difficult. Willow
Flycatchers can give a trisyllabic song (Kaufman 1990), and the identification of these

119

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification not established, Cont.

birds rested primarily on a trisyllabic song described as fee-bee-o. Short of a tape
recording, critical to adequate documentation of this species is a detailed description
of the quality of the vocalizations (duration, pitch, etc.). Several members noted that
fee-bee-o is not an appropriate description of an Alder Flycatcher song and that the
Willow Flycatcher can sound like this [fitz-bew-wick to one Committee member, or
fritz-be-yew as described by Kaufman (1990)]. It was also noted that vocalizations of
Willow Flycatchers are more variable than is widely known. Finally, there was concern
that neither the wee-bee nor the sharp pip call, probably diagnostic for distinguishing
the Alder from the Willow Flycatcher, was heard.

Descriptions of the birds as having more greenish olive-green backs, as opposed to
the more brownish olive-green backs of the nearby Willows, is appropriate for the
Alder Flycatcher, which tends to be greener on the upperparts in fresh plumage
(Kaufman 1990), but these species may not be consistently distinguishable, even in
the hand, by plumage (Pyle et al. 1987, Kaufman 1990).

As more information concerning identification criteria of these two species is
collected, we may find that the Alder Flycatcher is more regular in the state than is
currently known. In particular, if the sharp pip note of Alder (relative to the liquid whip
note of Willow Flycatchers) turns out to be diagnostic, records of accepted birds may
increase (see also Heindel and Patten 1996).

YELLOW-BELLIED FLYCATCHER ( Empidonax flaviventris). A calling bird was
reported from Gardena, LA, 16 Sep 1993 (38-1994) by a single observer. Although
much of the description was correct for this species, the/ Committee remains
conservative on eastern Empidonax flycatchers that are not photographed or tape-
recorded because of plumage variability and the difficulty involved in identification of
extralimital members of this genus.

DUSKY-CAPPED FLYCATCHER Myiarchus tuberculifer. One reported from
Montana de Oro SP, SLO, on 7 Nov 1992 (19-1993) was on the early side; although
there are a number of November records, most are for late November, and there is
only one accepted record earlier than this report (4-6 Nov 1992; Patten et al. 1995).
The bird was silent, and several key characters were not noted. In particular, the
rectrices were not seen from below, and the inner webs were evidently not seen from
above. The closed tail was described as being uniform brown without rusty on the
upperside. Most if not all previous California Dusky-capped Flycatchers have shown
thin rufous edgings on the outer webs of the rectrices. A number of Committee
members also believed that the pattern on the secondaries, another key point, was not
adequately described (the Dusky-capped is the only Myiarchus with rufous edgings to
the secondaries). Finally, several members pointed out that a bright freshly molted
Ash-throated Flycatcher (M. cinerascens) was not eliminated by the description, and
that California observers seldom see this plumage (by the time the birds return to the
state in spring, they are somewhat paler because of feather wear). Members that
believed the record adequately documented a Dusky-capped Flycatcher were im-
pressed by the description of the size as not much larger than a Black Phoebe
( Sayornis nigricans ) but smaller than an Ash-throated Flycatcher and by the colora-
tion of the underparts, including a bright yellow belly brighter than an Ash-throated’s,
a gray breast lighter than a Great Crested Flycatcher’s, and a throat darker than an
Ash-throated Flycatcher’s.

VEERY Catharus fuscescens. A bird thought to be this species was seen briefly at
Butterbredt Spring, KRN, 28 May 1993 (114-1993). Although the description of the
bird superficially fit the Veery, the description was not detailed enough to confirm this
extremely rare (in California) species, which represents a notoriously difficult identifi-
cation problem (only 8 of 20 individuals submitted have been accepted).

120

CALIFORNIA BIRD RECORDS

RECORDS NOT ACCEPTED, identification not established, Cont.

COMMON CRACKLE Quiscalus quiscula. A male was reported from Modoc
NWR, MOD, 22 Aug-7 Sept 1993, and a female was reported from the same
location on 22 Aug 1993 (130-1993). The Committee felt that the descriptions better
fit male (immature) and female Great-tailed Grackles (Q. mexicanus). In particular, the
female was described as having a light brown breast that gradually blended with the
darker body color, a description incorrect for the Common Grackle but appropriate
for the Great-tailed. The male was evidently all glossy iridescent black and lacked the
two-toned appearance of a male Common Grackle created by the bronze tones on the
back, wings, and underparts. Another report from the same location (31 May 1986;
86-1994) lacked detail and did not eliminate the Great-tailed Grackle.

SNOW BUNTING Plectrophenax nivalis. A bird reported from Baker, SBE, on 10
April 1993 (117-1993) would have been very far south on a late date. Therefore, the
majority of the Committee felt that the description should have been more detailed. In
addition, the bird was described as being in winter plumage. Several members felt that
the bird should have been in transitional or breeding plumage by this date.

A bird seen in November 1983 at Cape Mendocino, HUM (208-1992), was
recalled 9 years later. The Committee felt that the report did indeed pertain to a Snow
Bunting but that the documentation was insufficient to substantiate it.

RECORDS NOT ACCEPTED, natural occurrence questionable

COMMON CHAFFINCH Fringilla coelebs. One was well documented at a feeder
in San Jose, SCL, 9-11 Oct 1993 (MM, MMRt; 168-1993). The Committee
unanimously considered this bird an escape, although there was considerable dis-
agreement about whether the bird represented one of the migratory or sedentary
races. This species has been recorded seven times in the maritime provinces, is
currently on the Canadian list (Kaufman 1994), and has been accepted by the ABA
Checklist Committee (Dunn and Garrett in comments). However, all Committee
members felt that the likelihood of a vagrant chaffinch reaching California is
extremely remote.

CORRIGENDA TO THE EIGHTEENTH COMMITTEE REPORT (Heindel
and Patten 1996)

Under Records Accepted of Yellow-billed Loons, p. 3: the bird on San Francisco
Bay was actually in Alameda County and was present from 20 Dec 1992 to 14 Jan
1993 (Am. Birds 47:296, 945). Under Records Accepted of Reddish Egrets, pp. 5-
6: the adult at Anaheim Bay (Seal Beach NWR), ORA, 12-14 Apr 1992 remained
until 9 May 1992 (Am. Birds 46:479), and the immature at Bolsa Chica, ORA, 18
Oct 1992-3 Jan 1993 actually began to commute between Bolsa Chica and Seal
Beach NWR and remained to 20 Mar 1993 (Hamilton and Willick in press). Under
Records Accepted of Zone-tailed Hawks, p. 7: the L. Murray /Santee bird (records 78-
1993 and 79-1993) was judged to be a returnee, but not of record 107-1991/180-
1992, which was at L, San Marcos, SD. Either record 34A 1992 or 34B-1992, in
Records Accepted above, should be considered the initial visit to Santee.

121

CALIFORNIA BIRD RECORDS

CORRIGENDUM TO THE FOURTEENTH COMMITTEE REPORT
(Roberson 1993a)

Under Populations Accepted, pp. 138-139, it was suggested that Sonora Pass,
ALP/TUO/MNO might be a barrier to northward dispersal of White-tailed Ptarmi-
gans ( Lagopus leucurus). In fact, ptarmigans were then present north of the pass.
Paul L. Noble has observed and shot birds near Sonora Peak, ALP/MNO (3493 m
elevation), during hunting season, and states that the California Department of Fish
and Game has confirmed ptarmigan as far north as Ebbett’s Pass, ALP.

CONTRIBUTORS

Douglas W. Aguillard, Jonathan Alderfer, Brooks B. Allen, Peter Allen, Scot
Anderson, Derek John Angell, Ian Armstrong, Don Baccus, Stephen F. Bailey,
Robert A. Behrstock, Clyde Bergman, Harold Bond (HBo), Robert S. Braden, Chris
Brady (CB), Christine M. Brady, Ronald L. Branson, Hank Brodkin, Priscilla Brodkin,
James S. Burns, Kenneth Burton, Kurt F Campbell, Rita Carratello, Mark O.
Chichester, Henry E. Childs, Jr., Therese Clawson, Barbara Cohen, Charles T.
Collins, K. C. Corey, Kenneth A. Corey, Brian E. Daniels, J. Michael Danzenbaker,
Jeff N. Davis, Guy Deeks, Don Desjardins, Bruce E. Deuel (BEDe), Elizabeth T.
Dickey, Jon L. Dunn, Todd Easterla, Ray Ekstrom, Alan M. Eisner, Richard A.
Erickson, Carter L. Faust, Marc Fenner, Eric Feuss, George H. Finger, Shawneen E.
Finnegan, Jon Fisher, David Fix, Fran Floyd, Kimball L. Garrett, Douglas E. George,
Peter A. Ginsburg, Edward D. Greaves, Helen Green, Ginny Guess, Robert Guess,
William E, Haas, Chuck Hamilton (CHa), Robert A. Hamilton, Bob Hansen (BHn),
Keith Hansen (KH), George S. Hardie, Joan Hardie (JHa), Stanley W. Harris, David
P. Haupt, Sandy Haux, Gjon Hazard, Daniel R. Heathcote, Lori A. Heathcote, Jo
Heindel (JH), Matthew T. Heindel, Mitch Heindel, Tom Heindel, Robert W. Hewitt,
Brad Hines (BHi), Craig Hohenberger (CHo), Kenneth Howard, Andrew Howe,
Vernon Howe, Steve N. G. Howell, Richard Jeffers, Lin Jensen, Curtis O. Johnson,
Viginia P. Johnson, Joe Kaplan, Mark Kincheloe, Howard King, Andrew Kirk,
William S. Kossack, Kevin G. Larson, Kenneth Learned (KL), Ken Learnshaw (KLs),
Paul E. Lehman, Victor Leipzig, Tom W. Leskiw, Gary S. Lester, Nick Lethaby, Eric
R. Lichtwardt, Leslie Lieurance, Roger Linfield, Kim P. Loewer, James Lomax,
Michael Mammoser (MM), Curtis A. Marantz, John Mariani (JMa), Robert E. Mauer,
Jr., Sean McAllister (SMcA), Guy McCaskie (GMcC), Gerry McChesney (GM), Elliott
McClure, Mac McCormick (MMcC), Lynn McCulloch, Robert L. McKernan, Steve
Mlodinow (SMI), Richard Montgomery, Barbara Moore, Joseph Morlan (JM), Mary
Mosher (MMo), Joy Nishida, Rod Norden, Benjamin D. Parmeter, Michael A. Patten,
Roberta A. Phillips, James E. Pike, Peter Pyle, David E. Quady, William R. Radke,
Robert J. Richmond, Karen Rippens, Don Roberson, Jim Roberts, Harry Robinson,
Geoffrey L. Rogers, Michael M. Rogers, Stephen C. Rottenborn, Jim S. Royer,
Thomas P. Ryan, Ronnie L. Ryno, Mike San Miguel, Larry Sansone, Starr (Gussman)
Saphire, Buzz Scher, Barney S. Schlinger, Greg Schmidt (GSc), Kristen Schmidt,
Allan A. Schoenherr, Brad Schram (BSc), Dennis Serdehely, Brad Sillasen (BS), Brian
E. Sillasen, Daniel S. Singer, John C. Sterling, Greg Stewart (GSt), Bradley M. Stovall,
Mary Beth Stowe, Phil Swan, Monte M. Taylor, Linda S. Terrill, Scott B. Terrill,
Ronald S. Thorn, Robert F. Tintle, Gerald Tolman, Mike Tove, Richard R. Veit, Hal
Wasserman, Jan Wasserman, Richard E. Webster, Nicolas Whelan, Douglas R.
Willick, Mark Wimer, David Wimpfheimer, Thomas E. Wurster, David G. Yee, Herb
Young.

Birds banded on SE Farallon I. and at the Big Sur R. mouth, while credited here to
the bander(s), should also be credited to Point Reyes Bird Observatory and the Big Sur
Ornithology Lab, respectively.

122

CALIFORNIA BIRD RECORDS

ACKNOWLEDGMENTS

Every Committee report is the result of a tremendous team effort, beginning with
the many contributors listed above. Current and recent CBRC members voting on the
records reported here include Jon L. Dunn, Erickson, Shawneen E. Finnegan,
Kimball L. Garrett, Matthew T. Heindel, Steve N. G. Howell, Paul E Lehman, Gary
S. Lester, Guy McCaskie, Joseph Morlan, Michael A. Patten, Peter Pyle, Don
Roberson, and Terrill. Finnegan, Robert A. Hamilton, Paul L. Noble, and Roberson
alerted us to errors in previous Committee reports. David G. Ainley and Larry B.
Spear provided valuable input on the seabird accounts. Joseph R. Jehl, Jr. allowed us
to reproduce his oystercatcher table. Paul Brown prepared the map. Dunn, Finnegan,
Garrett, Hamilton, Heindel, Howell, Lehman, McCaskie, Morlan, Sabrina Nicholls,
Patten, Pyle, Roberson, Mike San Miguel, and Daniel S. Singer reviewed a draft of this
report and submitted comments that greatly improved the text. We also wish to
acknowledge the support and encouragement of Mrs. Catherine Morgan, our fifth
grade teacher at Lakeview Elementary School in Oakland, without whose influence
our early interest in birds might have waned. This is Contribution 37 of the California
Bird Records Committee.

LITERATURE CITED

American Ornithologists’ Union. 1983. Check-list of North American Birds, 6th ed.
Am. Ornithol. Union, Washington, D.C.

American Ornithologists' Union. 1995. Fortieth supplement to the American Orni-
thologists’ Union Check-list of North American Birds. Auk 112:819-830.

Baker, K. 1993. Identification Guide to European Non-Passerines. Br. Trust for
Ornithol. Field Guide 24.

Beck, R. H. 1910. Water birds of the vicinity of Point Pinos, California. Proc. Calif.
Acad. Sci. 3:57-72.

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.

Binford, L. C. 1986. Checklist of California birds. W. Birds 17:1-16.

California Bird Records Committee. 1991. Field list of California Birds. W. Field
Ornithol., San Diego.

Clapp, R. B., Klimkiewicz, M. K., and Kennard, J. H, 1982. Longevity records of
North American birds: Gaviidae through Alcidae. J. Field Ornithol. 53:81-124.

Dittmann, D, L., and Lasley, G. W. 1992. How to document rare birds. Birdinq
24:145-159.

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

Erickson, R. A., Hamilton, R. A., and Howell, S. N. G. In press. Additional
information on migrant birds in northern and central Baja California. Euphonia.

Everett, W. T., and Teresa, S. 1988. A Masked Booby at Islas Los Coronados, Baja
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124

CALIFORNIA BIRD RECORDS

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Accepted 6 May 1996

Palm Warbler

Sketch by Jamie M. Chauez

126

THE BLACK SKIMMER IN CALIFORNIA:
AN OVERVIEW

CHARLES T. COLLINS, Department of Biological Sciences, California State Univer-
sity, Long Beach. California 90840

KIMBALL L. GARRETT, Section of Vertebrates, Natural History Museum of Los
Angeles County, 900 Exposition Blvd., Los Angeles, California 90007

Although many avian species in western North America have suffered
recent population declines, a few have increased over the same period of
time (Jehl and Johnson 1994). Many of the increases, such as parrots’
(Psittacidae), can be attributed strictly to anthropogenic influences (Johnston
and Garrett 1994). Among those species showing apparent natural popula-
tion increases in California is the Black Skimmer ( Ryrtchops niger), which
first occurred in the state in 1962 (Small 1963, 1994) and is now a resident
breeder with a population in 1995 of about 1200 pairs. Recent studies in
this region have documented its nocturnal activity pattern in the breeding
season (Wilson 1995) and winter (Gazzaniga 1995, de la Cueva and
Fernandez 1996), food habits (Wilson 1995), and pattern of chick growth
(Schew and Collins 1990, 1991). In this paper we review the status of the
Black Skimmer in California with emphasis on the size and location of
breeding colonies and overwintering aggregations (Figure 1). We also
include a list of museum specimens of Black Skimmers taken in California
(Appendix).

The first Black Skimmer recorded in California was a single individual
observed at the mouth of the Santa Ana River in coastal Orange County on
8 September 1962 (Small 1963). The real invasion began 6 years later with
the sighting of five skimmers on the Salton Sea at the mouth of the
Whitewater River, Riverside County, on 3 July 1968 (McCaskie and Suffel
1971) and the discovery of five nests at the south end of the Salton Sea in
1972 (McCaskie et al. 1974). Although the skimmer populations at the
Salton Sea have fluctuated since then, approximately 487 pairs bred there
in 1995 (Molina 1996; Table 1). Skimmers spread to the Pacific coast
beginning in 1971 and bred in south San Diego Bay in 1976 (Unitt 1984).
They spread northward in the ensuing years as regular summer visitors and
occasional small overwintering groups (Unitt 1984, L. Hays pers. comm.)
before establishing a breeding colony at the Bolsa Chica Ecological Reserve,
Orange County, in 1985 (McCaskie 1985, Collins et at. 1991, L. Hays and
D. Yparraguerre pers. comm.) and Upper Newport Bay Ecological Reserve,
Orange County, in 1986 (McCaskie 1986). These two colonies now each
support an annual breeding population of greater than 200 paris (Table 1).
The increase in the breeding range of the Black Skimmer has continued with
the documentation of breeding on San Francisco Bay in 1994 and 1995
(Layne et al. 1996) and the formation of a new colony at Batiquitos Lagoon
in northern San Diego County in 1995 (Whelchel et al. 1996) (Figure 1). A
single pair nested at an inland site in the Tulare Lake basin, Kings County,
in 1986 (Erickson et al. 1986, Small 1994); four birds appeared at this site
again in 1993 but apparently did not nest (Yee et al. 1993). Six pairs bred at

Western Birds 27:127-135, 1996

127

BLACK SKIMMER IN CALIFORNIA

the Seal Beach National Wildlife Refuge in Anaheim Bay, Orange County,
in 1987 (McCaskie 1987, B. Massey pers. comm,).

Documentation of colony sizes has varied in detail from year to year. In
California, Black Skimmers have a prolonged breeding season lasting well
into August and September in some years (Grant and Hogg 1976, Schew
and Collins 1991, Stadtlander 1994, Konecny 1995, Molina 1996), and at
least some but not all (Collins pers. obs.) of the late-season nests are the
result of renesting. However, no detailed information on the rate of renesting
is available. Thus, an exact count of the number of nesting pairs at each site

Figure 1 . Breeding colony sites (filled circles) and important winter concentration sites
(hatched circles) of the Black Skimmer in California and northern Baja California.

128

BLACK SKIMMER IN CALIFORNIA

is usually not possible, and only crude estimates have been reported. We
regard the number of nests initiated as the most consistent year-to-year
index of the size of the skimmers’ breeding population, even though it will

Table 1 Number of Pairs or Nest Initiations (*) by
Black Skimmers in California Breeding Colonies

1972-1995

Year

a

KJ

0)

</)

c

o

<0

</)

-o

>

ro

CQ

u

(0

(0

o

u

uo

o

O

CQ

'G

tf>

CO

IB

tt

C

o «

0)

U

>— ■

. o

(0

.a c

3 O
CT O
S3 CO

a

c

<0

tn

cl a

rtj

c n

O

CQ

Cl cd

D Z

<5

cn CQ

S3

1972

5

1973

3

1974

10

1975

9

1976

25

1

1977

100

3

1978

100

6

1979

NI>

14

1980

0

30

1981

0

25

1982

0

35

1983

0

50

1984

0

+ +S

1985

47

150

10*

1986

300

130

60*

2

1987

500

++

106*

ND

1988

100

200

150*

15

1989

0

++

112*

45

1990

100

++

338*

14

1991

80

>157 h

398*

40

1992

100

++

278*

++

1993

300

326

284*

++

(473*)

1994

450

310

353*

++

(420*)

1995

487

>200 h

201*

451'

a Data from Molina (1996).

b Data from H. R. Carter et al. (unpubl. data), Stadtlander (1994),
Konecny (1995), and F. Schaffner, E. Copper, and D. Stadtlander
(pers. comm.).

c Data from E. Burkett, L. Hays, K. Gazzaniga, and M. Taylor (pers.
comm.).

d Data from Layne et al. (1996).

e Data from Whelchel et al. (1996).

■'ND, no data available.

9 ++, birds seen, possibly in large numbers, but no nest-census data
available.

^Minimal count; entire colony not censused.

129

BLACK SKIMMER IN CALIFORNIA

almost certainly exceed the actual number of breeding pairs by an amount
yet to be determined. This is the value, when known, listed in Table 1.

The breeding population of skimmers at the Salton Sea has shown the
most dramatic fluctuations, with more than 100 nests reported by 1977, few
if any nests from 1980 to 1983, and a rebound to a high of over 500 nests
in 1987 (Molina 1996, Table 1). Most of the coastal colonies have shown a
nearly steady year-to-year increase in numbers of nests with occasional
spurts such as that noted at Bolsa Chica, from 1 12 nests in 1989 to 338 in
1990 (Table 1).

The status of the Black Skimmer in adjacent Baja California, Mexico, has
been summarized by Palacios and Alfaro (1992). Skimmers have been
recorded regularly in Baja California since 1979 (Wilbur 1987) and are now
“considered a locally common bird on the northwestern coast of Baja
California, not only in winter but year round” (Palacios and Alfaro 1992).
There have also been winter and breeding-season records of skimmers in
Baja California Sur since 1985 (Palacios and Alfaro 1992, Carmona et al.
1995). The only known Baja California breeding colony is on Montague
Island in the northernmost Gulf of California in the Colorado River delta;
breeding was suspected in 1992 (Palacios and Mellink 1993) and confirmed
(14 nests) in 1993 (Peresbarbosa and Mellink 1994); 21 nests were found in
1994 (Peresbarbosa 1995). Some of the skimmers wintering in northwest-
ern Baja California and nesting on Montague Island were banded in
southern California colonies as chicks (Palacios and Alfaro 1992,
Peresbarbosa and Mellink 1994). Although no nesting has been noted,
skimmers have been observed since 1994 in spring and summer in man-
made ponds at Cerro Prieto, in the Mexicali Valley (K. Radamaker pers.
comm.). The skimmers in Baja California Sur may have originated from
mainland colonies in Sonora or Sinaloa, Mexico (Palacios and Alfaro 1992,
Carmona et al. 1995).

Away from the breeding colonies and known coastal wintering sites, Black
Skimmers are noted regularly along the coast from San Diego north to
Monterey Bay. For example, there are 37 records of single skimmers or
small groups (up to four) in coastal San Luis Obispo County since 1977, all
but seven of which were between March and October (T. Edell pers. comm.).
The first sighting in northern California was of a single bird at Bodega Bay,
Sonoma County, 24 July 1971 (DeSante and LeValley 1971); more
recently, birds have also reached coastal San Mateo County (Yee et al.
1995b, c), Marin County (Yee et al. 1993, 1994, 1995a), and coastal
Sonoma County again (Bailey and Fix 1994), as well as a number of sites on
San Francisco Bay. All records on the immediate coast of northern Califor-
nia are from 22 May to 14 August. The only Channel Islands record is of
four individuals seen on Santa Catalina Island, 28 June 1995 (McCaskie
1995b).

Rosenberg et al. (1991) summarized five records (involving six individuals)
for the lower Colorado River valley; the first record for that region was in
1977, and all records fall between 16 May and 3 September. Other inland
sightings for southern California are of a juvenile near Lakeview and at Lake
Elsinore, Riverside County, 27 August to 4 September 1978 (Garrett and
Dunn 1981), two at Twentynine Palms, San Bernardino County, 25 August

130

BLACK SKIMMER IN CALIFORNIA

1994 (McCaskie 1995a), and two at China Lake Naval Weapons Center,
extreme northeastern Kern County, 28 July 1990 {McCaskie 1990). At
least the first of these inland records suggests an occasional overland route
from the Salton Sea to the coast. Additional records of Black Skimmers at
inland sites, in Durango and Jalisco, Mexico, have been reported by Williams
(1982).

Unlike Atlantic-coast populations nesting north of North Carolina (Burger
and Gochfeld 1990, Gochfeld and Burger 1994), Black Skimmers breeding
in California are not all long-distance migrants; many winter locally in
southern California (Gazzaniga 1995, 1996). Wintering concentrations of
skimmers have been noted at Santa Barbara, Santa Barbara County, Seal
Beach and Upper Newport Bay, Orange County, and Mission Bay and San
Diego Bay, San Diego County (Gazzaniga 1995, 1996) (Figure 1). More
distant locations include Ensenada and San Quintin in Baja California,
Mexico (Palacios and Alfaro 1992). Observations of banded birds have
indicated that a few skimmers from the Salton Sea winter on the coast
(Molina 1996). Individuals banded at Bolsa Chica have been observed in
winter flocks from Santa Barbara south to San Quintin (Gazzaniga 1995,
1996), and birds from San Diego have been observed in both Long Beach
and Santa Barbara (M. Taylor and C. Collins unpubl.) and Ensenada (K.
Molina pers. comm.). Two of the chicks banded in San Francisco Bay in

1995 (Layne et al. 1996) have been observed in winter flocks in southern
California: one was observed in Santa Barbara on 11 February 1996 (K.
Molina and K. Garrett pers. obs.), another in Long Beach 4-21 April 1996
(Taylor and Collins pers. obs.). Observations of uniquely banded skimmers
have demonstrated a degree of year-to-year overwintering site fidelity as well
as some intraseasonal movements between sites (Gazzaniga 1995, 1996).
Further observations of these uniquely color-banded birds will aid in quanti-
fying the pattern of juvenile and adult survival during the winter (Gazzaniga
1995, Taylor and Collins unpubl.).

Skimmers banded as chicks at Bolsa Chica have been observed as
breeders in colonies at San Diego (J. Konecny pers. comm.), Seal Beach (B.
Massey pers. comm.), and Montague Island (Peresbarbosa and Mellink
1994). Although the colonies are occupied annually, these observations of
banded birds suggest reduced philopatry, at least among prebreeders, and a
noticeable amount of mixing of birds among the several breeding colonies.
Breeding at two years of age was documented for a banded skimmer nesting
at Seal Beach in 1987 (B. Massey pers. comm.).

The Black Skimmer is now a well-established resident breeding species in
southern California and Baja California. Further population increases at
both some of the well-established colonies and also at the three newly
colonized sites (Layne et al. 1996, Whelchel 1996) over the next few years
seem likely. The formation of additional breeding colonies, however, is more
apt to depend on the availability of suitable sites sufficiently protected from
human disturbance. Black Skimmers on both the Atlantic and Pacific coasts
frequently nest in association with various species of terns ( Sterna spp.)
(Gochfeld and Burger 1994, Collins et al. 1991), and such an association
may prove to be a pre- or co-requisite condition for the establishment of new
skimmer colonies in California and Baja California.

131

BLACK SKIMMER IN CALIFORNIA

ACKNOWLEDGMENTS

We are grateful for the permission granted us to monitor skimmer populations in
the several breeding colonies. We are also indebted to the numerous individuals
mentioned above, and particularly Guy McCaskie, who have so freely shared their
field observations of skimmers with us and thereby made this a much more complete
overview. Kathy Molina and Philip Unitt made helpful comments on earlier drafts of
this paper, and Mark C. Wimer prepared Figure 1.

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Coast region. Am, Birds 47:449-452.

Yee, D. G., Fix, D., and Bailey, S. F. 1994. The summer season. Middle Pacific Coast
region. Natl, Audubon Soc. Field Notes 48:984-987.

Yee, D. G., Bailey, S. F,, Fix, D., and Singer, D. S. 1995a. Middle Pacific Coast
region. Natl. Audubon Soc. Field Notes 49:95-99.

Yee, D. G., Bailey, S. F., and Singer, D. S. 1995b. The winter season. Middle Pacific
Coast region. Natl. Audubon Soc. Field Notes 49:304-307.

Yee, D. G., Bailey, S. F., and Singer, D. S. 1995c. The summer season. Middle Pacific
Coast region. Natl. Audubon Soc. Field Notes 49:975-979.

Accepted 27 April 1996

Appendix, Specimens of the Black Skimmer from California. CSULB,
California State University, Long Beach; CSUN, California State University,
Northridge; LACM, Natural History Museum of Los Angeles County;
SBCM, San Bernardino County Museum; SDNHM, San Diego Natural
History Museum. Inquiries to Louisiana State University, the Museum of
Vertebrate Zoology, University of California, Berkeley, and the University of
California, Los Angeles, revealed no Black Skimmer specimens.

South end Salton Sea, Imperial County

28 Apr 1979, adult, mount, SBCM M50894
19 Jul 1991, juv., study skin, LACM 106066
19 Jul 1991, chick, in alcohol, LACM 106446
31 Jul 1991, chick, in alcohol, LACM 106447
31 Jul 1991, chick, in alcohol, LACM 106448
31 Jul 1991, chick, in alcohol, LACM 106449
31 Jul 1991, chick, in alcohol, LACM 106450
31 Jul 1991, chick, in alcohol, ACM 106451
31 Jul 1991, chick, in alcohol, LACM 106452
31 Jul 1991, chick, in alcohol, LACM 106453
4 Jun 1993, adult, skeleton, LACM 107571
17 Jul 1993, chick, study skin, SDNHM 48801
19 Sep 1993, juv., flat skin/skeleton, LACM 107762
13 Aug 1994, juv., study skin, LACM 108428
3 Sep 1994, juv., study skin, LACM 108429
3 Sep 1994, juv., study skin, LACM 108430
12 Aug 1994, adult, skeleton, LACM 108447
12 Aug 1994, adult, skeleton, LACM 108448
3 Sep 1995, juv., study skin, LACM 108946
North end Salton Sea, Riverside County

3 Jul 1968, adult, study skin, LACM 76788
17 May 1970, adult, mount, SBCM S33298
24 Jul 1993, juv., study skin, ACM 107763
7 Aug 1993, juv., study skin, ACM 108431
7 Jul 1994, adult, skeleton, ACM 108446

134

BLACK SKIMMER IN CALIFORNIA

San Diego Bay, San Diego County

31 Jul 1977, adult, study skin/partial skeleton, SDNHM 40388
6 Jul 1978, imm., skeleton, SDNHM 42107
22 Jul 1990, postjuv., study skin/partial skeleton, SDNHM 47409
5 Jul 1994, adult, skeleton, SDNHM 49011
Mission Bay, San Diego County

22 Mar 1989, adult, study skin/partial skeleton, SDNHM 45694
Jan 1994 (exact date unknown), age?, skeleton, SDNHM 48839
Bolsa Chica, Orange County

Date unknown, chick, in alcohol, CSULB 6465
Date unknown, chick, in alcohol, CSULB 6466
28 Jun 1986, chick, study skin, CSULB 6482
10 Sep 1987, juv., study skin, CSULB 6783
16 Jun 1989, adult, skeleton, CSULB 7617
15 Aug 1989, adult, skeleton, CSULB 7166
20 Aug 1989, adult, skeleton, CSULB 7188
20 Jul 1990, adult, skeleton, CSULB 7398
31 Aug 1991, chick, study skin, CSULB 7555
5 Jun 1994, adult, skeleton, CSULB 7600
Terminal Island, Los Angeles County

10 Mar 1993, adult, study skin, CSUN 1282

Black Skimmer

Sketch by Tim Manolis

135

OVERWINTERING OF BLACK SKIMMERS
IN CALIFORNIA: SITE FIDELITY
AND INTER-SITE MOVEMENTS

KATHLEEN T. GAZZANIGA, Department of Biology, California State University,
Long Beach, California 90840

During the last two decades, Black Skimmers ( Rynchops rtiger) have
become increasingly common along the southern California coast. They are
now found year-round in southwestern California (Collins et al. in press) and
in northwestern Baja California (Palacios and Alfaro 1992). Little detailed
information has been published, however, about their winter distribution and
abundance in this region. Most previous studies of the Black Skimmer have
focused on the breeding season, with little attention paid to survival,
behavior, and habitat requirements in the wintering areas. Since the difficul-
ties skimmers face on the breeding grounds (e.g., predation, human distur-
bance, parasitism, disease, inclement weather, contaminants, entangle-
ments, and food shortage) may affect them also on the wintering grounds,
Burger and Gochfeld (1990) suggested that further studies of wintering birds
are needed. They suggested also that most mortality of adults takes place
away from the breeding grounds and that young birds are particularly
vulnerable during their first winter.

Because of their long migrations and an inability of researchers to follow
specific individuals or populations, the winter ecology of the Black Skimmer
in the eastern U.S. has been little studied. With just a few breeding colonies
and extensive overwintering, the Pacific coast offers a unique opportunity to
study the winter ecology of Black Skimmers from known colonies (Gazzaniga
1995). In this article, I delineate the skimmer’s important wintering sites,
examine its seasonal abundance on these wintering areas, document disper-
sion of skimmers among sites, and examine winter site fidelity.

METHODS

The principal colony of origin of the skimmers followed in this study is at
Bolsa Chica Ecological Reserve, Huntington Beach, California (33° 41' 30"
N, 118° 03' 00" W) (Figure 1). In 1988, Charles T. Collins began banding
skimmers at Bolsa Chica with the goal of determining whether young
returned to the natal colony. Marking consisted of colored tape, denoting
the annual cohort, placed around a United States Fish and Wildlife Service
numbered aluminum band. Beginning in 1992, chicks were not only color-
banded by year but also marked individually with a specially constructed
band of laminated plastic into which an alphanumeric code had been etched.
The plastic band was placed on the tarsus and then heat-sealed with a hand-
held butane burner. These bands were later read with a telescope or
binoculars on birds in winter roosting flocks. Older chicks were aged and
sexed by wing measurements and body weight (Schew and Collins 1990).

I established six survey sites (Figure 1) and organized a network of seven
cooperating observers. From September to May, from 1992 to 1995, Santa

136

Western Birds 27:136-142, 1996

OVERWINTERING OF BLACK SKIMMERS

Figure 1 . Sites of regular surveys for wintering Black Skimmers. 1 , beach front and
harbor sand spit. East Beach, city of Santa Barbara, Santa Barbara County. Monitor:
Florence Sanchez. 2, coastal sand spit, mouth of Callegaus Creek, Point Mugu Naval
Air Station, Ventura County. Monitors: Tom Keeney and Tiki Baron. 3, beach front,
city of Seal Beach, near the mouth of the San Gabriel River, Orange County. Monitor:
Kathleen Gazzaniga. 4, estuarine sand spit, near mouth of Big Canyon and Shellmaker
Island, Upper Newport Bay, Newport Beach, Orange County. No specific monitor. 5,
beach front, Kendall-Frost Ecological Reserve, Mission Bay, San Diego, San Diego
County. Monitor: Virginia “Ginger” Johnson. 6, sand spits near Cemetery Point,
Punta Azufre, and Sand Point, all in San Quintin Bay, Baja California, Mexico.
Monitors: Eduardo Palacios, Lucia Alfaro, and David Ward and associates.

137

OVERWINTERING OF BLACK SKIMMERS

Barbara (Santa Barbara County) and Seal Beach (Orange County) were
surveyed weekly, Point Mugu (Ventura County) and Mission Bay (San Diego
County) at least monthly, and Upper Newport Bay (Orange County) and San
Quintin (Baja California) irregularly.

To describe the pattern of the skimmers’ use of each site, I devised an
“observation index” to quantify the likelihood that a particular individual will
be seen. The observation index is defined as the percentage of times an
individual bird was seen at a site during the interval between the first and last
sightings in any single winter.

RESULTS

Skimmers roosted extensively at all sites monitored during this study
except Upper Newport Bay; each site was occupied during the entire winter
season. The results of the censuses for these five sites are presented in Figure
2. In addition to these sites, wintering skimmers were sighted at Ensenada
(Baja California, Mexico), the mouth of the Santa Margarita River, Camp
Pendleton (San Diego County), Shoreline Aquatic Park, Long Beach (Los
Angeles County), Malibu Beach (Los Angeles County), and Princeton
Harbor (San Mateo County). All of the winter sightings of roosting Black
Skimmers were near beaches and estuaries, usually with gulls and terns,
occasionally with shorebirds.

At Santa Barbara, in 1992, skimmers first arrived in September, in-
creased steadily until they reached their peak (117) in February 1993, and
then decreased during March and April. Only two, a banded yearling and an
adult, remained through the summer. During the 1993-1994 season,
skimmers arrived sooner, attained greater numbers, and left later than in the
previous year. During the summer of 1994, five skimmers remained in Santa
Barbara; two were unbanded yearlings and three were adults.

At Point Mugu, the first counts each season were not taken until October;
therefore, exact arrival dates are not known. Data were recorded inconsis-
tently from January to June of 1993. During each season, the skimmers
reached their peak (139 in 1992, 168 in 1993) in October and tapered off
until December (no data were taken in December of 1993), then increased
again in January, and tapered off from March to June.

At Seal Beach, the first skimmers arrived each season in September,
increased until they reached a peak (200) during November and December,
and then tapered off from January through March. There was a slight
increase in numbers during May of both years.

At Mission Bay, there was an increase in numbers each season during
October and November. The arrival date in 1992 is unknown; nonetheless,
numbers of skimmers were stable by November and began to decrease from
January to February. In 1993, skimmers began to arrive in September,
reached their peak (140) during October and November, and began to
decrease in January.

At San Quintin, in 1992, the first skimmers appeared in September,
followed by a steady increase in numbers until November. Then, although
there were wide monthly variations, the mean numbers roughly stabilized
until April, after which they started to decrease. The highest count was of

138

Santa * Point Mugu • Seal Beach — San Diego a San Quintin

Barbara

OVERWINTERING OF BLACK SKIMMERS

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139

Figure 2. Mean numbers of Black Skimmers observed by month, 1992-1994, at five Pacific coast sites

OVERWINTERING OF BLACK SKIMMERS

265 on 18 February 1993. No adequate data were taken for this site during
the winter of 1993-94.

For all sites except San Quintin, I used a t test to assess the difference in
skimmer numbers for the winters of 1992-93 and 1993-94. At Santa
Barbara, there was a significant increase (t = -5.93 , p < 0.01); at all other
sites, there was no significant difference between the two years.

At Bolsa Chica Ecological Reserve, 55 skimmers in 1992, 69 skimmers in
1993, and 14 in 1994 were color-banded. In 1992, 31 (56.4%) of these
birds were seen at least once during their first winter after banding. Twelve
(22%) of these were seen in their second winter, and five (9%) were seen in
their third winter. Of the young banded in 1993, 38 (55%) were seen at least
once their first winter. Of the young banded in 1994, 14 (100%) were seen
at least once their first winter.

Of the surviving 1992 cohort, 20 (65%) were seen at only one site over
their first winter season, while the remaining 1 1 (35%) were seen at more
than one site. During their second winter, 10 (84%) were seen at one site,
while two (16%) were seen at more than one site. Of the birds hatched in

1993, 23 (61%) were seen at one site during their first winter, while the
remaining 15 (39%) were seen at more than one site. Of those hatched in

1994, 12 (86%) were seen one site during their first winter, while the
remaining two (14%) were seen at more than one site.

Of the surviving 1992 cohort, in their second winter, six (50%) of the birds
returned to the same site as in their first winter, three (25%) moved to a new
site, and three (25%) moved among sites during both winter seasons. In their
third winter, three (60%) of the birds returned to the same site and two (40%)
moved to a new site. Of the surviving 1993 cohort, in their second winter,
12 (60%) returned to the same site, five (25%) moved to a new site, and
three (15%) moved among sites during both years.

I figured the observation index (the percentage of times an individual bird
was seen at a site during the interval between when it was first seen and
when it was last seen) for all sites, though at Point Mugu, Upper Newport
Bay, Mission Bay, and San Quintin repeated sightings of individual birds
were too few for this index to be useful. I did not include birds that were seen
only once, which would have greatly inflated the index for all sites. During
the 1992-93 season, the index for Santa Barbara was 65.4%; that for Seal
Beach, 52.2%. During the 1993-1994 season, the indices were 74.6% for
Santa Barbara, 83.5% for Seal Beach. These figures indicate that if a bird is
in the area, there is a high likelihood that it will be observed repeatedly.

DISCUSSION

The Princeton Flarbor sighting (260 kilometers to the north of Bolsa
Chica), 20 February 1993, was one of the northernmost records of the
Black Skimmer in California to date (see also Layne 1996). This bird was
banded at Bolsa Chica Ecological Reserve in 1992 and seen 12 times in
Santa Barbara between 20 October 1992 and 10 February 1993; it was not
resighted after 20 February 1993. At Seal Beach during the 1992-93
season numbers decreased in December, corresponding to a movement of
marked birds from Seal Beach to Santa Barbara. In addition, one bird moved

140

OVERWINTERING OF BLACK SKIMMERS

from Seal Beach to Ensenada and two moved from Seal Beach to Upper
Newport Bay. At this time, there were a number of winter storms and a
sharp decrease in sightings of young skimmers, implying that many died.
Skimmers appeared to have a higher mortality rate coupled with, and in part
due to, a higher dispersal rate among sites during this period of stormy
weather. Skimmers may be moving from the Bolsa Chica and Newport Bay
breeding colonies to Seal Beach at the onset of winter, then leaving the area
for other sites later in the season, thereby adding another component to the
decrease in numbers in midwinter at Seal Beach.

The movements of young skimmers often corresponded with increases
and decreases in the total number of skimmers at each site. This may signify
that adults and young are moving from site to site together. Therefore, the
site fidelity and movements 1 describe for the banded young may be
representative of the skimmer population as a whole.

At Point Mugu during the 1993-94 season, there was a significant
decrease in numbers of skimmers during December. This pattern was unlike
that at any other site monitored during this study, except Seal Beach. The
decrease may have been due to weather or food availability but is more likely
explained by the sampling technique at this location. The Point Mugu site is
located on a naval air station in which surveyors have been restricted from
some areas. Skimmers may have been roosting in these unsurveyed areas
and may not, in fact, have completely left the area. Unfortunately, data from
the first season were insufficient for comparison with the second season to
show if there was a similar decrease during December 1992. More complete
surveys of the Point Mugu Naval Air Station are needed for reliable
conclusions about the overall use of this site by wintering skimmers to be
drawn.

Numbers at Santa Barbara increased significantly from winter 1992-93
to winter 1993-94, while those at all other sites remained nearly the same.
The wintering areas farther south may already be well established, whereas
the northern sites are not as stable (or more dynamic) because of the
relatively recent range expansion. Other factors such as weather and food
resources may also come into play; these were not examined during this
study. Although my study provides a first analysis of the winter population
dynamics of the Black Skimmer in southern California, investigation of all
aspects of the species’ biology remains appropriate as it continues to expand
its range northward.

SUMMARY

Beginning in 1992, juvenile Black Skimmers at Bolsa Chica Ecological
Reserve, Orange County, were equipped with uniquely numbered color
banded so their subsequent movements could be tracked. At Santa Barbara,
Point Mugu, Seal Beach, and Mission Bay in Upper California and at San
Quintin in Baja California regular observations made from September to
May in 1992-93, 1993-94, and 1994-95. Skimmers arrived at their
wintering sites during September and October, reached peak population
levels in midwinter, then departed during April and May. Site fidelity was

141

OVERWINTERING OF BLACK SKIMMERS

high; over 50% of each cohort remained at one site through the winter,
although there was also some regular movement between sites within the
winter season.

ACKNOWLEDGMENTS

I thank Lucia Alfaro, Tiki Baron, Charles Collins, Virginia Johnson, Tom Keeney,
Eduardo Palacios, Florence Sanchez, and David Ward for their valuable field assis-
tance, and Kimball Garrett and Charles Collins for their useful comments on an earlier
draft of the manuscript.

LITERATURE CITED

Burger, J., and Gochfeld, M. 1990. The Black Skimmer: Social Dynamics of a
Colonial Species. Columbia Univ. Press, New York.

Collins, C. T., and Garrett, K. G. 1996. The Black Skimmer in California: An
overview. W. Birds 27:127-135,

Gazzaniga, K. T. 1995. Distribution and dispersal of Black Skimmers ( Rynchops
niger) in southern California. M. S. thesis, Calif. State Univ., Long Beach.

Layne, V. L., Richmond, R. T., Metropulos, P. T. 1996. First nesting of Black
Skimmers on San Francisco Bay. W. Birds 27:159-162.

Palacios, E., and Alfaro, L. 1992. Occurrence of Black Skimmers in Baja California.
W. Birds 23:173-176.

Schew, W. A., and Collins, C. T. 1990. Age and sex determination in Black Skimmer
chicks. J. Field Ornithol. 61:174-179.

Accepted 20 April 1996

142

POPULATION STATUS AND BREEDING BIOLOGY
OF BLACK SKIMMERS AT THE SALTON SEA,
CALIFORNIA

KATHY C. MOLINA, Salton Sea National Wildlife Refuge, P. O. Box 120, Calipatria,
California 92233

Black Skimmers ( Rynchops niger) are widely distributed along the eastern
and southern coasts of North America. Along the western coast their
distribution is more restricted, ranging from Mexico north to southern
California (American Ornithologists’ Union 1983, Collins and Garrett
1996); a few pairs have nested recently in coastal northern California (Yee
et al. 1995, Layne et al. 1996). The ecology, reproductive biology, and
behavior of Black Skimmer populations along the Atlantic coast and Gulf of
Mexico have been the subject of numerous investigations (Erwin 1977,
1979, Loftin 1982, Custer and Mitchell 1987, Quinn 1989, 1990, Burger
and Gochfeld 1990) and have been reviewed by Gochfeld and Burger
(1994). The potential effects of environmental contaminants on these
populations have also been described in several recent publications (Blus et
al. 1980, White et al. 1984, King et al. 1986, King 1989, and Burger and
Gochfeld 1992). Except by Schew and Collins (1990, 1991), little informa-
tion has been published on the Pacific coast breeding populations. Black
Skimmers nesting at the Salton Sea, a large interior saline basin in extreme
southern California, have received only cursory attention since the establish-
ment of breeding in 1972 (McCaskie et al. 1974, Grant and Hogg 1976,
Grant 1978). This unique interior population is well established, having
persisted for nearly 25 years. In this paper I describe the nesting habitat,
population trends, phenology, clutch size, and hatching success of Black
Skimmers nesting at the Salton Sea during the 1990s.

STUDY AREA AND METHODS

The Salton Sea lies within the Colorado Desert of Riverside and Imperial
counties in southeastern California (Figure 1). Covering only a portion of the
bed of ancient Lake Cahuilla and at an elevation of 84 m below sea level, the
Salton Sea measures some 48 km in length and 15 km across its greatest
width. Today this closed, saline basin is maintained primarily by an influx of
agricultural and industrial tailwater. Setmire et al. (1993) estimated over one
million acre-feet of water to enter the Salton Sea annually through an
extensive system of drains that either terminate directly into the sea or flow
into it via the Alamo and New rivers. The Whitewater River at the north end
similarly directs agricultural waste water and storm runoff from the Coachella
Valley into the sea. Several minor natural drainages that provide relatively
fresh seasonal flows to the basin are San Felipe Creek and Wash along the
western perimeter and Salt Creek along the eastern shore. Maximum sea
surface elevations occur in spring, while minimum elevations occur in the
fall. During the last decade, the mean sea elevation has been 69.2-68.7 m
below sea level (Imperial Irrigation District). Hagar and Garcia (1988)

Western Birds 27:143-158, 1996

143

BLACK SKIMMERS AT THE SALTON SEA

reported maximum salinity levels for the Salton Sea to be about 44 parts per
thousand; water near river mouths is fresher. Sea surface temperatures may
consistently exceed 30° C from spring through fall (Carpelan 1961).
Frequently following hot, windless days in summer, the oxygen in the water
is depleted, periodically killing fish. The Imperial Valley receives virtually no
rainfall in summer and minimal cloud cover (Ermak et al. 1976). Daily
ambient temperatures commonly exceed 40° C throughout the nesting
season, thus characterizing the Salton Sea as one of the harshest environ-
ments in which waterbirds nest (Grant 1982).

To determine nesting phenology and reproductive success, I surveyed
traditional and other suitable breeding sites for evidence of nesting at weekly
intervals beginning in mid-March of each year. I observed colonies from a
distance until I believed incubation was well advanced. During visits to the
colony, I marked nests individually, as encountered, with a section of PVC
tubing 10-15 cm long and a numbered plastic tag. Nest contents and their
condition were recorded on each visit. To minimize colony disturbance and

144

BLACK SKIMMERS AT THE SALTON SEA

possible abandonment, I visited colonies at weekly or near-weekly intervals.
Because all colonies (except at Rock Hill) are on private lands, and mamma-
lian predators including skunks ( Mephitis mephitis ), coyotes ( Canis latrans),
raccoons (Procyon lotor), and feral cats ( Felis catus) are abundant, I
refrained from isolating nests within enclosures. Mean clutch sizes for each
year were compared by means of a Kruskal-Wallis test. Single-egg clutches
were excluded from these analyses as they were likely incomplete. A clutch
was considered successful when at least one egg hatched. Hatching was
determined on subsequent visits by the presence of young and relatively
immobile chicks and a corresponding reduction in clutch size. This cautious
approach contributed to the large number of nests of unknown fate in all
years. Beginning in 1993, I marked young with U.S. Fish and Wildlife
Service stainless steel bands and Darvik plastic color bands to distinguish
annual cohorts.

RESULTS

Colony Sites and Utilization

Skimmers have established colonies at both the north and south ends of
the sea. Although they are known to have nested at other more ephemeral
or poorly defined sites, they used seven locations (Figure 1) from 1991 to
1995. With the exception of Mullet Island, all sites are less than 1000 rn 2 in
area. Except where otherwise noted, skimmers have nested at all sites since
the initiation of this study.

The Johnson Street site, near the Whitewater River mouth, consists of
two parallel and two perpendicular remnants of earthen levees, isolated
from the shoreline by rising sea surface elevation. The skimmers here usually
nest on compacted earth at the levee plateaus, which rise several meters
above sea level. The height of these plateaus affords protection against
wind-generated wave action and inundation of nests. Mullet Island (Figure 2),
with relatively high relief and large areas for nesting, lies 2.5 km north of the
Alamo River mouth. Skimmers use the bare earthen slopes and terraces.
Nests are placed upslope from barnacle beaches at 3-4 m from the water’s
edge. Morton Bay is an eroded impoundment near the Alamo River. The
substrates of both of its low-lying nesting islets consist of highly silty clay
soils. A nearly continuous perimeter levee provides some protection from
wave action and inundation of the colony site. Near Rock Hill, a series of
small flat earthen islets within a freshwater impoundment was first available
for nesting in 1995. Located within the Salton Sea National Wildlife Refuge,
Rock Hill is the only colony site under active management (control of water
level and protection from disturbance). Adjacent to Obsidian Butte is a low-
lying nearshore site consisting of a rocky perimeter and an interior nesting
beach composed of crushed barnacle. This islet is often completely inun-
dated during high winds. Ramer Lake, a California Department of Fish and
Game recreation area, lies 5 km southeast of the Salton Sea shoreline and
adjacent to the Alamo River. Here, skimmers nest on small man-made

145

BLACK SKIMMERS AT THE SALTON SEA

Figure 2. Aerial view of Mullet Island. Alamo River mouth in background.

Photo by Kathy Molina

Figure 3. Black Skimmer nesting habitat near Elmore Ranch on western shoreline,
Salton Sea, 1992.

146

Photo by Kimball Garrett

BLACK SKIMMERS AT THE SALTON SEA

compacted earth islets. They first colonized Ramer Lake in 1995, although
these islets had been formed three years earlier. The potential for the colony
to be disturbed is high owing to heavy levels of recreational use. The colony
at Elmore Ranch (Figure 3), on the southwest shore of the sea, lies on a
single earthen levee remnant that is highly susceptible to wave action,
erosion, and inundation.

To examine site fidelity, I report the pattern of colony occupation for
1991 through 1995. Black Skimmers did not use any single site continu-
ously throughout the study period. Johnson Street and Morton Bay had the
highest rates of occupation (Figure 4). The Ramer Lake and Rock Hill sites
are omitted from Figure 4 because the former site's population was small
and because the latter was available only one year. Successful colony sites,
those that did not experience widespread desertions or nest failures, were
reused the following year 82% of the time. Failed colony sites were still
reoccupied in the following year 33% of the time.

During the same 5-year period, the sites of earliest nesting were also
inconsistent (Figure 4). The novel Rock Hill site was occupied immediately
after the creation of nesting islets in 1995. Rates of earliest occupation are
distributed almost evenly among three of the five sites, suggesting low site
fidelity.

10 J

0.9

552 OCC RATE Egg early occ rate

Figure 4. Occupation rates (diagonal bars) and rates of earliest occupation (hatched
bars) for five long-standing Black Skimmer nesting sites around the Salton Sea, 1991-
1995. Excludes Ramer Lake and Rock Hill sites.

147

BLACK SKIMMERS AT THE SALTON SEA

Population Size

McCaskie and Suffel (1971) first described the appearance of Black
Skimmers at the Salton Sea in the summer of 1968; the nesting of five pairs
was documented in 1972 (McCaskie et al. 1974). Based on data published
in American Birds and from this study, the trend in breeding population size
over the last 23 years (Figure 5) is a dynamic one. Peak numbers of pairs
occurred in 1987 and again in 1995. Although skimmers nested in 1979,
an estimate of the number of pairs is not available. Black Skimmers were
thought not to be breeding at the Salton Sea from 1980 to 1984.

Phenology

Black Skimmers begin arriving at the Salton Sea in early to mid- April, with
3 April being the earliest arrival date during this study period; numbers
increase through June. Skimmers form loose aggregations and often roost
at locations that later serve as nesting sites. Colony sizes range from 10 to
several hundred pairs; colonies consisting of 50-200 pairs are most com-
mon. With few exceptions, Black Skimmers nested near nesting Gull-billed
( Sterna nilotica) and/or Caspian terns (S. caspia).

Figure 5. Trend in the number of breeding pairs of the Black Skimmer at the Salton
Sea, 1972-1995, based on data from American Birds and the present study.
Skimmers were present at the Salton Sea in 1979 and probably nested, but an
estimate of the number of pairs is not available. Skimmers were scarce from 1980 to
1984 and in 1989 and were believed not to be breeding in those years.

148

BLACK SKIMMERS AT THE SALTON SEA

Although egg-laying generally commences in late May and continues
through late August (Figure 6), a well-defined peak of nest initiation extends
from late June and late July. Every year, there has been a small wave of nest
initiations in September, suggesting renesting attempts of adults or perhaps
first attempts of younger birds.

Ffatching commences in mid-June and continues through early Septem-
ber with a peak in late July and August. Fledging first occurs by late July or
early August and continues through October. Nesting sites frequently serve
as post-breeding roosts until adults and young begin dispersing to wintering
grounds in September and October. Reports of Black Skimmers from the
Salton Sea in winter are few; however, observations of several juveniles in
late December and of birds in early March suggest that some skimmers
overwintered in 1995-1996 along with an unusually large number of Brown
Pelicans ( Pelecanus occidentalis), perhaps in response to abundant food
supplies.

Reproductive Parameters

The mean clutch size for Salton Sea skimmers (Table 1) ranged from 2.97
eggs in 1994 to 3.29 eggs in 1995. Mean clutch size was significantly lower
in 1994 than in 1993 and 1995 (Kruskal-Wallis, p < 0.001).

To determine hatching success (Table 2), I monitored the outcome of over
200 nests each year from 1993 to 1995. The proportion of nests with

MONTH

Figure 6. Pattern of Black Skimmer nest initiation at the Salton Sea, 1993-1995.
See text for methods. Sample sizes for each year in parentheses upper right.

149

BLACK SKIMMERS AT THE SALTON SEA

Table 1 Clutch sizes of Black Skimmers
Nesting at the Salton Sea, 1993-1995

1993

1994

1995°

Mean

3.15

2.97 b

3.29

Standard deviation

0.64

0.65

0.65

Range

2-4

2-5

2-6

Sample size

209

354

185

a Ramer Lake colony excluded since first visited after
hatching.

b Mean differs from all others, p < 0.001, Kruskal-
Wallis.

known fate among the total nests monitored ranged from 56% to 76%. The
number of successful nests reported, therefore, is a minimum value. The
hatching success for nests of known fate was highly variable from year to
year, ranging from 27% in 1994 to 71% in 1993.

In 1993 and 1994 large colonies at Morton Bay experienced complete
hatching failures despite continual attendance of nests throughout the
season. A large proportion of clutches were found cemented to the bottom
of the bare scrape. Here the substrate consisted of silty clay and many
embedded eggs also had dents and cracks. My attempts to dislodge clutches
often resulted in damage to the eggs. In 1995 Johnson Street also experi-
enced a widespread nesting failure. This failure differed from the failures at
Morton Bay in that eggs remained movable within the scrape and exhibited
little cracking or denting.

Since 1993, 622 young Black Skimmers have been banded at the Salton
Sea. With constant effort over the last three seasons, I banded 228 young in
1993, 90 in 1994, and 304 in 1995. Quantitative information on annual
fledging success is limited.

Since 1993 I have observed a few juveniles with defective wing develop-
ment characterized by loss of primary feather shaft integrity and by a
possible rotation of the wrist joint (Figure 7). I estimated this condition to
occur in 1-2% of the banded juveniles annually.

Table 2 Measures of Black Skimmer Hatching Success at the
Salton Sea, 1993-1995

1993

1994

1995

Total nests monitored

219

377

225

Nests of known fate (% of total)

139 (63%)

211 (56%)

171 (76%)

Successful nests

99

57

113

Failed nests

40

140

58

Percent success

71%

27%

66%

150

BLACK SKIMMERS AT THE SALTON SEA

Figure 7. Black Skimmer near fledging age with feather/wing deformity (at right) at
Obsidian Butte, 1994.

Photo by Kimball Garrett

DISCUSSION

The variation in nest-site fidelity of Salton Sea Black Skimmers is charac-
teristic of populations nesting in dynamic environments (Burger 1982).
Fluctuating sea levels may affect low-lying sites near shore, by either
inundation or by enhancing connectivity to the mainland (and increasing
susceptibility to predation) during a drop in sea level. Morton Bay and
Obsidian Butte were not used in 1995, a year when the level reached a 20-
year maximum. Levees protecting the low-lying islets of Morton Bay were
breached early in the season, and the nesting beaches of Obsidian Butte
were inundated by wind-generated wave action through most of the nesting
season.

The immediate colonization of novel nesting sites and the subsequent
reoccupation of some previously unsuccessful sites suggests that optimal
nesting habitat is limited at the Salton Sea. Black Skimmers formed a large
colony of some 400 pairs at the Rock Hill impoundments in Salton Sea
National Wildlife Refuge for the first time in 1995. Colonization of Rock Hill
is significant in that it is the only site actively managed for colonial ground-
nesting birds. Also in 1995, skimmers established a small colony of about 10
pairs at Ramer Lake, a popular recreation area managed by the California

151

BLACK SKIMMERS AT THE SALTON SEA

Department of Fish and Game; it is the first documented colony of Black
Skimmers nesting away from the Salton Sea’s perimeter.

Because estimates of population size since the early 1970s have been
generated primarily from casual observations rather than from focused
censuses, one may ask whether these numbers accurately reflect the true
population. Several factors may explain this pattern of fluctuating popula-
tion size at the Salton Sea. A graph of sea level versus the skimmer
population (Figure 8) suggests an inverse relationship between these two
variables during the late 1970s and early 1980s. The rapid and constant rise
in sea level may have rendered many existing low-lying sites unsuitable for
nesting. During the increase of sea level in the 1990s, however, the
relationship between the two variables was positive. This change may be
explained by a decrease in disturbance from recreational fishing and a
resultant shift to novel nesting habitat. Red Hill Marina is the single most
important boat launching ramp at the south end of the Salton Sea and is only
3 km from Mullet Island. Colonization of Mullet Island by larids was not
documented until 1992, although the island has been continuously isolated
since at least the early 1950s. Local folklore describes Mullet Island as an
anchorage popular with fishermen. A comparison of the marina’s activity
from 1987 through 1994 (Figure 9) and the population of nesting skimmers
demonstrates an inverse relationship between population size and the

# OF PRS -e- SURF. ELEV.

Figure 8. Number of breeding pairs of the Black Skimmer (filled squares) and Salton
Sea surface elevation in June (open squares), 1972-1995. Sea-surface elevation data
from Imperial Irrigation District.

152

ESTIMATE OF NUMBER OF PAIRS

BLACK SKIMMERS AT THE SALTON SEA

number of boat launches. The popularity of the sportfishery peaked in
1988, declined precipitiously the following year, and has continued to
decline since. The diminished sportfishery, resulting in decreased levels of
disturbance at or near Mullet Island, suggests a plausible explanation for the
skimmers’ increase despite rising sea level.

The nesting schedule of Salton Sea skimmers is similar to that reported for
coastal California (Schew and Collins 1991) and for some Gulf of Mexico
and Atlantic coast populations (Stewart and Robbins 1958; Portnoy 1977)
but differs markedly from peak nest initiation periods of late April and May
observed in Virginia (Erwin 1977) and in south Texas (Custer and Mitchell
1987).

The mean clutch sizes I observed are similar to those reported earlier for
this population (Grant and Hogg 1976) and to those reported from coastal
California (Stadtlander 1994) but slightly lower than those reported for Gulf
of Mexico populations (Custer and Mitchell 1987).

Reports of hatching success among North American Black Skimmer
populations are highly variable (Gochfeld and Burger 1994). The low mean
clutch size coupled with low hatching success and lowered abundance of
young for banding indicate that 1994 was a highly anomalous year. The
poor reproductive output in 1994 may imply a prolonged period of poor

# OF PRS -e- # OF BOATS

Figure 9. Number of breeding pairs of the Black Skimmer (filled squares) and number
of boats using the Red Hill Marina boat ramp (open squares), 1987-1995. Number of
boat launchings not available for 1991. Based on data from Imperial County
Department of Recreation.

153

BLACK SKIMMERS AT THE SALTON SEA

food availability; however, the role of contaminant-induced reproductive
depression, operating just below threshold levels, is still unclear and can not
be ruled out.

Quantitative information on the foraging behavior and diet of Black
Skimmers at the Salton Sea is lacking. The Salton Sea fishery is a simple
one, with marine game species, the Orangemouth Corvina ( Cynoscion
xanthulus), Sargo (Anisostremus davidsonii) and Bairdiella ( Bairdiella
icistia ) initially stocked. Tilapia ( Tilapia sp.) have since been introduced into
irrigation ditches (Setmire et al. 1993) and are abundant inshore. Small
tilapia are often observed dropped at nests. These and small Bairdiella are
occasionally regurgitated by chicks during handling. The comprehensive
investigation of the biota of the Salton Sea during the 1950s by Walker et al.
(1961) is now somewhat outdated, and few recent studies of the Salton Sea
fishery have 'been published. Matsui et al. (1992) recently examined the
reproduction of Bairdiella in the Salton Sea and reported abnormal embry-
onic development in addition to reproductive decline. The relationship of
developmental deformities and diminished reproduction to factors of salin-
ity, temperature, and contaminants is unclear. Fewer and smaller corvina, a
highly prized game species, are currently being caught by fishermen.
Diminished public use since 1990 suggests that the vitality of the sportfishery
has declined significantly.

The large-scale failures observed at Morton Bay in 1993 and 1994 may
be related to the apparent immobilization of eggs within the bare nest
scrape, possibly preventing proper embryonic development. Grant (1978)
has previously described the behavior of foot and belly soaking by Black
Skimmers and Gull-billed Terns nesting at the Salton Sea. By cementing the
eggs to the ground, this behavior adaptive to heat stress and the transport of
moisture to the nest and eggs may actually be detrimental to reproductive
success when the birds nest on substrates like that at Morton Bay. Gull-billed
Terns have nested successfully at this site during most years of this study.
Because Gull-billed Tern nests are lined with flotsam and debris, their
clutches have been unaffected by the stickiness of these clay soils when
moistened. Immobilization of clutches, as well as eggshell weakening and
other contaminant-induced reproductive impairment, may have contributed
to these large scale failures.

Setmire et al. (1993) reported elevated levels in DDE and selenium in
some Salton Sea biota, and Platter (1976) reported significant eggshell
thinning for the Snowy ( Egretta thula) and Cattle Egrets ( Bubulcus ibis )
nesting there. Preliminary analyses of eggshell quality (unpubl. data) for
Salton Sea Black Skimmers are difficult to interpret because pre-DDT
clutches from California do not exist. Comparisons of Black Skimmer
clutches over a wide geographic range within North America before and
after the ban on DDT do not demonstrate consistent thinning (White et al.
1984, Blus and Stafford 1980, King et al. 1991). Some studies of Black
Skimmers in Texas during the late 1970s and 1980s (White et al. 1984,
King et al. 1991) reported decreases in eggshell thickness but demonstrated
no significant relationship between residue levels and eggshell quality and
reproductive success. The results of studies examining the relationship of
contaminants, eggshell thinning, and reproductive success in other larid

154

BLACK SKIMMERS AT THE SALTON SEA

species are also mixed. Fox (1976) demonstrated eggshell thinning and a
correlation with DDE levels in Common Terns ( Sterna hirundo ) in Alberta,
Canada, in addition to differences in amino acid composition and pore area
between the shells of eggs that hatched and of those that failed to hatch.
Ohlendorf et al. (1985) documented eggshell thinning for Caspian Terns in
San Diego but found no clear relationship between eggshell thickness and
DDE residues. Fox (1976) reported intra-clutch variation in eggshell thick-
nesses due to laying sequence and suggested that this natural variation may
mask any contaminant-induced variability. Future investigation may help
resolve geographic trends and response to contaminants.

Several studies of east-coast tern populations (Gochfeld 1971, Flays and
Risebrough 1972) reported feather deformities during the early 1970s at
rates similar to that observed in Black Skimmers from the Salton Sea and
coastal California (C. T. Collins pers. comm.). Polychlorinated biphenyls,
chlorinated dioxins, and heavy metals have been implicated in these studies.
Curiously, I have rarely recovered dead chicks near fledging age with this
condition. Hays and Risebrough (1972) and my own observations suggest
new feather growth after subsequent handling of some affected birds. If
parents continue to provision these juveniles, the damaged primaries may be
replaced and ultimately fledging may proceed. Continued surveillance,
however, is warranted.

Little information is available on the dispersal and wintering patterns of the
Salton Sea breeding population of Black Skimmers. The current presumption
is that most of this population moves south through the Gulf of California and
winters in western Mexico. Gazanniga’s (1995, 1996) study of the wintering
behavior of resident California coastal populations suggests that Salton Sea
birds are generally absent from coastal wintering flocks. However, banded
Salton Sea skimmers are rarely but regularly observed along the coast. Such
observations were usually made in late winter or early spring and involved birds
in their first or second winter. Studies of east-coast Black Skimmers (Gochfeld
and Burger 1994) suggest that few first-year birds return to natal colonies.
During casual observations at one Salton Sea colony, 5 of 72 (7%) banded
young of the year were resighted the following year.

SUMMARY

Black Skimmers nesting at the Salton Sea now form one of the largest
nesting populations in western North America, numbering nearly 500 pairs
in 1995. This unique inland population varies widely in population size,
habitat availability, and reproductive success. Nesting in one of the harshest
environments in North America, it may be subject to enormous physiologi-
cal stress. The increasing salinity and pollutant levels of the Salton Sea also
contribute to the uncertain future of these and other piscivorous birds
residing there. These baseline demographic data and a maturing banded
population provide the foundation upon which more detailed studies of the
ecology and physiology of this interesting population of Black Skimmers can
be based.

155

BLACK SKIMMERS AT THE SALTON SEA

ACKNOWLEDGMENTS

Funding for this study was provided by the Salton Sea National Wildlife Refuge and,
in 1993, by the U.S. Fish and Wildlife Service, Ecological Services, Carlsbad. The
Natural History Museum of Los Angeles County provided logistical and clerical
support. Mark Wimer provided the map. I thank E. Clark Bloom and the following
persons for providing field assistance: Mike Clary, Marnie Crook, Kevin DesRoberts,
Corey Garza, Fritz Hertel, Mary Hunnicutt, Mark Marquez, Jean McGuiness, Robert
McKernan, Marcos Orozco, Marcia Radke, William Radke, Mike San Miguel, Ken
Sturm, Jean Tinsman, and Jacob Vasquez. 1 thank Charles Collins, Kathy Gazzaniga,
and Florence Sanchez for sharing their information on dispersal. I appreciate the
helpful comments of Charles Collins and Kimball Garrett on earlier drafts of the
manuscript. Finally, l am indebted to Kimball Garrett, who participated in numerous
aspects of this study.

LITERATURE CITED

American Ornithologists’ Union. 1983. Check-list of North American birds, 6th ed.
Am. Ornithol. Union, Lawrence, KS.

Bills, L. J., and Stafford, C. J. 1980. Breeding biology and relations of pollutants to
Black Skimmers and Gull-billed Terns in South Carolina. U.S. Fish & Wildlife
Serv. Spec. Sci. Rep. — Wildlife 230.

Burger, J. A. 1982. The role of reproductive success in colony site selection and
abandonment in Black Skimmers ( Rynchops niger). Auk 99: 109-115.

Burger, J. A. 1992. Heavy metal and selenium concentrations in Black Skimmers
'( Rynchops niger): Gender differences. Arch. Environ. Contam. Toxicol. 23:431-
434.

Burger, J. A., apd Gochfeld, M. 1990. The Black Skimmer: Social dynamics of a
colonial species. Columbia Univ. Press, New York.

Carpelan, L. H. 1961. Physical and chemical characteristics of the Salton Sea, in The
1 Ecology of the Salton Sea, California, in relation to the sportfishery (B. Walker,
ed.), pp 17-32. Calif. Dept. Fish & Game Fish Bull. 113.

Collins, C. T., and Garrett, K. L. 1996. The Black Skimmer in California: An
overview. W. Birds 27:127-135.

Custer, T. W., and Mitchell, C. A. 1987. Organochlorine contaminants and reproductive
success of Black Skimmers in South Texas, 1984. J. Field Ornithol. 58:480-489.

Ermak, D., Buchanan, M., and Layton, D. 1976. Land and air resources, in A
description of Imperial Valley, California, for the assessment of impacts of
geothermal energy, development (D. Layton and D. Ermak, eds.), pp. 7-21.
Lawrence Livermore Lab UCRL-52121, Univ. Calif., Livermore.

Enyin, R, : M. 1977. Black Skimmer breeding ecology and behavior. Auk 94:709-
717.

Erwin, R. M. 1979. Species interactions in a mixed colony of Common Terns (Sterna
hirundo ) and Black Skimmers ( Rynchops niger). Animal Behavior 27:1054-
1062.

Fox, G. 1976. Eggshell quality: Its ecological and physiological significance in a DDE-
contaminated common tern population. Wilson Bull. 88:459-477.

Gazzaniga, K. 1995. Distribution and dispersal of Black Skimmers ( Rynchops niger )
in southern California. M. S. thesis, Calif. State Univ., Long Beach.

156

BLACK SKIMMERS AT THE SALTON SEA

Gazzaniga, K. 1996. Overwintering of Black Skimmers in California: Site fidelity and
inter-site movements. W. Birds 27:136-142.

Grant, G,, and Hogg, N. 1976. Behavior of late-nesting Black Skimmers at Salton
Sea, California. W. Birds 7:73-80.

Grant, G. S. 1978. Foot-wetting and belly-soaking by incubating Gull-billed Terns and
Black Skimmers. J. Bombay Nat. Hist. Soc. 75:148-152.

Grant, G. S. 1982. Avian incubation: Egg temperature, nest humidity, and behavioral
thermoregulation in a hot environment. Am. Ornithol. Union, Washington, D.C.

Gochfeld, M. 1971. Premature feather loss: A new disease of terns on Long Island,
N. Y, Kingbird 21:206-211.

Gochfeld, M., and Burger, J. 1994. Black Skimmer (R^n chops niger), in The Birds of
North America, No. 108 (A. Poole and F. Gill, eds.), Acad. Nat. Sci., Philadelphia.

Hagar, J., and Garcia, J. 1988. A review of the potential biological response to
salinity changes in the Salton Sea. Biosystems Analysis, Sausalito, CA.

Hays, H., and Risebrough, R. Pollutant concentrations in abnormal young terns from
Long Island Sound. Auk 89:19-35.

King, K. 1989. Food habits and organochlorine contaminants in the diet of Black
Skimmers, Galveston Bay, Texas. Colonial Waterbirds 12:109-112.

King, K., Custer, T., and Quinn, J. 1991. Effects of mercury, selenium, and
organochlorine contaminants on reproduction of Forster’s Terns and Black
Skimmers nesting in a contaminated Texas Bay. Arch. Environ. Contam.
Toxicol. 21:32-40.

Layne, V., Richmond, R., and Metropulos, P. 1996. First nesting of Black Skimmers
on San Francisco Bay. W. Birds 27:159-162.

Loftin, R. W. 1982. Diet of Black Skimmers and Royal Terns in northeast Florida. Fla.
Field Nat. 10:19-20.

Matsui, M., Hose, J., Garrahan, P., and Jordan, G. A. 1992. Developmental effects
in fish embryos from Salton Sea, California. Bull. Contam. Toxicol. 48:914-
920.

McCaskie, G., and Suffel, S. 1971. Black Skimmers at the Salton Sea, California.
Calif. Birds 2:69-71.

McCaskie, G., Liston, S., and Rapley, W. 1974. First nesting of Black Skimmer in
California. Condor 76:337-338.

Ohlendorf, H. M., Schaffner, F. C., Custer, T. W., and Stafford, C. J. 1985.
Reproduction and organochlorine contaminants in terns at San Diego Bay.
Colonial Waterbirds 8:42-53.

Platter, M. 1976. Breeding ecology of Cattle Egrets and Snowy Egrets at the Salton
Sea, southern California. M. S. thesis, San Diego State Univ.

Portnoy, J. W. 1977. Nesting colonies of seabirds and wading birds — coastal
Louisiana, Mississippi, and Alabama. U. S. Fish & Wildlife Serv., Biol. Serv.,
FWS/OBS 77/07, Washington, D. C.

Quinn, J. 1989. Black Skimmer parental defense against chick predation by gulls.
Animal Behavior 38:534-541.

Quinn, J. 1990. Sexual size dimorphism and parental care patterns in a monomor-
phic and a dimorphic larid. Auk 107:260-274.

Schew, W. A., and Collins, C. T. 1990. Age and sex determination in Black Skimmer
chicks. J. Field Ornithol. 61:174-179.

157

BLACK SKIMMERS AT THE SALTON SEA

Schew, W. A., and Collins, C. T. 1991. Annual and within-year variability in growth
patterns of Black Skimmer ( Rynchops niger ) chicks. Proc. Int. Symp. Mar. Biol.
8:87-94.

Setmire, J. G., Schroeder, R., Densmore, Goodbred, S., Audet, D., and Radke, W.
1990. Detailed study of water quality, bottom sediment, and biota associated
with irrigation drainage in the Salton Sea area, California, 1988-90. U.~ S.
Geological Survey, Water Res. Investi. Rept 93-4014

Stadtlander, D. 1994. Colonial seabirds and the Western Snowy Plover nesting in
south San Diego Bay 1993. Bay and Estuary Program, U. S. Fish & Wildlife
Service, 2730 Loker Ave. W., Carlsbad, CA 92008.

Stewart, R. E., and Robbins, C. S. 1958. Birds of Maryland and the District of
Columbia. N. Am. Fauna 62:1-401.

Walker, B., Whitney, R., and Barlow, G. 1961. The fishes of the Salton Sea, in The
ecology of the Salton Sea in relation to the sportfishery (B, Walker, ed.), pp. 77-
92. Calif. Dept. Fish & Game Fish Bull. 113.

White, D., Mitchell, C., and Swineford, D. 1984. Reproductive success of Black
Skimmers in Texas relative to environment pollutants. J. Field Ornithol. 55: 18-30.

Yee, D. G., Bailey, S. F., and Singer, D. 1995b. The summer season. Middle Pacific
Coast region. Natl. Audubon Soc. Field Notes 49:975-979.

Accepted 26 April 1996

158

NOTES

FIRST NESTING OF BLACK SKIMMERS
ON SAN FRANCISCO BAY

VALERIE L. LAYNE, ROBERT J. RICHMOND, and PETER J. METROPULOS, San
Francisco Bay Bird Observatory, P. O. Box 247, Alviso, California 95002

Black Skimmers ( Rynchops niger) have been observed on south San Francisco Bay
during the nesting season since the late 1970s (Bailey et al. 1992, Le Valley and Evens
1982, San Francisco Bay Bird Observatory unpubl. data. Winter and Manolis 1978,
Yee et al. 1992), but nesting was never documented. They have nested in southern
California since 1972, when five nests were discovered at the Salton Sea (McCaskie
et al. 1974). The northernmost previously recorded nesting of the Black Skimmer in
California was inland, at the Tulare Lake Basin in Kings County during the summer of
1986 (Erickson et al. 1986).

On 3 June 1994, we found two separate pairs of Black Skimmers on south San
Francisco Bay. Layne found one pair roosting in a Forster’s Tern ( Sterna forsteri )
nesting colony in Santa Clara County, and Richmond found the other pair making a
nest scrape in a Forster’s Tern nesting colony in Alameda County.

The Santa Clara County tern colony was on a dredge-spoil island in a salt
evaporation pond on the San Francisco Bay National Wildlife Refuge. The nest island
was sparsely vegetated, with approximately 45% cover. The dominant plant species
was pickleweed ( Salicornia uirginica); there were also scattered patches of ice plant
( Mesembryanthemum nodiflorum), Alkali Heath ( Frankenia salina), saltgrass
(. Distichlis spicata), and Curly Dock (Rumex crispus ). Other bird species nesting on
islands in this pond were the American Avocet ( Recurvirostra americana), Black-
necked Stilt ( Himantopus mexicanus ), Gadwall (Anas strepera), and California Gull
(j Larus californicus). The female skimmer was once seen foraging on a nearby salt
pond approximately 0.5 km from the nest island.

On 19 June the skimmers appeared to be incubating eggs. The nest scrape was on
the southeast side of the island, sheltered from the prevailing northwest winds. On 6
July there were three downy young; five days later a fourth chick was seen. The
number of chicks dwindled to one by 5 August. On 17 August, the young skimmer
fledged and by 19 August was observed making short flights between islands in the
pond. Both adults and the fledgling were last observed on 23 August; by 24 August all
had left the area.

In 1995, a pair of Black Skimmers nested on a dredge-spoil island in a salt
evaporator approximately 1.5 km north of the pond used in 1994. Both adults were
frequently observed foraging on this pond and in Charleston Slough. On 2 August, the
first chick was visible; a second chick was seen on 5 August. No other chicks were
observed. On 12 August 1995 we banded one chick from this nest site (Figure 1). A
U. S. Fish and Wildlife Service band was placed on the left leg, and a white plastic color
band with a black number was placed on the right leg. The banded chick was seen
flying on 6 September; the other chick was not observed flying and shortly thereafter
disappeared. Subsequently the two adults and single chick moved to Charleston
Slough, where they remained until December. The last reported sighting at Charleston
Slough was of one adult and one immature bird on 18 December 1995 (M. Rogers
pers. comm ).

The Alameda County tern colony was on artificial islands in a series of man-made
freshwater to brackish ponds at the East Bay Regional Park District’s Hayward

Western Birds 27:159-162, 1996

159

NOTES

Regional Shoreline. The skimmers nested on a sparsely vegetated island in a brackish
pond. The dominant vegetation on this island was Spearscale (Atriplex triangularis).
Other bird species nesting on islands in this pond were the Forster’s Tern, Black-
necked Stilt, American Avocet. Western Snowy Plover ( Charadrius alexandrinus
niuosus) and Killdeer ( Charadrius uociferus). The adult skimmers were frequently
seen foraging on a salt pond approximately 3 km from the nest island.

At Hayward, the skimmers continued scrape-making behavior through 8 June
1994. The final nest scrape was near the top of the island. On 9 June they appeared
to be incubating eggs. They continued in the same way until 30 June, when the first
chick was observed. On 2 July a second chick was seen, on 4 July a third, and on 7
July a fourth (Figure 2).

By 9 July the chicks had moved to a clump of Spearscale 1 .5 to 3 m away from the
nest scrape and were being fed whole fish. On 23 July only three chicks were present.
An additional adult female Black Skimmer was on a nearby pond from this date until
early August and was constantly harassed by the nesting pair. In the mid-afternoon on
31 July three chicks were evident, but several hours later only two could be seen. The
missing chick was not seen later and may have fledged. On 2 August one of the other
chicks fledged. It was seen through the next day but not later. The last chick fledged on
5 August. This fledgling and the pair of adults were last seen in the Baumberg salt
ponds (just south of Hayward Regional Shoreline) on 26 August (L. Feeney pers.
comm.).

In 1995, a pair of skimmers again nested at Hayward Regional Shoreline. On 26
May two pairs of adults were seen, one of the pairs occupying the approximate site of
the 1994 nest scrape. On 10 June this pair was alone. The next day they moved

Figure 1 . Valerie Layne preparing to band a Black Skimmer chick at the Santa Clara
County nest site, August 1995.

160

Photo by Janet T. Hanson

NOTES

Figure 2. Black Skimmers with four downy chicks on an island at Hayward Regional
Shoreline, July 1994.

Photo by Phil Gordon

approximately 30 m northeast to another island where they began a new nest scrape.
The first chick was seen on 9 July, a second chick was seen on 12 July, a third chick
was seen on 14 July and a fourth chick was seen on 19 July. On 29 July only three
chicks remained and all three were banded that night. On 8 August two of the chicks
had fledged, the third fledged three days later. All five birds were last seen together on
28 August; one immature bird was seen on 4 September.

We believe the pair nesting at Hayward to be the same pair that used the site in
1994, as the male had a U. S. Fish and Wildlife Service band on its right leg. Black
Skimmers have been banded at several nesting colonies in southern California in
recent years (1988-1995). Those banded in south San Diego Bay were banded on the
left leg; those banded at Bolsa Chica in Orange County have been banded on the right
leg (C. Collins pers. comm.), possibly indicating the colony of origin.

Black Skimmer populations in southern California have increased greatly in the
past five years (C. Collins pers. comm.), and this further northward expansion of the
species’ breeding range is perhaps not unexpected.

We gratefully acknowledge the San Francisco Bay National Wildlife Refuge, East
Bay Regional Park District, the city of Mountain View, and Cargill Salt Division for
permission to conduct these observations. We also thank Janet Hanson, Sue Macias,
Howard Cogswell, Mark Taylor, and Mike Mammoser for assistance in the field.
Special thanks are due Charles Collins and Howard Cogswell for reviewing the
manuscript and making many invaluable comments and suggestions.

LITERATURE CITED

Bailey, S. F., Yee, D. G., and Deuel, B. E. 1992. The summer season. Middle Pacific
Coast region. Am. Birds 46:1173-1176.

Erickson, R. A., Bailey, S. F., and Barron, A. D. 1986. The nesting season. Middle
Pacific Coast region. Am. Birds 40:1248-1254.

LeValley, R., and Evens, J. 1982. The nesting season. Middle Pacific Coast region.
Am. Birds 36:1011-1015.

161

NOTES

McCaskie, G., Liston, S., and Rapley, W. A, 1974. First nesting of Black Skimmer in
California. Condor 76:337-338.

Winter, J., and Manolis, T. 1978. The nesting season. Middle Pacific Coast region.
Am. Birds 32:1203-1206.

Yee, D., Bailey, S. F., and Deuel, B. E. 1992. The autumn migration. Middle Pacific
Coast region. Am. Birds 46:142-147.

Accepted 26 April 1992

NIGHT FEEDING OF BLACK SKIMMERS

AT ESTERO FUNTA BANDA, BAJA CALIFORNIA,

MEXICO

HORACIO DE LA CUEVA and GUILLERMO FERNANDEZ, Centro de Investigacion
Cientifica y de Educacion Superior de Ensenada, Km. 107 Carretera Tijuana-
Ensenada, Ensenada, Baja California, Mexico (U.S. mailing address P. O. Box
434844, San Diego, California 92143-4844)

The Black Skimmer ( Rynchops niger ) feeds strictly in shallow inshore waters, alone
or in small groups (Erwin 1977a). Its diet is narrow; in Virginia, silversides ( Menidia
spp.) and killifishes ( Fundulus spp.) make up 90% of its prey (Erwin 1977b). Both its
feeding method and efficiency have been reported (Irby 1951, Tomkins 1951, Zusi
1959), but until recently little was known about its nocturnal feeding behavior
(Gochfeld and Burger 1994).

Black Skimmers have recently colonized southern California (McCaskie et al.
1974, Palacios and Alfaro 1992) and the Gulf of California (Massey and Palacios
1994). They are now not rare along the Baja California peninsular coast (Palacios and
Alfaro 1992, Carmona et al. 1995).

We present here observations of night feeding of Black Skimmers in northwestern
Baja California at Estero Punta Banda (31° 40-31° 48' N, 1 16° 34 '-1 16° 40' W), 13
km south of Ensenada, Baja California, Mexico. On 19 January 1996 we caught six
Black Skimmers (three at 20:00, one at 21:30, and two at 21:50) while netting
Western Sandpipers ( Colidris mauri). Captures were made during a new moon and
a rising tide; high tide was 1.26 m at 20:49, with about a 40-minute lag between
Punta Banda and the tide gauge at the port of Ensenada. We obtained from three birds
a total of four Topsmelt ( Atherinops affinis) (Rosales-Casian pers. cornm). One
complete fish (length 17,1 cm) had to be extracted by hand from a gagging bird; three
others were regurgitated and had no head but were otherwise undigested (partial
lengths 9.5, 13.4, and 15.0 cm). These sizes are larger than most reported Black
Skimmer prey (see Gochfeld and Burger 1994, Wilson 1995). Hamman and Rosales-
Casian (1989) considered the Topsmelt to be a visitor to the estuary, entering at high
tide and feeding at the mouth of the estuary, where the Black Skimmers were caught.

Up to 238 Black Skimmers have been recorded at Punta Banda and in the
Ensenada area (October 1990), and banded birds from Bolsa Chica, Orange County,
California, have been observed in the area (Palacios and Alfaro 1992). One Black
Skimmer we captured had been banded as a chick on 19 July 1989 in San Diego,
California (33° 40' N, 118° 10' W) (U.S. Fish and Wildlife Service band 634-54818).
We counted 150 roosting Black Skimmers in the Estero Punta Banda on 13 January

Western Birds 27:162-163, 1996

162

NOTES

1996. These birds appear to be a winter population that breeds, at least in part, in
southern Upper California. Availability of the Black Skimmer's food is determined by
tide level (Erwin 1977b, 1990). In Virginia, Erwin (1977b) found most skimmers
feeding in marshes at low tide, and night feeding was thought possible (Erwin 1977b).
At Punta Banda it is common to see them feeding during the day, mainly near low tide
(Palacios and Alfaro 1992). Our observations show that Black Skimmers do feed at
night and at high tide, possibly as a consequence of food availability. Feeding habits of
Black Skimmers in Baja California in winter agree with the primarily nocturnal
foraging recorded for breeding birds in southern California (Wilson 1995). Further
studies of their diet and feeding efficiencies could help us further understand their
success as a colonizing species in this area.

Support was provided in part by the Canadian Wildlife Service-Natural Science and
Engineering Research Council (Canada) Wildlife Ecology Chair at Simon Fraser
University. We thank Nils Warnock and Charles Collins for helpful suggestions to the
manuscript, Felipe Becerril for logistic support, and Jorge Rosales-Casian of Ecologia
Pesquera C1CESE for fish identification.

LITERATURE CITED

Carmona, R., Fernandez, G., Brabata, G., and Arvizu, E. 1995. Variation temporal
en la abundancia del rayador, Rgnchops niger (Charadriiformes: Laridae), en
Baja California Sur, Mexico. Rev. Biol. Trop. 43:313-315.

Erwin, R. M. 1977a. Foraging and breeding adaptations to different food regimes in
three seabirds; the Common Tern, Sterna hirundo, Royal Tern, Sterna maxima,
and Black Skimmer, Rgnchops niger. Ecology 58:389-397.

Erwin, R. M. 1977b. Black Skimmer breeding ecology and behavior. Auk 94:709-
717

Erwin, R. M. 1990. Feeding activities of Black Skimmers in Guyana. Colonial
Waterbirds 13:70-71

Gochfeld, M., and Burger, J. 1994. Black Skimmer (Rgnchops niger), in The Birds of
North America, No. 108 (A. Poole and F. Gill, eds.). Acad. Nat. Sci., Philadel-
phia.

Hamman, G., and Rosales-Casian, J. A. 1989. Taxonomia y estructura de la
comunidad de peces del estero Punta Banda y Bahia Todos Santos, Baja
California, Mexico, in Temas de Oceanografia Biologica en Mexico (J. de la
Rosa-Velez and F. Gonzalez-Farias, eds.), pp. 153-192. Univ. Autonoma Baja
Calif., Ensenada.

Irby, D. L. 1951. Fishing efficiency of the Black Skimmer. Condor 53:259.

Massey, B. W., and Palacios, E. 1994, Avifauna of the wetlands of Baja California,
Mexico: Current status. Studies Avian Biol. 15:45-57

McCaskie, G., Liston, S,, and Rapley, W. A. 1974. First nesting of Black Skimmer in
California. Condor 76:337-338.

Palacios, E., and Alfaro, L. 1992. Occurrence of Black Skimmers in Baja California.
W. Birds 23:173-176.

Tomkins, I. 1951. Method of feeding of the Black Skimmer. Auk 68:236-239

Wilson, J. F. 1995. Diel periodicity and dietary breadth in the Black Skimmer
( Rgnchops niger): Implications for coexistence in a mixed-species colony of
breeding seabirds. Master’s thesis, Calif, State Univ., Fullerton.

Zusi, R. L. 1959. Fishing rates in the Black Skimmer, Condor 61:298.

Accepted 1 Mag 1996
163

NOTES

ESTABLISHMENT OF A NEW BLACK SKIMMER
BREEDING COLONY IN SOUTHERN CALIFORNIA

ADAM W. WHELCHEL, Wetlands Research Associates Inc., 7102 Batiquitos Drive,
Carlsbad, California 92009

KATHY M. KEANE, Keane Biological Consulting, 5546 Parkcrest Street, Long
Beach, California 90808

MICHAEL N. JOSSELYN, Wetlands Research Associates Inc,, 2169 East Francisco
Boulevard, San Rafael, California 94901

Batiquitos Lagoon (33° 05' N, 117° 17' W) is a 241-hectare nontidal coastal
wetland situated in northern San Diego County, California, within the city of
Carlsbad, approximately 56 km north of San Diego and 145 km south of Los Angeles
(Figure 1). The lagoon extends approximately 4 km inland from the Pacific Ocean and
ranges in width from 0.2 to 0.4 km, with steep canyon slopes along the southern
border and more gradual slopes to the north.

Over the last century, the coastal wetlands of northern San Diego County have
been subjected to increased siltation and subsequent reduction of tidal action (Coastal
Conservancy 1986, City of Carlsbad 1990, Appy 1991). In an attempt to reverse
these detrimental effects, an enhancement plan is currently being implemented that
will permanently open Batiquitos Lagoon to the Pacific Ocean through dredging and
the stabilization of the inlet. The enhancement plan will ultimately create five nesting
sites, totaling 13 hectares, designed to accommodate the Least Tern ( Sterna
antillarum) and the Snowy Plover ( Choradrius alexandrinus). The first three nesting
sites were created prior to the 1995 breeding season. During 1995, one of the nesting
sites was colonized by 14 pairs of the Black Skimmer { Rynchops niger ). Their nesting
effort represents the first record of breeding by this species at Batiquitos Lagoon and
in northern San Diego County.

The site where Black Skimmers nested at Batiquitos Lagoon, referred to as W-2
(Figure 1A), is in the west basin of the lagoon adjacent to Highway 101. Its
construction began on 19 November 1994 and was completed by 5 December 1994.
Approximately 45,900 m 3 of medium to coarse sand with shell fragments was
dredged from the central basin of the lagoon and deposited at W-2, covering
approximately 2 hectares. The plateau of the nesting site stands at +9.5 National
Geodetic Vertical Datum (NGVD) with a gradual decrease in elevation from west to
east. Fencing was installed along the north, south, and west sides of the site to restrict
use by humans and help reduce predation.

Because of the sensitivity of Black Skimmers to human disturbance during the pre-
laying, egg-laying, and early incubation phases (Safina and Burger 1983, Schew and
Collins 1990), we observed from outside the colony until the initial nests were
established. Subsequently, we checked nests within the colony three times a week for
15 minutes between 0800 and 1100 during August and September.

After the first observations at the lagoon on 20 April, the number of Black
Skimmers increased from 18 individuals on 12 May to a high of 81 on 18 August.
Following a large influx of 50-55 skimmers, nesting was initiated on 30 July and
continued through 21 August. The incubation period for all nests extended from 30
July to 13 September, and hatching dates ranged from 22 August to 13 September.
The first juvenile fledged on 25 September; the last, on 17 October. The skimmers
nesting at Batiquitos Lagoon included two uniquely banded adults hatched at the Bolsa
Chica Ecological Reserve (Orange County). Flights by Heermann’s Gulls ( Larus
heermanni ), Western Gulls ( Larus occidentalis), and a White-tailed Kite (Elanus
leucurus) near the colony elicited intensive chasing by small groups or individual
skimmers. No nests were lost to predation.

164

Western Birds 27:164-167, 1996

NOTES

In the 14 nests, skimmers laid a total of 37 eggs; of these, 16 hatched (32%
hatching rate). Clutch sizes ranged from 1 to 4 [mode 3, mean 2.6, standard error (SE)
0.4], while the number of chicks hatched per nest ranged from 0 to 3 (mode 0, mean
0.9, SE 0.5). Seven chicks successfully fledged (0.5 fledglings per pair). The breeding
“colony,” situated along the eastern edge of the W-2 site, was 15.1 m in length and
10.8 in in width. The distance between nests varied from 1.9 to 3.9 m (mean 2.6 m,
SE 0.3 m). The nest elevations ranged from +4.6 to +5.7 NGVD.

The Batiquitos Lagoon colony did not become established until atypically late in the
season (Tomkins 1951, Erwin 1977, Erwin 1979, Safina and Burger 1983, Burger

Figure 1. Batiquitos Lagoon, San Diego County, California. A, location of nesting
sites.

165

NOTES

and Gochfeld 1990). However, Black Skimmers nesting for the first time at Bolsa
Chica Ecological Reserve in 1988 similarly initiated nesting in early August (C. T.
Collins pers. comm.). Exceptionally late nesting may be more common when colonies
are first being initiated.

Erwin (1977) suggested that the Black Skimmer may be adapted to colonizing new
or ephemeral sites rapidly. Small colonies on the Atlantic Coast have been shown to
have a high incidence of colony abandonment and reestablishment (Erwin et al. 1981 ,
Burger and Gochfeld 1990). The skimmer’s comparatively prolonged breeding
season (Burger and Gochfeld 1990, Schew and Collins 1991) may give it nesting or
renesting flexibility, within a year or in a subsequent year, in response to disruptions
like predation, flooding, and perhaps interspecific displacement in crowded mixed
colonies.

The recent nesting at Batiquitos Lagoon Ecological Reserve is further evidence of
the Black Skimmer’s range expansion. The five nesting sites incorporated in the
Batiquitos Lagoon Enhancement Plan will provide additional habitat to support
further skimmer colonies and help stabilize this expanding population. On 4 June
1996, 10 pairs of Black Skimmers were nesting at Batiquitos Lagoon, incubating a
total of 21 eggs.

This work is a result of the Batiquitos Lagoon Enhancement Project, a joint
restoration project of the city of Carlsbad and the port of Los Angeles in cooperation
with the United States Fish and Wildlife Service, California Department of Fish and
Game, National Marine Fisheries Services, and the California State Lands Commis-
sion. We are especially grateful to Justine Gibb, Don Kogle, and Roxanne Crestman
for assistance in the field. Special acknowledgement is due of the forethought,
continued support, and assistance of Ralph Appy, John Cahill, Betty Dehoney, Tracy
Notebaert, Gary Wayne, Angus Whelchel, and the tireless efforts of Aaron English.
We must recognize also Jim Van Norman and Nick Gennaro. The comments of
Charles Collins and Philip Unitt improved the manuscript.

LITERATURE CITED

Appy, R. G. 1991. Enhancement of subtidal and intertidal estuarine habitats in
southern California, in Recent Advances in Aquatic Habitat Technology (M.
Nakamura, R. S. Grove, and C. J. Sonu, eds.). Proc. of the Japan-U.S. Symp.
on Artificial Flabitat for Fisheries.

Burger, J., and Gochfeld, M. 1990. The Black Skimmer: Social Dynamics of a
Colonial Species. Columbia Univ. Press, New York.

City of Carlsbad. 1990. Final Environmental Impact Report. Batiquitos Lagoon
Enhancement Project. City of Carlsbad, 2075 Las Palmas Dr., Carlsbad, CA
92009.

Coastal Conservancy. 1987. Revised Draft Batiquitos Lagoon Enhancement Plan.
City of Carlsbad, 2075 Las Palmas Dr., Carlsbad, CA 92009.

Erwin, R. M. 1977. Black Skimmer breeding ecology and behavior. Auk 94:709-
717.

Erwin, R. M. 1979. Species interactions in a mixed colony of Common Terns { Sterna
hirundo) and Black Skimmers ( Rynchops niger). Animal Behaviour 27:1054-
1062.

Erwin, R. M., Galli, J., and Burger, J. 1981. Colony site dynamics and habitat use in
Atlantic coast seabirds. Auk 98:550-556.

Safina, C., and Burger, J. 1983. Effects of human disturbance on reproductive
success in the Black Skimmer. Condor 85:164-171.

166

NOTES

Schew, W. A., and Collins, C. T. 1990. Age and sex determination in Black Skimmer
chicks. J. Field Ornithol. 61:174-179.

Schew, W. A., and Collins, C. T. 1991. Annual and within-year variability in growth
patterns of Black Skimmer ( Rynchops niger) chicks. Proc. Int. Symp. Mar. Biol.
8:87-94.

Tomkins, I. T. 1951. Methods of feeding of the Black Skimmer (Rynchops niger). Auk
68:236-239.

Accepted 9 May 1 996

THE NAME OF THE CRAVERI BROTHERS’
MURRELET

STORRS L. OLSON, Department of Vertebrate Zoology, National Museum of
Natural History, Smithsonian Institution, Washington, D.C. 20560

Federico Craveri was a chemist, geologist, and naturalist who resided in Mexico for
18 years beginning in 1840. In 1847 he was joined for two years by his brother
Ettore, who shared similar interests. Upon the death of their father, Ettore returned
home to Italy to attend to the family museum in Bra, near Turin. Later, during his
investigation of the economic potential of guano deposits on islands in the Gulf of
California in 1856, Federico obtained specimens of a new species of murrelet, which,
after considerable delay, was described and named by Tomasso Salvadori (1865) as
Uria craueri (now Endomychura or Synthliboramphus craveri).

Practically from the outset this was known in North American literature as
“Craven’s Murrelet,” as, for example, in all six editions of the American Ornithologist’s
Union Check-list of North American Birds (1886-1983). Numerous sources concern-
ing the origin of bird names invariably treat this murrelet as being dedicated solely to
Federico Craveri (Coues 1882, Palmer 1928, Gruson 1972, Choate 1973, Jobling
1991). This is perpetuated even in the superb series of biographies by Mearns and
Mearns (1992), from which the preceding biographical information was extracted,
the error being the result of the authors’ having had access only to an incomplete copy
of Salvadori ’s paper that did not include the dedication (R. Mearns in litt. 15 July
1995).

Federico was the only one of the two brothers that Salvadori (1865:388) men-
tioned by name, and he was also identified as the collector of the type specimen,
which has probably contributed to various authors’ having long overlooked the fact
that the species was clearly named for both brothers, as shown in Salvadori ’s original
dedication (1865:388): “If it should truly be new I propose to name it Uria Craveri in
memory of the generosity with which the brothers Mssrs. Craveri of Bra [i signori
fratelh Craveri di Bra ] have enriched the Turin Museum with many species of birds
from Mexico and California” [my translation from the original Italian],

Had Salvadori intended the name for Federico alone, he would surely have used the
spelling “ craverii ,” just as he named Lamprocolius defilippii in the same paper in
honor of Filippo De Filippi. The unmodified family name “ craveri ” was surely
intended as a noun in apposition, probably deliberately to avoid the more cumber-
some genitive plural “craveriorum,'’ meaning “of the Craveris.” Thus, although the
scientific name is not subject to emendation, in the interest of historical accuracy it
should be noted that the English name “Craveri’s Murrelet” is incorrect. “Cravens’

Western Birds 27:167-168, 1996

167

NOTES

Murrelet” is too subtle a change to be noticed and perpetuated, and “Craveris’s
Murrelet” is neither euphonious nor easily comprehended. Nor is “Craveri Brothers’
Murrelet” ever likely to gain much currency. Perhaps we shall have to do as Salvadori
did in this case and drop the possessive (the use of which I would otherwise defend),
and simply refer to the bird as the Craveri Murrelet.

LITERATURE CITED

Choate, E. A. 1973. The Dictionary of American Bird Names. Gambit, Boston.

Coues, E. 1882. The Coues Check List of North American Birds, 2nd ed. Estes and
Lauriat, Boston.

Gruson, E. S. 1972. Words for Birds. Quadrangle Books, New York.

Jobling, J. A. 1991. A Dictionary' of Scientific Bird Names. Oxford Univ. Press,
Oxford, England.

Mearns, B,, and Mearns, R. 1992. Audubon to Xantus: The Lives of Those
Commemorated in North American Bird Names. Academic Press, London.

Palmer, T. S. 1928. Notes on persons whose names appear in the nomenclature of
California birds. Condor 30:261-307.

Salvadori, T. 1865. Descrizione di altre nuove specie di uccelli esistenti nel museo di
Torino nota seconda. Atti Soc. Ital. Sci. Nat. 8:370-389.

Accepted 22 April 1996

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Published July 15, 1996

ISSN 0045-3897

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Volume 27, Number 4, 1996

A Review of the Status of the White-faced Ibis in Winter in
California W. David Shuford, Catherine M. Hickey,

Rebecca J. Safran, and Gary W. Page 169

First Record of a Lanceolated Warbler in California

Catherine M. Hickey, Phil Capitolo, and Brett Walker 197

NOTES

Notes on Nesting Birds of the Cienega de Santa Clara Saltflat,
Northwestern Sonora, Mexico Eric Mellink, Eduardo
Palacios, and Salvador Gonzalez 202

Age and Sex Determination in Anna's Hummingbird By Means
of Tail Pattern Shirley Wells, Luis F. Baptista,

Stephen F. Bailey, and Helen M. Horblit 204

INDEX Jack W. Schlotte and Philip Unitt 207

Cover photo by © Jim & Deva Burns/NATURAL IMPACTS of

Scottsdale, Arizona: Flame-colored Tanager (Piranga bidentata),

Madera Canyon, Arizona, May, 1995

Western Birds solicits papers that are both useful to and understandable by
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WESTERN BIRDS

Volume 27, Number 4, 1996

A REVIEW OF THE STATUS OF

THE WHITE-FACED IBIS IN WINTER IN CALIFORNIA

W. DAVID SHUFORD and CATHERINE M. HICKEY, Point Reyes Bird Observatory,
4990 Shoreline Highway, Stinson Beach, California 94970

REBECCA J. SAFRAN, Department of Wildlife, Humboldt State University, Areata,
California 95521

GARY W. PAGE, Point Reyes Bird Observatory, 4990 Shoreline Highway, Stinson
Beach, California 94970

The White-faced Ibis ( Plegadis chihi) has been classified as a Bird Species
of Special Concern in California (Remsen 1978, S. Laymon pers. comm.)
and a potential candidate for federal threatened or endangered status
(USFWS 1991, Trapp 1995) because of population declines in the western
United States, particularly in the 1960s and 1970s {USFWS 1985, Ryder
and Manry 1994). Although the breeding status of the ibis in this region has
been reviewed (Ryder 1967, USFWS 1985, Ryder and Manry 1994), little
has been published on its abundance and distribution in winter. Here we
summarize data on the winter distribution, abundance, and habitat use of the
White-faced Ibis in California during the last half century. We also estimate
the current winter population size and review historical population trends.

METHODS

We determined the winter status of the White-faced Ibis from wetland
censuses, roost counts, and published and unpublished observations. As part
of Point Reyes Bird Observatory’s Pacific Flyway Project, we organized
surveys of all shorebirds and ibis in all key wetlands of California’s Central
Valley and the Mojave, Colorado, and southern Great Basin deserts once to
twice per winter from November 1992 to February' 1995. Surveys were
conducted from the ground, except in the Central Valley where logistical
constraints dictated a combination of aerial and ground counts. The aerial
counts were conducted primarily from a Cessna 172 aircraft by Page and

Western Birds 27:169-196, 1996

169

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

Shuford, the ground counts by a network of skilled volunteers, agency
personnel, and project staff. We relied on ground counts for all wetlands in
the San Joaquin Valley, except for the southern Tulare Basin, where we used
aerial surveys for private duck clubs, a few other private wetlands, and
flooded agricultural lands. Aside from the Tulare Basin, we did not survey
much agricultural habitat in the San Joaquin Valley. We knew of no ibis
concentrations in agricultural habitat in this region except next to the
72,000-ha Grasslands wetlands complex near Los Banos, Merced County,
where roost counts described below appear to have included ibis from
agricultural lands. Aerial surveys were the primary census method for the
Suisun Marsh, Sacramento-San Joaquin River Delta (Delta), and Sacra-
mento Valley, though we regularly undertook ground counts on federal and
state wildlife areas and a few selected private wetlands and sewage ponds.
We gathered data on habitat use by assigning observations of ibis occurrence
to broad habitat categories, namely, managed state or federal wildlife
refuges, managed duck clubs, pasture lands, rice-stubble fields, fallow fields,
alfalfa fields, and reservoirs or ponds. We were not able to assign some flying
ibis to specific habitats.

We also obtained data from counts of ibis coming to nighttime roost sites
in four known areas of concentration. From 29 January to 1 1 April 1995,
Safran and colleagues made 14 counts of ibis at a primary roost and 3 at a
secondary roost at duck clubs in the Grasslands wetlands complex. Four to
seven observers conducted coordinated counts at several roosts in the
Grasslands and at Mendota Wildlife Area (WA), Fresno County, on 28
December 1995 and 29 January 1996. Three additional counts were taken
at the main Grasslands roost site from 16 to 22 February 1996. From 5
December 1994 to 29 March 1995 and on 16 January 1996, K. Sturm,
other Salton Sea National Wildlife Refuge (NWR) personnel, and volunteers
made five counts at three to five roosts near Calipatria and Imperial in the
Imperial Valley south of the Salton Sea, Imperial County. J. Pike conducted
roost counts at the Prado Basin, Riverside and San Bernardino counties, on
28 February and 28 November 1995 and on 8 January and 26 February
1996. A. Montoya and B. Rasch counted ibis at a roost at Cibola NWR,
Imperial County, on 7 dates from 5 December 1995 to 18 January 1996.

We also examined ibis counts taken by the California Department of Fish
and Game during aerial waterfowl surveys of the Grasslands and Mendota
WA, Fresno County, from November through February, 1980-81 to 1993-
94; surveys for 1994-95 and 1995-96 were not used because they included
only areas closed to hunting, where few ibis occurred.

For additional winter (Nov-Mar) records of White-faced Ibis in California,
we searched the published literature, including the seasonal reports and
Christmas Bird Counts (CBC) in Audubon Field Notes (AFN), American
Birds (AB), and National Audubon Society Field Notes (NASFN); we
checked the unpublished notebooks of the regional editors of the middle
Pacific coast region of NASFN (cited as NB) and contacted regional and local
experts in California. We summarized all CBC data and used them to assess
population trends from 1970 to 1994 and to estimate the number of ibis
wintering on the coastal slope of central and southern California in 1994-
95, when our surveys from the more inland sections of California were most

170

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

complete. CBC data for given years are reported by the beginning year of
the count period (e.g,, 1994 for 1994-95). We graphed data for only the
two inland CBCs that sampled core areas for wintering ibis and had
complete [Salton Sea (south)] or nearly complete (Los Banos, missed 1987)
records from 1970 to 1994. We graphed numbers for all coastal CBCs
(combined) from Ventura County southward from 1980 to 1994, when data
were nearly complete for all sites. We also obtained specimen records of
wintering ibis from the Los Angeles County Museum of Natural History
(LACM), 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
Vertebrate Zoology (WFVZ).

Our designations of various drainage basins in the Central Valley follow the
maps of the Central Valley Habitat Joint Venture (USFWS 1990), except that
we include Mendota WA in the San Joaquin rather than the Tulare Basin.

RESULTS

Historical Status, Pre-1945

Data on the winter status of the White-faced Ibis in California prior to
1945 are very limited. Grinnell and Miller (1944) believed that the White-
faced Ibis was chiefly a summer resident in California and that “in some
years a few have wintered.” They listed the following wintering localities:
between Colusa and Williams, Colusa County, in the Sacramento Valley;
Stockton, San Joaquin County, in the Sacramento-San Joaquin River
Delta; Los Banos, Merced County, in the San Joaquin Valley; and in Los
Angeles County and near San Diego, San Diego County, along the southern
California coast. They also listed records of “migrant or vagrant occur-
rence,” including a 10 December 1925 record from Humboldt Bay,
Humboldt County, which falls outside the main historical or current winter-
ing range (Figure 1). Other sites of pre-1945 winter ibis occurrence
apparently unknown to Grinnell and Miller were Mendota Pool, Fresno
County, and Tulare Lake in the southern San Joaquin Valley (see below and
Appendix) and the Salton Sea, Imperial County (specimen [SDNHM 18121]
collected by B. Bailey on 28 February 1940).

Grinnell et al. (19 18) summarized most of what was known of the former
abundance of ibis wintering in California. Up to that time the largest winter
numbers noted were “several dozen” in the markets of Stockton in the winter
of 1885, “more than a hundred” near Stockton on 9 February 1886, and
“about 200” near Los Banos on 30 October 1914. W. Minturn (unpubl. field
notes) recorded 100 on the Los Banos Game Refuge (now Los Banos WA) on
7 Dec 1935. He also recorded flocks of 300 and 200 on 28 Nov and 10 Dec
1938, respectively, from Tulare Lake (other records in Appendix) and of 12
on 28 March 1936 and 2 on 11 Feb 1939 near Mendota Pool, Fresno
County. Holterhoff (1885) reported 20 from Mission Valley, San Diego
County, on 1 January 1885, but considered a flock of this size “especially
unusual” for the area. The only historical report from the Sacramento Valley
was of two birds between Colusa and Williams, Colusa County, on 23 and 27

171

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

miles

0 50 100 150 200

1 1 ■ 1 i I

100 200 300

kilometers

Figure 1. Historical and recent distribution of the White-faced Ibis in winter in
California. Records since 1945 were not plotted if they fell within the key areas of ibis
concentration, 1990 to 1996 (see Appendix for additional records). County abbrevia-
tions: ALA, Alameda; BUT, Butte; COL, Colusa; CC, Contra Costa; FRE, Fresno;
GLE, Glenn; HUM, Humboldt; IMP, Imperial; INY, Inyo; KER, Kern; KIN, Kings;
LAK, Lake; LAS, Lassen; LA, Los Angeles; MER, Merced; MTY, Monterey; NAP,
Napa; ORA, Orange; RIV, Riverside; SAC, Sacramento; SBT, San Benito; SBE, San
Bernardino; SD, San Diego; SJ, San Joaquin; SLO, San Luis Obispo; SM, San
Mateo; SBA, Santa Barbara; SCZ, Santa Cruz; SOL, Solano; STA, Stanislaus; SUT,
Sutter; TUL, Tulare; VEN, Ventura; YOL, Yolo; YUB, Yuba.

February 1941 (Harwell 1941). The largest number reported at any season
was Belding’s (1905) observation of a northbound passage of 4000 to 5000
ibis near Stockton from 5 to 7 May 1879. But neither he nor other authors
(Grinnell et al. 1918, Grinnell and Miller 1944) speculated on whether or not
these birds may have wintered in the Delta or elsewhere in California.

172

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

Status, 1945 to Present

During the past 50 years, White-faced Ibis have wintered in California
primarily in the Sacramento, San Joaquin, Coachella, Imperial, and Colo-
rado River valleys and on the coastal slope from Ventura County southward
(Figure 1), as documented below by region.

Great Basin Desert. The only winter record of ibis in the Great Basin is of one
bird near Standish on the Honey Lake CBC on 2 1 December 1995 (Appendix).

Interior Coast Range. The only winter record of ibis in the northern
Coast Range is of one bird at Clear Lake, Lake County, from 2 January to
5 February 1981 (Appendix).

Sacramento Valley. Wintering ibis were rare and irregular in the Sacra-
mento Valley through the 1970s, with high counts of 11 in both November
1978 and March 1979 (Appendix). Numbers of sightings increased greatly in
the 1980s, when flocks of up to 225 were seen regularly, usually at or near
Colusa and Delevan NWRs in Colusa County (Appendix, M. Wolder in litt.).
Numbers continued to increase in the 1990s. In 1990, up to 145 wintering
ibis appeared at Sutter NWR, Sutter County, for the first time (M. Wolder in
litt.). Eleven hundred ibis on 12 January 1994 and 1370 on 5 December
1994 at Delevan NWR (M. Wolder pers. comm.) may have represented the
entire population in the Colusa Basin at the time (cf. Table 1). Ibis numbers on
Pacific Flyway Project counts of the Sacramento Valley from November and
January, 1992-93 to 1994-95, ranged from 763 to 3120 birds (Table 1). On
these counts ibis concentrated in the Colusa Basin (Glenn and Colusa counties)
from Willow Creek Waterfowl Management Area (WMA) south through
Delevan NWR, Lurline WMA, and Colusa NWR; in the Butte Basin (Butte,
Glenn, and Sutter counties) from the vicinity of the Little Dry Creek Unit of
Upper Butte Basin WA south through the Butte Sink WMA; in District 10 of

Table 1 Numbers of White-faced Ibis on Pacific Flyway Project Winter
Surveys of the Central Valley (Figure 1), 1993-1995

Subarea

Jan 1993

Nov 1993

Jan 1994

Nov 1994

Jan 1995

Colusa Basin

362

679

883

1275

1507

Butte Basin

401

755

862

1432

21

American Basin

0

102

110

101

75

Sutter Basin

0

116

28

12

6

Yolo Basin

0

25

282

300

2

Delta

0

0

0

13

60

Suisun Marsh 3

0

1

2

—

—

San Joaquin Basin b

1479

3409

2949

3559

2556

Tulare Basin

54

1

0

206

1

Totals

2296

5088

5116

6898

4228

“No surveys of Suisun Marsh were conducted in November 1994 and January 1995.

^Numbers of ibis on these surveys underrepresented the size of the wintering population of the
San Joaquin Basin; see text for possible explanations.

173

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

the American Basin north of Marysville {Yuba County); in the Sutter Basin
(Sutter County) on or near Sutter NWR; and in the southern portion of the
Yolo Bypass (Yolo County) (Figure 1).

Sacra mento-San Joaquin River Delta. After 1886, ibis were not re-
corded in the Delta again until two were reported from Staten Island, San
Joaquin County, on 3 Dec 1988 (NB). That ibis have been recorded on only
3 of 25 Stockton CBCs since 1969 (Table 2) documents the paucity of
recent winter records for the Delta. We found 13 and 60 ibis on 2 of 5 winter
surveys of the Delta from January 1993 to January 1995 (Table 1).

Suisun Marsh. The first winter records of ibis in the Suisun Marsh were of
six birds at Grizzly Island WA, Solano County, in December 1975 and nine
near West Pittsburg, Contra Costa County, in December 1982 (Appendix,
Table 2). That ibis have been recorded on only 3 (all in 1990s) of 26 Benicia
CBCs since 1969 (Table 2) indicates the scarcity of wintering ibis in the
Suisun Marsh. We found only one to two ibis on two of three winter surveys
from January 1993 to January 1994 (Table 1).

San Joaquin Valley. For the last 50 years, the Los Banos area, Merced
County, has been a stronghold of ibis in the San Joaquin Valley. Although
systematic surveys of the entire area are lacking, high numbers from
opportunistic winter counts in the mid-1960s to late 1970s ranged from
100 to 250 (Appendix). Median numbers of wintering ibis on multi-species
surveys of Los Banos WA were 0 in 1969 (min.-max. = 0-1 1 1 , n = 5), 124
in 1970 (min. -max. = 20-200, n = 7), 72 in 1971 (min. -max. = 0-171, n
= 9), 37 in 1972 (min-max. = 0-50, n = 4), and 75 in 1973 (min.-max. =
0-130, n = 7); no ibis were seen on Volta WA on these surveys (R. O. Wilbur
unpubl. data). Median numbers of ibis on the Los Banos CBC increased
from 115 in both the 1970s and 1980s to 595 from 1990 to 1994 (Table 2,
Figure 2). The more comprehensive California Department of Fish and
Game aerial surveys of the Grasslands wetland complex near Los Banos and
Mendota WA, Fresno County, also showed a marked increase in ibis
numbers from 100-300 in the early 1980s, to 500-700 in the mid- to late
1980s, to 2000-2200 in 1992-93 and 1993-94 (Figure 3). Pacific Flyway
counts in these same wetlands between January 1993 to January 1995
ranged from 1479 to 3559 ibis (Table 1).

Ten roost counts from late January to mid-March 1995 at the Willow
Farms duck club in the north Grasslands, however, yielded 4323 to 7872
birds (median = 6050), and two mid-March counts at a smaller roost in the
south Grasslands found 434 and 635 ibis, which were probably additional
(Safran et al. pers. obs.). Coordinated roost counts in the greater Grasslands
area on 28 December 1995 yielded 8682 ibis and on 29 January 1996
10,115-12,115 ibis. Of these, 6064 and about 6000-8000 were at Willow
Farms duck club in the north Grasslands, 2300 and 3235 at one to two duck
clubs in the south Grasslands, and 318 and 880 at Mendota WA (S.
Brueggemann, M. Peters, T. Poole, D. Shuford et al. pers. obs.). Three
additional counts at Willow Farms duck club from 16 to 22 February 1996
ranged from 5439 to 8192 ibis (S. Frazer in litt ).

Up to 145 ibis were reported to the north of the Grasslands along the San
Joaquin River, Stanislaus County, from the late 1970s to the early 1990s
(Appendix). Although ibis numbers may have increased there over this

174

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

period, limited and irregular observer coverage in the 1990s makes assess-
ment of trends difficult (H. Reeve pers. comm.).

After occasional sightings in the late 1940s and 1950s, small numbers of
ibis began to be recorded regularly in the southern San Joaquin Valley,
beginning in the 1980s in the Tulare Lake basin and Goose Lake bottoms
areas of Kings, Tulare, and Kern counties (Appendix, Table 2). Numbers in
these areas appear to have increased in the 1990s (Appendix). The highest
count in the southern San Joaquin Valley was 500 ibis on 30 Dec 1995
foraging at shallow ponds along Brimhall Road southwest of Rosedale, Kern
County and roosting at night about 3.5 km to the south in the Kern River
recharge ponds southwest of Bakersfield (M. Chichester pers. comm.).

Northern and Central California Coast. Except for a 10 December
1925 record for Humboldt County previously cited, and recent records

Figure 2. Trends in numbers of White-faced Ibis on Christmas Bird Counts, 1970 to
1994. Data presented separately for the two key inland counts — Los Banos and
Salton Sea (south) — and for all counts combined on the southern California coast
(Ventura County southward, 1980 to 1994). See Methods for explanation of data
presentation and Table 2 and Appendix for additional CBC data.

175

Table 2 Numbers of White-faced Ibis on California Christmas Bird Counts, 1970-1994°

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177

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

YEAR

Figure 3. Numbers of White-faced Ibis on California Department of Fish and Game
winter (Nov-Feb) waterfowl surveys of the Grasslands wetlands complex around Los
Banos, Merced County, and Mendota WA, Fresno County, 1981-82 to 1993-94.
Data expressed as means (±1 standard error).

there in early November (presumably representing late fall migrants), there
are no winter records of ibis for the California coast north of San Francisco
Bay (Appendix). In the San Francisco Bay area there are only four winter
records (from Napa, Alameda, and San Mateo counties; Appendix). In Santa
Cruz County, one to six ibis have been recorded irregularly in winter since
1991 (Appendix). In Monterey County, aside from one sighting in 1953, all
winter records are post-1980 and range from one to seven individuals each
(Appendix, Table 2). The lone record for San Benito County is of one ibis at
Paicines Reservoir on 24 December 1995 (D. Serdehely fide K. Van Vuren).

Southern California Coast. Ibis have continued to winter on the south-
ern California coast in recent decades. They occur irregularly in San Luis
Obispo and Santa Barbara counties and regularly, though locally, from
Ventura County south to the Mexican border (Figure 1, Table 2, Appendix).
The core areas of most regular occurrence are near Point Mugu, Ventura

178

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

County; the Prado Basin and adjoining upper Santa Ana River Valley area of
western San Bernardino and Riverside counties; and lowlands of northwest-
ern San Diego County from the Santa Margarita River to the San Dieguito
River (Del Mar and Lake Hodges). The largest numbers have been at a
nighttime roost at the Prado Basin, where there were 630 birds on 28
February 1995 and 680 birds on 26 February 1996 (J. Pike in litt.). The
Santa Ana River Valley CBC, on which ibis numbers have increased greatly
from the 1980s to the 1990s, samples only a portion of the agricultural
fields of that river valley and the Prado Basin used by ibis (L. LaPre in litt.).

Reports of declines in wintering ibis on the southern California coast in
the 1970s (Remsen 1978; AB 25:627, 29:741) seem equivocal in light of
CBC data. Median ibis numbers on the Orange County (coastal) CBC
decreased from 5 (min. = 0, max. = 16) from 1960 to 1969 to 0.5 (min. =

0, max. = 8) from 1970 to 1979, whereas on the Oceanside-Vista-
Carlsbad CBC they increased from 2 (min. = 0, max. - 20) to 9.5 (min. =

1, max. = 68) over a similar period. Overall ibis numbers increased on the
southern coast in the 1980s and, particularly, the 1990s (Table 2, Figure 2).
This was not universal, though; despite increases on most counts, ibis
numbers decreased from the 1980s to the 1990s on the Rancho Santa Fe
and San Diego counts (Table 2). During this period, however, there was
inconsistent observer coverage of potential ibis habitat on the Rancho Santa
Fe CBC, and decreases in ibis numbers on the San Diego CBC are
attributable to the termination of alfalfa growing and abandonment of moist
agland in the Tijuana River Valley, the only area where the species was ever
regular on the count (P. Unitt pers. comm.).

Imperial and Coachella Valleys. Although first recorded in the region in
winter in 1940, by the late 1940s and early 1950s up to 3500 White-faced
Ibis were being reported from the vicinity of the Salton Sea, Imperial County
(Appendix). By the mid-1950s numbers had declined sharply, and through
the 1970s the highest counts were in the low hundreds (Appendix).
Numbers increased greatly in the 1980s to 1990s, as evidenced by oppor-
tunistic January counts of 450 near Seeley in 1983 and 6000 near Brawley
in 1989 (Appendix) and by sharp upward trends on the Salton Sea (south)
(Table 2, Figure 2) and Salton Sea (north) CBCs (Table 2). The true
magnitude of the increase was revealed by Pacific Flyway Project counts of
up to 16,000 ibis at various nighttime roosts in agricultural lands in the
Imperial Valley in 1994-95 and 1995-96 (Table 3).

Colorado River Valley. Rosenberg et al. (1991) considered the White-
faced Ibis a rare but regular winter visitor along the lower Colorado River
Valley. They did not list any specific winter records for the California side of
the river but did cite counts of up to 50 ibis for adjacent Arizona. On a 8
December 1993 Pacific Flyway Project survey, 95 ibis were found in agricul-
tural lands south of Blythe, Riverside County, California (B. W. Anderson in
litt.). In recent years, wintering ibis have been associated with agricultural fields
on the California side of the Colorado River Valley in two disjunct areas: from
Parker Dam south to Cibola NWR and from Imperial Dam south to Yuma (B.
W. Anderson pers. comm.). Numbers of ibis at a roost north of Oxbow Lake,
Cibola NWR, Imperial County, that reached a peak of 350 on 5 December
1995 had dwindled to 40 by 18 January 1996 (B. Rasch in litt.).

179

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

Table 3 Numbers of White-faced Ibis Counted at Evening
Roosts at Various Sites in the Imperial Valley, Imperial County,
Winters 1994-95 and 1995-96°

1994

1995

1996

Roost Sites

Dec

Jan b

Feb

Mar

Jan c

Ramer Lake d

7935

1007

2144

7100

4046

Ostercamp duck dub e

2500

115

dry

dry

3500

Mesquite Lake duck club e

5400

1

3000

2169

700

McElvaney duck club e

—

—

838

—

—

Wilderness Unlimited
duck club e

—

3420

3354

435

Totals

15,835

1123

9402

12,623

8681

a Data from K. Sturm et a!./Sa!ton Sea NWR.

b Heavy rain showers prior to count may have influenced numbers.

‘Windy at time of count, and many ibis already at roost sites when survey began,
making them hard to count.

^Located 4,5 km S of Calipatria.

“Located within an 8-km arc NE to SE of Imperial.

Other Sites in the Interior of Southern California. One or two ibis have
been recorded in winter in Death Valley, Inyo County, at China Lake, Kern
County, at Corona and the San Jacinto Valley, Riverside County, and near
Lancaster, Los Angeles County (Appendix).

Estimated Winter Population Size: 1994-95

From counts we estimated that a minimum of 27,800 to 28,800 ibis were
wintering in California in 1994-95. Of these, 2000-3000 were in the
Sacramento Valley (Table 1), < 60 in the Sacramento-San Joaquin River
Delta (Table 1), at least 13 in the Suisun Marsh (Benicia CBC), up to 8000
in the Grasslands wetlands area in the San Joaquin Valley, < 200 in the
Tulare Basin of the San Joaquin Valley (Table 1), at least 570 in the
Coachella Valley [Salton Sea (north) CBC), up to 16,000 in the Imperial
Valley (Table 3), at least 95 along the Colorado River in the Palo Verde
Valley, Riverside County (B. W. Anderson in litt.), and at least 873 along the
coastal slope of central and southern California (630 in Prado Basin,
Riverside Co. — J. Pike in litt.; rest on various CBCs, NASFN 49:788-835).

Habitat Use

Habitat use by wintering ibis in California varies by region. On five winter
surveys of the Sacramento Valley, ibis were concentrated in agricultural
fields and managed wetlands (Table 4). Agricultural fields supported an
average of 66% (standard error (SE) = 6.45, min. = 52%, max. = 87%] of
all ibis on these surveys; rice stubble fields were the single most important
habitat, as they held on average 53% (SE = 7.98, min. = 23%, max. = 79%)
of all ibis. State, federal, and private wetlands combined supported an

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WHITE-FACED IBIS IN WINTER IN CALIFORNIA

average of 28% (SE = 6.90, min. = 7%, max. = 47%) of the ibis. Pasture
lands supported 6% of all ibis on one of the five surveys. Flying birds that we
were unable to assign to habitat ranged from 0% to 14% of the ibis on the
surveys. We believe the percentages reported in Table 4 reflect the habitat
distribution of foraging rather than roosting ibis. Despite the presence of
apparently suitable foraging habitat throughout much of the Sacramento
Valley during our winter surveys, all ibis recorded were within five kilometers
of managed wetlands. We did not locate nighttime ibis roosts in the
Sacramento Valley, but suspect that they were in managed wetlands, as in
the San Joaquin and Imperial valleys.

It was difficult to compare ibis use among habitats in the San Joaquin
Valley because we did not survey most agricultural fields directly. At the
Grasslands wetlands, much larger ibis numbers at evening roosts suggest
that we either greatly undercounted ibis foraging during the day and/or
missed many ibis because of minimal coverage of agricultural lands. Informa-
tion on use of agricultural habitats in the San Joaquin Valley is fragmentary.
The largest number reported from agricultural lands in winter was about 500
in an irrigated pasture near Los Banos in winter 1994-95 (D. Wollington
pers. comm.). Safran observed about 200 ibis foraging in flooded alfalfa
fields west of Kesterson NWR, Merced County, on 18 March 1995. During
March that year, water levels in nearby duck clubs were high from an
extended period of heavy rain, and ibis were rarely seen foraging in these
wetlands. Hundreds of ibis flying south along the San Joaquin River in
northern Merced County on 1 1 February 1995 had likely been foraging in
nearby pasture lands (S. Frazer pers. comm.). G. Gerstenberg and H. Reeve
(pers. comm.) also have seen smaller numbers of ibis foraging periodically in
pastures and other agricultural fields in Merced and Stanislaus counties in
winter.

On five ground counts in managed wetlands in the Grasslands, about
66.6% of the ibis (SE 6.54, min. = 47%, max. = 84%) were on private duck

Table 4 Percentage of White-faced Ibis Found in Vari-
ous Habitats on Surveys of the Sacramento Valley, Win-
ters 1992-93 to 1994-95

Habitats

Nov

1993

Nov

1994

Jan

1993

Jan

1994

Jan

1995

Managed refuges

7

1

8

7

41

Managed duck clubs

0

35

5

31

6

Pasture lands

0

0

0

0

6

Rice stubble fields

79

57

53

53

23

Fallow fields

0

0

34

0

23

Alfalfa fields

0

<1

0

0

0

Flying birds

14

6

0

9

0

Total numbers

1677

3120

763

2165

1611

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WHITE-FACED IBIS IN WINTER IN CALIFORNIA

clubs and 33.4% {SE = 6.54, min. = 16%, max. = 53%) were on state and
federal wildlife refuges. This suggests that on average ibis showed no
preference for either type of wetland, as private lands make up about two-
thirds and public lands about one-third of the wetlands in the Grasslands (T.
Poole pers. comm.). At the large nighttime roost at the Willow Farms duck
club in the Grasslands, ibis were standing in shallow open water at the center
of a 52.6-ha pond bordered on the margins with 90% emergent vegeta-
tion — 75% Broad-leaved Cattail ( Typha lati folia) and 25% Hardstem Bul-
rush (Scirpus acutus) {Safran pers. obs.) At Mendota WA in December 1995
ibis were roosting amid annual vegetation up to a meter tall on slightly
submerged or exposed islands in ponds (S. Brueggemann in litt.).

In the Coachella Valley-Salton Sea-Imperial Valley area, the vast majority
of the thousands of ibis appeared to forage in irrigated agricultural lands,
particularly alfalfa and wheat (K. Sturm pers. comm ). U. S. Fish and Wildlife
aerial waterfowl surveys of all key wetland habitats there on 15 February and
23 March 1994 found only 75 and 30 ibis, respectively (K. DesRoberts in
litt.). By contrast, all large nighttime ibis roosts in the Imperial Valley were on
managed wetlands (Table 3), where birds roosted either in open ponds, in
stands of drowned Saltcedar trees ( Tamarix chinensis), or in cattails (K.
Sturm pers. comm.). Ibis wintering near the Colorado River also concen-
trated their foraging in alfalfa fields (B. W. Anderson pers. comm.).

On the coastal slope of central and southern California wintering ibis use
a variety of habitats including marshy pasture lands, managed or natural
freshwater marsh, pond edges and lakeshores, and, occasionally, the mar-
gins of brackish lagoons and estuaries (R. L. Barber, D. DesJardin, L. LaPre,
D. Roberson, K. Weaver, and D. Willick in litt.).

DISCUSSION
Historical Status

It is difficult to compare the picture of the historical status of wintering ibis
in California painted by Grinnell and Miller (1944) to that which we have
compiled for the last half century. Grinnell and Miller (1944) listed only 5
sites where ibis were known to winter, but from unpublished sources we have
located three additional sites where ibis wintered prior to 1941. Two of
these sites — the Mendota area and the Salton Sea — are currently of major
importance to wintering ibis. The Tulare Lake area currently does not
support large numbers of wintering ibis, but given that under favorable
conditions it was formerly the largest freshwater lake and marsh system west
of the Mississippi River (Johnson et al. 1993, Thelander and Crabtree
1994), it seems likely that this site, along with the Los Banos area, had the
potential historically to have been a stronghold of wintering ibis in Califor-
nia. In fact, the highest numbers recorded before 1940 were from Tulare
Lake, the Los Banos area, and the Delta.

Grinnell and Miller (1944) implied that the ibis formerly wintered only
irregularly in California. By contrast, unpublished observations by W. Minturn
indicate that in the late 1930s and early 1940s, at least, ibis were of regular
occurrence in the San Joaquin Valley. This single observer recorded ibis in

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WHITE-FACED IBIS IN WINTER IN CALIFORNIA

winter in this region in at least 6 of the 8 years from 1935 to 1942 and had
at least two sightings in each of 4 years (Appendix). Grinnell et al. (1918)
concluded that because of the small winter population at the time hunting
probably had little effect on ibis numbers in California. But the state’s having
from 1866 to 1915 an October to March open season and a bag limit of 20-
25 ibis argues that the species must have occurred at least somewhat
regularly to warrant such regulations. Prior to these regulations, Kennedy
(1859) and Heermann (1859), respectively, reported that ibis were “very
common” in the market in San Francisco and often on sale in the California
markets.

The remark by Grinnell et al. (1918: 1) that California up to that time had
a small number of careful observers, coupled with the difficulty then of travel
to remote parts of the state, must have biased these authors’ appreciation of
the status of ibis in comparison to our knowledge from recent decades, when
both observer coverage and ease of travel have increased greatly. Today the
Mendota area still gets limited observer coverage as reflected in the few
reports of wintering ibis there (Appendix) even in the 1980s and 1990s
when ibis numbers were expanding rapidly and hundreds were seen on
systematic surveys. By contrast, the Los Banos area has had much better
coverage, and during the species’ population low for the last half century in
the 1970s the species was still recorded annually (Appendix). It is unclear
whether ibis were not recorded in winter in the Imperial Valley until 1940
because they first colonized the area then, possibly in response to changing
agricultural practices, or because they were previously overlooked. Although
Grinnell and his colleagues made superlative efforts to document the
avifauna of the state via various monographs (e.g., Grinnell 1923, Grinnell
et al. 1930), no substantial historical publications exist on the waterbird
avifauna of most of the state’s great (or formerly great) interior wetlands and
lakes, such as Tulare, Mono, and Owens lakes and the Salton Sea (see Jehl
1994). Hence, our historical knowledge of the wetland avifauna of these
areas and the Central Valley is fragmentary at best.

It is also difficult to compare the numbers of ibis reported by Grinnell et al.
(1918) to those from similar unsystematic surveys in recent decades. For
example, the low numbers cited above for the Los Banos area prior to 1940,
when observers were also few, ranged up to 200 ibis. By contrast, when
multi-observer systematic surveys of most wetland habitat at the Grasslands
and Mendota WA in the 1990s found up to 3500 ibis and roost counts found
up to 10,000-12,000, other single observers making occasional observa-
tions reported numbers only up to the 300-500 range (Appendix). Simi-
larly, during studies of foraging ibis in duck clubs in the Grasslands in 1994-
95, Safran’s records of 49 scattered flocks with an average size of 18 birds
(SE = 4.27, min. = 1 , max. 183) did not even hint at the total size of the ibis
population documented by roost counts.

In the post-Grinneil and Miller era, both an increase in observers and the
publication of seasonal reports in Audubon Field Notes and its predeces-
sors improved the documentation of ibis numbers. Still, through the 1950s
and 1960s, data for most regions of the state remained too limited to reveal
populations trends. An exception to this was in the Imperial Valley, where
high counts of up to 3500 ibis in the late 1940s and early 1950s dropped

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WHITE-FACED IBIS IN WINTER IN CALIFORNIA

to the low 100s by the 1970s, when numbers appeared to reach a nadir
statewide.

By far the best documented population change in wintering ibis in
California was from the 1980s through the 1990s, when our compilation of
ground and aerial wetland surveys, roost counts, CBCs, and anecdotal
observations all showed a many-fold increase over numbers in the 1970s.
Although population estimates of wintering ibis in 1994—95 were the
highest yet recorded this may not necessarily have been the peak period of
ibis abundance in California, given the limited prior data available. For
example, the high counts of up to 3500 ibis in the Imperial Valley in the
1940s and 1950s may have rivaled those in the 1990s. In the latter period,
single-observer counts (comparable to those in the earlier period) rarely
exceeded 1000 birds (a count of 6000 in 1989 was exceptional; Appendix),
whereas only by roost counts were 16,000 ibis found in 1994.

Causes of Recent Population Increases

We suspect that recent large increases in the wintering White-faced Ibis
population in California reflect increased numbers on the breeding grounds,
particularly in the western portion of the range. Despite a lack of rangewide
surveys of breeding colonies, Ryder and Manry (1994) concluded that White-
faced Ibis populations have increased in the West in the last two decades
because of improved nesting habitat management, increased planting of
alfalfa used by foraging ibis, the ban on DDT and other pesticides in the
1970s, and improved breeding success at major colonies. At Lower Klamath
NWR, Siskiyou County, a large increase in nesting ibis from the 1980s to the
1990s appears to have been aided by the conversion of 1600 hectares of
planted grain crops to new marshlands, since used extensively as colony sites,
and changing water management practices improving ibis foraging habitat (D.
Mauser pers. comm.). On a broader scale, efforts in the 1980s to enhance
habitat quality and increase the extent of wetlands in California for waterfowl
(Heitmeyer et al. 1989) also may have benefited wintering ibis. Fieury and
Sherry (1995) reported dramatic increases in ibis and other colonial waders in
Louisiana from 1949 to 1988, particularly during the last 20 years, which
they attributed to an increase in acreage of crayfish aquaculture. By contrast,
we know of no large increases in habitat used by ibis at the key California
wintering areas at the Grasslands (T, Poole pers. comm.) or the Imperial Valley
that would explain recent increases in the wintering population. In the Imperial
Valley, acreage of alfalfa increased somewhat from the 1970s to the 1980s
while acreage of other field crops, some of which probably were also used by
ibis, decreased sharply (Figure 4).

That ibis readily shift breeding sites as fluctuating water levels affect
habitat conditions makes assessment of rangewide population trends diffi-
cult. Large population increases in the 1980s and early 1990s of breeders
at the western edge of the range in the Harney Basin, Oregon, and Lower
Klamath NWR, California (and in eastern Idaho), may have resulted at least
in part from displacement of ibis from Great Salt Lake, Utah, by flooding in
the early and mid-1980s (Ivey et al. 1988, Taylor et al. 1989) or shifting
among various colonies during droughts in the late 1980s and early 1990s.
The key colonies in the eastern Great Basin at Great Salt Lake were reduced

184

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

80% from 1982 to 1985 by flooding (Ivey et al. 1988). Conversely, Oregon
populations increased from <1000 pairs in the early 1980s to 2595 pairs in
1987 {Ivey et al. 1988), and the Lower Klamath population increased from
12 pairs in 1986 to 3900 pairs in 1994 (D. Mauser pers. comm.). These
rates of increase seem too rapid to be from recruitment of locally produced
young (Ivey et al. 1988). In the Lahontan Valley, Nevada, there was no
unidirectional population trend in the 1980s. Instead, a population that
exceeded 3000 pairs (peak 5930) in 7 of 12 years from 1979 to 1990
dropped to 0 and 450 pairs, respectively, during the extreme drought years
of 1977 and 1992 (Henny and Herron 1989, L, Neel in litt.). A dearth of
non-breeders remaining during these droughts suggests that birds from
Nevada shifted to other areas to breed.

Limited band-recovery data also suggest that the increase in the wintering
ibis population in California mirrors the western expansion and productivity
of breeding ibis. The 11,462 ibis banded in the Great Basin/Intermountain
West region from 1916 to 1994 produced 172 winter (Nov-Mar) recoveries
(National Biological Service, Bird Banding Lab unpubl. data; Ryder 1967).
California accounted for 2 of 15 recoveries from 3597 ibis banded in the

ALFALFA OTHER FIELD CROPS

Figure 4. Acreage of irrigated alfalfa and other field crops in the Imperial Valley,
Imperial County, California, 1968 to 1995. Data from Imperial Irrigation District via
J. Setmire, Bureau of Reclamation.

185

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

western portion of the region (California, Oregon, Nevada) and 1 of 157
recoveries from 7865 banded in the eastern portion of the region (Idaho,
Utah). Although the number of recoveries from California is too low to allow
for a powerful statistical test, these data suggest that ibis wintering in
California are more likely to originate from the western rather than the
eastern portion of the breeding range. The small sample size of winter
recoveries also suggests that many ibis wintering in the San Joaquin Valley
of California may be coming from breeding colonies in Oregon or perhaps
from nearby Lower Klamath NWR, California, where thousands of ibis are
now breeding (banding first began in 1995; J. Hainline pers. comm.). All
three winter recoveries in California were from the San Joaquin Valley (2
from Oregon colonies [1572 banded], 1 from Utah [6674 banded]). Color-
banding of 1205 ibis in 1995 at various breeding sites in the western Great
Basin has yielded promising preliminary results in unraveling the species’
migratory pathways to wintering grounds (B. Henry and E. Kelchlin pers.
comm.). As of late January 1996, of 15 winter (Nov-Jan) recoveries of ibis
color-banded in the Lahontan Valley, Nevada, 10 were from California (8
from Imperial Valley, 1 from San Joaquin Valley, 1 from interior Monterey
County), 3 from the Arizona side of the Colorado River at Cibola NWR, and
2 from Bosque del Apache NWR, New Mexico (Kelchlin 1996, E. Kelchlin
pers. comm.). As at least six of these ibis, including adults, were banded in
September, they may have represented birds from other colonies that were
staging at Stillwater NWR during migration.

Habitat Use

Although our data document broad patterns of habitat use on the
wintering grounds in California, there is much more to be learned about ibis
foraging and roosting needs. Visual observations or radio-tracking of ibis
coming to or leaving roosts would be valuable to better determine their local
dispersal and habitat use patterns. Observations in the Grasslands area
suggest that wintering ibis may respond opportunistically to changing food
resources, particularly by shifting from managed wetlands to agricultural
lands after heavy winter rains. Similarly, during extreme flooding in the
Sacramento Valley in January 1995, ibis were forced from favored foraging
areas (Shuford and Page pers. obs.). Detailed work has been conducted on
foraging-site preferences of ibis in agricultural fields near breeding colonies
in Nevada (Bray and Klebenow 1988), but little such information is available
for the wintering grounds and how ibis respond to temporal changes in
habitat conditions.

Threats to Wintering Ibis

Ryder and Manry (1994) reported that the size of the North American
nesting population of the White-faced Ibis decreased precipitously in the
1960s and 1970s because of pesticides and loss of habitat to drought and
drainage. In California, a loss of 91% of the state’s wetlands (Dahl 1990),
much of it prior to the 1960s (Frayer et al. 1989), must have had a great
impact on both breeding and wintering populations of ibis. It is unclear to what
degree an increase in agricultural habitats used by ibis has offset losses of
wetlands. Nevertheless, that the increase in the number of ibis wintering in

186

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

California in the 1980s and 1990s occurred after a period of great habitat loss
emphasizes the need to protect habitat that may be used intermittently by a
nomadic species that is responding to habitat conditions over a broad range.

Although most organochlorine pesticides have been banned for use in the
U.S. since the 1970s, White-faced Ibis are still being affected. At Carson Lake,
Nevada, in 1985 and 1986, DDE accumulation affected about 40% of the
breeding ibis population and lowered overall reproductive success by about
20% (Henny and Herron 1989). Investigations from 1989 to 1991 at Lower
Klamath and Colusa NWRs also found high levels of DDE and eggshell
thinning in ibis (S. Schwarzbach in litt.). At Colusa, at least, reproductive
success was impaired, and eggshell thinning was similar to that in the DDE-
contaminated colony at Carson Lake (Dileanis et al. 1992, S. Schwarzbach in
litt.). Birds from these Nevada and California breeding colonies are thought to
have been exposed to pesticides on the wintering grounds (Henny and Herron
1989, S. Schwarzbach pers. comm.), perhaps to DDT used recently in
Mexico (Henny and Herron 1989). Between 1986 and 1990, wintering
White-faced Ibis in the Imperial Valley had DDE levels in their tissues similar to
those found in ibis eggs at Carson Lake, but, in contrast, appeared to
accumulate DDE by foraging in agricultural fields on invertebrates that were
concentrating pesticides remaining in the soil from historical, rather than
recent, use (Setmire et al. 1993). Levels of DDE residues in the Imperial Valley
are among the highest in the U. S. (J. Bennett pers. comm.). Comparisons of
the various organochlorine compounds in ibis samples from Colusa NWR and
the Imperial Valley suggest that the Colusa birds were not wintering in the
Imperial Valley (S. Schwarzbach pers. comm.).

When agricultural drainage was formerly a main source of water for the
Grasslands wetlands in the San Joaquin Valley, selenium accumulated to
levels sufficient to cause reproductive harm to various birds (Ohlendorf et al.
1987). Since a change to an uncontaminated supply of water for the
Grasslands in 1985, selenium levels have declined steadily, though concen-
trations in some species are still above those associated with impairment of
reproduction (Hothem and Welsh 1994a, 1994b; F. L. Paveglio pers.
comm.). Although agricultural fields in the area might prove to be a source
of pesticide contamination, this important foraging habitat for ibis serves as
a buffer from urbanization that might replace or degrade the adjacent
wetland habitat upon which ibis and many other wetland species depend
(Fredrickson and Laubhan 1995, Thomas Reid Associates 1995).

More work is needed in both the U. S. and Mexico to assess whether
current wintering habitat is too contaminated to provide for the long-term
health of ibis populations.

Monitoring

Ryder and Manry (1994) recommended long-term monitoring of ibis popula-
tions via coordinated, standardized surveys covering colonies throughout the
entire breeding range. They did not make any recommendations regarding
monitoring of wintering populations. We feel that population monitoring in
wintering areas would complement that on the breeding grounds by identifying
key wintering habitats, determining trends in winter distribution and abundance,
and pinpointing areas where wintering ibis face risks to their survival.

187

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

Current methods are not adequate to monitor wintering populations of
ibis. Data gathered opportunistically or by Christmas Bird Counts have only
a limited ability to track trends in winter populations of ibis. Aerial surveys in
the Grasslands of the San Joaquin Valley have proved valuable for detecting
trends of ibis using local wetlands, but these counts give only an index of
population trends for that whole region. Because prior aerial surveys were
designed to monitor waterfowl populations they did not cover agricultural
lands and often concentrated their efforts on zones closed to hunting, which
few ibis use. Although aerial surveys could be used to monitor ibis popula-
tions, they would work best if surveys for ibis were conducted separately
from those for waterfowl and all ibis habitats were covered thoroughly.

We believe that annual coordinated roost counts taken at all key ibis
wintering areas over a short period would be the best method to monitor
population trends of wintering ibis. Roost counts need survey only a few sites
where ibis concentrate after foraging over a large area and can be conducted
by relatively few people at low cost. Because White-faced Ibis are opportu-
nistic and may shift wintering areas, local foraging areas, and roost sites over
relatively short periods, to be successful monitoring efforts will also have to
be opportunistic. Periodic aerial surveys might be best used to identify
locations of roosts.

SUMMARY

Historical data on the distribution and abundance of the White-faced Ibis
in winter in California are limited. Winter numbers declined to a low point in
the 1970s, began to increase in the 1980s, and increased sharply in the
early 1990s. Winter surveys in 1994-95 found at least 28,000 ibis in
California, with the largest concentrations in the Sacramento Valley (2000-
3000), the Grasslands of the San Joaquin Valley (8000), and the Imperial
Valley (16,000). Additional surveys in 1995-96 estimated about 10,000 to
12,000 ibis in the greater Grasslands area. The wintering population in
California likely increased as a byproduct of a westward shift in the
abundance of breeding ibis, perhaps caused by a combination of flooding at
Great Salt Lake, Utah, in the 1980s, similar shifts caused by drought
conditions in the late 1980s to early 1990s, and improved habitat conditions
on the breeding grounds in Oregon and northern California. Most ibis
wintering in California forage in managed wetlands or agricultural fields, and
private lands provide the majority of foraging habitat in all of the state’s main
wintering areas. Even in areas, such as the Imperial Valley, where ibis forage
mostly in fields, managed wetlands are extremely important as nighttime
roost sites. Ibis wintering in California remain at risk from accumulation of
toxins, particularly in the Imperial Valley where they concentrate DDE
residues that persist in the soil from historical use. Population monitoring on
the wintering grounds is needed to identify key wintering areas, assess trends
in wintering populations, and pinpoint areas where wintering ibis may face
risks to their survival.

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WHITE-FACED IBIS IN WINTER IN CALIFORNIA

ACKNOWLEDGMENTS

Major funding for the Pacific Flyway Project was provided by the Bay Foundation
of Morro Bay, the Bradford Foundation, the Bureau of Reclamation, the Central
Valley Habitat Joint Venture, Chevron USA Inc. , the Dakin Foundation, the David and
Lucille Packard Foundation, the Dean Witter Foundation, Ducks Unlimited,
Genentech, the Walter and Elise Hass Fund, the J. M. Long Foundation, the Marin,
Morro Coast, and Stockton chapters of the National Audubon Society, the National
Fish and Wildlife Foundation, the San Francisco Foundation, the Strong Foundation,
and the True North Foundation. Funding and support for Safran’s research on ibis in
the Grasslands was provided by the Oakland Land and Cattle Company, the
Grasslands Water District, California Department of Fish and Game, the Garden Club
of America, the Marin Rod and Gun Club, Redwood Region Audubon Society, and
the Department of Wildlife stockroom at Humboldt State University.

The Pacific Flyway Project has become a large-scale, cooperative venture, and we
are grateful to all who have supported our work. We would particularly like to thank
everyone who participated in our surveys and the numerous landowners and land
managers that have graciously allowed access to their lands without which our studies
would not have been possible. The Grassland Water District and Tim Poole were
invaluable in organizing counts that enabled us to survey both private and government
lands in the Grasslands wetlands. The following individuals gave crucial help in
counting ibis at nighttime roosts: Maurie Beck, Tom Bergemann, Joe Cayting, Mike
Chouinard, Mark Colwell, Scott Frazer, Jen Frincke, Craig Isola, Tony Leonardini,
Peter Metropulos, Bob Nardi, Mike Peters, Tim Poole, Mike Taft, and Oriane Williams
in the Grasslands; Steve Brueggemann at Mendota WA; Ken Sturm in the Imperial
Valley; Jim Pike at the Prado Basin; and Angel Montoya and Barbara Rasch at Cibola
NWR.

Many thanks to John Beam and Greg Gerstenberg for allowing us to use ibis counts
from California Department of Fish and Game winter waterfowl surveys of the
Grasslands, Eric Kelchlin for supplying unpublished data on winter recoveries of color-
banded ibis, Helen Green and Daniel Singer for providing records from the files of the
editors of the middle Pacific coast region of National Audubon Society Field Notes ,
and Brett Hoover and Kathy Klimkiewicz of the National Biological Service, respec-
tively, for providing computerized Christmas Bird Count data for California and band-
recovery data for North America. Lynne Stenzel gave helpful advice on how best to
present CBC and band-recovery data. The following individuals kindly provided
additional information or unpublished ibis records: Jack Allen, Bert Anderson,
Richard L. Barber, Edward C. Beedy, Jewel Bennett, David Blue, Karen Cebra, Mark
O. Chichester, Carla Cicero, Don DesJardins, Kevin DesRoberts, Bruce E. Deuel,
Tom M. Edell, Joe Engler, Krista Fahy, Scott Frazer, Kimball Garrett, Freeman F. Hall,
Jr., Rob Hansen, Tom and Jo Heindel, Roger Hothem, Gary Ivey, Ned Johnson,
Larry LaPre, Joan E. Lentz, H. Elliot McClure, Bob McKernan, Tim Manolis, Dave
Mauser, Peter J. Metropulos, Larry Neel, Michael A. Patten, Don Paul, Fred Paveglio,
Tim Poole, Bernadette Ramer, Harold Reeve, Fritz Reid, Mick Rivera, Don Roberson,
Steve Schwarzbach, Arnold Small, James H. Snowden, David L. Suddjian, Sam
Sumida, Philip Unitt, Ken Weaver, Roger Wilbur, Doug Willick, Mike Wolder, and
David Yee. Kimball Garrett, Kathy Molina, Ronald A. Ryder, and Philip Unitt kindly
provided helpful comments on an earlier draft of the manuscript. Last but not least we
would like to thank our pilots Bob Van Waggenen and, especially, Terry Pinder for
their expert and safe flying on our aerial surveys. This is Contribution 720 of Point
Reyes Bird Observatory.

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WHITE-FACED IBIS IN WINTER IN CALIFORNIA

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Dileanis, P. D., Sorenson, S. K., Schwarzbach, S. E., and Maurer, T. C. 1992.
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Fleury, B. E., and Sherry, T. W. 1995. Long-term population trends of colonial
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on Louisiana populations. Auk 112:613-632.

Frayer, W. E., Peters, D. D., and Pywell, H. R. 1989. Wetlands of the California
Central Valley: Status and trends. U. S. Fish & Wildl. Serv., 911 NE 11th St.,
Portland, OR 97232-4181.

Fredrickson, L. H., and Laubhan, M. K. 1995. Land use impacts and habitat
preservation in the Grasslands of western Merced County, California. Grasslands
Water District, 22759 S. Mercey Springs Rd., Los Banos, CA 93635.

Garrett, K., and Dunn, J. 1981. Birds of Southern California: Status and Distribution.
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Grinnell, J. 1923. Observations upon the bird life of Death Valley. Proc. Calif. Acad.
Sci., 4th ser. 13:43-109.

Grinnell, J., Bryant, H. C., and Storer, T. 1. 1918. The Game Birds of California.
Univ. Calif. Press, Berkeley.

Grinnell, J., Dixon, J., and Linsdale, J. M. 1930. Vertebrate natural history of a
section of northern California through the Lassen peak region. Univ. Calif. Publ.
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Grinnell, J., and Miller, A. H. 1944. The distribution of the birds of California. Pac.
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Harris, S. W. 1991. Northwestern California Birds: A Guide to the Status, Distribu-
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Holterhoff, G. 1885. The Glossy Ibis and Avocet at San Diego, Cal. Auk 2:31 1-312.

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191

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

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13.

Accepted 5 August 1 996

APPENDIX

Winter (Nov-Mar) Records of the White-faced Ibis in California, 1908-09
to 1995-96, Other Than Those Listed or Summarized in the Text

Great Basin Desert

Lassen County: Bass Hill WA, near Standish, 21 Dec 1995 (T. D. Manolis).

Interior Coast Range

Lake County: Anderson Marsh, 1, 2 Jan 1981 (AB 35:331); Clear Lake CBC, 1,
4 Jan 1981 (AB 35:705); 3 km S of Lower Lake, 1, 5 Feb 1981 (AB 35:331, NB);
all records probably pertain to the same bird.

Sacramento Valley

Glenn County: 11 km S of Willows, 1, 16-18 Mar 1955 (AFN 9:354, NB);
Willows, 1, 16 Mar 1976 (AB 30:761); Sacramento NWR, 5 individual records, Dec-
Jan 1965-66 (AFN 20:454); present, 12 Feb 1973; 1, 16 Mar 1976 (NB); 11, 4 Nov
1978 (AB 33:210); 1-3, Nov 1982; 33, 31 Jan 1984; 40, winter 1983-84; 25, 3
Jan 1985; 50, 22 Nov 1986; McGowan Ranch, Biggs-Afton Rd., 25, 2 Dec 1990
(NB).

Butte County: 1.6 km E of Butte Creek at Gridley-Colusa Hwy, 9, 24 Nov 1987;
Gray Lodge WA, 1, 17 Mar 1981 (NB); 3, 20 Dec 1986 (AB 41:322); 2, 27 Nov
1987 (NB); 80, 3 Dec 1988 (B. E. Deuel); 60, 1 Dec 1990 (E. C. Beedy); 4, 26 Dec
1991; 1,4 Dec 1993; 1,28 Dec 1993 (B. E. Deuel); 65, 4 Dec 1991 (NB); 6, 28 Dec
1995 (E. C. Beedy); W of Biggs, 1, 14 Nov 1993 (T. D. Manolis); Little Dry Creek
Unit, Upper Butte Basin WA, 7, 16 Nov 1989 (J. H. Snowden); 400, 5 Dec 1990 (B.
E. Deuel); SW of Dayton, 1 10+, 2 Nov 1995 (J. H. Snowden).

Colusa County (other records for Colusa and Delevan NWRs available via Sacra-

192

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

mento NWR complex): Delevan NWR, 3, 3 Nov 1973 (NB); 11, 16 Mar 1979 (AB
33:803); 45, 11 Nov 1982; 80, 27 Jan 1984; 60, 28 Jan 1985; 50-60, winter
1986-87; 12,13 Feb 1991 (NB); Colusa NWR, 30, winter 1981-82; 75, 19-22 Jan
1983; 100, 29 Dec 1983 (NB); 125, 1 Dec 1984 (AB 39:97); 225, 17 Dec 1985
(AB 40:325); 50-60, winter 1986-87; 10, 26 Nov 1987; 3, 11 Dec 1988; 8, 11
Nov 1989 (NB); 40, 24 Nov 1990 (E. C. Beedy); 23, 23 Dec 1990 (NB); 60, 28 Nov
1994 (E. C. Beedy); Colusa and Delevan NWRs, 30, winter 1981-82 (AB 36:326);
50-60, winter 1986-87 (AB 41:322); Butte Creek on Gridley-Colusa Hwy, 13, 5
Nov-7 Dec 1986; 300, Colusa-Grimes Rd., 24 Nov 1990 (NB); Hwy 20 near
Colusa, 500, 10 Nov 1991 (AB 46: 143, NB); 50, 24 Jan 1995 (NB); Hwy 20 x Hwy
45, 190, 25 Jan 1995 (T. D. Manolis); rice field N of Laux Rd., 700, 6 Jan 1995 (fide
M. Wolder/USFWS); 1-5 near Maxwell, 60, 3 Dec 1995 (E. C. Beedy).

Yuba County: District 10, about 11 km N of Marysville, 60-70, 14 Nov 1993 (T.
D. Manolis); 140, 20 Feb 1994 (D. Shuford); 155, 22 Nov 1994 (T. D. Manolis).

Sutter County: Pennington Rd., 30-40, 25 Nov 1990; Sutter NWR, 4, 24 Dec
1990; 21, 29 Jan 1991; 14, 4 Dec 1991; 2, 3 Jan 1993 (NB).

Yolo County: Univ. Calif. Davis, 1 flyover, 30 Nov 1972 (NB); 4, 18 Dec 1993
(NASFN 48:856, E. C. Beedy pers. comm.); Rd. 155, 6, 29 Mar 1992; Yolo Bypass
at Rd. 25, 9, 31 Jan 1993 (NB); Laurel G duck club, Yolo Bypass, 12, 22 Feb 1992;
15, mid- Jan 1993 (E. C. Beedy).

Sacramento-San Joaquin River Delta

Sacramento County: Brannan Island, 11, 30 Dec 1992 (NB); flying over Sacra-
mento Metro Airport. 19, 3 Jan 1995 (T. D. Manolis); Consumnes River Preserve, 2,
26 Mar 1994 (NB).

San Joaquin County: Staten Island, 2, 19 Dec 1993; Bouldin Island, 5, 24 Dec
1990; 22, 31 Dec 1990; 1, 5 Jan 1991; 75, 21 Nov 1992 (NB).

Contra Costa County: Holland Tract, 1-7, 7-9 Dec 1994; Webb Tract, 20-25, 25
Jan 1995 (NB).

Suisun Marsh

Solano County: Grizzly Island WA, 6, 23 Dec 1975 (AB 30:761); Joice Island Unit,
Grizzly Island WA, 1, 26 Nov 1991 (NB).

Contra Costa County: W. Pittsburg, 9, 18 and 25 Dec 1982 (AB 37:333, 749; NB).

San Joaquin Valley

Stanislaus County (all H, Reeve unless otherwise noted): along Hwy 132, 84, 26
Mar 1978 (NB); near Newman. 145, 16 Mar 1985; valley floor in SW part of county,
1, 9 Feb 1986; Mapes Ranch, 5, 23 Mar 1986; 7, 17 Dec 1989; River Rd. NE of
Newman, 20, 23 Mar 1986; 15, 29 Nov 1987; W. Main St., 27, 31 Mar 1986; 125,
26 Nov 1988; 3-6, 13-14 Jan 1989; 60, 12 Mar 1989; fields at Modesto sewage
ponds, 1, 16 Feb 1987; 1, 27 Jan 1989; 2 flybys, 3 Dec 1989; 40, 16 Dec 1989;
Jennings Rd., 1, 17 Feb 1989; Faith Ranch, 28, 30 Dec 1991.

Merced County: sites unspecified, 2, 9 Nov 1908 (CAS 12687, 12832); 1, 26 Nov
1908 (CAS 12834); 1, 30 Nov 1908 (CAS 12833); 1, 12 Dec 1908 (CAS 12831);
1, 4 Feb 1909 (CAS 13220); 1, 6 Feb 1909 (CAS 13219); 5, 18 Feb 1909 (CAS
13218, 13221-13224); Kesterson NWR, 14, 23 Dec 1974 (NB) ; Los Banos WA,
10, 14 Dec 1935; 34, 10 Jan 1946 (W. Minturn); 16, 11 Dec 1955; 20, 30 Mar
1963; 12, 13 Feb 1965 (NB); 100, 23 Jan 1966 (AFN 20:454); 27, 24 Mar 1968
(AFN 22:473); 160, 2 Feb 1969 (AFN 23:515, NB); 200, winter 1969-70 (AFN
24:90, 534); 140, 16 Feb 1974 (NB); 60, 12 Feb 1977 (AB 31:368); 120, 19 Feb
1978 (NB); 160, 3 Feb 1979 (AB 33:309); 49, 27 Jan 1980; 40-50. 7 Feb 1981;
50, 5 Feb 1984; 6, 6 Dec 1984 and 25 Feb 1985; 130, 1 Mar 1987; 300, 10 Feb
1990 (NB); Los Banos CBC, 21, 30 Dec 1969 (AFN 24:443); “Los Banos Road,” 2,
31 Jan 1942; 1, 10 Jan 1946; 16, 28 Mar 1947 (W. Minturn); near Gustine, 2, 3

193

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

Nov 1967 (AFN 22:84); 300, 1 Mar 1983 (AB 37:333); 60, 14 Mar 1987 (NB); San
Luis NWR, 200, 6 Dec 1967 (AFN 22:473); 250, 15 Dec 1971; 40, 10 Dec 1972;
2, 13 Mar 1982 (NB); San Luis NWR and Los Banos WA, up to 250, winter 1971-
72 (AB 26:650); Los Banos area, 1, 25 Nov 1911 (MVZ 22085); 1, 4 Dec 1911
(MVZ 22086); 1,23 Dec 1911 (MVZ 22087); 1, 8 Mar 1939 (MVZ 91174); 23, 24
Mar 1962 (NB); 80, 26 Feb 1967 (AFN 21:453); 200, winter 1970-71 (AB 25:621);
122, 22 Feb 1972; 35, 13 Mar 1975 (NB); 56, 25 Jan 1976 (AB 30:761); 30, 11-
25 Mar 1978; 130, 25 Feb 1980; 20, 4 Feb 1981 (NB); 78, 29 Dec 1981 (AB
36:326); 60, 28 Feb 1982; Los Banos to Merced NWR area, 30, 21 Feb 1981;
Merced NWR, 54, 2 Dec 1982; 300, 29 Nov 1983 (NB); 220, 24 Nov 1984 (AB
39:97); 36, 15 Dec 1986; present, 22 Mar 1988; Santa Fe Grade, 30, 4 Feb 1973;
1, 23 Nov 1975; 12, 5 Feb 1977; 1, 20 Nov 1977; 65, 25 Jan 1980; 32, 4 Jan
1981; 30, 3 Mar 1985; 30, 6 Feb 1987; 100-130, 9 Jan-6 Feb 1988; 250-500,
23 Feb 1991; 80, 9 Nov 1991; 40, 21 Nov 1994 (NB); South Dos Palos, 6, 18 Feb
1939; 3, 23 Jan 1946 (W. Minturn); Dos Palos, 1, 10 Jan 1985; Sandy Mush Rd.,
50, 19 Nov 1986; Volta WA, 150, 24 Nov 1971 (NB).

Fresno County: 3 mi S of Dos Palos, Merced County, 2, 7 Dec 1935; Mendota
Pool, 12, 28 Mar 1936; Herminghaus Ranch, S of Mendota Pool, 2, 11 Feb 1939
(W. Minturn); Mendota WA, 1, 26 Dec 1974 to 9 Feb 1975; 250, 21 Feb 1985 (NB).

Kings, Tulare, and Kern counties: mouth of Tule River, 3, 16 Nov 1940; Tulare
Lake, 4, 4 Dec 1927 (W. Minturn); 1, winter 1941-42 (CAS 58375); 1, 23 Mar 1946
(W. Minturn); Tulare Lake basin, 1, Nov 1957 (NB).

Tulare County: Creighton Ranch Preserve, 3, 3 Dec 1982 to 19 Jan 1983 (NB);
Pixley NWR, 6, 6 Dec 1993; Alpaugh Irrigation District Reservoir, 20, 27 Mar 1995
(Kern NWR waterfowl survey).

Kern County (except as noted, all records from Kern NWR aerial waterfowl
surveys): Goose Lake Bottoms, 10, 4 Nov 1980; 5, 5 Dec 1991; 2, 4 Feb 1992; 17,
3 Mar 1994; Kern NWR, 3, 23 Jan and 1 1 Feb 1981; Kern-Wasco duck clubs near
Kern NWR, 15, 3 Nov 1989 and 6 Mar 1990; 31, 4 Nov 1991; 15, 5 Dec 1991; 20,
8 Jan 1992; 2, 4 Feb 1992; 1, 6 Dec 1993; 1, 4 Mar 1993; 30, 10 Jan 1994; 5, 3
Mar 1994; 5, 15 Nov 1994; 6, 8 Dec 1994; 4, 13 Jan 1995; X, 15 Feb 1995; 1, 27
Mar 1995; duck clubs near Arvin, 10, 3 Nov 1989; 30, 4 Nov 1992; 1, 1 Feb 1993;
5, 1 Feb 1993; 10, 3 Mar 1994; 55, 8 Dec 1994; 50, 13 Jan 1995; Tenneco sewage
overflow ponds, SW of jet. 1-5 x Hwy 119, 40, 5 Dec 1991; 50, 8 Jan 1992;
Bakersfield sewage ponds, 1, 21 Mar 1994; Kern NWR, 1, 16 Mar 1984 (M. O.
Chichester); SW of Kern NWR, 2, 22 Feb 1985 (M. O. Chichester); Kern River
groundwater recharge ponds W of Bakersfield, 4, 19 Nov 1995 (M. O. Chichester).

Southern California Interior and Deserts

Kern County: China Lake sewage ponds, 2, 24 Nov 1991 (D. V. Blue, M. O.
Chichester).

Inyo County: Death Valley National Monument CBC, 1, 22 Dec 1965 (AFN
20:366).

Los Angeles County: near Lancaster, present, 11 Nov 1979 (Garrett and Dunn
1981); Piute Ponds, 2, 3 Dec 1993 (K. Garrett, M. San Miguel).

San Bernardino County: Chino Basin, 20, 1 Dec 1990 (M. A. Patten).

Riverside County: Corona, 1, winter 1952-53 (AFN 7:234); duck clubs, San
Jacinto Valley, 1, 29 Jan 1994 (B. Carlson et al.); north end of Salton Sea, 4, 20 Mar
1987; 25, 2 Jan 1989; 2, 17 Dec 1989; 120, 29 Dec 1990; 25, 2 Feb 1991; 21,
15 Dec 1991, 15, 2 Jan 1994; 30, 4 Dec 1994; 25, 21 Jan 1995; Lake Norconian,
1, 23 Nov 1989; Hidden Valley WA, 30, 11 Feb 1990; Santa Ana R. Valley, 12, 19
Dec 1992; Oasis Station, 10, 26 Jan 1991; 40, 22 Jan 1994 (M. A. Patten); Prado
Basin, 375, 28 Nov 1995; 180, 8 Jan 1996 (J. Pike).

Imperial County: Imperial Valley, 1000, 28 Dec 1947 (AFN 2:149); numbers “far

194

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

below normal," winter 1962-63 (AFN 17:357); “flocks of up to 50,” winter 1966-
67 (AFN 21:457); 1, 20 Nov 1988; 2, 28 Jan 1989; 30, 3 Nov 1990; 25, 18 Dec
1993; 150, 29-30 Jan 1994; 12, 13 Feb 1994; 150, 11 Dec 1994; 2000, 11 Jan
1995 (M. A. Patten); Seeley, 275, 9 Dec 1956 (AFN 1 1:290); 450, 14 Jan 1983 (AB
37:337); nearBrawley, 6000, 29 Jan 1989 (AB 43:365); 57, 20 Mar 1987; 150, 27
Jan 1990; Fig Lake, 75, 29 Dec 1994 (M. A. Patten); Salton Sea, 1, 6 Jan 1945
(LACM 86530); 1, 29 Dec 1945 (SBCM M13); 300, winter 1948-49 (AFN 3:185);
numbers down, winter 1953-54 (AFN 8:269); 1, 27 Nov 1977 (SBMNH 4319); 2,
12 Nov 1978 (SBMNH 1735, 4268); Ramer Lake, 2000 at roost, winter 1950-51
(AFN 5:226); 50, 19 Feb 1955 (AFN 9:285); 70, 13 Jan 1962 (AFN 16:364); Salton
Sea NWR, 50, 25 Nov 1960 (AFN 15:75); vicinity Salton Sea NWR, Unit 1, 35, 20
Nov 1979 (P. Unitt); south end of Salton Sea, 3500, winter 1952-53 (AFN 7:234);
34, 27 Dec 1955 (AFN 10:281); “quite common,” winter 1969-70 (AFN 24:538);
100, 8Jan 1977 (AB 31:373); 3, 1 Feb 1987; 75, 22 Dec 1987; 100, 17 Jan 1988;
200, 23 Jan 1988; 1, 11 Nov 1988; 50, 24 Dec 1988; 30, 10 Dec 1989; 125, 21
Dec 1989; 94, 21 Nov 1992; 32, 22 Dec 1992; 250, 6 Feb 1993; 30, 29 Dec
1993; 25, 20 Dec 1994 (M. A. Patten); Salton Sea (south) CBC, 2, 31 Dec 1965
(AFN 20:377); 15, 28 Dec 1968 (AFN 23:423); 4, 28 Dec 1969 (AFN 24:453); near
Sheldon Reservoir, 7 km NW Imperial, 250, 30 Jan 1988; duck club 5 km NE
Imperial, 2000, 30 Dec 1988 (P. Unitt).

Coastal California

Humboldt County: School Rd., McKinleyville, 1, 6 Nov 1988 (NB); Humboldt
County, fall records through 7 Nov (Harris 1991).

Napa County: 1, 24-28 Jan 1996, Skaggs Island Rd. (NB).

Alameda County: Fremont, 31 circling, 15 Feb 1970 (AFN 24:534).

San Mateo County: Pescadero Marsh, 1, 14 Dec 1985 (AB 40:325); Half Moon
Bay, 1, 28 Dec 1985 (AB 40:325).

Santa Cruz County: Pajaro River mouth, 2, 2 Jan 1991 (NB); Harkins Slough, 1-
2, 16-26 Mar 1993 (R. Merrill); 4-6, 12-27 Dec 1993 (D. E. George); 1-2, 1-4 Jan
1995, on Moss Landing CBC (NASFN 49:192,

808; fide D. L. Suddjian); College Lake, 2, 1 Jan 1994, on Moss Landing CBC
(NASFN 48:836, D. L. Suddjian).

Monterey County (all records from Roberson 1985 or D. Roberson in litt. ; includes
all Moss Landing CBC records): Moss Landing/Elkhorn Slough vicinity, 1, 14 Aug-
25 Dec 1953 (probably the same bird at McClusky Slough, 19 Nov 1953); 5, 20 Mar
1982; 1, 1 Jan-25 Feb 1984 (Kirby Park); 1, 30 Oct 1988-4 Jan 1989; 1-2, 20
Aug-3 Nov 1990; 1, 12 Dec 1990 (possibly one of the previous birds); 1, 1 Jan 1992
(Packard Ranch); 1-2, 16 Oct-24 Dec 1992 (Zmudowski State Beach); 1, 12 Dec
1992; 1, 24 Dec 1992 (Packard Ranch, possibly one of the preceding individuals); 5,
7 Feb 1993 (Packard Ranch); up to 7, 14 Nov 1993-25 Feb 1994 (groups at Moss
Landing WA and adjacent Packard Ranch and Moro Cojo Slough and adjacent
Castroville ponds); 1-2, 27 Mar-9 May 1994 (Moonglow Dairy); 1, 19 Nov 1994
(Moonglow Dairy); 1-2, 11 Feb-23 Apr 1995 (Moonglow Dairy); 1, 27 Dec 1995-
29 Feb+ 1996 (Moonglow Dairy); San Juan Grade, Salinas, 1, 6 Feb 1983; 1, 19 Feb
1996; Salinas River mouth, 1-3, 17 Sep-8 Dec 1990; Crespi Pond, Pt. Pinos, 1, 2-
5 Jan 1993; King City vineyard, 5, 21 Jan-1 Feb 1996.

Southern California coast (as whole): flocks of up to 9, winter 1963-64 (AFN
18:386); “a few,” winter 1966-67 (AFN 21:457); a few in coastal Ventura, Orange,
and San Diego counties, winter 1968-69 (AFN 22:477).

San Luis Obispo County: Laguna Lake, 13 Oct-11 Nov 1974 (fide T. M. Edell);
Villa Creek, 1, 15 Oct 1979-21 Apr 1980 (T. M. Edell); Los Osos Valley, 1, 27 Dec
1989 (AB 44:327, D. Elmendorf); upper Morro Bay estuary, 10-12, 6 Nov 1990 (D.
Stinson).

195

WHITE-FACED IBIS IN WINTER IN CALIFORNIA

Santa Barbara County: Goleta, on Santa Barbara CBC, 1, 30 Dec 1967 (AFN
22:396, Lehman 1994); Goleta, 1, Oct 1977-Mar 1978 (AB 32:398, Lehman
1994); 2, 15-20 Feb 1984; Santa Barbara, 1,11 Nov 1978-10 Jan 1979 (Lehman
1994); Santa Ynez River mouth, 1, 1 Dec 1988-3 Feb 1989 (Lehman 1994, AB
43:1 149); 1, 8 Feb 1994; Lake Cachuma, 1-2, 1 Nov 1991-17 Feb 1992; 1, 3 Nov
1992 (Lehman 1994); near Santa Maria, 1, 28 Jan 1995 (D. Quesenberry).

Ventura County: Pt. Mugu area, 1, 19 Jan 1948 (AFN 2:149); 1, 15 Feb 1962
(AFN 16:364); small group, winter 1962-63 (AFN 17:357); 3-8, 11-18 Jan 1964;
6, 29 Jan 1967; 7, 28 Jan 1968; 1-3, Jan 1969 (SBMNH files); present, winter
1969-70 (AFN 24:538); 15, 24 Jan 1971; 12, 28 Nov 1971 (SBMNH files); 1, 5
Dec 1971 (LACM 85222); 1, 12 Dec 1978 (fide D. DesJardin); 8-10, 2 Feb 1974
(SBMNH files); up to 85, through 22 Nov 1980 (AB 35:225, fide D. DesJardin); 40,
1 Nov 1981 (fide D. DesJardin); 37, 4 Mar 1996 (D. DesJardin); Mugu Lagoon, 16,

15 Dec 1992 (W. Wehtie et al.j; near Saticoy, 15+, 9 Feb 1985 (fide D. DesJardin);
4, 18 Feb 1996 (D. DesJardin); Santa Clara River estuary, 1, 1 Nov 1970 (SBMNH
files); 25, 4 Feb 1986 (fide D. DesJardin); Sespe WA CBC, 66, 3 Jan 1988 [AB
42:1138 (probably from Santa Clara River Valley near Fillmore, K. Garrett pers.
comm.)].

Los Angeles County: Playa del Rev, 1, 5 Jan 1953 (AFN 7:234); El Monte, 3, 12
Nov 1988 (AB 43:167); Whittier Narrows, El Monte, 2, 1 Dec 1991-29 Jan 1992
(Long 1993).

Orange County: Bolsa Chica, 1, 14 Feb 1949 (AFN 3: 185); 1, 29 Mar 1956 (AFN
10:363); 1, 9 Nov 1957 (AFN 12:58); 2, 4 Feb 1985 (fide D. Willick); Upper
Newport Bay, 1-2, 21 Feb and 28 Mar 1959 (AFN 13:321); Upper Newport Bay, 8,
28 Jan 1962 (AFN 16:364); Upper Newport Bay, small group, winter 1962-63
(AFN 17:357); 21, 18 Dec 1990 (fide D. Willick); San Joaquin Marsh, Irvine, 8, 16
Feb 1981; 1, 15 Jan-19 Feb 1983; 2, 28 Dec 1984-“Mar” 1985; 1, 5 Feb 1987
(fide D. Willick); 2, 24 Jan 1988 (M. A. Patten); 1, 5-11 Feb 1988; 10, 4 Mar 1990;
1, 4 Nov 1990 (fide D. Willick); 6-11, Dec 1994-Feb 1995 (fide J. Pike); Corona del
Mar, 30 flying N along shore, 5 Jan 1984; Fountain Valley, Santa Ana River, 2, 21
Feb-“Mar” 1988; 14, 31 Jan-24 Feb 1990; 1, 15 Dec 1991; San Diego Creek,
Irvine, 2, 12 Dec 1990; 1, 12 Dec 1991; Anaheim, up to 20, 20 Dec 1990-Teb"
1991 (fide D. Willick).

San Diego County: San Diego area, 3, 29 Dec 1956 (AFN 11:290); Carlsbad, 1,
Jan-Feb 1962 (AFN 16:364); Buena Vista Lagoon, small group, winter 1962-63
(AFN 17:357); San Diego CBC, 2, 2 Jan 1966 (AFN 20:378); Oceanside-Vista-
Carlsbad CBC, 2, 30 Dec 1961 (AFN 16:284); 3, 31 Dec 1962 (AFN 17:280); 2, 28
Dec 1963 (AFN 18:311); 20, 30 Dec 1966 (AFN 21:370); 3, 30 Dec 1967 (AFN
22:388); 13, 28 Dec 1968 (AFN 23:417); Santa Margarita River mouth, small
group, winter 1962-63 (AFN 17:357); present, winter 1968-69 (AFN 23:520);
present, winter 1969-70 (AFN 24:538); San Elijo Lagoon, present, winter 1969-70
(AB 24:538); 1, 17 Nov 1991 (R. Patton et al.); 4, 18 Nov 1993 (R. Patton, B.
Foster); Oceanside, present, winter 1970-71 (AB 25:627); 2, winter 1974-75 (AB
29:741); 35, winter 1976-77 (AB 31:373); Guajome Lake (Oceanside-Vista-
Carlsbad CBC), 3, 26 Dec 1987 (P. Unitt); San Luis Rey River Valley between
Oceanside and Bonsall, 45, 1 Jan 1979; 30, 28 Dec 1980 (Unitt 1984); 27, 9 Mar
1988 (P. Unitt); Tijuana R. mouth, 1, 19 March 1966 (Unitt 1984); Tijuana R. Valley,
4, 17 Dec 1983 (on San Diego CBC, P. Unitt); 12, 3 Nov 1985 (P. Unitt); 3, 8 Dec
1990 (M. A. Patten); Lake Hodges, 40, 7 Nov 1995; 72, 9 Nov 1995; 160, 16 Nov
1995; 40, 5 Dec 1995; 65, 12 Jan 1996; 40, 18 Feb 1996 (R. L. Barber); Mission
Valley, 1, 3 Feb-7 Apr 1991 ; San Dieguito River estuary (Rancho Santa Fe CBC). 10,

16 Dec 1994 (P. Unitt). 1

196

FIRST RECORD OF

A LANCEOLATED WARBLER IN CALIFORNIA

CATHERINE M. HICKEY, Point Reyes Bird Observatory, 4990 Shoreline Highway,
Stinson Beach, California 94970

PHIL CAPITOLO, 4 Pacifico Avenue, Daly City, California 94015

BRETT WALKER, Institute For Bird Populations, P. O. Box 1346, Point Reyes
Station, California, 94956

On 1 1 September 1995, on Southeast Farallon Island, 42 km west of San
Francisco, California, we found and banded a Lanceolated Warbler
( Locustella lanceolata), the first recorded in the state.

Strong northwest winds characterized the weather of the week preceding
1 1 September. The morning of 9 September brought diminished southeast
winds and high cloud cover. At approximately 1540 on 11 September,
Hickey and Capitolo were censusing birds near the east landing of the island
with the intention of catching any unbanded birds. Hickey spotted a small,
brown bird scampering like a mouse to hide under the dead vegetation near
a mist-net. She slowly approached the bird as it scurried short distances. At
this time, Capitolo saw it dart into the opening of an auklet burrow, after
which Hickey successfully flushed the bird into the net. Hickey and Capitolo
had no previous experience with the genus Locustella and were unable to
identify the bird at the time of capture.

We identified the bird as a Locustella by using Bruun and Singer (1970),
then telephoned Peter Pyle and Keith Hansen for assistance in identifying
the bird to species. We used plumage criteria, measurements, and wing
formula information from Svensson (1992) to distinguish the bird as L.
lanceolata. We took all appropriate measurements, wrote a detailed de-
scription, and sketched key plumage features. After photographing the bird,
we pulled three undertail coverts and released it. Documentation has been
provided to the California Bird Records Committee, and the undertail
coverts have been deposited at the California Academy of Sciences, San
Francisco (accession number 5107).

We resighted the bird the following morning around 1100 near the two
houses on the southwest side of the island. Capitolo inadvertently flushed the
bird and saw it fly and land on the ground under the bush mallow ( Lavatera )
around the houses, giving one loud, sharp chip. The bird also gave this call
once in the banding lab. Hickey and Capitolo saw it preening at a distance
of 10 m in good lighting. All three of us then observed the bird fly low to the
ground for approximately 25 m when its brown, graduated tail was clearly
visible. The bird was not seen again.

MEASUREMENTS AND DESCRIPTION

The bird (Figure 1) was mainly in fresh first basic plumage but appeared to
have substantial juvenal plumage remaining. It had a partially pneumatized
skull and no indication of active molt. The upperparts were pale brown with
dark brown centers, giving the back and crown a boldly streaked appear-

Western Birds 27:197-201, 1996

197

LANCEOLATED WARBLER IN CAUFORNIA

Figure 1. Lanceolated Warbler (Locustella lanceolata ), Southeast Farailon Island,
California, 1 1 September 1995. Note the unbarred graduated tail, the boldly streaked
appearance of the back and uppertail coverts, and the streaking on the sides. It is
highly unusual for the Pallas' Grasshopper Warbler ( Locustella certhiola) to have
streaking from the breast to the undertail coverts.

Photo by Mike Schultz

ance. The supercilium was buff, and a buff-yellow submoustachial stripe was
set off by a dark brown malar streak and solid pale brown auriculars. Except
for the belly, the underparts were streaked with brown. The throat was pale
yellow-buff, the flanks were buff, and the belly was buffy white. The undertail
coverts were pale buff with thin, dark brown shaft streaks along the distal
one-third of each feather {Figure 2), while the rectrices were uniformly
brown and the tail clearly graduated. The upper mandible was dark,
contrasting with the uniformly pink lower mandible. The legs and feet were
also pink, and the iris was olive-brown.

We recorded the following measurements: total length, 126 mm; bill
length from the nostril, 7.1 mm; exposed culmen, 11.1 mm; tarsus, 19.7
mm; wing chord, 57 mm; notch on primary 9, 6.6 mm; tail (central
rectrices), 45 mm; tail (outer rectrices), 32 mm; weight (with band), 12.3 g.
Wing formula measurements were taken with primaries (p) numbered
distally and secondaries (s) numbered proximally, as in Pyle et al. (1987).
Wing formula: plO reduced, longer than primary coverts by less than 1 mm;
p9 notched; p8 emarginate and the longest primary; p9 < p8 by less than 1
mm; p7 < p8 by 2.0 mm; p6 < p8 by 4.2 mm; p5 < p8 by 6.8 mm; p4 <
p8 by 7.0 mm; p3 < p8 by 9.0 mm; longest primary (p8) minus the longest
inner secondaries (si— 6), 14.0 mm; primary projection beyond tertials
(longest primary minus the longest tertial, s7), 11.0 mm.

198

LANCEOLATED WARBLER IN CALIFORNIA

Figure 2. Lanceolated Warbler { Locustella lanceolata ), Southeast Farallon Island,
California, 11 September 1995. Note the thin and distinct central streaks of the
undertail coverts. The difference in undertail covert pattern is valid for separating all
races of the Grasshopper Warbler ( Locustella naevia ) from lanceolata. The central
streaks on the Grasshopper Warbler’s undertail coverts are wide, diffuse, and reach
the base of the feathers.

Photo by Mike Schultz

IDENTIFICATION SUMMARY

The genus Locustella is characterized by a broad well-graduated tail, long
broad undertail coverts, brown upperparts, and skulking behavior (Cramp
1992). The genus consists of eight or nine species of varying size and with
varying amounts of streaking and tail graduation. Of these, five or six species,
the River (L. fluviatilis), Sava’s [L, luscinioides), Gray’s (L. fasciolata, including
amnieola), Middendorff’s { L . ochotensis), and Pleske’s or Styan’s (L. pleskei)
warblers, are unstreaked so should not be confused with the Lanceolated.
Within the genus Locustella, only the Grasshopper (L. naevia) and Pallas’
Grasshopper (L. certhiola ) warblers resemble the Lanceolated closely.

There are several plumage characteristics that are useful in separating the
Lanceolated from Pallas’ Grasshopper Warbler, but not all of these features
can be used conclusively. The tail of Pallas’ has distinctive dark barring, a
black subterminal band, and a pale grayish tip, although the subterminal
dark patches may not be a constant feature, so their absence may not rule
out the species (Galsworthy 1990). The Pallas’ has a white bulge on the tip
of the inner web of the tertials, a feature not found on the Lanceolated. It is
unusual for Pallas’ to have streaking that extends from the breast to the
undertail coverts (Galsworthy 1990), a feature that is a constant for the
Lanceolated. A well-marked and broad supercilium characterizes the Pallas’

199

LANCEOLATED WARBLER IN CALIFORNIA

but its absence can not rule out the species. The supercilium of a Lanceolated
is much less distinct and sometimes absent. One of the most useful features
in separating these two species is the ground color of the upperparts. A
distinct contrast between the olive-gray crown and the rufous back and rump
of the Pallas’ has been found to be constant in both adults and first-winter
birds {Galsworthy 1990). The ground color of the Lanceolated, however, is
a uniform olive-brown. Using a combination of the above criteria for
separation of the Pallas’ from Lanceolated, we have ruled out Pallas’ as the
possible identity of the Farallon bird. Ranging northeast to Kamchatka,
Pallas’ is the only other streaked Locus tel la likely to reach North America.

Separation of the Lanceolated from the Grasshopper Warbler { L . naeuia ) is
challenging, but several features can be used to eliminate the latter. First,
Cramp (1992) stated that the difference in undertail covert pattern is valid for
separating all races of naeuia from lanceolate. On the Lanceolated, the dark
brown central streaks of the undertail coverts are thin, distinct, and restricted
to the distal one-third of the feathers, as they were on the Farallon bird (Figure
2). The central streaks on the Grasshopper Warbler’s undertail coverts are
wide and diffuse, reaching the base of the feathers (Lewington et al 1991,
Svensson 1992). Second, the range of the measurement for the notch on p9
recorded by Cramp (1992) for the Grasshopper (8.0-1 1.0 mm) is larger than
that of the Lanceolated (6. 0-8.0 mm). The Lanceolated’s tertials have a well-
defined border between the dark brown center and the chestnut edging, while
the tertials of the Grasshopper tend to have a wide, diffuse margin between
the central area and edging. Furthermore, the distinct streaking on the crown,
rump, upper breast, and flanks of the Lanceolated differs from the more ill-
defined and rounded or triangular streaks of the Grasshopper Warbler. These
criteria clearly identify the Farallon bird as a Lanceolated Warbler. The
Grasshopper Warbler breeds east only as far as northwestern Mongolia so is
far less likely as a vagrant to North America than the Lanceolated.

The Japanese Marsh Warbler ( Megalurus pryeri ), with a very localized
and limited breeding range in the Far East, resembles the Lanceolated in its
streaked upperparts but differs in its unstreaked underparts, rufous upper-
parts, unstreaked nape, and much longer tail (P. J. Leader pers. comm.).
Beaman (1995) recently placed this species in the genus Locustella.

DISTRIBUTION

The Lanceolated Warbler breeds in Eurasia from northern European Russia
to Kamchatka, the Kurile Islands, and northern Japan. It winters in south-east
Asia south to the Greater Sunda Islands, west to northern India and the
Andaman Islands, and east to the Philippines (Cramp 1992, Rogers et al.
1995). With 63 records through 1994, this species is a rare vagrant to Britain,
with the majority of records for Fair Isle, Shetland (Lewington et al. 1991,
Rogers et al 1995). It is considered accidental in France, Belgium, Nether-
lands, Germany, Denmark, Norway, Sweden, and Yugoslavia. Finnish records
include singing males in the summers of 1971, 1981, 1983, 1984, and 1985
(Lewington 1991), suggesting sporadic breeding. At Beidahe, Hebei Prov-
ince, China, with a latitude almost identical to Southeast Farallon Island’s, the
passage of Lanceolated Warbler covers the period 22 August to 28 October,

200

LANCEOLATED WARBLER IN CALIFORNIA

with a peak in numbers in the last days of September and the first week of
October (M. Williams, fide P. J. Leader pers. comm.).

The Lanceolated Warbler found on Southeast Farallon Island constitutes the
first record of this species for California. The only other published record for
North America is of at least 25 birds on Attu Island in the western Aleutian
Islands, Alaska, 4 June-15 July 1984 (Tobish 1985). The Southeast Farallon
bird’s occurrence coincided with a remarkable variety of other Asian land birds
that reached the west coast of North America during the fall of 1995: there were
reports of several Yellow Wagtails ( Motacilla flava), a Black-backed Wagtail
(Motacilla lugens), an Arctic Warbler (Phylloscopus borealis), two Dusky
Warblers (Phylloscopus fuscatus), and several Northern Wheatears (Oenanthe
oenanthe) (G. McCaskie, P. Pyle, and D. Yee pers. comm.). Evidently, many
migratory birds of northeastern Asia are capable of reaching California.

ACKNOWLEDGMENTS

We thank the Point Reyes Bird Observatory for the opportunity to volunteer on
Southeast Farallon Island as well as Peter Pyle and Keith Hansen for their assistance
in identification. Jon Dunn, Steve N. G. Howell, Paul Leader, Peter Pyle, and Philip
Unitt read an earlier draft of this paper and provided valuable comments. Mike Schultz
provided photographs of the bird.

LITERATURE CITED

Beaman. M. 1995. Palearctic Birds. A Checklist of the Birds of Europe, North Africa
and Asia North of the Foothills of the Himalayas. Harrier Publ., England.

Bruun B., and Singer, A. 1970. Birds of Europe. McGraw-Hill, New York.

Cramp S. 1992. Handbook of the Birds of Europe, the Middle East, and North Africa,
Vol. VI. Oxford Univ. Press, Oxford, England.

Galsworthy, A. C. 1990. Separation of first-winter Pallas's Grasshopper Warbler
from Lanceolated Warbler. Hong Kong Bird Rep., pp. 155-164.

Lewington L, Alstrom, P., and Colston, P. 1991. A Field Guide to the Rare Birds of
Britain and Europe. Harper Collins, London, England.

Pyle P., Howell, S. N. G., Yunick, R. P, and DeSante, D. F. 1987. Identification Guide
to North American Passerines. Slate Creek Press, Bolinas, CA.

Rogers M. J., and the Rarities Committee. 1995. Report on rare birds in Great Britain
in 1994. Br. Birds 88:535-538.

Svensson L. 1992. Identification Guide to European Passerines, 4th ed. L. Svensson,
Stockholm.

Tobish T. G. 1985. The first record of Locustella lanceolata for North America. Auk
102:645.

Accepted 30 May 1 996

201

NOTES

NOTES ON NESTING BIRDS OF

THE CIENEGA DE SANTA CLARA SALTFLAT,

NORTHWESTERN SONORA, MEXICO

ERIC MELLINK, EDUARDO PALACIOS, and SALVADOR GONZALEZ, Centro de
Investigation Cientifica y Educacion Superior de Ensenada, Apdo. Postal 2732,
Ensenada, Baja California, Mexico (international mailing address P. O. Box 434844,
San Diego, California 92143)

The Cienega de Santa Clara is a 20,000-hectare brackish wetland on the east side
of the delta of the Rio Colorado in Sonora, Mexico. It has developed as a result of the
discharge of brine from the Wellton-Mohawk Irrigation District, in southwestern
Arizona, through the Wellton-Mohawk Main Outlet Drain Extension, since 1977.
The northern third of the cienega is covered by dense cattails (Typha domirtgensis ),
Common Reed ( Phragmites communis), and bulrush ( Scirpus americanus ). The
southern two-thirds of the wetland consist of unvegetated evaporative saltflats (Glenn
et al 1992). The area is important for conservation, yet little effort has been devoted
toward its birds. Investigations have focused mainly on its vegetated portion, which
supports a large population of the endangered Yuma Clapper Rail (Rallus longirostris
yumanensis; see Eddleman 1989) and of wintering waterfowl. The use of the saltflats
by birds has been mostly overlooked. Only Eddleman (1989) has reported on the birds
his team recorded incidentally while surveying Yuma Clapper Rails.

On 20 April and 3-4 May 1994, we visited two sites on the saltflat, both adjacent
to pools of fresh water. These are fed by underground springs located on the San
Jacinto Fault, which runs through the eastern boundary of the cienega to the Estero
de Santa Clara and beyond into the Gulf of California. We have named the sites after
the nearest villages, El Doctor and La Flor del Desierto, from which they are about 2
and 3.5 km to the southwest, respectively.

American Avocet (Recuruirostra americana). On 20 April 1994 we found 20
adults and 2 nests at El Doctor. One nest had four eggs, the other three eggs and one
fledgling. On 3 May one of the nests had only eggshell fragments, and we presume
successful hatching. We could not refind the other nest. Although no nesting of this
species in Sonora has been confirmed previously, Mellink and Palacios (1993)
suspected that avocets breed near Puerto Penasco, also in the northern Gulf of
California. Howell and Webb (1995) reported the species as a breeder only in
northwestern Baja California and on the central plateau of Mexico.

Black-necked Stilt (Himantopus mexicanus). On 20 April we recorded about 20
adults, some of which were performing distraction behavior, at El Doctor. On 3 May
three adults were performing the broken-wing display there. Eddleman (1989)
reported stilts in roughly the same area in 1984, and G. Monson (pers. comm.) and
S. M. Russell found a nest with three eggs a few kilometers north of the site on 9 April
1994. Howell and Webb (1995) did not record the species as breeding in Sonora.

Snowy Plover (Charadrius alexandrinus). At El Doctor there were about 40 adults
and we located two nests. To reduce disturbance we did not search for more nests, but

202

Western Birds 27:202-203, 1996

NOTES

it was evident that many more pairs were nesting. The nests had two and three eggs,
respectively. One of the nests was lined with broken shells; the other had a dried mud
bottom. Both nests were in old horse tracks. At La Flor del Desierto on 4 May we
found 14 adults apparently attending chicks. This species had been reported in this
area by Eddleman (1989). Our finding of over 50 adults at only two small sites
surveyed, and Eddleman's report that the species nests at “at least a few sites,” suggest
that the breeding concentration is an important one. Van Rossem (1945) commented
on the apparent summer absence of this species in Sonora, and Howell and Webb
(1995) did not include the species as a breeder for Sonora. Its confirmed breeding in
this area, as well as at La Salina oasis, northwestern Sonora (Mellink and Palacios
1993) and at Estero San Jose, southern Sonora (Palacios and Mellink 1995), indicates
that scattered populations may inhabit suitable sites along the entire Sonoran coast.

Killdeer ( Charadrius uociferus). We saw four adults, and heard more calling, at La
Flor del Desierto on 4 May. We suspected nesting, but could not find evidence of this.
That nesting might occur is not surprising, as this species breeds widely in northern
Mexico (Howell and Webb 1995) and is a “common resident everywhere in suitable
territory” in Sonora (van Rossem 1945).

Least Tern (Sterna antillarum). We found four pairs occupying nests and courting
on the ground at El Doctor on 3 May. One nest had two eggs. On 4 May we found two
pairs performing aerial courtship and fishing in the pool at La Flor del Desierto. This
species, whose breeding in the area had been suspected by Eddleman (1989), is a
common summer resident throughout the Gulf of California (Howell and Webb 1995)
and breeds widely along its continental shore (Palacios and Mellink 1995).

Gale Monson, Gary Rosenberg, and Philip Unitt provided useful editorial com-
ments, and Gale Monson also shared unpublished field observations with us.

LITERATURE CITED

Eddleman, W. R. 1989. Biology of the Yuma Clapper Rail in the southwestern U.S.
and northwestern Mexico. Final report, U.S. Bureau of Reclamation and U.S.
Fish & Wildlife Service, 7301 Calle Agua Salida, P. O. Box D, Yuma, AZ 85364.

Glenn, E. P., Felger, R. S., Burquez, A., and Turner, D. S. 1992. Cienega de Santa
Clara: Endanqered wetland in the Colorado River Delta. Nat. Res. J. 32:817-
824.

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

Mellink, E., and Palacios, E. 1993. Notes on the breeding coastal waterbirds in
northwestern Sonora. W. Birds 24:29-37.

Palacios, E., and Mellink, E. 1995. Breeding birds of Estero Tobari and Estero San
Jose, southern Sonora. W. Birds 26:99-103.

Palacios, E., and Mellink, E. 1996. Status of the Least Tern in the Gulf of California.
J. Field Ornithol. 67:48-58.

Van Rossem, A. J. 1945. A distributional survey of the birds of Sonora, Mexico.
Occas. Pap. Mus. Zool., La. State Univ. 21.

Accepted 31 Ju/y 1996

203

AGE AND SEX DETERMINATION IN ANNA’S
HUMMINGBIRD BY MEANS OF TAIL PATTERN

SHIRLEY WELLS, deceased

LUIS F. BAPTISTA, Department of Ornithology and Mammalogy, California Acad-
emy of Sciences, Golden Gate Park, San Francisco, California 94118

STEPHEN F. BAILEY, Pacific Grove Museum of Natural History, 165 Forest Avenue,
Pacific Grove, California 93950

HELEN M. HORBLIT, Department of Ornithology and Mammalogy, California
Academy of Sciences, Golden Gate Park, San Francisco, California 94118

While banding Anna’s Hummingbirds ( Calypte anna) on the Palos Verdes Peninsula,
southern California, between 1970 and 1976 (Wells et al. 1978), Wells noted three
predominant color patterns on the outermost rectrices of the birds handled (Figure 1). By
pulling the outermost rectrix on one side of fledglings and then subsequently recapturing
these marked individuals and noting the shape, color, and pattern of the regrown rectrices,
she confirmed that these patterns were age- and sex-specific. This method of sexing may
be applied to nestlings as well as fledglings and adults. We describe these differences for
banders and population biologists interested in sex ratios or life tables to enable them to
determine the sex and age of Anna’s Hummingbirds. Our confirming data are based on
an examination of 1 2 1 specimens in the collections of the California Academy of Sciences
(CAS), San Francisco, California, and the Museum of Vertebrate Zoology (MVZ),
Berkeley, California. These included 79 females and 42 males.

B

C

D

E

F G H

Figure 1 . Outermost rectrices of three age classes of Anna’s Hummingbirds. A, adult
male; B-E, adult or immature females; F-H, immature males.

204

Western Birds 27:204-206, 1996

NOTES

Understanding the timing and sequence of molts is important in any age and sex
determination by plumage. Williamson (1956) found that all Anna’s Hummingbirds,
both adults and juveniles, have one complete molt each year. An individual’s post-
juvenile molt lasts 4 to 6 months. An adult’s annual molt requires about 3 months.
Complete periods of molt are as follows: juvenile females, April to January; juvenile
males, May to February; adult males, early June to January; adult females, May to at
least October. The outer rectrices tend to be molted late in the sequence of feather
tracts, after the central rectrices are nearly or fully grown. Adults molt outer rectrices
from July to October. Juveniles molt outer rectrices from July to perhaps January.

We noted, as did Williamson (1956), that the distinctive outermost rectrix (Figure
1 A) and full gorget of adult males easily distinguish them from the other age and sex
classes. Therefore, we don't consider them further here. Williamson (1956) and
Baltosser (1987) also noted that immature males and females in fresh plumage can be
distinguished from adult females by the form of the secondaries, which are rounded in
immatures (Figure 2A) but are obtusely pointed centrally and incised on each side of
the rachis in adult females (Figure 2B). This method is sometimes difficult to use,
notably when the feather tips are worn.

Williamson also noted that the tail is a useful criterion to separate adult females
from immatures prior to their post-juvenile molt. The outermost two rectrices in
immature males are similar to those of females in being tricolored, with a greenish or
grayish basal zone, a black subterminal band, and a white distal zone. He pointed out
that females have more white than males but did not comment on how adult and
immature females could be distinguished. Baltosser (1987) noted that the outermost
rectrices of immature males differ from those of females in that males have black
rachises that bisect the white rectrix tips whereas the distal portions of females’
rectrices are all white. During our banding we encountered several females with black
rachises. However, Baltosser’s criteria are still useful if used in conjunction with other
characters, as developed below.

In some females the boundary between the white tip and the black subterminal band
runs almost straight across the feather, that is, it is perpendicular to the rachis (Figure
IB). More commonly there is a white notch intruding into the middle of the subterminal
band where the rachis and small portions of one or both vanes are devoid of melanin
(Figure 1C). On some females, the white notch projects inward on only one vane (Figure
ID). Occasional females have a short projection of the black rachis into the white rectrix
tip, but not enough to bisect this tip. Very rarely a female has a black rachis that actually
bisects the white tip (Figure IE). All but one of the 79 specimens marked female on the
label possessed one of these tail patterns. The exceptional individual had red feathers
growing into the crown and was thus an immature male misidentified as a female.

Figure 2. Secondary feather tips of Anna’s Hummingbirds. A, immature; B, adult.

205

NOTES

Immature males’ outermost tail feathers differ from those of nearly all females in that
the rachis is black, extending well out into the white rectrix tip, so that a black line bisects
this white tip (Figure 1F-H), Moreover, the subterminal band forms a black chevron
where it narrows into the black rachis, with the chevron’s apex pointing distally toward
the rectrix tip. This black chevron is absent from the rectrices of females. The black
chevron may be angled acutely (Figure IF), moderately (Figure 1G), or quite obtusely
(Figure 1H), but, in combination with the black rachis bisecting the white tip, it is
diagnostic of a male. Baltosser (1987) described and illustrated the black rachis but did
not comment on the inverted chevron. All but seven of 42 specimens marked “male” on
the label had both the black chevron and black rachis bisecting the rectrix tip. These
seven exceptions (CAS 14302, 18977, and 46005; MVZ 52207, 145598, 158804,
and 168423) we believe to have been missexed. Six of the seven have no or very slight
corrugation of the bill, indicating they are adults (Ortiz-Crespo 1972, Baltosser 1987).
The seventh, CAS 46005, appears to have moderate bill corrugation, but it also has
unworn secondaries clearly of the adult shape. None of these specimens has any
iridescent red feathers in the crown, on the auriculars, or on the lower corner of the
gorget, suggesting that all seven were in fact missexed adult females. All seven
exceptional “males” had outermost rectrix patterns entirely typical of what we’ve found
in adult females, not intermediate or ambiguous in any way. Adult females often have a
large patch of iridescent red feathers on the center of the throat that may have caused
some collectors to assume they were immature males.

Three known females handled during the banding studies had a black rachis bisecting
the white tip, as found in immature males, but were lacking the black chevron. These
rectrices were pulled and are in the collection of tine California Academy of Sciences. Wells
noted uncorrugated bills on two of them at the time the rectrices were pulled. These two
birds still exhibited adult female plumage (absence of gorget) the following year. The third
was an adult when first captured and, when captured two years later, still had no gorget.

In summary, immature males can be distinguished from both age classes of females by
the black chevron narrowing into the black rachis that bisects the white rectrix tip.
Conversely, females (both adult and immature) usually have a white rachis and always
have a white notch intruding into the black subterminal band. The adult males’ outermost
rectrix is narrow and lacks the broad white tip. These same characteristics may be used
to age and sex the related Costa’s Hummingbird (C. costae, P. Pyle pers. comm ).

We thank Ned K. Johnson and Barbara Stein for permission to examine the
specimens at the Museum of Vertebrate Zoology, and for loaning some of them. We
also thank William Baltosser and Peter Pyle who commented on an earlier version of
this paper. Judy Merrill drew the fine reproductions of rectrices.

LITERATURE CITED

Baltosser, W. H. 1987. Age species and sex determinations of four North American
hummingbirds. N. Am. Bird Bander 12:151-166.

Ortiz-Crespo, F. 1. 1972. A new method to separate immature and adult humming-
birds. Auk 89:851-857.

Wells, S., Bradley, R. A., and Baptista, L. F. 1978. Hybridization in Calypte
hummingbirds. Auk 95:537-549.

Williamson, F. S. L. 1956. The molt and testis cycles of the Anna Hummingbird.
Condor 58:342-366.

Accepted 1 July 1996

206

WESTERN BIRDS, INDEX, VOLUME 27, 1996

Compiled by Jack W. Schlotte and Philip Unitt

Accipiter cooperii , 49, 51
gentilis, 50, 52
striatus , 49, 50, 51
Aimophila cassinii, 115
Ajaia ajaja, 89-90
Alauda aruensis, 86-88
Albatross, Laysan, 70-76
Light mantled, 95
Short-tailed, 115
Amador, Edgar, and Juan Jose

Ramirez, A record of the Roseate
Spoonbill on the Pacific coast of
the peninsula of Baja California,
89-90

Amazilia violiceps, 13, 23
Ammodramus leconteii, 20, 115
Anas strepera, 159

querquedula , 7, 117-118
Ani, Groove-billed, 13, 93, 107
Anser indicus, 25
Anthus cervinus, 24, 111
rubescens, 94
spragueii, 24
Aquila chrysaetos, 50
Ardea herodias, 83
Auklet, Parakeet, 13, 106
Auriparus flauiceps, 79
Avocet, American, 159, 160, 205
Aythya ferina, 1
fuligula, 22

Baicich, Paul J., Steven C. Heinl, and
Mike Toochin, First documented
breeding of the Eurasian Skylark in
Alaska, 86-88

Bailey, Scott J., see Maender, G. J.
Bailey, Stephen F., see Wells, S.
Baptista, Luis F., see Wells, S.
Bartramia longicauda, 22, 103
Becerril, Felipe, see Carmona, R.
Bonasa umbellus, 43
Booby, Blue-footed, 81, 100
Brown, 4, 81-82, 100-101
Masked, 3-4, 5
Red-footed, 4, 117

Brachyramphus marmoratus, 30, 31,
35, 94
Brant, 94

Branta bemicla , 94
Bubulcus ibis, 154

Western Birds 27:207-212, 1996

Bulweria bulwerii, 95
Bunting, Painted, 20, 115
Rustic, 93, 113, 115
Snow, 20, 115, 121
Buteo albonotatus, 7, 22, 50, 93,
101-102, 103, 118, 121
jamaicensis, 49, 51
regal is, 50
swainsoni, 50

Calidris ferruginea, 22
fuscicollis, 10

minuta, 9, 10, 22-23, 119
ruficollis, 22-23, 119
subrninuta, 23
Calonectris leucomelas, 20
Calypte anna, 78-80, 204-206
costae, 206

Canachites canadensis, 41-47
Capitolo, Phil, see Hickey, C. M.
Caracara, Crested, 95
Caracara plancus, 95
Cardellina rubrifrons, 12, 19, 25
Carmona, Roberto, Saudiel Ramirez,
Bulmara Zarate, and Felipe
Becerril, Some nesting waterbirds
from southern San Jose Island and
adjacent islands, Gulf of California,
Mexico, 81-85
Carpodacus mexicanus, 19
purpureus, 94
Catbird, Gray, 1, 16
Cathartes aura, 48-53
Catharus fuscescens, 24, 120
guttatus, 65-69, 94
minimus, 15, 24
Chaetura vauxi, 30-40
Chaffinch, Common, 94, 121
Charadrius alexandrinus, 160, 164,
202-203
mongolus, 7-9
morinellus, 9
uociferus, 160, 203
wilsonia, 8, 9
Circus cyaneus, 50
Collins, Charles T., and Kimball L.
Garrett, The Black Skimmer in
California: An overview, 127-135
Columbina talpacoti, 13, 106-107,
119

207

INDEX

Contopus pertinax, 13, 24
Coragyps atratus, 95
Cormorant, Neotropic, 4
Coturnicops noveboracensis, 7, 103
Creagrus furcatus, 95
Crotophaga sulcirostris, 13, 93, 107
Curlew, Little, 93, 103, 105
Long-billed, 105

Cyclorrhynchus psittacula, 13, 106
Cygnus buccinator, 6-7, 21, 101, 102
columbianus, 21, 94
Cynanthus latirostris, 13, 93, 107-
108

De la Cueva, Horacio, and Guillermo
Fernandez, Night feeding of Black
Skimmers at Estero Punta Banda,
Baja California, Mexico, 162-163
Dendragapus canadensis, 41-47
obscurus, 41, 42, 43
Dendrocygna autumnalis , 6
Dendroica cerulea, 18
dominica, 17, 114
graciae, 17-18, 114
palmarum, 94
pinus, 18, 114

Dickerman, Robert W., and Jack
Gustafson, The Prince of Wales
Spruce Grouse: A new subspecies
from southeastern Alaska, 41-47
Diomedea albatrus, 115
immutabilis, 70-76
Dotterel, Eurasian, 9
Dove, Ruddy Ground, 13, 106-107,
119

Dryocopus pileatus, 30, 35
Duck, Black-bellied Whistling, 6
Tufted, 22

Dumetella carolinensis , 1, 16

Eagle, Golden, 50
Egret, Cattle, 154
Reddish, 5-6, 101, 117, 121
Snowy, 154

Egretta rufescens, 5-6, 101, 117,

121

thula , 154
tricolor, 5, 101
Eider, King, 7, 101
Elanus leucurus, 164
Emberiza rustica, 93, 113, 115
Empidonax alnorum, 14, 119-120
flaviventris, 120
Endomychura craueri, 167-168
Eremophila alpestris, 24

Erickson, Richard A., and Scott B.
Terrill, Nineteenth report of the
California Bird Records Commit-
tee: 1993 records, 93-126

Falcipennis canadensis , 41-47
Falco mexicanus , 50
peregrinus, 50
rusticolus, 93, 102-103
sparverius, 49, 50, 51
Falcon, Peregrine, 50
Prairie, 50

Figueroa-Carranza, Ana-Luisa, see
Gallo-R., J.-P.

Finch, House, 79
Purple, 94

Flycatcher, Alder, 14, 119-120
Dusky-capped, 14, 93, 108, 120
Fork-tailed, 1, 11, 15
Great Crested, 14, 108
Scissor-tailed, 15, 108, 110
Sulphur-bellied, 93, 108, 109
Yellow-bellied, 120
Fregata minor, 1, 4-5
Frigatebird, Great, 1, 4-5
Fringilla coelebs, 94, 121
Fry, Adam J., Octavio R. Rojas- Soto,
and Adolfo G. Navarro S., A winter
record of the Gray Vireo from San
Luis Potosi, Mexico, 54-55

Gadwall, 159

Gallion, Terri, see Rowe, S. P.
Gallo-Reynoso, Juan-Pablo, and Ana-
Luisa Figueroa-Carranza, The
breeding colony of the Laysan
Albatrosses on Isla de Guadalupe,
Mexico, 70-76
Garganey, 7, 117-118
Garrett, Kimball L., see Collins, C. T.
Gavia adamsii, 3, 20, 115, 121
Gazzaniga, Kathleen T. , Overwintering
of Black Skimmers in California:
Site fidelity and intersite move-
ments, 136-142
Gnatcatcher, Black-tailed, 54
Godwit, Bar-tailed, 10, 106, 119
Hudsonian, 106

Gonzalez, Salvador, see Mellink, E.
Goose, Bar-headed, 25
Goshawk, Northern, 50, 52
Grackle, Common, 20, 121
Greenshank, Common, 93, 119
Ground-Dove, Ruddy, 13, 106-107,
119

208

INDEX

Grouse, Blue, 41, 42, 43
Ruffed, 43
Spruce, 41-47

Gull, Black-headed, 106
Black-tailed, 1, 10
California, 159
Common Black-headed, 10,
106

Heermann’s, 83, 164
Ivory, 95
Little, 10, 106
Swallow-tailed, 95
Western, 164
Yellow-footed, 83

Gustafson, Jack, see Dickerman,
R. W.

Gyrfalcon, 93, 102-103

Haematopus hachmani, 104-105
pailiatus, 103, 104-105, 118

Harrier, Northern, 50

Hawk, Cooper s, 49, 51
Ferruginous, 50
Harris, 95
Red-tailed, 49, 51
Sharp-shinned, 49, 50, 51
Swainson’s, 50
Zone-tailed, 7, 22, 50, 93,
101-102, 103, 118, 121

Heindel, Matthew T., and Michael
A. Patten, Eighteenth report
of the California Bird Records
Committee: 1992 records, 1-
29

Heinl, Steven C., see Baicich, P.

J.

Helmitheros uermiuorus, 18,

114

Heron, Great Blue, 83
Tricolored, 5, 101
Yellow-crowned Night, 6, 101

Heteroscelus breuipes, 22
incanus, 22

Hickey, Catherine M., Phil
Capitolo, and Brett Walker,
First Record of a Lanceolated
Warbler in California, 197-
201; see also Shuford, W. D.

Hiett, Katherine L., see Maender,
G. J.

Himantopus mexicanus, 159,
160, 202

Horblit, Helen M,, see Wells, F.

Howell, Steve N. G., Sophie
Webb, and Larry B. Spear,

Identification at sea of Cook’s, De
Filippi’s, and Pycroft’s Petrels, 57-
64

Hummingbird, Anna’s, 78-80, 204-
206

Blue-throated, 23
Broad-billed, 13, 93, 107-108
Costa’s, 206
Violet-crowned, 13, 23
Hylocichla musteiina, 15, 110

Ibis, White-faced, 169-196
Ictinia mississippiensis, 1, 7

Josselyn, Michael N., see Whelchel, A.
W.

Junco, White-winged, 94
Junco hyemalis , 94

Keane, Kathy M., see Whelchel, A. W.
Kestrel, American, 49, 50, 51
Killdeer, 160, 203
Kingbird, Thick-billed, 14-15, 108
Kite, Mississippi, 1, 7
White-tailed, 164
Kittiwake, Red-legged, 95

Lagopus leucurus, 122
Lampornis clemenciae, 23
Lark, Eurasian Sky, 86-88
Horned, 24

Larus californicus, 159
crassirostris, 1, 10
heermanni, 83, 164
livens, 83
minutus, 10, 106
occidentalis, 164
ridibundus, 10, 106
Layne, Valerie L„, Robert J. Richmond,
and Peter J, Metropulos, First
nesting of Black Skimmers on San
Francisco Bay, 159-162
Limosa haemastica, 106
lapponica, 10, 106, 119
Locustella amnicola, 199
certhiola , 199-200
fasciolata, 199
fluviatilis, 199
lanceolata, 95, 197-201
luscinioides, 199
naevia, 199-200
ochotensis, 199
pleskei, 199
pryerf, 200

Loon, Yellow-billed, 3, 20, 115, 121

209

INDEX

Maender, Gloria J,, Katherine L. Hiett,
and Scott J. Bailey, Nesting Anna’s
Hummingbirds in urban Tucson,
Arizona, 78-80
Meadowlark, Eastern, 25
Megalurus pryeri, 200
Mellink, Eric, Eduardo Palacios, and
Salvador Gonzalez, Notes on
nesting birds of the Cienega de
Santa Clara saltflat, northwestern
Sonora, Mexico, 202-203
Metropulos, Peter J., see Layne, V. L.
Mimus polyglottos, 79
Mockingbird, Northern, 79
Molina, Kathy C., Population status
and breeding biology of Black
Skimmers at the Salton Sea,
California, 143-158
Motacilla alba, 24
flam, 16, 24, 201
lugens, 24, 201
Murre, Thick-billed, 13, 106
Murrelet, Craveri’s, 167-168
Long-billed, 94
Marbled, 30, 31, 35, 94
Xantus’, 74

Myiarchus crinitus, 14, 108
tuberculifer, 14, 93, 108, 120
Myiodynastes luteiventris , 93, 108, 109

Navarro S,, Adolfo G., see Fry, A, J.
Night-Heron, Yellow-crowned, 6, 101
Numenius americanus, 105
minutus, 93, 103, 105
phaeopus, 94

Nyctanassa violacea, 6, 101
Nycticorax violaceus, 6, 101

Oceanodroma castro, 21, 117
sp., 83
tethys, 100

Oenanthe oenanthe, 15, 24, 201
Olson, Storrs L., The name of the Craveri
Brothers’ Murrelet, 167-168
Oporornis agilis, 19, 114
formosus, 11, 18-19, 114
Philadelphia, 19, 25, 114
Osprey, 50, 83
Owl, Spotted, 30

Oystercatcher, American, 103, 104-
105, 118
Black, 104-105

Page, Gary W., see Shuford, W. D.
Pagophila eburnea, 95

Palacios, Eduardo, see Mellink, E.
Pandion haliaetus, 50, 83
Parabuteo unicinctus , 95
Passer domesticus, 19
Passerina ciris, 20, 115
Paton, Peter W. C., see Sterling, J.
Patten, Michael A., see Heindel, M. T.
Pelecanus occidentalis, 149
Pelican, Brown, 149
Petrel, Band-rumped Storm, 21, 117
Black-winged, 60, 61, 63
Bulwer’s, 95
Cook’s, 57-64
Dark-rumped, 93, 116
De Filippi's, 57-64
Mottled, 3

Pycroft’s, 57, 58, 62, 63
Stejneger’s, 3, 60, 63
Wedge- rumped Storm, 100
Pewee, Greater, 13, 24
Phaethon rubricauda , 3, 4, 93, 100
Phalacrocorax brasilianus , 4, 6
olivaceus, 4, 6
Phoebetria palpebrata, 95
Phylloscopus borealis, 95, 201
fuscatus, 93, 110, 201
Picoides tridactyl us, 23-24
Pipit, American, 94
Japanese, 94
Red-throated, 24, 111
Sprague’s, 24
Piranga oliuacea, 20, 115
Plectrophenax nivalis, 20, 115, 121
Plegadis chihi, 169-196
Plover, Mongolian, 7-9

Snowy, 160, 164, 202-203
Wilson’s, 8, 9
Pochard, Common, 7
Polioptila melanura, 54
Polyborus plancus, 95
Ptarmigan, White-tailed, 122
Pterodroma cookii, 57-64
defilippiana, 57-64
inexpectata, 3
longirostris, 3, 60, 63
nigripennis, 60, 61, 63
phaeopygia, 93, 116
pycrofti, 57, 58, 62, 63
Puffinus gravis, 93, 116-117
pad ficus, 117
puffinus, 93, 98-99, 117

Quiscatus quiscu/a, 20, 121

Rail, Clapper, 202

210

INDEX

Yellow, 7, 103
Rallus longirostris, 202
Ramirez, Juan Jose, see Amador, E.
Ramirez, Saudiel, see Carmona, R.
Recuruirostra americana, 159, 160,202
Richmond, Robert J., see Layne, V. L.
Rissa brevirostris, 95
Robin, Rufous-backed, 16
Rodriguez Estrella, Ricardo, see Unitt, P.
Rojas- Soto, Octavio R., see Fry, A. J.
Rowe, Sean P., and Terri Gallion, Fall
migration of Turkey Vultures and
raptors through the southern Sierra
Nevada, California, 48-53
Rynchops niger, 127-167

Safran, Rebecca J., see Shuford, W. D.
Sandpiper, Curlew, 22
Upland, 22, 103
White-rumped, 10
Seiurus motacilla, 18
Shearwater, Greater, 93, 116-117
Manx, 93, 98-99, 117
Wedge-tailed, 117
Shelduck, Ruddy, 25
Shuford, W. David, Catherine M.
Hickey, Rebecca J. Safran, and
Gary W. Page, A review of the
status of the White-faced Ibis in
winter in California, 169-196
Skimmer, Black, 127-167
Skylark, Eurasian, 86-88
Somateria spectabi/is, 7, 101
Sparrow, Cassin’s, 115
Field, 12, 20
House, 79
Le Conte’s, 20, 115
Spear, Larry B., see Howell, S. N. G.
Spizella pusilla, 12, 20
Spoonbill, Roseate, 89-90
Sterling, John, and Peter W. C. Paton,
Breeding distribution of Vaux’s
Swift in California, 30-40
Sterna anaethetus, 93-94, 119
antillarum, 164, 203
forsteri, 159, 160
fuscata, 23
hirundo , 94, 155
lunata, 93-94, 119
nilotica, 154

Stilt, Black-necked, 159, 160, 202
Stint, Little, 9, 10, 22-23, 119
Long- toed, 23
Red-necked, 22-23, 119
Rufous-necked, 22-23, 119

Storm-Petrel, Band-rumped, 21, 117
sp., 83

Wedge-rumped, 100
Strix occidentals, 30
Sturnella magna, 25
Sula dactylatra, 3-4, 5

leucogaster, 4, 81-82, 100-101
nebouxii, 81, 100
sula, 4, 117
Swan, Bewick’s, 94
Trumpeter, 6-7, 21, 101, 102
Tundra, 21, 94
Swift, Vaux’s, 30-40
Synthliboramphus craueri, 167-168
hypoleucus, 74

Tadorna ferruginea, 25
Tanager, Scarlet, 20, 115
Tattler, Gray-tailed, 22
Wandering, 22
Tern, Bridled, 93-94, 119
Common, 94, 155
Forster’s, 159, 160
Gray-backed, 93-94, 119
Gull-billed, 154
Least, 164, 203
Sooty, 23

Terrill, Scott B., see Erickson, R. A.
Thrasher, Curve-billed, 16, 79
Thrush, Gray-cheeked, 15, 24
Hermit, 65-69, 94
Wood, 15, 110

Toochin, Mike, see Baicich, P. J.
Toxostoma curuirostre, 16, 79
Tringa nebularia , 93, 119
Troglodytes troglodytes, 94
Tropicbird, Red-tailed, 3, 4, 93, 100
Turdus rufopalliatus, 16
Tyrannus crassirostris, 14-15, 108
forficatus, 15, 108, 110
sauana, 1, 11, 15

Unitt, Philip, and Ricardo Rodriguez
Estrella, Winter distribution of
Hermit Thrush subspecies in the
Sierra de La Laguna, Baja
California Sur, 65-69
Uria lomvia, 13, 106

Veery, 24, 120
Verdin, 79

Vermivora chrysoptera, 17
pinus, 17, 93, 111, 113, 114
Vireo, Bell’s, 94
Blue-headed, 94

211

INDEX

Gray, 54-55

Philadelphia, 17, 25, 93, 111, 112
Solitary, 94
White-eyed, 16, 111
Yellow-green, 17, 111
Yellow-throated, 16-17, 111
Vireo bellii, 94
flauifrons, 16-17, 111
flauoviridis, 17, 111
griseus, 16, 111

philadelphicus, 17, 25, 93, 111, 112
solitarius, 94
uicinior , 54-55
Vulture, Black, 95
Turkey, 48-53

Wagtail, Black-backed, 24, 201
White, 24

Yellow, 16, 24, 201
Walker, Brett, see Hickey, C. M.
Warbler, Arctic, 95, 201

Blue-winged, 17, 93, 111, 113, 114

Cerulean, 18

Connecticut, 19, 114

Dusky, 93, 110, 201

Golden-winged, 17

Grace’s, 17-18, 114

Grasshopper, 199-200

Gray’s, 199

Japanese Marsh, 200

Kentucky, 11, 18-19, 114

Lanceolated, 95, 197-201

Middendorff’s, 199
Mourning, 19, 25, 114
Pallas’, 199-200
Palm, 94
Pine, 18, 114
Pleske’s, 199
Red-faced, 12, 19, 25
River, 199
Savi’s, 199
Styan’s, 199
Worm-eating, 18, 114
Yellow-throated, 17, 114
Waterthrush, Louisiana, 18
Webb, Sophie, see Howell, S. N. G.
Wells, Shirley, Luis F. Baptista, Stephen
F. Bailey, and Helen M. Horblit,

Age and sex determination in
Anna’s Hummingbird by means of
tail pattern, 204-206
Wheatear, Northern, 15, 24, 201
Whelchel, Adam W., Kathy M. Keane,
and Michael N. Josselyn, Establish-
ment of a new Black Skimmer
breeding colony in southern
California, 164-167
Whimbrel, 94

Whistling-Duck, Black-bellied, 6
Woodpecker, Pileated, 30, 35
Three-toed, 23-24
Wren, Winter, 94

Zarate, Bulmara, see Carmona, R.

BULLETIN BOARD

“WINGS OVER WILLCOX” BEGINS 17 JANUARY 1997

The fourth annual Wings over Willcox Sandhill Crane celebration will take place
17-19 January 1997 in Willcox, Arizona, about 80 miles east of Tucson. Each year
approximately 10,000 cranes return to Willcox in mid-January to feast on the corn
stubble and head to Willcox Playa, their winter home. Guided tours to see the cranes
will be offered with trips to the Willcox Playa, Cochise Lake, and the AEPCO Ash
Pond. Seminars, workshops, and field trips are planned for both the novice and the
expert birder. Field trip participation is limited, so early registration is encouraged.
Registration forms may be obtained by calling the Willcox Chamber of Commerce, 1-
800-200-2272 or 520-384-2272. The event coincides with Kokopelli Winery’s
second annual wine extravaganza and “celebrity chef’ culinary superbowl; informa-
tion also available from the Willcox Chamber of Commerce.

212

WESTERN BIRDS

Quarterly Journal of Western Field Ornithologists

President: Kimball L. Garrett, Natural History Museum of Los Angeles County, 900
Exposition Blvd., Los Angeles, CA 90007

Vice-President: Mike San Miguel, 2132 Highland Oaks Dr., Arcadia, CA 91006

Treasurer/Membership Secretary: Dorothy Myers, 6011 Saddletree Lane, Yorba
Linda, CA 92686

Recording Secretary: Jean-Marie Spoelman, 4629 Diaz Drive, Fremont, CA 94536

Directors: Kimball Garrett, Daniel D. Gibson, Tim Manolis, Guy McCaskie, Mike
San Miguel, W. David Shuford, Bill Tweit, David Yee

Editor: Philip Unitt, San Diego Natural History Museum, P.O. Box 1390, San
Diego, CA 92112

Associate Editors: Cameron Barrows, Tim Manolis, Thomas W. Keeney

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

Secretary, California Bird Records Committee: Michael A. Patten, P. O. Box
51959, Riverside, CA 92517-2959

Editorial Board: Robert Andrews, Alan Baldridge, Laurence C. Binford, R. Wayne
Campbell, David F. DeSante, Jon L. Dunn, Richard Erickson, William T. Everett,
Kimball L. Garrett, Joseph R. Jehl, Jr., Ned K. Johnson, Virginia P. Johnson,
Brina Kessel, Stephen A. Laymon, Paul Lehman, John S. Luther, Guy McCaskie,
Joseph Morlan, Harry B. Nehls, Dennis R. Paulson, Gary H. Rosenberg, Oliver K.
Scott, Ella Sorensen, Richard W. Stallcup, Charles Trost, Terence R. Wahl,
Bruce Webb

Membership dues, for individuals and institutions, including subscription to Western
Birds: Patron, $1000; Life, $350; Supporting, $50 annually; Contributing, $30
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Back issues of Western Birds : $20 per volume, $5.00 for single issues. Plus $1.00
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Published October 15, 1996

ISSN 0045-3897