1

I

Vol. II, No. 3, 1980

WESTERN BIRf rS

Quflrtisly Journal ^ U/trsitrrh F&M €k ni-tholbgtas

PhjMfdrmr JohnS Lurtvr
Irtwufi:'* Cftrth Alton
Secrafarjj • . iliM L*. mors

ViCf -P, 1 idcnl. Twen^iift Wahl
fac i ritotn-Wp $^errtmv fi Klcdbeth C ■ r| ysm
Spocirti PwvtfficteSttwteiTy: LrrtdU D^tariey

IX reef of i UufvftM- C BmFani Jitfnmt A Conry
Laymens, John. 5 L-urhiij Guv
R Vl : ah- .Uriel Wilzt.' i nan

Eriiroi. AUn M Crfl;^|

Awm iETii- Editor M.iffa A

i VJh^id F DuSanu. Stephen A
Slttlkup. Tgrrcrii u

Edtoiaf S<w^, Hi Utin Andrei AUrt faldftiat-. Wfcm H Behkf Aiuiivw J

lainence C Btotorp fChfllnnfinjL Jeanne A Cornu, tfrwkd F_
D^Sar.L- RicWd Eflc^u. Jtttrfipfl Gatvr^mf^ -k>siph H J*hL Jr Ned
K Johnson Vlnjiirtn P. Jfthnsm, Brims Knwl, Chattes S. U^r k .
■btopbcfi A. taytrtonu John 5 Lutfm. Tim Monolbs, Brim J, MtCirfkry,
Guy MeCiakk, M T|mn% Myr«, Harry B Nyhlf . Themis* L FW<jvr>
Slil^wn M ReewH Oliver K Scott P fig. V id Skaar frehtfd W
Stalfeup, Davkl SlitfJftg. G Shum**^ S^VOwrk* Tmsi. Tcr^n R
Rfii-mrl H Vta&jrr Pin rev Webtt tJfik* A Zimmei man

I^Vnul ttmt? cower by VrrgtnLa P .luhnson

MviuEwtahip duai. tor individuals arid msUttllMnrR.. inetijillna suhstflpttan te te&fom
Smd -1 ftUron, tJODO' L.rff $1 hU| Si.rppnlliTrtg $20 artniuaiy. C<inJriiliUa¥iLj SlOan
nualli/, Re^tilar, %7 Dm*.* *md srjniTlbiJiiHinif. iff im deductible to the «i'

fr!] 1 \iic~ <■*»*'!■ IR 1 ivaikbll ttM fur Vdilitr:.: I iNumbtfllg 3 all. I

4, S3 Ini VyJyrtt# 5? iNiimbens 2 iiHid X 19?] J, $5" per valuTitE f-nr Volume-s 3

itVtJdgb 7,. and $7. I’i 1 I toi Volume fi 1 1 97 ) s .i n 1 1 su bseq lujtiI v> jIuni**

MaintMisIwp dues, ehfrtgtft d Address, uridr]IV.in^ 3 |e^Oj!i]«iaiKl orders fur bflckkuues
of Caf^brnifl Btxl* - v Wmi em flfrds should be Mrrf'Hl BJ^beih C-^ppi m, F O Ek?jc 595
CqpaPrtrlo, Celdomia ®f|#; Make chkf^t payable Irt WvuLurri PboJiJ Omltiwlo^lftl *,

S*mi r,ip L - bird nrpurh. fnr Cdllrardn U\ Jnhn S Lud.j-i. Coik^ of Alnrm-diJ ^
AlUnlrc Aviuiuff , A]nmedn CA ; -Beia CdHF Blrdi 2r 109 - 1 10, For A^lrfona, wW
r%TJorta to Robifl A 4619 £ AicaiJifl Laire. Phoenb AZ 85TTIS For Coki

Jldo. pand report! tr> CFO Recnrtt* CormtllttfW, Etanvi'j Musturn ol NaJutaJ Hfitorv
Cay Park i EVttiw, CCl 1 W^>ifd&. For On^jcjn, ifnd reporff to One^taT: iEHni Roirisrda
Coil i millet!,, P,0 fkv* 10373. EugpTHt . -OR 9744i I

I’nbu'-lii'- ■ Pvbtuary tb

WF.SIFKM H1HT>S MWBn^G RATES AND SS’KCfFfCATIONS

Fuji PfiQf 4 K b ^ midlH feD per Issue J2CX? per vk^P

H-i. l Pal$e 4 & 3|& Midwifi p« Ksuv $ 1 10 p«r vear

Quair^r PayL= 4 <t W tn bos S30 per Issuv 1] JO p f n V var

^'.r -1 printing, (Ifw coliimm pur payt, 4 Inches WWfe. Glossy, btodk«|ld wWtophc«P»
OECepE.itjbH ; huF TOntf 1 wi isNfl i sto? J33 lltlnr. 'Tfiflliy fOpy i!TBO|il#SEtfd Elf hi* if.

nor pfflfriate, ejcii.i-f ImiLjes iiir rypwstttkhy; udJt few mark ais toJIows. t!5 full pa^p, $10
lind p*ye, SA quarter paya . S#rtd rppy -with nrmiliance to Ehfflb«ll| Copp^ r P 6 Box
Pj 95. < nrurwli’i < id* I oir id 92 ]• Jh Make dnot’k^ fU^blv to Wv.^vin F ield 0r-

‘!lh ‘loywh A R T *% r-Tmmixiiw r m flihiw™ Frif rtgehr

WESTERN BIRDS

Volume 11, Number 3, 1980

BIRDS OF HASTINGS RESERVATION,

MONTEREY COUNTY, CALIFORNIA

JOHN DAVIS, WALTER D. KOENIG and PAMELA L. WILLIAMS, Hastings Reser-
vation, University of California, Star Route Box 80, Carmel Valley, California 93924

The Hastings Natural History Reservation was established in Oc-
tober 1937 as a field station of the Museum of Vertebrate Zoology
(MVZ), University of California, Berkeley. At that time, Jean M.
Linsdale of the Museum staff became the first resident director and
initiated a program of research and instruction. Human disturbance
to the land was kept to a minimum, a policy which continues to be
enforced. Since the beginning of the Reservation’s history at least
one ornithologist has been permanently resident and a large file of
records and field notes on the avifauna has been compiled. Con-
tributors to this file include Reservation and Museum staff members,
students, postdoctoral fellows, visiting scientists and members of
visiting classes.

Information has been provided by George A. Bartholomew, Jer-
ram L. Brown, Gene M. Christman, Nicholas E. and Elsie C. Collias,
Keith L. Dixon, Harvey I. Fisher, Ralph J. Gutierrez, Elgin Hurlbert,
Ned K. Johnson, Nancy E. Joste, Carl B. Koford, Jean M. Linsdale,
Michael H. and Barbara R. MacRoberts, Joe T. Marshall, Jr., Alden
H. Miller, Ron L. Mumme, Sandy Nishimura, Frank A. Pitelka,
Richard B. Root, Charles G, Sibley, William L. Thompson, J.J.A.
van Iersel, Nicolaas A.M. Verbeek, Laidlaw Williams and Henry G.
Weston, Jr. Many of these workers are cited in the species accounts
which follow. In addition, we have used information provided by
many other zoologists not primarily ornithologists who have worked
at the Reservation including Floyd E. Durham, Robert B. Finley, Jr.,
Henry S. Fitch, Lawrence M. Hanks, Lloyd P. Tevis, Jr. and P.
Quentin Tomich.

Western Birds 11:113-128, 1980

113

BIRDS OF HASTINGS RESERVATION

As a result of the efforts of these workers, the occurrence of birds
at the Reservation has been monitored continuously for 42 years.
Therefore, it is possible to compile a reasonably complete annotated
list for this station which may serve 1) as a basis for comparison with
other areas, 2) as a baseline against which future changes in the avi-
fauna may be measured, and 3) to assess changes which have oc-

Figure 1. Location of Hastings Reservation (HNHR) in Monterey Co., California

BIRDS OF HASTINGS RESERVATION

curred since the Reservation’s founding. Linsdale (1947) provided a
list of the birds which had been recorded at the Reservation in the
first 10 years of its operation, but the arrangement of species in his list
makes it difficult to use and many new records have been added in
subsequent years, making the compilation of a new list desirable.

The Reservation lies in the drainage of the upper Carmel River
although not on the river proper (Figure 1). It is on the USGS Rana
Creek and Chews Ridge quadrangles, covering 770 ha, with eleva-
tions ranging from 470 to 940 m. Location of headquarters, near the
center of the Reservation, is 36°23' N and 121 °33 W.

The Reservation contains five major vegetation types (Figure 2)
typical of south coast range foothill vegetation (Griffin 1974). These
are: mixed evergreen forest, including Black (Quercus kelloggii) ,
Golden (Q. chrysolepis) , and Coast Live (Q. agrifolia ) oaks, Califor-
nia Laurel ( Umbellularia californica) . and Madrone ( Arbutus men-
ziesii), with an understory of Poison Oak {Rhus diuersiloba) , Cof-
feeberry (Rhamnus californica) , gooseberry (Ribes sp,), Cream Bush
( Holodiscus discolor), and Brake Fern ( Pteridium aquilinum ); foothill
woodland, dominated by Blue Oaks (Q. douglasii) with Valley Oaks
(Q. lobata) locally present, especially in oak savannas; riparian
woodland of Western Sycamores ( Platanus racemosa ), Coast Live
and Valley oaks, willows ( Salix sp.), and Bigleaf Maple ( Acer
macrophyllum) and Red Alder ( Alnus rhombifolia ) locally; chapar-

Figure 2. View of Hastings Reservation showing the five major vegetation types.

Photo by W.D. Koenig

115

BIRDS OF HASTINGS RESERVATION

ral, dominated by Chamise (Adenostoma fasciculatum) , with Coast
Ceanothus ( Ceanothus ramulosus) and Eastwood Manzanita (Arc-
tostaphylos glanduiosa) locally; and grassland, dominated by
Mediterranean annual grasses, especially Soft Chess (Bromus
mollis), Wild Oat ( Aoena fatua), and Bronco Grass { Bromus dian-
drus). Conifers are essentially absent. There are three intermittent
creeks on the Reservation.

Weather records have been kept at Reservation headquarters con-
tinuously since 1938. Forty-year means (1938-1977) are as follows:
annual precipitation, 52.3 cm (range 26.2 cm in 1975-76 to 105.2
cm in 1940-41); mean monthly maximum temperatures range from
30.7°C (July) to 15.5°C (January); mean monthly minima range
from 9.7°C (July and August) to 1.3°C (January). Very little rainfall
(an average of 2.2 cm) falls between May and September, inclusive.

ANNOTATED LIST

Species are listed according to whether they are residents (perma-
nent, summer or winter), migrants (spring or fall), visitants (recorded
several times, but neither residents nor migrants), or accidental.
Abundance categories are common (present in numbers each year),
uncommon (present in small numbers each year), and rare (not
recorded some years). Irregular species are those which vary
markedly in abundance between years. Nomenclature generally
follows the current AOU checklist except in a few cases where we
have chosen to follow the more recent changes of Mayr and Short
(1970) . Species known to have bred at least once are indicated by an
asterisk (*).

COMMON LOON, Gauia immer. Accidental. One seen flying over the Reservation
18 Dec 1937 (Linsdale).

ARCTIC LOON, G. arctica. Accidental. An injured bird found in a creek on the
Reservation 15 Apr 1941 was collected (Tevis, specimen, Hastings Reservation).

RED-THROATED LOON, G. stellata. Accidental. One record of a bird stranded in a
field 28 Mar 1973 (M. MacRoberts).

GREAT BLUE HERON, Ardea herodias. Visitant. Five records: 15 Aug 1946
(Riney), 18 Sep 1953 and 10 Aug 1974 (Davis), 16 Jul 1979 (Joste) and 28 Jun
1980 (P. Williams).

GREEN HERON, Butorides striatus. Rare spring migrant and fall visitant. Six records,
four between 19 Apr and 29 May. one each 23 Jul and 23 Aug.

CANADA GOOSE, Branta canadensis. Accidental. Three records of small flocks
passing over the Reservation on 18 Nov 1947 and 21 Dec 1948 (Tomich) and 22
Dec 1948 (Linsdale).

MALLARD, Anas platyrhynchos. Accidental. One record, two birds flying over on 22
Mar 1951 (Christman). Resident in small numbers on stock ponds adjacent to the
Reservation.

116

BIRDS OF HASTINGS RESERVATION

PINTAIL, A. acuta. Visitant. Several fall and winter records of flocks passing over the
Reservation.

CINNAMON TEAL, A. cyanoptera. Accidental. Two records of three on a stock pond
adjacent to the Reservation 12 Mar 1979 (Koenig) and 25 Jan 1980 (Mumme).

COMMON MERGANSER, Mergus merganser. Accidental. The dried remains of one
were found on 5 Jan 1951 (Tomich).

TURKEY VULTURE, Cathartes aura. Uncommon summer resident. Rarely reported
in winter.

'WHITE-TAILED KITE, Elanus leucurus. Irregular summer resident. Recorded 17
out of 43 years between 1938 and 1980. Bred in at least five years.

'SHARP-SHINNED HAWK, Accipiter striatus. Uncommon resident. Numbers in-
crease in fall and winter.

'COOPER’S HAWK, A. cooperii. Uncommon resident. Numbers increase in fall and
winter.

'RED-TAILED HAWK, Buteo jamaicensis. Common resident.

'RED-SHOULDERED HAWK, B. lineatus. At present a common resident. Only one
record until 1948. Recorded nearly every year since 1949 and has nested regularly
since 1959.

GOLDEN EAGLE, Aquila chrysaetos. Uncommon resident. Known to breed within 2
km of the Reservation.

MARSH HAWK, Circus cyaneus. Formerly an uncommon visitant, especially in
winter, recorded in all but two years between 1938 and 1952. Only three records
since 1953, all in Dec.

OSPREY, Pandion haliaetus. Visitant. Four records: 21 Apr 1938 (Linsdale); 16 Sep
1951 (Miller); 9 Mar 1970 (Verbeek); and 15 May 1977 (N. and E. Collias).

PRAIRIE FALCON, Fatco mexicanus. Formerly an uncommon visitant with 19
records between 1937 and 1942. Since 1942 only four records: 7 Dec 1951
(Tomich); 28 Apr and 31 Aug 1977 (Koenig); 9 Jul 1979 (Joste).

PEREGRINE FALCON, F. peregrinus. Nine records; none since 1950.

MERLIN, F. columbarius . Rare and irregular winter resident. Observed in eight
winters between 1937 and 1954; only two subsequent records, 18 Nov 1976 and
13 Oct 1979 (Koenig).

'AMERICAN KESTREL, F. sparuerius. Common resident.

'CALIFORNIA QUAIL, Lophortyx calif brnicus. Common resident.

'MOUNTAIN QUAIL, Oreortyx pictus. Common resident.

'TURKEY, Meleagris gallopauo. Introduced into the area by the California Depart-
ment of Fish and Game in 1968. Present at the Reservation since 1970. After an
initial increase in numbers the population has steadily declined and birds are
seldom seen.

VIRGINIA RAIL, Rallus limicola. Accidental. One record, a bird caught in a mist net
11 Nov 1973 (Koenig, specimen, MVZ).

K1LLDEER, Charadrius vociferus. Now accidental. Formerly rare visitant: 28 records
between 1937 and 1954. Only two subsequent records: winter 1975 and 25 Mar
1980.

COMMON SNIPE, Capella gallinago. Winter visitant. Ten records between 1938 and
1959; only one subsequently, 13 Jan 1976 (Koenig).

SOLITARY SANDPIPER, Tringa solitaria. Rare migrant. Four records of a single in-
dividual at a stock pond adjacent to the Reservation: 29 Apr 1976; 21 Apr 1977;
21 Apr 1978 (all Koenig); 2 May 1979 (Hanks).

RED PHALAROPE, Phalaropus fulicarius. Accidental. A mummified carcass was
found 7 Apr 1947 (Linsdale, specimen, Hastings Reservation).

BONAPARTE’S GULL, Larus Philadelphia. Accidental. One bird seen flying over on
26 Dec 1968 (Verbeek).

117

BIRDS OF HASTINGS RESERVATION

CASPIAN TERN, Sterna caspia. Accidental. Three seen flying over on 21 Jul 1957
(Davis, van Iersel) .

BAND-TAILED PIGEON, Columba fasciata. Irregular winter resident; common in
some years.

ROCK DOVE, C. liuia. Visitant; seven records.

‘MOURNING DOVE, Zenaida macroura. Common resident, irregular in winter.

ROADRUNNER, Geococcyx californianus. Formerly a common resident, now rare.
Records for four decades are as follows: 1938-47, 90; 1948-57, 52; 1958-67, 0;
1968-77, 2. Single records in 1978 and 1979. One male calling persistently in the
spring of 1980. Possibly bred at one time but no definite record.

‘BARN OWL, Tyto alba. Common resident.

‘SCREECH OWL, Otus asio. Common resident.

‘GREAT HORNED OWL, Bubo uirginianus. Common resident.

‘PYGMY OWL, Glaucidium gnoma Uncommon resident.

‘LONG-EARED OWL, Asr'o otus. Rare resident, apparently less common in later
years. Recorded in 1938, 1939, 1940, 1948, 1951, 1975 and 1980.

‘SAW-WHET OWL, Aegolius acadicus Rare resident.

‘POOR-WILL, Phalaenoptilus nuttallii. Uncommon summer resident. Records fall
between 6 Feb and 30 Nov, suggesting that some individuals may overwinter.

BLACK SWIFT, Cypseloides niger. Rare migrant. Two records, both of three in-
dividuals flying overhead, 31 Aug 1954 and 7 Jul 1956 (Davis).

VAUX’S SWIFT, Chaetura uauxi. Rare spring migrant. Ten records in six different
years of small groups flying over. All records fall between 19 Apr and 19 May.

WHITE-THROATED SWIFT, Aeronautes saxatalis. Uncommon visitant, but resident
within several km of the Reservation. Seventeen records of birds flying overhead
are distributed throughout all seasons.

‘BLACK-CHINNED HUMMINGBIRD, Archilochus alexandri. Uncommon summer
resident. Recorded 18 Mar 1946 (Linsdale 1947) through 29 Sep. Subsequent
earliest record is 2 Apr 1978 (P. Williams).

‘ANNA’S HUMMINGBIRD, Calypte anna. Common resident; numbers typically
reduced in winter.

RUFOUS HUMMINGBIRD, Selasphorus rufus. Uncommon spring migrant; rare sum-
mer migrant. Recorded 13 Feb-4 May; two summer records, 23 Jul 1942
(Durham) and 7 Sep 1950 (Tomich).

‘ALLEN’S HUMMINGBIRD, S. sasin. Uncommon summer resident. Recorded 22
Feb- 13 Aug.

CALLIOPE HUMMINGBIRD, Stellula calliope. Rare spring migrant. Three records:
25-26 Apr 1951 (Tomich); 2 May 1955 (Davis); and 8 Apr 1969 (Verbeek).

BELTED KINGFISHER, Megaceryle alcyon. Uncommon permanent resident along
Finch Creek. No breeding records for the Reservation but breeds nearby.

‘COMMON FLICKER, Colaptes auratus. Common resident, more numerous in
winter. Hybrids with the “Yellow-shafted” form are rare winter residents recorded
in six years.

‘ACORN WOODPECKER, Melanerpes formiciuorus. Common resident.

LEWIS’ WOODPECKER, M. lewis. Presently a rare winter resident Formerly oc-
curred more commonly, recorded in 7 of 10 winters between 1937-38 and
1946-47, 4 of 10 in next decade, only twice subsequently (1 each in Sep and Oct
1972, M. MacRoberts). Records fall between 13 Sep and 16 May.

RED-BREASTED SAPSUCKER, Sphyrapicus ruber. An uncommon winter resident,
recorded from 18 Sep to 16 Apr.

FtED-NAPED SAPSUCKER, S. nuchalis. Visitant; recorded four times: 19-21 May
1958 (Davis) ; 15 Oct 1972 and 24 Nov 1973 (M. MacRoberts) ; and 15 Mar 1976
(Koenig) .

‘HAIRY WOODPECKER, Picoides uillosus. Uncommon resident.

118

BIRDS OF HASTINGS RESERVATION

'DOWNY WOODPECKER, P. pubescens. Uncommon resident.

'NUTTALL’S WOODPECKER, P. nuttallii. Common resident.

’WESTERN KINGBIRD, Tyrannus uerticalis. Uncommon summer resident.

* ASH- THROATED FLYCAlCHER, Myiarchus cinerascens. Common summer
resident.

'BLACK PHOEBE, Sayorrtrs nigricans. Common resident,

SAY’S PHOEBE, S. saya. Uncommon winter resident. Single birds were recorded on
17 Jun and 4 Jul 1976 (Koenig).

WILLOW FLYCATCHER, Empidonax traillii. Recorded in fall migration, few cer-
tain records.

HAMMOND’S FLYCATCHER, E. hammondii. Recorded each year since 1978 when
noted as common (Johnson). Probably a more regular spring migrant than in-
dicated by these records.

'WESTERN FLYCATCHER, E. difficilis. Common summer resident.

'WESTERN WOOD PEWEE, Contopus sordidulus. Uncommon summer resident.

’OLIVE-SIDED FLYCATCHER, Nuttallornis borealis. Uncommon summer resident.

HORNED LARK, Eremophila alpestris. Present from 6 Nov to 10 Jan 1937-38, as
many as 35 in one flock (Linsdale, Miller) . “About 60” seen 12 Jan 1948, not pre-
sent two days later (Tomich). Not recorded subsequently.

'VIOLET-GREEN SWALLOW, Tachycineta thalassina. Common summer resident.

TREE SWALLOW, Iridoprocne bicolor. Accidental, small groups flying over, moving
N, 21 Feb 1970 (Verbeek).

ROUGH-WINGED SWALLOW, Stelgidopteryx ruficollis. Visitant. Two, 12 Apr 1943
(Linsdale); three, 4 May, and one, 5 May 1975 (Koenig); six, 29 Jun, and one, 30
Jun, 1 Jul 1978 (P. Williams).

'BARN SWALLOW, Hirundo rustica. One pair bred in 1980; only two prior records:
10 May 1938, 1 Jul 1979.

'CLIFF SWALLOW, Petrochelidon pyrrhonota. Nested regularly in small numbers
from 1938 to 1941. Small numbers recorded between Apr and Aug in ten years
between 1942 and 1954, but no nesting observed. One nest in 1955. Next recorded
19 May 1977, when six were seen prospecting for nest sites; then 24 and 29 May
1980 (Nishimura) .

'PURPLE MARTIN, Progne subis. Seen every year but one between 1938 and 1955.
Nested in 1942, 1948 and 1951. Last recorded 30 Jun 1958.

‘STELLER’S JAY, Cyanocitta stelleri. Common resident.

'SCRUB JAY, Aphelocoma coerulescens. Common resident.

'YELLOW-BILLED MAGPIE, Pica nuttalli. Common resident.

COMMON RAVEN, Corvus corax. Accidental. Single birds seen flying over the
Reservation 30 Sep 1953, 18 Feb 1956, and 9 May 1957 (Davis).

'COMMON CROW, C. brachyrhynchos. Common resident.

CLARK’S NUTCRACKER, Nucifraga Columbiana. Single birds seen 4, 5 and 8 Nov
1950 (Koford, Tomich), 15 Oct 1972 (M. MacRoberts) and 20 Oct 1972 (Davis).
One collected near Reservation boundary 26 Oct 1955 (Davis, specimen, MVZ).
Widespread invasions occurred in California in 1950, 1955 and 1972 (Davis and
L. Williams 1957, DeSante and Remsen 1973).

'CHESTNUT-BACKED CHICKADEE, Parus rufescens. Uncommon resident.

'PLAIN TITMOUSE, P. mornatus. Common resident.

'BUSHTIT, Psa/triparus minimus. Common resident.

'WHITE-BREASTED NUTHATCH, Sitta carolinensis. Common resident.

RED-BREASTED NUTHATCH, S. canadensis. Irregular and uncommon migrant.
Single records for Apr and May 1976. The remainder fall between 15 Jul and 27
Nov.

'BROWN CREEPER, Certhia familiaris. Uncommon resident.

'WRENTIT, Chamaea fasciata. Common resident.

119

BIRDS OF HASTINGS RESERVATION

‘DIPPER, Cindus mexicanus. One nesting pair recorded in 1942, 1943, 1944 and
1946 on Finch Creek. Single birds recorded in 1938, 1948 and 1952. No subse-
quent record.

‘HOUSE WREN, Troglodytes aedon. Common summer resident

WINTER WREN, T. troglodytes. Rare winter resident.

‘BEWICK’S WREN, Thryomanes bewickii. Common resident.

CA5JON WREN, Catherpes mexicanus. Rare, irregular visitant. All records but one
are for Jul and Aug.

ROCK W'REN, Salpinctes obsoletus. Visitant. Three records: 12 Sep 1951 (Tomich);
31 May 1970 (Verbeek); 28 Aug 1970 (Davis).

MOCKINGBIRD, Mimus polyglottos. Visitant. Two records in Mar; all others fall be-
tween 7 Aug and 8 Jan.

BROWN THRASHER, Toxostoma rufum. Accidental. A first-year female collected 3
Nov 1966 (specimen, MVZ) pertains to the race longicauda (Davis 1968).

‘CALIFORNIA THRASHER, T. redivivum. Uncommon resident.

'AMERICAN ROBIN, Turdus migratorius. Common late summer to spring resident
until recently, when some individuals remained throughout the summer. Breeding
was established in 1979 when three nests were found (Koenig, P. Williams) . Some
individuals now apparently permanent residents.

VARIED THRUSH, Ixoreus naeoius. Irregular winter resident; common in some
years.

HERMIT THRUSH, Catharus guttatus. Common winter resident.

SWAINSON’S THRUSH, C. ustulatus. Common spring migrant. Recorded Apr- Aug,
with most records in May. A singing male recorded 18 Jun 1944 (Miller) suggests
occasional breeding but no definite record.

‘WESTERN BLUEBIRD, Sialia mexicana. Common resident.

TOWNSEND’S SOLITAIRE, Myadestes townsendi. Accidental. One record, 10 Oct
1951 (Tomich).

‘BLUE-GRAY GNATCATCHER, Polioptila caerulea. Common summer resident.

GOLDEN-CROWNED KINGLET, Regulus satrapa. Rare winter resident.

RUBY-CROWNED KINGLET, R. calendula. Common winter resident.

WATER PIPIT, Anthus spinoletta. Flocks noted 12 Nov- 10 Dec 1937 (Fitch,
Linsdale) and 1 Dec-12 Jan 1939-40 (Linsdale, Tevis). A lone bird noted 14 Feb
1940 (Tevis) was the last record at the Reservation.

CEDAR WAXWING, Bombycilla cedrorum. Common winter resident, recorded in all
months except Jul (extreme spring and late summer dates 2 Jun and 30 Aug).

PHAINOPEPLA, Phainopepla nitens. Visitant. Seen in 13 of 42 years with most
sightings in Oct and Nov, none in Jan, Mar, Jul and Dec.

LOGGERHEAD SHRIKE, Lanius ludouicianus. Rare winter resident and spring
migrant; seen in all months except Apr. One or two birds present Jul 1939-Mar
1940. Sighted in eight years since then.

‘STARLING, Sturnus vulgaris. Uncommon resident, increasing in numbers. First
seen Nov 1964. Next recorded Jan 1968 and first nesting noted in the spring of
that year.

‘HUTTON’S VIREO, Vireo huttoni. Common resident.

‘SOLITARY VIREO, V. solitarius. Uncommon summer resident.

‘WARBLING VIREO, V. gilvus. Common summer resident.

‘ORANGE-CROWNED WARBLER, Vermiuora celata. Common summer resident.

NASHVILLE WARBLER, V. ruficapilla. Uncommon spring migrant.

NORTHERN PARUL.A, Parula americana. Accidental; one record, a singing male 22
Jul 1979 (Mumme; also seen by us).

‘YELLOW WARBLER, Dendroica petechia. Uncommon summer resident.

YELLOW-RUMPED WARBLER, D. coronata. Both “Audubon’s” and “Myrtle”
warblers are common winter residents. Audubon’s Warbler nests within 3 km of
the Reservation.

120

BIRDS OF HASTINGS RESERVATION

‘BLACK-THROATED GRAY WARBLER, D. nigrescens. Common summer resi-
dent; has occurred in every month but Jan.

TOWNSEND’S WARBLER, D. townsendi. Uncommon winter resident. Numbers in-
crease in fall and during spring migration. Recorded in all months but Jun and Jul.

HERMIT WARBLER, D. occidentals- Uncommon spring and fall migrant.

‘MACGILLIVRAY’S WARBLER, Oporornis tolmiei, A breeding bird in the early
years. Recorded infrequently since 1954, it is now an uncommon spring migrant.

YELLOWTHROAT, Geothlypis trichas Uncommon visitant; records in Mar-Jul, Oct.

YELLOW-BREASTED CHAT, Icteria uirens. Uncommon spring and rare fall
migrant, Apr-May and Aug-Sep.

WILSON’S WARBLER, Wilsonia pusilla. Common migrant and visitant, Mar-Oct.
Nests in vicinity.

HOUSE SPARROW, Passer domesticus. Visitant. Recorded in 1939, 1962 and in
seven years from 1967 to 1979.

‘WESTERN MEADOWLARK, Sturnella neglecta. Common resident.

RED-WINGED BLACKBIRD, Agelaius phoeniceus. Visitant. Breeds at stock ponds
adjacent to the Reservation.

TRICOLORED BLACKBIRD, A. tricolor. Formerly an uncommon winter visitant; last
seen in 1949.

HOODED ORIOLE, Icterus cucullatus. Accidental. Recorded in two years; 27 Apr
1968 (Hurlbert) and 12, 15 May 1980 (P. Williams).

SCOTT’S ORIOLE, I. parisorum. Accidental. One record, 26 Nov 1955 (Miller,
specimen, MVZ).

‘NORTHERN ORIOLE, I. galbuia. Common summer resident.

BREWER’S BLACKBIRD, Euphagus cyanocephalus , Uncommon summer resident.
Breeds adjacent to the Reservation.

‘BROWN-HEADED COWBIRD, Molothrus ater. Rare summer resident, first recorded
in 1952, seen in five years subsequently. Has parasitized nests of the Blue-gray
Gnatcatcher (Root, specimen, Hastings Reservation).

WESTERN TANAGER, Piranga ludouiciana. Common migrant. Migration period is
long, with spring and fall migrations almost overlapping, although mid-June
records are few. Breeds in vicinity.

‘BLACK-HEADED GROSBEAK, Pheucticus melanocephalus. Common summer
resident.

BLUE GROSBEAK, Guiraca caerulea. Accidental. One record, 31 Aug 1938
(Linsdale) .

‘LAZULI BUNTING, Passerina amoena. Uncommon summer resident.

‘PURPLE FINCH, Carpodacus purpureus. Common resident.

‘HOUSE FINCH, C. mexicanus Common resident, with marked reduction of
numbers in winter.

PINE SISKIN, Carduelis pinus. Common winter resident. Recorded in every month
but Jun and Jul.

AMERICAN GOLDFINCH, C. tristis. Uncommon winter resident.

‘LESSER GOLDFINCH, C. psaltria. Common resident.

‘LAWRENCE'S GOLDFINCH, C. lauirencei. Common resident; uncommon in
winter.

GREEN-TAILED TOWHEE, Pipilo chlorurus. Rare fall migrant, recorded three times
in Sep (1953, 1954, 1964) and once in Oct (1947). Two of these birds were
trapped and banded.

‘RUFOUS-SIDED TOWHEE, P. erythrophthalmus. Common resident. Specimens
(MVZ) are P . e. megalonyx.

‘BROWN TOWHEE, P. fuscus Common resident. Specimens (Hastings Reserva-
tion) are P. f. crissalis.

SAVANNAH SPARROW, Passerculus sandwichensis. Uncommon winter resident.

121

BIRDS OF HASTINGS RESERVATION

GRASSHOPPER SPARROW, Ammodramus sauannarum. Two records, 22 Nov
1964 (Miller) and 16 Nov 1976 (Koenig).

VESPER SPARROW, Pooecetes gramineus. Three records: 26 Jan 1946 (Finley);
two, 24 Mar 1954 (Davis); and 13 Oct 1969 (one trapped, Davis).

‘LARK SPARROW, Chondestes grammacus. Uncommon resident.

‘RUFOUS-CROWNED SPARROW, Aimophiia ruficeps. Rare resident.

‘SAGE SPARROW, Amphispiza belli. Rare resident.

‘DARK-EYED JUNCO, Junco hyemalis. Common resident. Numbers increase in fall
as winter residents arrive, decrease in spring as they leave. One record of the
“Gray-headed” Junco (J. h. caniceps), 5 Jan 1967 (Davis, specimen, MVZ).

‘CHIPPING SPARROW, Spizella passerina. Common summer resident.

BLACK-CHINNED SPARROW, S. atrogularis. Accidental. Three records: 8 Jun
1938 (Sibley); 30 Aug 1939 (Linsdale); and one circa 1970 (Pitelka).

HARRIS’ SPARROW, Zonotrichia querula. Accidental. One record, 18 Nov 1944
(Weston, bird trapped and banded).

WHITE-CROWNED SPARROW, Z. leucophrys. Common winter resident. A single
tailless bird seen 17, 25, 27 Jul 1957 appeared to be of the coastal race, nuttalli
(Davis) .

GOLDEN-CROWNED SPARROW, Z. atricapilla. Common winter resident. A male
collected 25 Jul 1961 (Davis, specimen, MVZ) had a testis 2 mm long and slight fat
and had apparently failed to migrate.

WHITE-THROATED SPARROW, Z. albicollis. Irregular and rare winter resident.

FOX SPARROW, Passerella iliaca. Irregular winter resident; common in some years.

LINCOLN’S SPARROW, Melospiza lincolnii. Uncommon winter resident.

‘SONG SPARROW, M. melodia. Uncommon resident.

CHANGES IN THE AVIFAUNA

Our search of the records of bird occurrence at Hastings reveals
many changes in the bird community from the founding of the Reser-
vation in 1937 to the present. The following species have increased
or been added to the breeding community: Red-shouldered Hawk,
Turkey, Barn Swallow, American Robin, Starling and Brown-
headed Cowbird. Two of these, the Turkey and Starling, are exotics
which have spread into the area in recent years. Both Red-
shouldered Hawks and Brown-headed Cowbirds have increased in
other parts of California in the same period. We know of no obvious
environmental change which might correlate with the addition of
American Robins or Barn Swallows, both of which have occurred as
breeding birds since 1979.

Sixteen species appear to have decreased significantly or disap-
peared almost entirely from the community: Marsh Hawk, Prairie
Falcon, Peregrine Falcon, Merlin, Killdeer, Roadrunner, Long-eared
Owl, Lewis’ Woodpecker, Horned Lark, Cliff Swallow, Purple Mar-
tin, Dipper, Mockingbird, Water Pipit, MacGillivray’s Warbler and
Tricolored Blackbird.

Two wintering species which prefer short grass, the Horned Lark
and Water Pipit, quickly disappeared with the return of tall, dense
grass to the Reservation after the cessation of grazing. The three

122

BIRDS OF HASTINGS RESERVATION

falcons and the Marsh Hawk have decreased markedly throughout
much of California and elsewhere, presumably in part due to
pesticide contamination (e.g., Hickey 1969, Temple 1972, Fyfe et
al. 1976), robbing of nests for falconry (Small 1974) and/or habitat
destruction (Arbib 1979). Purple Martins and Lewis’ Woodpeckers
have similarly declined throughout their ranges in recent years (Arbib
1979), while Roadrunners have declined in northern California
generally (Small 1974). The Dipper nested in the period 1942-46,
when the Reservation’s major creeks flowed continuously. After
1946 all three creeks became intermittent and the Dipper soon disap-
peared except for an occasional visitant. Concurrent with this change
in rainfall patterns has been that of a gradual decline in the riparian
thickets along the watercourses, well documented by comparison of
early photographs with the same areas today. This decline probably
accounts for the present rarity of the MacGillivray’s Warbler, Killdeer
and Tricolored Blackbird, species which prefer mesic environments.
We can offer no unambiguous reasons for the decline of the remain-
ing two species, the Cliff Swallow and Mockingbird; the latter is par-
ticularly surprising given its recent increase in the nearby Monterey
Peninsula (Davis pers. obs.)

COMPARISON WITH A “SEMIURBAN” AVIFAUNA

Raunkiaer’s Law of Frequency, originally used by botanists, was
used by Linsdale (1928) and several subsequent authors to census
birds. Basically, this method does not yield information on relative
abundance but rather on the relative frequency of occurrence of the
individual species comprising an avifauna. Species are ranked
according to the percentage of standard censuses on which they
were recorded. Linsdale suggested that this method would afford a
satisfactory basis for comparing different avifaunas at a given point of
time and for assessing changes in a given avifauna over a period of
time. Although the technique was used in several early studies
(Linsdale 1928, 1932, 1936; Linsdale and Rodgers 1937; Rodgers
and Sibley 1940), none of these workers tested the method by mak-
ing any comparisons.

Linsdale (unpubl. data on file at Hastings Reservation) established
the frequency of occurrence for a total of 123 species recorded on
689 censuses at Hastings Reservation from November 1937 through
December 1940. Here we compare these results with those obtained
by Rodgers and Sibley (1940), who established frequency of occur-
rence for a total of 65 species recorded on 120 censuses (10 per
month) made on parts of the campus of the University of California,
Berkeley, in 1938 and 1939. The two census periods are almost
directly comparable chronologically.

123

BIRDS OF HASTINGS RESERVATION

Table 1. The 20 most frequently recorded species on the University of California,
Berkeley, campus and at the Hastings Reservation.

Hastings

Campus

Rank

Campus 1

Rank

Hastings 2

Rank

1

American Robin

33

Scrub Jay 3

12

2

Brown Towhee 3

3

Rufous-sided Towhee 3

11

3

Song Sparrow

37

Brown Towhee 3

2

4

White-crowned Sparrow

32

Plain Titmouse 3

15

5

Bushtit

23

Dark-eyed Junco 3

7

6

Brewer’s Blackbird

44

Common Crow

—

7

Dark-eyed Junco 3

5

House Finch 3

9

8

Anna’s Hummingbird

27

Yellow-billed Magpie

—

9

House Finch 3

7

Acorn Woodpecker

—

10

House Sparrow

—

California Quail 3

17

11

Rufous-sided Towhee 3

2

Common Flicker 3

18

12

Scrub Jay 3

1

Black Phoebe

26

13

Purple Finch

22

Wrentit

46

14

Lesser Goldfinch 3

17

Western Bluebird

65

15

Plain Titmouse 3

4

White-breasted Nuthatch

—

16

Pine Siskin

91

Western Meadowlark

—

17

California Quail 3

10

Lesser Goldfinch 3

14

18

Common Flicker 3

11

Lark Sparrow

—

19

Swainson’s Thrush

95

California Thrasher

63

20

“Audubon’s” Warbler

52

Nuttall’s Woodpecker

—

‘All species permanent residents except Swainson’s Thrush (summer resident) and
“Audubon’s” Warbler (winter resident).

2 A!1 species permanent residents.

‘Common to both lists.

The campus area was 34.4 ha in extent and included 11 buildings,
extensive lawns, scattered deciduous trees, conifers and eucalyptus,
a large eucalyptus grove, two creeks which flowed until late summer,
and shrubbery around the buildings and along the creeks. We have
compared the composition of the 20 most frequently recorded
species on each list (Table 1) , as these would be the most important
in indicating similarities and differences between the two avifaunas.

The greater diversity of habitats and reduced human disturbance
at Hastings is suggested by the fact that 7 of the first 20 species
(35%) on the Hastings list were not recorded at all at Berkeley
whereas only one of the Berkeley top 20 (5%) was not recorded at
Hastings (the House Sparrow).

Nine species (45%) are common to both lists (Table 1). All are
birds commonly found in both natural areas and in city parks,
gardens and suburban areas wherever suitable vegetation, native or
introduced, is present.

124

BIRDS OF HASTINGS RESERVATION

Of the 11 species present at Berkeley but not in the first 20 at
Hastings, the White-crowned Sparrow is represented on the campus
by a resident race { nuttalli ) and by winter residents of other races, but
only by wintering birds at Hastings, where the species is absent from
early May to mid- or late September, The House Sparrow is primari-
ly an urban species closely tied to human habitation (Witherby et al.
1948, Summers-Smith 1963), and tends to drop out in undisturbed
natural situations as at Hastings.

The Brewer’s Blackbird, like the House Sparrow, has established
successfully in suburban situations. At Hastings, nearly all records of
the blackbird are of transients flying over, although some nesting oc-
curs on the grazed savannas immediately adjacent to the Reserva-
tion, Thus the tall, ungrazed grass would appear to be limiting this
species at Hastings.

The Anna’s Hummingbird is much reduced in numbers at Hastings
in late fall and winter but no such reduction is evident in Berkeley (F.
Pitelka pers. comm.). Grinnell and Miller (1944) noted the impor-
tance of introduced flowering shrubs and trees in providing food for
this species from October to January, allowing a much larger popula-
tion to overwinter. In this period virtually no plants flower at
Hastings. The greater frequency of this species at Berkeley most like-
ly depends on winter food provided by garden flowers and ornamen-
tal plantings.

The higher frequency of American Robins at Berkeley, where they
are a common permanent resident, correlates with the presence of
extensive campus lawns which provide ideal foraging sites. The Pine
Siskin, also a common breeder in Berkeley but not at Hastings, may
be more frequent because of the extensive plantings of conifers on
campus. Only two mature native pine trees occur at Hastings. The
Purple Finch is better adapted physiologically to more mesic habitat
(Salt 1952). The cooler, more humid climate at Berkeley probably
accounts for its greater frequency there. At Hastings, this species is
confined almost entirely to mesic canyon bottom sites from June to
October.

The greater frequency of the Song Sparrow and Swainson’s
Thrush at Berkeley probably results from the presence of creeks flow-
ing at least through the breeding and immediate postbreeding
seasons, and the higher humidity and presence of green vegetation
along these watercourses.

Only two species are difficult to account for, the Bushtit and
Yellow-rumped (Audubon’s) Warbler. The problem is not why these
two species were so common at Berkeley but why they were recorded
so infrequently at Hastings. Linsdale (1947) suggested that Bushtits
may have declined markedly during the severe winter of 1936-37;
this special circumstance may in part be the cause of the lowered

125

BIRDS OF HASTINGS RESERVATION

ranking of this species at Hastings. We do not know why the
Audubon’s Warbler, which winters in a wide variety of habitats, is
relatively less common at Hastings, although the wider variety of
flowering exotics in Berkeley may make this area more suitable than
Hastings.

Of the 11 Hastings species not in the Berkeley first 20, most can be
accounted for by obvious habitat preferences: Acorn Woodpeckers,
NuttalPs Woodpeckers and White-breasted Nuthatches are absent
from most of the humid coastal environment of Berkeley; Yellow-
billed Magpies, Common Crows, Western Bluebirds, Western
Meadowlarks, and Lark Sparrows typically occur in grassland
and/or oak savanna with a grassy understory; California Thrashers
and Wrentits are most typical of chaparral. The only remaining
species in this list is the Black Phoebe, which was 26th on the cam-
pus list. This species bred on the upper campus but strayed only rare-
ly to the lower campus where the censuses were done (Rodgers and
Sibley 1940).

Nearly all differences in relative frequency between Hastings and
Berkeley are consistent with known habitat or climatic differences,
and the similarities between the two areas involve species which are
known to occur commonly in both natural and suburban areas.
Thus, although there are far more refined methods which may be used
to analyze the species composition of an avifauna, the Raunkiaer
method is useful, and may be particularly valuable as a means to
recover information from carefully kept records made by competent
observers over an appreciable period of time.

ACKNOWLEDGMENTS

We take this opportunity to acknowledge gratefully the long-
continued support of the research program at Hastings Reservation
by the late Mrs. Russell P. Hastings and the continuing support of the
program by her daughter, Mrs. Thomas Arnold. The comments of
Richard Erickson and editorial help of A. Craig and N. Moore were
greatly appreciated. Financial assistance to the second author was
provided by the National Science Foundation and the Department of
Zoology, University of California, Berkeley.

LITERATURE CITED

Arbib, R. 1979. The blue list for 1980. Am. Birds 33: 830-835.

Davis, J. 1968. A third specimen of the Brown Thrasher from California. Auk 85:
128-129.

Davis, J. and L. Williams. 1957. Irruptions of the Clark Nutcracker in California. Con-
dor 59: 297-307.

126

BIRDS OF HASTINGS RESERVATION

DeSante, D. and V. Remsen. 1973, Middle Pacific coast region. Am. Birds 27:
110-119.

Fyfe, R.W., R.W. Risebrough and W. Walker II. 1976. Pollutant effects on the
reproduction of the Prairie Falcons and Merlins of the Canadian prairies. Can.
Field-Nat. 90: 346-355.

Griffin, J.R. 1974. Notes on environment, vegetation, and flora, Hastings Natural
History Reservation. Unpubl. report on file at Hastings Reservation.

Grinnell, J. and AH. Miller. 1944. The distribution of the birds of California. Pac.
Coast Avif. 27

Hickey, J.J. ed. 1969. Peregrine Falcon populations: their biology and decline. Univ.
Wisconsin Press, Madison.

Linsdale, J.M. 1928, A method of showing relative frequency of occurrence of birds.
Condor 30: 221-226.

Linsdale, J.M. 1932. Frequency of occurrence of birds in Yosemite Valley, California.
Condor 34:221-226,

Linsdale, J.M. 1936. Frequency of occurrence of summer birds in northern Michigan.
Wilson Bull. 48: 158-163.

Linsdale, J.M. 1947. A ten-year record of bird occurrence on the Hastings Reserva-
tion. Condor 49: 236-241.

Linsdale, J.M. and T.L. Rodgers, 1937. Frequency of occurrence of birds in Alum
Rock Park, Santa Clara County, California. Condor 39: 108-111.

Mayr, E. and L L. Short, Jr 1970. Species taxa of North American birds. Publ. Nut-
tall Ornithol. Club 9.

Rodgers, T.L. and C.G. Sibley. 1940. Frequency of occurrence of birds on the
Berkeley campus, University of California. Condor 42: 203-206.

Salt, G.W. 1952. The relation of metabolism to climate and distribution in three
finches of the genus Carpodacus. Ecol. Monogr. 22: 121-152.

Small, A. 1974. The birds of California. Winchester Press, New York.
Summers-Smith, D. 1963. The House Sparrow. Collins, London.

Temple, S.A. 1972. Chlorinated hydrocarbon residues and reproductive success in
eastern North American Merlins. Condor 74: 105-106.

Witherby, H.F., F.C.R. Jourdain, N.F. Ticehurst and B.W. Tucker. 1948. The hand-
book of British birds. Fifth impression. H.F. and G. Witherby, Ltd., London.

Additional References of Ornithological Work Conducted Wholly or in Part at
Hastings Reservation.

Davis, J. 1957. Comparative foraqinq behavior of the Spotted and Brown towhees.
Auk 74: 129-166

Davis, J. 1958. Singing behavior and the gonad cycle of the Rufous-sided Towhee.
Condor 60: 308-336.

Davis, J. 1960. Nesting behavior of the Rufous-sided Towhee in coastal California.
Condor 62: 434-456.

Davis, J. 1973. Habitat preferences and competition of wintering juncos and Golden-
crowned Sparrows. Ecology 54: 174-180.

Davis, J., G.F. Fisler and B.S. Davis. 1963. The breeding biology of the Western
Flycatcher. Condor 65: 337-382.

Dixon, K.L, 1962. Notes on the molt schedule of the Plain Titmouse. Condor 64:
134-139.

Dixon, K.L. 1969. Patterns of singing in a population of the Plain Titmouse. Condor
71:94-101

Gutierrez, R.J. 1979. Comparative ecology of the Mountain and California quail in
the Carmel Valley, California. Living Bird 18:71-93.

Jenkins, J.M. 1979 Foraging behavior of male and female Nuttall Woodpeckers. Auk
96: 418-420.

127

BIRDS OF HASTINGS RESERVATION

Koenig, W.D, 1980. Variation and age determination in a population of Acorn
Woodpeckers. J. Field Ornithol. 51: 10-16.

Koenig, W.D. 1980. The incidence of runt eggs in woodpeckers. Wilson Bull.
92:169-176.

Koenig, W.D. 1980. Acorn storage by Acorn Woodpeckers in an oak woodland: an
energetics analysis. In Symposium on the ecology, management, and utilization
of California oaks, Claremont, California USDA, Forest Service General Tech.
Rep. (in press).

Koenig, W.D. 1981. Space competition in the Acorn Woodpecker: power struggles in
a cooperative breeder. Anim. Behav. 29 (in press).

Koenig, W.D 1981. Group size, reproductive success, and the evolution of
cooperative breeding in the Acorn Woodpecker. Am. Nat. 117 (in press).

Koenig, W.D. and F.A. Pitelka. 1979. Relatedness and inbreeding avoidance:
counterploys in the communally nesting Acorn Woodpecker. Science 206:
1103-1105.

Koenig, W.D. and F.A. Pitelka. 1980. Ecological factors and kin selection in the
evolution of cooperative breeding in birds. In Natural selection and social
behavior: recent research and new theory. R.D. Alexander and D.W. Tinkle,
eds. Chiron Press, Newton, MA (in press).

Linsdale, J.M. 1957. Goldfinches on the Hastings Natural History Reservation. Am.
Midi. Nat. 57: 1-119.

MacRoberts, M.H. and B.R. MacRoberts. 1976 Social organization and behavior of
the Acorn Woodpecker in central coastal California. Ornithol. Monogr. 21:
1-115.

Miller, A. FI. and C.E. Bock. 1972. Natural history of the Nuttall Woodpecker at the
Hastings Reservation. Condor 74: 284-294.

Root, R.B. 1967. The niche exploitation pattern of the Blue-gray Gnatcatcher. Ecol.
Monogr. 37: 317-350.

Thompson, W.L. 1968. The songs of five species of Passehna. Behaviour 31:
261-287.

Thompson, W.L. 1976. Vocalizations of the Lazuli Bunting. Condor 78: 195-207.

Verbeek, N.A.M. 1972. Comparison of displays of the Yellow-billed Magpie ( Pica
nuttaili) and other corvids, J.f. Ornithol. 113: 297-314.

Verbeek, N.A.M. 1972. Daily and annual time budget of the Yellow-billed Magpie.
Auk 89: 567-582.

Verbeek, N.A.M. 1973. The exploitation system of the Yellow-billed Magpie. Univ.
California Publ. Zool. 99: 1-58.

Verbeek, N.A.M. 1975. Comparative feeding behavior of three coexisting tyrannid
flycatchers. Wilson Bull. 87: 231-240.

Verbeek, N.A.M. 1975. Northern wintering of flycatchers and residency of Black
Phoebes in California. Auk 92: 737-749.

Williams, P.L. and W.D. Koenig. 1980. Water dependence of birds in a temperate
oak woodland. Auk 97: 339-350.

Accepted 23 July/ 1 980

128

THE LEAST BELL’S VIREO
IN BAJA CALIFORNIA, MEXICO

SANFORD R. WILBUR, U.S. Fish and Wildlife Service, 1190 East Ojai Avenue.
Ojai, California 93023

The Least Bell’s Vireo (Vireo bellii pusillus ) has been recorded as a
breeding species in California and in Baja California, Mexico, south
to about latitude 30° N (AOU 1957). Recent field work has shown
this vireo to be rare or absent from about two-thirds of its former
breeding range in California (Goldwasser et al. 1980), so it seemed
desirable to make a preliminary survey of its status in Mexico.

Review of literature and museum records and consultation with or-
nithologists resulted in the identification of 14 Mexican locations
where Least Bell’s Vireos had been seen or collected during the
breeding season (April- July) , and that probably represented
breeding localities (Figure 1 and Appendix). During 19-23 June
1980, Keith Axelson and I visited eight of those localities to see if
vireos were present. We also checked for vireos in potential habitat
enroute. Because habitat loss and degradation and brood parasitism
by Brown-headed Cowbirds ( Molothrus ater) are implicated in the
decline of the Bell’s Vireo in California (Goldwasser et al. 1980), we
made a preliminary assessment of these factors.

RESULTS

Bell’s Vireos were found at five of the eight historical locations
checked, as described below.

San Fernando Mission , 20-21 June. The habitat at San Fernando
is apparently much as Anthony (1895) described it, consisting of
about 1.5 km of dense Catclaw ( Acacia greggii ) and related species
along an open stream bed. We located at least eight singing male
Bell’s Vireos in about 0.5 km of habitat downstream from the Mission
site, and two more at the Mission. Habitat between the two points
was similar and presumably supported similar densities of vireos.

Valladares, 21 June. We were not at the exact location visited by
other observers, but we did see and hear a male Bell’s Vireo in the
vicinity. The habitat was atypical — the bird was singing from a lone
dense bush near an open stream bed — and there did not seem to be
other vireos nearby.

Rancho San Jose (Meling Ranch), 21-22 June. Altogether,
riparian woodland extends for about 10 km along Arroyo San Jose'
in the vicinity of the Meling Ranch (Short and Crossin 1967). We
surveyed about 0.75 km at the north end adjacent to the San Telmo-
Observatory road, and located at least 10 singing males. Most were
in the younger denser growth of willows (Salix sp.) near the road,

Western Birds 11:129-133. 1980

129

LEAST BELL'S VIREO

PACIFIC

OCEAN

Figure 1. Northern Baja California. Mexico, showing locations where Bell’s Vireos
have been recorded during the breeding season. Locations where vireos were recorded
in 1980 are underlined. 1. Carrizo Valley. 2. Valle de las Palmas. 3. Guadalupe
Valley. 4. El Gato. 5. San Ysidro. 6. Cerro Prieto. 7. Erendira. 8. Las Cabras. 9. Ran-
cho San Jose. 10. Valladares. 11. Canon El Cajon. 12. E! Salto. 13. Rancho
Rosarito. 14. El Rosario. 15. San Fernando.

130

LEAST BELL’S VIREO

where several could be heard at one time within 20 m of one
another, but some were found in the older, more open woods
downstream.

Las Cobras, 22 June. Riparian woodland formerly occurred along
the Rio San Telmo at this point (Short and Crossin 1967). Now the
only dense vegetation in the vicinity is just upstream from Rancho
Cortez, and consists of about 500 m z of 3-4 m tall Tree Tobacco
(Nicotiana glauca) and tamarisk ( Tamarix sp.). We found a pair of
Bell’s Vireos at that site, apparently the only ones in the otherwise
open river bottom.

El Goto, 22-23 June. About 22 km SE of Ojos Negros, a spring-
fed stream flows from the Sierra Juarez and is lined with willows, cot-
tonwoods ( Poputus sp.), and Catclaw for about 1.5 km (Short and
Crossin 1967). In about 0.5 km of this habitat, we located 10 singing
males. Most of the birds were in Catclaw rather than the more open
willow or cottonwood growth. At one point four males were singing
simultaneously within 15 m of one other.

We also found Bell’s Vireos at one location where they had not
been reported previously:

“Erendira, ” 8.8 km SW of Highway 1 at El Descanso, 19-20 June.
About 1.5 km of dense willows grow along a tributary to Rio San
Isidro. We accounted for six singing males in about one-third of the
available habitat.

We were unable to find any suitable habitat for Bell’s Vireos in
Guadalupe Valley, Valle de las Palmas or at El Rosario, the other
historical locations checked. In fact, the only other location we found
on the entire trip that looked suitable for Bell’s Vireos was a 0.5 km
stretch of dense willow growth along a stream at Santa Rosa on
Highway 1, 20 km south of La Mision. No Bell’s Vireos were seen or
heard there. Agricultural development has resulted in the elimination
of river bottom vegetation in the Guadalupe Valley, at El Rosario
and elsewhere. More importantly, the severe floods of 1978-1979
eradicated major areas of riparian growth, leaving virtually all
streams in northern Baja California denuded from the coast far back
into the mountains.

Cowbirds were seen at San Fernando (7 birds), Rancho San Jose
(7), Erendira (1), and in agricultural areas around Ensenada (3).

DISCUSSION

No firm conclusions can be drawn about the status of the Least
Bell’s Vireo in Mexico from such a brief survey, but a few observa-
tions seem appropriate.

1. The populations found at San Fernando, Rancho San Jose, El
Gato and Erendira are probably healthy and relatively secure at pre-

131

LEAST BELL’S VIREO

sent. Breeding densities (8 to 20 pairs per km of habitat) are greater
than any found in California recently (Goldwasser et al. 1980), and
rival the greatest densities reported in California historically (Grinnell
and Storer 1924). The habitat is not immediately threatened with
destruction or modification. Cowbirds are present in some areas, but
apparently not in numbers likely to be a serious detriment to the vireo
population.

2. While we certainly did not find all the Bell’s Vireos in Baja
California, it is obvious that habitat of the “classic” type is limited both
naturally and (more recently) as a result of agricultural development
and floods. It seems likely that the number of breeding pairs is
measurable in hundreds rather than thousands.

3. Bell’s Vireos will probably be adversely affected by the continu-
ing development of Baja California. Mexican Highway 1 has recently
been paved and improved the length of the peninsula, as has
Highway 3 from Ensenada to San Felipe. Concurrently, the Mexican
Government has been working to improve water distribution for ir-
rigation and other uses. Together, these improvements are making
agriculture in Baja California much more feasible and profitable.
Farm crops will continue to replace bottomland vegetation. Brown-
headed Cowbirds can be expected to increase in numbers as
agriculture provides more attractive habitat for them, and they may
eventually reach levels of significance for vireos. As in California, on-
ly the larger and more isolated populations of Bell’s Vireos can be ex-
pected to remain unaffected.

ACKNOWLEDGMENTS

This survey was funded by the U.S. Fish and Wildlife Service,
Region 1, Portland, Oregon.

LITERATURE CITED

American Ornithologists’ Union. 1957. Check-list of North American birds. 5th ed.
Am. Ornithol. Union, Baltimore, MD.

Anthony, A.W. 1895. Birds of San Fernando, Lower California. Auk 12:134-143.
Goldwasser, S., D. Gaines and S.R. Wilbur. 1980. The Least Bell’s Vireo in Califor-
nia: a de facto endangered race. Am. Birds 34:742-745.

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

Grinnell, J. and T.L Storer. 1924. Animal life in the Yosemite. Univ. California Press,
Berkeley.

Short, L.L., Jr. and R.C. Banks. 1965. Notes on birds of northwestern Baja Califor-
nia. Trans. San Diego Soc. Nat. Hist. 14:43-52.

Short, L.L., Jr. and R.S. Crossin, 1967. Notes on the avifauna of northwestern Baja
California. Trans. San Diego Soc. Nat. Hist. 14:283-299.

132

LEAST BELL’S VIREO

APPENDIX

Previous breeding season records of Least Bell’s Vireos in Baja California. Locations
are shown in Figure 1.

CARRIZO VALLEY: specimens 20-21 April (year?) (Grinnell 1928). GUADALUPE
VALLEY: specimens 28 April and 2 June (year?) (Grinnell 1928). VALLE DE LAS
PALMAS: specimens 5-6 April (year?) (Grinnell 1928). 22 KM SE OF OJOS
NEGROS: up to 10 birds, 4-15 April 1967 (Short and Crossin 1967). SAN YS1DRO
(ISIDRO?): 2 egg sets 1936. Western Foundation of Vertebrate Zoology (WFVZ). 11
KM E OF CERRO PRIETO: 2 collected June 1928, Museum of Vertebrate Zoology
(MVZ). LAS CABRAS: 1 collected 4 June 1923, San Diego Natural History Museum
(SDNHM). RANCHO SAN JOSE (MELING RANCH): common 20-28 April 1967
(Short and Crossin 1967): 1 pair seen 5 May 1975 (S Wilbur field notes); 1 pair seen
3 August 1977 (Wilbur field notes). VALLADARES: 2_collected April 1925 (MVZ); 6
seen 24-25 April 1967 (Short and Crossin 1967). CANON EL CAJON: 15 collected
May 1926 (MVZ). EL SALTO, 48 km E of San Quintln: several seen 28 April 1964
(Short and Banks 1965). RANCHO ROSAR1TO. 54 km E of San Quintfn:
“common,'' 2 collected 27 April 1964 (Short and Banks 1965). EL ROSARIO: 5 col-
lected May 1925 (SDNHM); 3 egg sets 1925 (WFVZ); 3 collected April 1926 (Los
Angeles County Museum of Natural History). SAN FERNANDO; “quite common’’
1894 (Anthony 1895); 2 collected 28 April 1928 (SDNHM).

Accepted 9 August 1 980

133

ft* .V»*/ ; , - ; • ' \

tyl V- v V V

•■■/>•;(/■ :.c.*y .<■ Vi--.

Bell’s Vireo

Sketch by Narca Moore

134

DISTRIBUTION AND POPULATION
STATUS OF WHISKERED AUKLET
IN THE ALEUTIAN ISLANDS, ALASKA

G. VERNON BYRD, Hawaiian Islands NWR, P.O. Box 87, Kilauea, Kauai, Hawaii
96754

DANIEL D. GIBSON, University of Alaska Museum, Fairbanks, Alaska 99701

The little known Whiskered Auklet ( Aethia pygmaea) occurs only
in the Aleutian (Figure 1) , Commander and Kuril islands of the North
Pacific. In the Aleutian Islands it occurs from Unimak Pass to the
Near Islands (Kessel and Gibson 1978), but the only documented
nesting records are from Umnak Island (R.J. Gordon in lift.),
Chagulak Island (Murie 1959), Atka Island (Turner 1886), and
Buldir Island (Knudtson and Byrd in press) .

This paper summarizes new information on the distribution of
Whiskered Auklet in the Aleutian Islands, and provides a significantly
higher estimate of the minimum population.

METHODS

During the period 1972-1974 we were aboard the R/V Aleutian
Tern as it traveled to every major island in the Aleutians. In 1972 and
1974 nearly the entire island chain was traversed. In 1972 the trip
was made during the breeding season, but in 1974 observations
were made in April, prior to nesting. In 1973 observations were con-
fined to the eastern Aleutians. Travel was generally confined to
daylight hours so that continuous observations could be made. One
or two observers counted birds within approximately 300 m of both
sides of the ship. The Aleutian Tern traveled at 16 km/h except
when near islands when the speed was reduced to as low as 8 km/h.

Island groups within the Aleutians are identified as follows: 1) Fox
Islands - Unimak Pass to Umnak Island (the area of each island
group ends 16 km west of the westernmost island, to include birds
associated with nesting colonies) ; 2) Islands of Four Mountains - Um-
nak Island to Amukta Island; 3) Andreanof Islands - Amukta Island
to Unalga Island; 4) Rat Islands - Unalga Island to Buldir Island; 5)
Near Islands - Buldir Island to Attu Island.

RESULTS AND DISCUSSION

The largest numbers of Whiskered Auklets were found in the Fox
Islands prior to (April 1974) and during (24-27 May 1972 and 3 July
1973) the breeding season (Table 1). Nearly 60% of 13,118 birds
(approximate density 1000/km 2 ) recorded in this area in 1974 were
near Baby Pass, where Spindler (in litt.) estimated 265 Whiskered

Western Birds 11:135-140, 1980

135

WHISKERED AUKLET

Table 1. The distribution of Whiskered Auklets observed in the Aleutian Islands,
Alaska, 1972 to 1974.

YEAR

ISLAND GROUP

Fox

Is. of
4 Mt.

Andreanof

Rat

1972 (24 May to
7 July)

1702

12,100

771

527

1973 (3 July)

7780

—

—

1974 (4 to 30
April)

13,118

2519

9196

14

‘No data

TOTAL

Near

15,010

0 24,847

Auklets per km 2 in April 1976. During the 1973 breeding season,
nearly 7800 auklets were counted on 3 July at a time when one
member of many breeding pairs was probably at the nest. As in the
April counts in this area, birds were concentrated in Baby Pass. In
1972 the count was low because Baby Pass was not reached until
after dark, so only birds in the less densely populated east end of the
Fox Islands were tallied. Few Whiskered Auklets were seen west of
Baby Pass in the Fox Islands during late winter or summer.

The largest single flock of Whiskered Auklets (an estimated
10,000) we found was in the Islands of Four Mountains near the
west side of Yunaska Island on 30 May 1972 (Kessel and Gibson
1978) . Smaller flocks were encountered near Herbert and Chagulak
islands during the breeding season. In April 1974 only 21% as many
Whiskered Auklets were found in the Islands of Four Mountains dur-
ing the breeding season, and the late winter distribution of birds
within this area was slightly more westerly than the summer distribution.

The reverse situation occurred in the Andreanof Islands, where we
found over 9000 auklets prior to, but fewer than 800 during, the
breeding season. Nearly 70% of the auklets seen prior to the
breeding season were near the southwest side of Great Sitkin Island.
Great Sitkin Island and all islands around it were intensively surveyed
for birds in July 1971 by Gibson and P.C. Sekora, and Whiskered
Auklets were not present. Therefore, the birds seen in the area in
April 1974 bred elsewhere, probably in the Islands of Four Mountains.

Of the 527 Whiskered Auklets counted in the Rat Islands in 1972,
about 200 were at Segula Island, and 300 at Buldir Island. The 14
birds identified in April 1974 were scattered over the entire area.

136

Bering Sea

WHISKERED AUKLET

137

Figure 1. Map of the Aleutian Islands, Alaska, showing five major island groups.

WHISKERED AUKLET

During our study, Whiskered Auklets were scarce in the Near
Islands: four near Attu Island 12 June (1975) (E.P. Hoberg pers.
comm.) and two near Agattu Island 1 July 1975 (Byrd). Apparently
the species was formerly more common in this area, since Turner
(1886) considered Whiskered Auklet abundant in the Near Islands.

Nearly all the Whiskered Auklets we saw in the Aleutian Islands
were associated with tide rips where they were presumably feeding,
usually within 16 km of land. Although the species was recorded
throughout the island chain, its distribution was distinctly clumped.
This phenomenon was particularly pronounced prior to the breeding
season; 97% of the Whiskered Auklets in the Fox Islands were be-
tween the west side of Tigalda Island and the west side of Baby Pass,
98% of the birds in the Islands of Four Mountains were between
Herbert and Yunaska islands, and 95% of the total in the Andreanof
Islands were in two locations (30% near Seguam Island, and 65%
near Great Sitkin Island). These three concentrations combined ac-
counted for 85% of the Whiskered Auklets we saw in the Aleutians
in April 1974.

The breeding season distribution is generally less clumped, with
smaller flocks scattered over broader areas. The exception was the
flock of 10,000 birds in the Islands of Four Mountains.

Little is known about the distribution of Whiskered Auklets after
they complete nesting activities in August. The birds apparently
winter near their breeding area (AOU 1957). J.L. Trapp (pers.
comm.) saw 2000 auklets near the east end of the Islands of Four
Mountains 21-22 September 1974, and on 27 September 1974 he
counted 638 birds at the east end of the Fox Islands. Only 39% and
31% of the auklets were identified to species in the Islands of Four
Mountains and Fox Islands respectively, but ail those whose identity
was known were Whiskered Auklets.

Although is is impossible to determine what percentage of the total
Whiskered Auklets in the Aleutian Islands we actually observed in
1972 and 1974 (the two years when the entire area was censused), it
is apparent that Murie’s (1959:201) estimate of “at least 2000” in the
Aleutians was low. We counted 15,000 Whiskered Auklets on the
sea in 1972 when one bird of many pairs was probably in a nest
crevice. The 1974 total of 25,000 birds counted prior to the nesting
season is considered more representative of the population, and we
use this as the minimum population estimate of Whiskered Auklets in
the Aleutian Islands.

138

WHISKERED AUKLET

Whiskered Auklets, Buldir Island, Alaska, 25 May 1976

Photo by G. Vernon Byrd

139

WHISKERED AUKLET

ACKNOWLEDGMENTS

We gratefully acknowledge the following U.S. Fish and Wildlife
Service personnel who contributed observations: Edgar P. Bailey,
George J. Divoky, Eric P. Hoberg, Palmer C. Sekora, John L.
Trapp and Gorden W. Watson, Michael A. Spindler made his un-
published manuscript, “Pelagic and near-shore seabird densities in
the western Aleutian Islands as determined by transect counts in
1975 and 1976,” available to us.

Captain George A. Putney and deckhands Lazio Hanko, Christian
Anderson and Dave Clemens provided invaluable logistic support.
Robert H. Day, Brina Kessel and John L. Trapp critically reviewed
the manuscript. Heidi Russell prepared the figure.

LITERATURE CITED

American Ornitholgists’ Union. 1957. Check-list of North American birds. 5th ed.
Am. Ornithol. Union, Baltimore, MD.

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

Knudtson, E. and G.V. Byrd. In press. Breeding biology of Crested, Least, and
Whiskered auklets at Buldir Island, Alaska Condor.

Murie, O.J, 1959. Fauna of the Aleutian Islands and Alaska Peninsula. N. Am.
Fauna 61.

Turner, L.M. 1886. Contributions to the natural history of Alaska. Arctic Series in
connection with the Signal Service, U.S. Army, No. 2. Washington, D.C. Part
5:115-196.

Accepted 21 March 1980

140

FLAMMULATED OWLS IN
NORTHWESTERN CALIFORNIA

BRUCE G. MARCOT, Fisheries and Wildlife Branch, Six Rivers National Forest, 507
F Street, Eureka, California 95501

RANDY HILL, 354 Foreman Lane, Healdsburg, California 95448

Habitat selection and distribution of the Flammulated Owl ( Otus
flammeolus) in California is incompletely known. Grinnell and Miller
(1944) noted only two locations in the northeastern part of the state.
Johnson and Russell (1962) provided records of at least 33 in-
dividuals in seven additional northeastern California locations. The
most comprehensive survey to date has been by Winter (1974),
reporting 59 specimen and 89 sight records since 1860 in California.
Two of the records Winter reported for the northwestern portion of
the state are from Humboldt County and five are from Trinity Coun-
ty.

We collected records (visual or aural) in these two counties and
conducted springtime, nocturnal surveys of Flammulated Owls,
mostly on the Six Rivers National Forest, during 1976-1980 (see Ap-
pendix). The surveys were made primarily in potential timber sale
areas. We elicited Flammulated Owl responses with recorded calls or
vocal imitations of this and other owl species, at half-mile intervals
along trails or roads. Flammulated Owls responded readily to Spotted
Owl calls, which we often used. The surveys were made in conjunc-
tion with a study of Spotted Owls, and were conducted April to June
under varying lunar phases and times of the night. Most surveys
were conducted on fairly calm, clear nights.

To date, we have compiled previously unreported records of 75
territorial male Flammulated Owls. No territories have been located
in either Del Norte County or western Siskiyou County, but lack of
records probably reflects inadequate field surveys rather than an
absence of the species. Thirty-eight territories were located in Hum-
boldt County and 37 in Trinity County, generally in the southern
portions along the common boundary (Figure 1), in the Northern
Coast and Trinity Faunal Districts (Miller 1951, Winter 1974).

High, local concentrations of territorial pairs, as noted by Marshall
(1939), Winter (1974) and Johnson and Russell (1962), suggest a
propensity for forming loose breeding colonies. Similarly, we found
“quasi-colonies” containing 2, 3, 4, 5, 6, 7 and 10 territorial males, in
areas ranging from 8 to 2400 ha in size. Crude densities (defined as
number of birds per unit area, including areas of suboptimal habitat)
ranged from 0.03 to 1.09 males/40 ha. These estimates are lower
densities than found elsewhere (Table 1) . The minimum density
estimate (0.03 males/40 ha) from the present study may indicate

Western Birds 11:141-149, 1980

141

FLAMMULATED OWLS

suboptimal habitat, but may also reflect the high variation in calling
responsiveness that Flammulated Owls exhibit, We found that the
“quasi-coloniality” of the Flammulated Owl leaves some apparently
optimal habitat vacant, as suggested by Tyler and Phillips (1978).

Breeding habitat of the Flammulated Owl in California has been
described as open or broken conifer woodlands, containing various
mixes of true firs ( Abies spp.), pines (Pin us spp.), Douglas-fir
( Pseudotsuga menziesii), Oregon White Oak ( Quercus garryana)
and California Black Oak ( Q . kelloggii ) (Grinnell and Miller 1944,
Johnson and Russell 1962, Marshall 1939). Winter (1974) reported
that Flammulated Owls have a high affinity for yellow pine ( Pinus
ponderosa or P. jeffreyi) dominant habitat throughout their range.
Upon intensively analyzing the vegetation composition of seven ter-
ritory sites and extensively surveying many more, we found that
California Black Oak was as ubiquitous in the sites examined (67%
presence in study sites) as yellow pine (50% presence). At least one
of these two tree species was present at all sites. Winter (1979)
recognized the potential importance of California Black Oak for
nesting to Flammulated Owls and other wildlife species. We
speculate that Flammulated Owls may use the many natural cavities
for nesting sites that California Black Oak provides. Other tree
species present included Douglas-fir, Incense Cedar ( Calocedrus
decurrens ), Jeffrey Pine ( Pinus jeffreyi), and White Fir (Abies con-
color) .

Table 1, Crude densityt of Flammulated Owl males in northwestern California, com-
pared with that found in four other studies.

AREA

NO. MALES
PER 40 HA

INVESTIGATOR

Northwestern California

0.03 to 1.09

Marcot and Hill
(present study)

Placer Co.. California

2.1

Winter (1974)

Tulare Co.. California

1.4

Marshall (1939)

Chiricahua Mtns. .
southern Arizona

4

Baida (1977)

White Mtns..

southern Arizona

5. 1 to 5.3j

Franzreb and Ohmart
(1978)

+Crude density computations include areas of unsuitable habitat.

tlnferred from a reported 10.2 to 10.6 Flammulated Owls per 40 ha. but Franzreb
and Ohmart (1978) did not clarify how this density estimate was made.

142

FLAMMULATED OWLS

Figure 1. Location of 78 records of Flammulated Owl in northwestern California. Open circles
denote encounters with territorial males; open circles with central dots denote non-territorial
males: black dots represent towns; X’s represent mountains.

143

FLAMMULATED OWLS

<T3

cn

X

C

0)

5

c

cn

o

a)

a

0)

c

>-

u

-*- 1

0

u

5

>

0

0

a

cn

v-

p

CD

J3

X

c

U

3

«/)

c

X

c

rO

X

X

cn

3

"5

>— i

X

u

JO

i—

CD

(T3

cn

C

cn

CD

c

X

5 -£

O

IT

X

cn

,

V-

5

CD

>

c

1_

0

o

CJ

■H—

>,

"5

a

U

o

c

c

ra

J-

u

CD

X

on

CD

c

z>

JZ

CD

-4—1

a

J—

o

c

C

-

o

>N

-4 — 1

c

(3

-*— i

3

CD

0

CD

U

CD

>

C

o

X)

X

<T3

E

CD

3

X

X

ca

c

o

-*— 1

3

■4—1

3

o

CD

U

X

(3

~o

X

IT 3

3

O

E

cn

p

(3

u

*0

CD

J—

X

ra

X

X

o

CQ

0

cn

CD

CD

V-

3

'i/5

cn

>>

_o

k-

u

O

>»

'C

a

Q)

0

c

0

ra

u

5

f-

c

CD

u

oq

J—

CD

0)

a

3

X

CO

cn

Ll.

X

FLAMMULATED OWLS

Slope at territory sites varied from 0 to 55% . We found no correla-
tion with slope aspect, as sites occurred on slopes facing all compass
points. Elevations ranged from 830 to 1310 m. All territory sites
surveyed were on xeric mid-slopes or near ridge tops. Canopy cover
varied considerably, from 20 to 80%. Typically, two canopy layers
were present in each territory core. Adjacent to or within this core
stand was brush of 10 to 80% cover. Within the territory core, tree
density averaged 1270 trees/ha {range 148 to 2473 trees/ha) and
tree basal area averaged 58 sq m/ha (range 47 to 73 sq m/ha).

These stand characteristics closely correspond to those measured
by Bull and Anderson (1978) at four Flammulated Owl nest trees in
northeastern Oregon. Of special note is the presence in most ter-
ritories of a locally dense clump of tall, mature trees located near a
break in canopy closure and vegetation type (Figure 2). A Flam-
mulated Owl territory site in the Klamath National Forest in Trinity
County, that we did not survey, also had similar characteristics:
California Black Oak and Ponderosa Pine, with Douglas-fir, Incense
Cedar and Oregon White Oak; and nest tree, a mature dying oak
located on a ridge and near a break in vegetation type (dense firs and
pines to the north, and more open stands with oaks to the south) (D.
Claypole pers. comm.). We found Flammulated Owls calling from
the dense foliage of mature trees, but the owls may need brush cover
as habitat for additional insect prey and feeding cover when foraging
is done near the ground. Edges and broken woodlands seemed to
offer both high dense canopies and low dense brush.

On the night of 23 March 1978 J. Gardetto and C. Cox (pers.
comm.), while playing a recorded tape of Spotted Owl calls, heard
two male Flammulated Owls in a dense, mature stand of Douglas-fir
along Bluff Creek in Humboldt County. Prior to this discovery, the
earliest spring record in California was 19 April in Monterey County
(Winter 1974) ; and the earliest spring record north of Mexico was 26
March in Arizona (Phillips et al. 1964). Flammulated Owls are
thought to be highly migratory (Winter 1974, Baida et al. 1975).
Johnson (1962) hypothesized that they may remain torpid near the
breeding grounds during winter, but Winter (1974) presented cir-
cumstantial evidence against this notion. To test the conjecture that
some individuals are overwintering in the North Coast area, Marcot
spent the evening of 1 February 1979 playing a recorded tape of
Flammulated Owl calls at five known territory sites in southern Trinity
County and received no response, but snowy, subfreezing weather
conditions may have biased the results. More surveys are planned for
future winter seasons.

Based on our surveys, we recommend the following for manage-
ment of Flammulated Owls in northwestern California: 1) More noc-

145

FLAMMULATED OWLS

turnal surveys, using tape recorded calls or vocal imitations, are
needed to locate addition “quasi-colonies,” especially in broken
coniferous woodlands with yellow pine or California Black Oak. 2)
Identify and preserve the locally dense stand of mature trees that
forms the core of each territory. Such stands may vary roughly from
0.8 to 4 ha in size and often occur on mid-slopes or ridge tops, near
breaks in vegetation type and canopy closure. 3) Maintain brush ad-
jacent to the core stand. 4) Leave undisturbed all conifers and hard-
woods, especially yellow pine and California Black Oak, having
natural cavities or cavities excavated by woodpeckers, in and adja-
cent to the stand. Importantly, allow for snag recruitment within and
adjacent to the core stand by continually retaining the larger, over-
mature trees. Franzreb (1977), Baida (1977) and many others have
described the importance to secondary-cavity nesters of snag reten-
tion and recruitment. Management for Flammulated Owls may in
part involve a more general, multi-species, habitat approach by
establishing criteria for managing snags and hardwoods. Although
we have found Flammulated Owls calling from dense stands next to
roads and ciear-cuts, more information is needed about the effects of
disturbance on the long-term viability of breeding pairs and “quasi-
colonies.”

We thank William Brock, Alan Craig, Gordon Gould and Jon
Winter for reviewing the manuscript. We also thank Hamilton Tyler
for his stimulating discussions; Greg Leisten for furnishing records
and conducting field surveys; Stan Harris for compiling and allowing
us to publish some of the records; and the numerous biologists and
technicians of the Six Rivers National Forest involved in the field
surveys.

LITERATURE CITED

Baida, R.P., B.C. McKnight and C.D. Johnson. 1975. Flammulated Owl migration in
the southwestern United States. Wilson Bull. 87:520-533.

Baida, R.P. 1977. The relationship of secondary cavity nesters to snag densities in
western coniferous forests. Wildl. Hab. Tech. Bull. No. 1, Forest Service,
USDA. 37 pp. (Mimeogr.)

Bull, E.L. and R.G. Anderson. 1978. Notes on Flammulated Owls in northeastern
Oregon. Murrelet 59:26-27.

Franzreb, K.E. 1977 Bird population changes after timber harvesting of a mixed coni-
fer forest in Arizona USDA Forest Service Research Paper RM-184. 26 pp.

Franzreb, K.E and R.D. Ohmart. 1978. The effects of timber harvesting on breeding
birds in a mixed-coniferous forest. Condor 80:431-441.

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

Johnson, N.K. arid W.C. Russell. 1962. Distributional data on certain owls in the
western Great Basin. Condor 64:513-514.

146

FLAMMULATED OWLS

Marshall, J.T., Jr. 1939. Territorial behavior of the Flammulated Screech Owl. Con-
dor 41:71-78.

Miller, A H. 1951. An analysis of the distribution of the birds of California. Univ.
California Publ. Zool. 50:531-644.

Phillips, A.R 1942. Notes on the migrations of the Elf and Flammulated Screech
owls. Wilson Bull. 54:132-137.

Phillips, A., J. Marshall and G. Monson. 1964. The birds of Arizona. Univ. Arizona
Press, Tucson.

Tyler, H.A. and D. Phillips. 1978. Owls by day and night. Naturegraph Publ., Happy
Camp, CA.

Winter, J. 1974. The distribution of the Flammulated Owl in California. West. Birds
5:25-44.

Winter, J. 1979. The status and distribution of the Great Gray Owl and the Flam-
mulated Owl in California. Pp. 60-85 in P.P. Schaeffer and S.M. Ehlers, eds.
Proceedings of the National Audubon Society symposium on owls of the West.
Natl. Audubon Soc., West. Ed. Center, Tiburon, CA.

APPENDIX

Flammulated Owl records listed below are of birds heard calling in Humboldt and
Trinity counties, California, 1975 through 1980. All are believed to have been ter-
ritorial males except the two birds west of Grouse Creek on 30 June 1978 and one
bird in Elk Valley on 24 July 1979. Additionally, eight specimen records (all in Trinity
County) and six non-specimen records (four in Humboldt County and two in Trinity
County) are listed by Winter (1974, 1979). Township and range data refer to Hum-
boldt Base Line and Meridian, except as noted.

LOCATION

DATE

NO. BIRDS

OBSERVER

HUMBOLDT COUNTY

Horse Mt.

T6N, R4E, Sec 33

15 Jun 1975

1

S. Harris,

T. Harris

Bluff Ck.

T11N, R4E, Sec 29,33

23 Mar 1978

2

J. Gardetto,
C. Cox

West of Sims Mt.
T4N, R5E, Sec 8

13 Jun 1978

3

B. Marcot,
J. Brack

West of Grouse Ck.
T3N, R4E, Sec 1
T3N, R5E, Sec 18

30 Jun 1978

2

B. Marcot,
R. Escano

Nelson Flat
T2N, R5E, Sec 35
TIN, R5E, Sec 1,2

24 May 1976

7

R. Hill

North of Buck Mt.
TIN, R5E, Sec 22, 23

9 Aug 1976

6

R. Hill

West of Mt. Lassie
T1S, R5E, Sec 36

18 May 1978

2

C. Hohenberger,

D. Rudholm

Slate Ck. Butte
T11N, R4E, Sec 13

2 May 1979

1

M. Delamore

147

FLAMMULATED OWLS

Ammon Station
T5N, R5E, Sec 16

16 May 1979

1

M. Delamore

Corral Ck.

T8N, R6E, Sec 21

15 Jul 1979

2

W. Brock

Oak Knob
T6N, R5E, Sec 33

8 Apr 1980

1

G. Leisten,
J. Mattison

So. of No. Trinity Mt.

T8N, R6E, Sec 11, 15, 22

10 Jun 1980

4

M. Stohl,

J. Mattison,
J. Shipman

Mt. Lassie
T1S, R6E, Sec 31

7 Jun 1980

2

L. Doerflinger,
R. LeValley,

G. Friedrickson,

H. Genger

Bret Hold
T8N, R6E, Sec 22

10 Jun 1980

2

J. Mattison,
M. Stohl

Grogan Hole
T8N, R6E, Sec 11

10 Jun 1980

1

J. Mattison,
M. Stohl,

J. Shipman

Twin Lakes

T11N, R4E, Sec 25, 36

24 Mar 1978

2

J. Gardetto

Le Perron Pk.

T10N, R6E, Sec 29,32

TRINITY COUNTY

12 May 1980

2

J. Miller

Hasting Ck.

TIN, R6E, Sec 5,8

17 May 1978

3

B. Clow

Mad River Rock
T1S, R6E, Sec 14

10-14 May 1978

1

E. Payne

Mad River Rock
T1S, R6E, Sec 14

24-28 May 1978

2

R. Hill

Van Duzen River
T1S, R6E, Sec 8,22

7 June 1979

2

B. Marcot

Long Ridge

T4S, R7E, Sec 11,14,15

14 Apr 1980

3

K. O’Halloran,
Hadley

Ruth Lake Campground
T1S, R7E, corner Sec 28,
29,32,33

15 May 1974

1

R. Wilmarth

Hetten Ck.

T2S, R7E, Sec 9

26 May 1978

1

J. Gardetto,
C. Cox

Swim Ridge*

T3S, R12W, Sec 13,24
T3S, R11W, Sec 30

Jones Ridge and

28-30 Jun 1976

5

R. Hill

Mad River* 28-30 Jun 1976

T3S, R12W, Sec 34
T4S, R12W, Sec 9,10,11,12,14
T4S, R11W, Sec 7

10

R. Hill

148

FLAMMULATED OWLS

Mikes Rock*

T4S, R12W, Sec 26

28-30 Jun 1976

2

R. Hill

Lone Pine Ridge
T7N, R6E, Sec 22

27 May 1980

2

M. Stohl,

J. Mattison,

K. Baker

Lone Pine Ridge
T7N, R6E, Sec 22

28 May 1980

1

M. Stohl,
J. Brack

Lone Pine Ridge
T7N, R6E, Sec 23

29 May 1980

1

M. Stohl,
J. Brack

Lone Pine Ridge
T7N, R6E, Sec 21,22

5 Jun 1980

2

B. Marcot,
M. Stohl,

C. Sakai

SE of Hettenshaw Pk.
T2S, R7E, Sec 34

30 Apr 1980

1

G. Leisten,

K. O’Halloran

Blue Slide Ck.
T2S, R7E, Sec 12

29 Apr 1980

2

G. Leisten,

K. O’Halloran

DEL NORTE COUNTY

Elk Valley

T14N, R4E, Sec 23

24 Jul 1979

1

B. Marcot

’Mount Diablo Meridian.

Accepted 14 August 1980

149

WESTERN FIELD ORNITHOLOGISTS'

SIXTH ANNUAL CONVENTION

ESTES PARK, COLORADO, 26 - 28 JUNE 1981

The sixth annual WFO convention is being held jointly with the Colorado Field Or-
nithologists at Estes Park, Colorado.

BOARD NOMINATIONS. There will be three vacancies on the WFO Board of Direc-
tors. If you wish to submit a nomination for consideration, please submit the name,
address and phone number of the nominee to Jeanne Conry (address below).

CALL FOR PAPERS. If you have a presentation that would be of interest to the
general membership (particularly bird identification, distribution or field observations),
please submit an abstract for consideration to: Bruce E. Webb, EPO Biology Dept.,
University of Colorado, Boulder, CO 80309.

LOCATION AND TRANSPORTATION. Mt. Ypsilon Lodge at YMCA of the Rockies
will be the convention headquarters. YMCA of the Rockies borders Rocky Mt. Na-
tional Park, and is located 70 miles NW of Denver and 5 miles SW of Estes Park off
spur 66. Bus service is available from Denver by Gray Line of Colorado. However for
birding flexibility, vehicle rental at Stapleton International Airport in Denver is recom-
mended. Early registrants will be provided with local maps. The YMCA offers lodging,
meals, conference accommodations, and a variety of activities.

Registration will take place in the Mt, Ypsilon lobby from 2-8 pm on 26 June and from
8 am to noon on 27 June, Registration will be $5.00 per person. PREREGISTRA-
TION BY 15 MAY 1981 is requested.

LODGING AND MEALS. Rates quoted for participants staying at YMCA include
lodging, grounds fee and three meals per day, including banquet dinner. See enclosed
registration details.

A group campground in RMNP will be available for campers and tents. No showers
are available; meals and banquet dinner must be arranged upon arrival. Campers are
charged a YMCA gounds fee for daily use.

CLIMATE. Participants will encounter temperature extremes from very hot on the
Pawnee to cold on the alpine tundra. Mornings and evenings are always cool at this
altitude, but daytime temperatures are pleasant. Afternoon thundershowers are common.

FIELD TRIPS. Planned field trips to RMNP and PNG will be led by CFO members
familiar with the birds and best areas for birding. We intend to have many of the Colo-
rado specialities pinpointed. Multi-passenger vans will probably be available for per-
sons who have not arranged their own transportation at a charge of $10.00 for the
PNG trip and $5.00 for RMNP (prices subject to increase). PREREGISTRATION FOR
SCHEDULED FIELD TRIP VEHICLES IS NECESSARY.

June 29-30: A 2 day post convention CFO field trip to parts of eastern Colorado.
Special arrangements can be made at the convention. Likely eastern species are
Mississippi Kites, Red-bellied Woodpecker, Dickcissels and Bobolinks, possibly Black-
billed Cuckoos, Scissor-tailed and Great Crested flycatchers to name but a few.

RESERVATIONS for the convention may be made immediately by sending the
enclosed registration form and a check or money order payable to Western Field Or-
nithologists, C/O Dr. Jeanne Conry, Biology Dept., University of Colorado, 1100
14th St. , Denver, CO 80202. The full name of each person for whom you are making
the reservation and a STAMPED, SELF-ADDRESSED ENVELOPE must accompany
each request. For further information call Jeanne Conry 303-629-2657. Persons
preregistering will receive a packet containing an updated Colorado checklist, daily
field cards of RMNP and PNG, and detailed maps for locating several species of interest.

NOTES

FIRST RECORDS OF THE WHITE-TAILED KITE
IN WASHINGTON

BILL HARRINGTON-TWEIT, 900 N Wilson, Olympia. Washington 98506

The range and population size of the White-tailed Kite (Elanus leucurus) have been
increasing in western North America and Central America since the late 1940s (Eisen-
mann 1971) This expansion was evident in Oregon in the 1970s, as kites became
established residents at several Rogue and Willamette valley locations ( American Birds
Regional Editor’s files) and the first breeding record for the state was obtained at Finley
National Wildlife Refuge, Benton Co., in 1977 (Henny and Annear 1978).

Figure 1. White-tailed Kite ( Elanus leucurus) 6 km west of Raymond, Pacific Co
Washington, on 23 February 1978.

Western Birds 11:151-153. 1980

Photo by J. Davis

151

NOTES

The first sighting of a White-tailed Kite in Washington was on 10 July 1975, at the
Nisqually National Wildlife Refuge, Thurston Co. Stephanie Mason, Ellen Ratajak,
Pam Searles and I observed the bird for 4 minutes in good light. I recorded the follow-
ing details immediately after the observation:

At 1340 I saw a light colored bird approximately 100 m away being mobbed
by swallows. The bird was harrier sized with a white head, underparts and tail,
medium gray mantle, and black on the upper wing coverts creating a sharply
defined black patch on the shoulder. As 1 watched, it veered away and flew
higher, heading in a southerly direction and keeping its wingtips pointed as it
flapped or soared. In contrast to two gulls soaring near it, its wings appeared
much longer and slenderer, and its tail longer. I did not see the shape or color
of the soft parts.

Notes from the others present indicate that they saw a dark, decurved beak, white
tail, wings on top “lightish gray blue with darker shoulder patches," and the
resemblance of the bird to a gull and a harrier. I was the only observer with previous
experience with this species. Identification was unanimous. The bird could not be
relocated subsequently, though we were in the area for several weeks after the
sighting.

The Nisqually National Wildlife Refuge is located at the mouth of the Nisqually River
on southern Puget Sound. The refuge lands were formerly salt marsh which was diked
and converted to agricultural land. The extensive meadows are no longer grazed, but
were hayed regularly through 1975. The area supports a high microtine population
(Bowman and Dobos 1975).

The second substantiated sighting in Washington was on 27 November 1977. when
1 located a single kite 6 km west of Raymond, Pacific Co, This bird was not seen again,
despite several searches, until 29 January 1978 when Phil Mattocks and Gene Hunn
found it at the same location. Subsequently it was readily found by many observers
through 9 April 1978 and was photographed (Figure 1). On one occasion, 17 March

1978, two kites were present (American Birds Regional Editor’s files). A single bird
was noted there in late July 1978 (Harrington-Tweit et al. 1978) and on 29 April

1979, a kite was seen 1 .5 km northwest of South Bend, Pacific Co. (Hunn and Mat-
tocks 1979) This site is only 2 km west of the Raymond airport. All of these sightings
were from diked pasture land in the Willapa River estuary Abundant runways and
droppings throughout the many Juncus tussocks and patches of short grasses indicate
the presence of a large microtine population.

Two additional sightings have been recorded from Clark Co., just north of the Col-
umbia River and the areas where kites were first reported from Oregon almost 50
years ago (Gabrielson and Jewett 1940). On 17 September 1978, a single bird was
reported from Ridgefield National Wildlife Refuge, diked bottomland along the Col-
umbia River ( American Birds Regional Editor’s files) and a pair was seen on 8 March
1979 near Vancouver (Hunn and Mattocks 1979). The most recent sighting in the
state was of a single kite flying south over the sand dunes, 1 km east of the ocean
beach, at Ocean Shores, Grays Harbor Co. . on 17 August 1979 (Mattocks and Hunn
1980).

I thank Jack and Ada Davis for providing photographs, and Phil Mattocks for pro-
viding additional information on sightings.

152

NOTES

LITERATURE CITED

Bowman, K.J. and A.M. Dobos. 1975. Distribution and abundance of some small
mammal species on the Nisqually National Wildlife Refuge, Thurston County,
Washington. Pages 199-213 in S.G Herman and A.M. Wiedemann eds. Con-
tributions to the natural history of the southern Puget Sound region,
Washington. The Evergreen State College, Olympia, Washington. 249 p

Eisenmann, E. 1971, Range expansion and population increase in North and Middle
America of the White-tailed Kite (Elanu s leucurus ) . Am. Birds 25:529-536.

Gabrielson, I N. and S.G. Jewett. 1940. Birds of Oregon. Oregon State Coll.,
Corvallis.

Harrington-Tweit, B.. P.W. Mattocks, Jr. and E.S. Hunn. 1978. The nesting season.
Northern Pacific Coast region. Am. Birds 32:1199-1203.

Henny, C.J. and J.T. Annear. 1978. A White-tailed Kite breeding record for Oregon.
West. Birds 9:131-133.

Hunn, E.S, and P.W. Mattocks, Jr 1979. The spring migration. Northern Pacific
Coast region. Am Birds 33:799-802

Mattocks, P.W., Jr. and E.S. Hunn. 1980. The autumn migration. Northern Pacific
Coast region. Am. Birds 34:191-194.

Accepted 22 June 1980

White-tailed Kite

Sketch by Tim Manolis

153

NOTES

DIURNAL LAND VISITATIONS
BY RHINOCEROS AUKLETS

ASA CLIFFORD THORESEN, Biology Department, Andrews University, Berrien
Springs, Michigan 49104

Scott et al, (Western Birds 5:13-20, 1974) reported the range expansion and diur-
nal activity of Rhinoceros Auklets (Cerorhinca monocerata) on the coasts of Oregon
and California in recent years. Diurnal activity has been noted on the Farallon Islands,
California, and at Sea Lion Caves, Oregon. In this latter location they have been seen
carrying fish into the cave indicating that they were feeding young during daytime.

My ornithology students from Walla Walla College Marine Biological Station,
Anacortes, Washington, and I observed a Rhinoceros Auklet associating on rocks,
and flying circles, with Tufted Puffins (Lunda cirrhata). On 23 June 1977 a single
auklet came to Williamson Rocks, Rosario Strait, Washington, while our boat was an-
chored close to shore. It entered a burrow and remained there for at least 10 minutes.
The auklet then emerged to rest on the rocks for another 30 minutes or more until a
Glaucous-winged Gull ( Larus glaucescens ) landed nearby.

Visits to the location were made at least three times a week after the first sighting.
The single auklet was always present and usually came to land while I observed other
alcids.

On 31 July two Rhinoceros Auklets landed on the rocks in association with Pigeon
Guillemots ( Cepphus columba ) and Tufted Puffins.

On one occasion the two auklets disappeared into a rock crevice for several minutes
during which time I could plainly hear their growls and fricative wheezings. Since I had
no permit to land on Williamson Rocks, I could not determine if an actual nest attempt
had been made by the pair.

On 3 August 1 noticed that a Tufted Puffin kept edging towards a Rhinoceros
Auklet. The auklet moved to maintain distance until it had been displaced approx-
imately 15 m and then, apparently tired of the threat, it flew to the sea.

Additional diurnal activity was seen on an islet in Mackaye Harbor, Lopez Island, in
mid-July. Two auklets flushed from the turf as my boat approached at about mid
morning.

These observations show that Rhinoceros Auklets do occasionally come to land
during daylight hours and may do so over a wide extent of their range.

Accepted 9 September 1 980

Rhinoceros Auklet Sketch by Narca Moore

154

Western Birds 11:154, 1980

NOTES

PYGMY NUTHATCH FEEDS MOUNTAIN
BLUEBIRD NESTLINGS

BENEDICT C. P1NKOWSKI, P.O. Box 308, New Town, North Dakota 58763

Instances of adults of one avian species unilaterally feeding the young of another
species have been reported for a variety of passerines (Powell 1946, Logan 1951,
Eddinger 1970, Moore 1973) . This unusual behavior sometimes occurs following a re-
cent nesting failure by the feeding adults (Lack 1946:87, Norris 1958, Skutch
1976:370), but there are also reported nest failures caused by errors in feeding
(Williams 1942) Documentation of whether a nest failure precedes or follows a
feeding error requires knowledge of the nesting histories of all birds involved in an in-
terspecific feeding, and these histories are often unknown.

At 1045 on 4 July 1979 I found a nest containing four young Mountain Bluebirds
(Sialia currucoides) about 12 days old. The nest was in an abandoned woodpecker
cavity in the main trunk of a Quaking Aspen ( Populus tremuloide s) near Wilkerson
Pass, Park County, Colorado (elev. 2600 m). The cavity opening was 1.9 m above
ground and faced a compass direction of 224°. The young bluebirds were being fed
by adult male and female bluebirds as well as an adult-plumaged Pygmy Nuthatch
(S/tfa p^gmaea). During the following 2 hours 1 observed 14 feedings by the bluebirds
and 19 by the nuthatch. The nuthatch also removed excreta by leaning into the cavity;
it did not enter the cavity but did utter alarm notes in response to my presence near the
nest tree. Both adult bluebirds briefly chased the nuthatch when both species arrived at
the nest cavity with food, in which case the nuthatch fed the nestlings after the adult
bluebirds departed. The young bluebirds always gaped vigorously in response to the
arrival of the nuthatch at the nest entrance. A second adult-plumaged nuthatch was
also in the area but it did not feed the bluebirds. It soon became apparent that this
second nuthatch was attending a nest in another cavity in the main trunk of the same
tree; this cavity opening was 2.4 m above the ground and faced a compass direction of
249°, so the entrances to the two cavities were not far apart and had similar orienta-
tions. At 1230 I checked the second cavity with a mirror and found that it contained 7
nuthatch eggs.

I revisited the nest tree at 1800 on 7 July and recorded 8 bluebird feedings and 15
nuthatch feedings at the bluebird nest in the following 1.5 hours. The second nuthatch
accompanied the feeding nuthatch in searching for food, but it did not approach either
cavity. At 1930 I checked the nuthatch nest and found six dead young about 24 hours
old. Inasmuch as both male and female nuthatches feed the young and the male
sometimes feeds the female while she incubates (Bent 1948, Norris 1958). the feeding
bird was evidently the male of the pair nesting above the bluebird cavity. On neither
occasion did the male nuthatch approach the nuthatch nest. Thus it seems that the
male's unusual behavior led to the nest failure because the young nuthatches were in-
sufficiently fed, although the female may have deserted the nest or stayed off the nest
for excessively long periods while searching for food.

Two other instances of Pygmy Nuthatch and Mountain Bluebird nests in a same tree
were found in the general area of these observations. No abnormal feeding behavior
was observed though in one case the nuthatch and bluebird young hatched at about
the same time in cavities having opening heights and compass directions more similar
(2 5 m, 355° and 2.1 m, 3°. respectively) than was the case for the nests at which in-
terspecific feeding occurred. Thus, although the proximity of the nests may have con-
tributed to the error that resulted in failure of the nuthatch nest, a greater influence
may have been the timing of the nestings, which allowed the calling bluebirds to
stimulate the nuthatch to feed them at a time when the nuthatch's own nest did not
contain young. Such errors that result in nest failures appear uncommon among the

Western Birds 11:155-156, 1980

155

NOTES

large number of instances of interspecific feeding that have been summarized for many
species by Skutch (1976).

This research was supported by the Frank M, Chapman Memorial Fund of the
American Museum of Natural Ffistory.

LITERATURE CITED

Bent, A.C. 1948. Life histories of North American nuthatches, wrens, thrashers, and
their allies. U.S. Natl. Mus. Bull. 195.

Eddinger, C.R. 1970. The white-eye as an interspecific feeding helper. Condor 72:240.

Lack, D. 1946. The life of the robin. H. F. and G. Witherby, Ltd., London.

Logan, D. 1951. Cardinal, Richmondena cardinalis, assists in feeding robins.
Auk 68:516-517.

Moore, M. 1973. Male Blackbirds ( Turdus merula) helping to rear young Song Thrushes
(T. philomelos) . Brit. Birds 66:365.

Norris, R.A. 1958. Comparative biosystematics and life history of the nuthatches Sitta
pygmaea and Sitta pusilla Univ. California Publ. Zoo!. 56:119-300.

Powell, H. 1946. Nuthatch feeds nestling Starlings, Brit. Birds 39:316.

Skutch, A.F 1976. Parent birds and their young Univ. Texas Press, Austin.

Williams. L. 1942. Interrelations in a nesting group of four species of birds. Wilson
Bull. 54:238-249.

Accepted 23 May 1980

Pygmy Nuthatch Sketch by Cameron Barrows

156

NOTES

SONGS OF MACGILLIVRAY’S AND TOWNSEND S
WARBLERS IN COASTAL BRITISH COLUMBIA

MARTIN K. McNlCHOLL, Beak Consultants Ltd., 3530 11A St. N.E., Calgary,
Alberta T2E 6M7 Canada

Intraspecific variation in bird song has received considerable investigation in recent
years (e.g. Borror 1961, Armstrong 1973, Falls and Brooks 1975, Adkisson and Con-
ner 1978, Lein 1978). In this note, I comment on the use of two distinct song types by
each of two species of wood warbler (Parulidae) on Vancouver Island and adjacent
mainland British Columbia, and discuss these song types in relation to known types of
intraspecific variation. Individual variation within a particular song type has been
demonstrated for many species and appears to be important in facilitating individual
recognition (see references in Falls and McNicholi 1979). Such variation within a given
type of song will not be addressed in this note.

1 spent the summers of 1971 to 1974 inclusive studying Blue Grouse ( Dendragapus
obscurus ) on the Comox Burn study area on Vancouver Island, British Columbia
(Zwickel and Bendell 1972). These studies involved frequent visits and often prolong-
ed time in the territories of particular male grouse. While on these territories, I noticed
that MacGillivray’s Warblers ( Oporornis tolmiei) sang two distinct types of song. The
first was that depicted by Robbins et al. (1966), resembling the song of the Mourning
Warbler (O. Philadelphia) , including both variations on the record by Kellogg et al.
(1962). Bondesen (1977) described this song in detail, and correctly noted that
segments of it may be reversed. This song type was sung by most birds encountered
on Comox Burn and surrounding areas. Two birds, however, consistently sang a song
resembling that of the Yellow-rumped (Audubon’s) Warbler (Dendroica coronata
auduboni), another common species in the area. These birds, presumed to be con-
sistently the same by their territorial behavior, were never heard singing the more com-
mon song, and no others were heard singing the Audubon-like song. However, when
J. Bruce Falls and I played an Audubon-like song to a bird with the common song, the
latter flew to the speaker aggressively, indicating recognition of some aspect of the
unusual song as a conspecific song. The subject of the experiment was not likely
familiar with the song of either Audubon-like singer, as his territory was not within
hearing distance of either bird which sang the unusual song. His reaction cannot be
considered as one of interspecific aggression, as an Audubon’s Warbler sang regularly
within his territory without stimulating an attack.

Townsend's and Black-throated Gray warblers ( Dendroica touinsendi and D.
nigrescens) were both present in small numbers (three to five pairs) each year at our
camp on Piercy Creek, about 5 km downslope from Comox Burn Although the songs
of these two species are often said to be similar (e.g. Pough 1957, Peterson 1961) , the
song of the Townsend’s Warblers in camp bore no resemblance to that of the Black-
throated Gray Warblers, nor to the song of the Black-throated Green Warbler (D.
virens), with which it has also been compared (e.g. Stein 1962). Rather, the Town-
send's Warblers in camp invariably sang three rising notes, unlike the recordings in
Kellogg et al (1962). or any written description or sonagram 1 have seen for this
species. In conducting Breeding Bird Surveys near Port Alberni on Vancouver Island
and Gibson’s Landing on the adjacent mainland, 1 noted that the more typical song of
this species was sung at stops w-here Black-throated Gray Warblers were not heard,
whereas the three-note song was heard where both species occurred (Table 1).

Western Birds 11:157-159, 1980

157

NOTES

Table 1. Song types of Townsend's Warblers heard on two Breeding Bird Surveys in
British Columbia, 1974.*

TYPES

TYPE A TYPE B A&B

Port Alberni, Vancouver Island:

Stops at which only Townsend’s was singing 10 0 2

Stops at which Townsend's and

Black-throated Gray were both singing 0 7 0

Gibson's Landing, mainland B.C.:

Stops at which only Townsend’s was singing 3 0 0

Stops at which Townsend’s and

Black-throated Gray were both singing 0 5 0

*Type A = Black-throated Gray Warbler-like song; type B = three note song com-
monly heard in Piercy Creek camp.

In both the MacGillivray’s and Townsend s warblers the apparently atypical songs
were sung throughout the breeding season, and different songs were not sung with time
of day, as evidenced by my almost daily visits to their territories at varying times of day
and always hearing the same song type. Thus, seasonal and diurnal variation does not
account for these different songs (Borror 1961). Similarly geographic variation does
not apply, as all observations were in the same general area, although the songs could
have been learned in different places. Borror (1961) and James (1976) noted that
several species usually not known to mimic other birds do so occasionally. The two
MacGillivray’s Warblers that sang Audubon-like songs may have learned the song
from the latter species, although our brief experiment showed that some component
of this song enabled other MacGillivray’s to recognize it as a conspecific song. As men-
tioned above, the two species frequently sang and foraged in close proximity on Corn-
ox Burn with no sign of interspecific hostility. Thus, if this case represented mimicry,
the mimicry apparently was not used in territorial defense against the model species,
as reported in some cases (Adkisson and Conner 1978) Different song types may
convey different messages or more precise messages (Craig 1943, Lein 1978), but as
these song types were specific to particular males, rather than behavioral contexts, the
Audubon-type song did not appear to convey a different meaning than the more
typical song. 1 did hear variation within the more typical song and suspect that this may
have been due to a graded series of song types of the sort described by Lein (1978).
but 1 have no direct evidence for this. Verner (1975) described another case in which
different song types did not appear to convey different meanings.

Armstrong (1973) has noted that character displacement of song takes place in
some species with similar songs, with these songs being less similar where both species
come together The limited data in Table 1 suggest this as a possible explanation for
the two song types of Townsend’s Warblers. However, 1 have heard Townsend’s
Warblers sing Black-throated Gray-like songs in Stanley Park, Vancouver, in close
proximity to Black-throated Gray Warblers. Thus, character displacement, which
could take place at a much more subtle level, does not seem to be a total explanation.
Perhaps habitat has some influence on this situation.

158

NOTES

In both cases, the less common song types warrant further investigation.

Alan M. Craig and Narca Moore offered several useful editorial comments, and the
perceptive questions asked by Thomas L. Rodgers proved very helpful in improving
the manuscript.

LITERATURE CITED

Adkisson, C. S. and R. N. Conner. 1978. Interspecific vocal imitation in White-eyed
Vireos. Auk 95:602-606.

Armstrong, E. A. 1973. A study of bird song 2nd ed. Dover, New York.
Rondesen, P. 1977. North American bird songs — a world of music. Scandinavian Sci.
Press, Klampenborg, Denmark.

Borror, D. J. 1961. Intraspecific variation in passerine bird songs. Wilson Bull.
73: 57-78.

Craig, W. 1943. A song of the Wood Pewee Myiochanes uirens Linnaeus: a study of
bird music. New York State Mus. Bull. 334.

Falls, J. B. and R. J. Brooks. 1975. Individual recognition by song in White-throated
Sparrows. 11. Effects of location. Can. J. Zool. 53:1412-1420.

Falls, J. B. and M. K. McNicholl. 1979. Neighbor-stranger discrimination in male Blue
Grouse. Can, J. Zool. 57:457-462.

James, R. D. 1976. Unusual songs with comments on song learning among vireos.
Can. J. Zool. 54:1223-1226.

Kellogg, P. P., A. A. Allen, R. T. Peterson and W. W. H. Gunn. 1962. Afield guide
to western bird songs. Houghton Mifflin Co., Boston.

Lein, M. R. 1978. Song variation in a population of Chestnut-sided Warblers ( Den -
droica pensyluanica): its nature and suggested significance. Can. J. Zool.
56:1266-1283.

Peterson, R. T. 1961. A field guide to western birds. 2nd ed. Houghton Mifflin Co.,
Boston.

Pough, R. H. 1957. Audubon western bird guide. Doubleday & Co., Garden City,
New York.

Robbins, C. S.. B. Bruun and H. S. Zim. 1966. Birds of North America. Golden
Press, New York.

Stein. R. C. 1962. A comparative study of songs recorded from five closely related
warblers. Living Bird 1:61-71.

Verner, J. 1975. Complex song repertoire of male Long-billed Marsh Wrens in
eastern Washington. Living Bird 14:263-300.

Zwickel, F. C. and J, F. Bendeil. 1972, Blue Grouse, habitat, and populations. Proc.
15th Internatl. Ornithol. Congr.: 150-169.

Accepted 25 April 1980

159

ENCOUNTER

CONTINENTAL
BIRDLIFE

the bimonthly journal of
North American field ornithology

During its first year of publication this new journal
drew praise from amateurs and professional ornitholo-
gists alike. Combining a dedication to scientific accur-
acy with contents of wide appeal, Continental Birdlife
is for everyone with an interest in North American birds
afield.

Recent contents have included:

Plumage variations in Black-throated Blue Warblers,
by Kenneth C. Parkes
Washington’s second Dotterel record,
by Dennis Paulson

Great Gray Owls at Hatfield, Massachusetts,
photography by David Stemple
Identification of “Myrtle” and “Audubon’s” warblers,
by Kenn Kaufman

Plain-capped Starthroats in Arizona,
by Janet Witzeman

Subscribe now for 1981: $12.00 per calendar year in
the U.S., Canada and Mexico, $13.50 elsewhere.

Or write for free sample copy: Continental Birdlife

Post Office Box 43294
Tucson, Arizona 85733

Make checks or money orders payable to Continental Bird Observatory, Inc.

160

Volume 1 L Number 3, 1 980

Birds of Hastings Reservation. Monterey County. California
John Dams , , Wttfie? D. Koenig and Pam&!& L With® t ns

The Least Belfs Vireo in Baja California, Mexico

Sanford R WUbur

Distribution and Population Status of Whiskered Auklet Jfi
the Aleutian Islands, Alaska G Vernon Byrd OJid
Don fe. D Gibson

plammulated Owls in North western California
Bruce G. Marc of and Randy Hill

NOTES

113

129

135

341

Rrsl Records id ihi? White - railed Kile in Washington
BM Harrington Hu cut

Diurnal Land Visitations by Rhinoceros Auklets
Asa Clifford Thoresen

Pygmy Nuthatch Fet'd* Mountain Bluebird Nestlings
Benedict C PinkouislH

Stmgs jf MdcGiQltJf ay $ and Townsend’s Warbler’s in
Coastal British Columbia Martin K McNkhdll

153

154

155

1 57

Mflntjsacfipus smiiili! t» «vnff to Alton M Cniy. W M WjFiatRn Way Gw^itehsi'l C A
9£|Ml8 F<if ititoUtfri at consul! Suy^Biloni to Confrftoutor* to lAfentow Rivth 16
pp. mrrtu^B ftvwlabW *1 iw can bm«|hv Id.ftw} md Cetsri cff-a/ Btofogu Erfli^ &ryJr
Manual 4to edttkm ft7R finpiaftitrlt Anam-the Ameucnn of BiotogtoHl

StffolKM 14411 Wilson Bdufetfitfd AihrsgUm VA fflSPS l.-.r $15T (Hl|

Pajiorb n* du-ituvri Itul at«f tiflSfld u|K<>n El mid U'udimof birds III ill fin* hijfb LHidenfaniS
aJUk ami lawM-to -nmatirf tm ami itur * ngnifliEiRrti ctwvfHbw*tocr rsv v--

f:ro.AluiE> Appropipnih; 1 Urf uc - hrkuU dHThfeuilam mkmiftkwi. *l-afu». behflki6!

■ - - prjpytottffll dyp»Tmln htrtillitf TvqLuii'rmiiil t . ihc- irttocEt if polkutiiMi ilu-

irfliriiLVJCi lm idenlirutfHt. irrn&iKSjiiij usuntft mtffldtng «n i i pl-iMtrfcpiiiuhiiiii hit A*, m tlif
field I .ipuTH rtf 'Ktrioriu mini *r i*il ^rcnrnHdvn'r) rivnixirir is m ll i4ru yetwirapdriE: w:gin
bur fhwticiatariy dented arii p^pem diafaig Ab Bludtei urerimpSafledi in ut b*army oh:
Hmi-Ii,!,- MukmiAiai auirt and province wwt*wd indudinfi 'AWw nrfd Htownfl
mlpscL^m pwrtHsn*ol tkm fWdk Ort-rtn nm! Mexico. ami wiMteru Tvsai

AutbfWi ton? pt. Varied Jib fnH‘ ipimhiE* qf p^h pfflp*n Addlflntttoi nif*rmti ctoR bf
or J. r.nl a? fiiiihnr ■ I’Kjwnu. irtUh iti • ■ Fd4r.ii wto'h |?raal - jvi urhyn ■ ■ Maril^t

Good piwi^flfaohfl sr^rr «num*l turds un'flECtimjMiitod by an Arid# buF wiih
tflfH|nri indudrirg ipepi^ dMr, tnriaJlfv atnd other ywrttnimr uitruin^kiii -. luptiEd lm
MabnsLllc^l l«j ^li rsiirii A Liymui, vS^HU At kWiv H/mi I CA 95*1''* -: