SHORT COMMUNICATIONS

The Condor90~931-933 0 The CooperOrnithological Society 1988

NOTES ON THE DISTRIBUTION AND STATUS OF CERTAIN IN ’

F. GARY STILES Escuela de Biologta,’ Universidad de Costa Rica, Ciudad Universitaria “Rodrigo Facie,” Costa Rica, Central America

Key words: Costa Rica: avifauna; specimens. KILLDEER (CHARADRIUS VOCIFERUS) Well known in Costa Rica as a migrant and winter resident (Slud 1964) the Killdeer also appearsto be a Fieldwork over the last severalyears has produced many permanent resident in small numbers in the Cartago advances in our knowledge of Costa Rican birds. In area, and perhaps elsewherein the central highlands. this note I summarize recent additions to the country’s Having observedKilldeers in June and July in several avifauna,and one major changeof status,that are based years at Las Concavas, 5 km southeastof Cartago, J. upon specimensor photographicdata. New sight rec- E. Sanchezand I began to seek evidence of breeding. ords and much new information on distribution within On 28 June 1984, at a newly-dug farm pond at Las Costa Rica will be presented elsewhere (Stiles and Cbncavas,an adult gave vigorous distraction displays Skutch, in press).All specimensreferred to here are in to us. After searchingthe flat, muddy shore for over the collection of the Museo de Zoologia, Universidad 30 min, we found and collected a downy chick (UCR de Costa Rica (UCR collection number given). 2689); not over a day or two old, it still had yolk in GRAY-BREASTED CRAKE its stomach. We withdrew some 50 m, and eventually (LATERALLUS EXILIS) the adult landed, called two more chicks out of the grassnearby, and led them away. We found egg frag- The first Costa Rican specimen of this elusive but not ments and a probable nest scrape,but no other eggsor uncommon rail was taken by D. Levey and me, with chicksin the vicinity, suggestingthat the original clutch the enthusiasticassistance of E. Brennan and M. Ed- was three eggs.In June 1985, Sanchez noted a brood dison, on 23 February 1983, in a wet pasture across of three being attended by two adults at this pond, and the Rio Puerto Viejo from the La Selva Biological Sta- on 5 July 1986, L. Rosselli and I found a singledowny tion, Provincia de Heredia. The specimen(UCR 2685) chick at another pond nearby. I have seenadults giving is an adult female with ovaries slightly enlarged. Fur- similar distraction displaysat this time of year at Coris ther details, including vocalizations, previous sight- and Laguna Dotia Ana, also in the Cartago area, but ings, and local distribution, will be presented else- not in the lowlands of either slope, where the species where. appearsto be exclusivelya winter resident,and in much WATTLED (JACANA JACANA) greater numbers. The status of the Killdeer in Costa Rica is thus preciselythe same as that of the Mourning With help from M. Marin, I took the first Costa Rican Dove (Zenaida macroura) (cf. Slud 1964; Stiles and specimenon 11 July 1984 at Laural, Prov. Puntarenas, Skutch, in press).This is the first reported breeding of ca. 3 km west of the Panamanian border. The the Killdeer in Central America. (UCR 2880) an adult male with greatlyenlarged testes, was behaving very aggressivelytowards the numerous Northern Jacanas(J. spinosa) presentwith it in a flood- CURLEW SANDPIPER ed but drying rice field. It shows no sign of hybridiza- (CALIDRIS FERRUGINEA) tion or introgressionwith the latter species,such as has On 7 November 1984, while mist-nesting shorebirds been reported in western , evidently in asso- with J. E. Sanchez,R. Fyfe, and U. Banaschat Salina ciation with a westward range expansion (cf. Ridgely Bonilla, 1.5 km southeastColorado, Prov. Guanacaste, 1981). I captured an adult female of this speciesin a flock of Western (C. Mauri) and Semipalmated (C. pusilla) sandpipers.The specimen (UCR 3048) is in full basic body plumage, and is molting the primaries. This is I Received 15 June 1987. Final acceptance28 May the first record of this species for Central America; 1988. however, it is an increasingly regular winter visitor

[9311 932 SHORT COMMUNICATIONS

alongthe Atlantic coastof North America (AOU 1983) B. Richardson, and describedas a new species,N. lau- and occasionalindividuals should not be unexpected tus, by Miller and Griscom (1925). The Costa Rican further south. specimen agreeswell with la&us in size (wing chord 117.7 mm, tail length 98.2 mm), but is more blackish, SOOTY TERN (STERNA FUSCATA) less rufescent in overall coloration. This may not be This specieshas been known from Costa Rican waters significant,however, as femalesare more rufescentthan on the basis of several sight reports (Slud 1964) but males in other speciesof the genus, as currently rec- the first specimenrecord for the country is a youngbird ognized (Ridgway 1914, cf. AOU 1983). There is also picked up by G. Hartshom beside the Rio Sarapiqui much variation, from rufous to blackish, in South at the La Selva BiologicalStation on 2 April 1983. The American populations of ocellatus(Hilty and Brown specimen(UCR 269 1) is in full juvenile plumage;weak 1986). Therefore, I am confident in assinnincrmv snec- and emaciated, it died soon after being picked up. imen’to lautus,of which it is the first kn~wnmaje. -The fact that my bird was in breeding condition indicates POMARINE JAEGER that there is a distinct Central American population (STERCORARIUS POMARINUS) (althoughthis doesnot excludethe possibilitythat these This specieswas also known from Costa Rican waters birds might migrate to during the non- from severalsight records;with E. Wimmer, I took the breeding season).My collecting locality is ca. 15 km first specimen for the country (UCR 2716), a fat im- south of the Nicaraguan boundary, and the Brasilia mature male, off Caldera in the eastern Golfo de Ni- area has been largely deforestedonly in the last 1O-l 5 coya on 11 June 1983, after it landed near our boat years, suggestingthat the presence of N. ocellatusin during chumming operations. Interestingly, a second Costa Rica may representa recent range extension. specimen (UCR 3321) is a subadultfemale nicked UD in a moribund state by J. Alvarado and O.*Paniagua PRAIRIE WARBLER (DENDROICA DISCOLOR) near Chilamate de Sarapiqui, Prov. Heredia, on 31 The first Costa Rican specimen of this rare migrant is March 1986. Like the Sooty Tern above, this bird was an immature female that I collected (UCR 3166) in weak and emaciated, and died soon after being picked scrubby second growth 0.5 km northeast of Ciudad up; both were probably storm-driven waifs. Universitaria, Prov. SanJose, on 3 1 August 1985. First seen on 29 August as it deliberately worked through OILBIRD (STEATORNIS CARIPENSIS) tall shrubsgleaning , the bird was mostly silent In late January 1986, P. Pyle and S. G. Howell found and not associatedwith any other birds. The species the desiccated,partial remains of an Oilbird beneath was previouslyknown in Costa Rica from two sightings a power line ca. 100 m from the Pan American High- (Stiles and Smith 1980). way at Villa Mills, Prov. Cartago,at 3,100 m elevation on the north end of the Cordillera de Talamanca. When PALM WARBLER (DENDROICA PALMARUM) told of their find S. Perkins, realizing its importance, I took the first Costa Rican specimen of this migrant collected the remains and brought them to me. The specimen(UCR 3507) consistsof most of the left wing at Playuelas,Prov. Alajuela, near the Nicaraguanbor- and assortedother feathers, unmistakably those of an der, on 15 October 1982. The bird (UCR 2627) an Oilbird from the size and the distinctive white spotting immature female, was with a feeding flock of other migrant warblersand resident species,along a roadside on the wing coverts; the dark color of the primaries in low, wet scrub. In addition, L. Rosselli and I saw may indicate a young bird (cf. Wetmore 1968). It may be surmised that a wandering bird collided with the six or seven and banded two Palm Warblers in open power line while crossingthe mountains at night, pos- grassyareas along the Caribbean coastbetween Puerto Viejo and Manzanillo, Prov. Lim6n, during stormy sibly confusedby the bright lights of a nearby restau- weather between 5 and 8 November 1985. All birds rant-the only such lights in a wide radius, as the sur- seenor handled to date have been representativeof the rounding area is heavily forested except for a narrow nominate race. strip of clearingsand scrub along the highway. Young Oilbirds in particular are noted for their wandering propensities;this is the first report for Costa Rica, and MELODIOUS BLACKBIRD ( DIVES) by far the northernmost for the species,whose nearest The only Costa Rican record to date is a bird seen and breedingcaves are probably in east Darien or adjacent photographed by S. G. Howell 5.1 km northeast of (Wetmore 1968). Puente Lagartos,along the road to Monteverde, Prov. Puntarenas,on 17 March 1987. The bird was associ- ating with a group of Groove-billed Anis (Crotophaga ( OCELLA sulcirostris),in trees along the edge of a pasture. The On the moonlit evening of 28 March 1988, in an area photographsshow the bird to be about the same bulk of dense, tall secondgrowth adjacentto ca. 4 km as the anis, its eye and bill are dark, the bill is more south-southeastof Brasilia, Prov. Alajuela, I heard a slender and sharp-pointed than that of a , the call I could not identify. Returning the next bird shows no sign of a neck ruff, and its tail is of evening, I succeededin obtaining tape recordingsand medium length, without a keel. In one photo a slight a specimen (UCR 3580) an adult male with enlarged bluish glossis apparent on the entirely black plumage. testes. The only previous record for Central America The combination ofthese featureseliminates any other is a single adult female specimen collected at Petia speciesof blackbird or cowbird, in addition, Howell Blanca, in northeastNicaragua, on 5 June 1909 by W. was familiar with Dives from , and recognized SHORT COMMUNICATIONS 933 it immediately (Howell, pers. comm.). The occurrence LITERATURE CITED of this speciesin Costa Rica is to be expected,as it has been expandingits range in in recent years; AMERICANORNITHOLOGISTS UNION.’ 1983. Check- it is now known they are south at least to Rivas, just list of North American birds. 6th ed. American north of the Costa Rican boundary (J. C. Martinez, Ornithologists’ Union, Washington, DC. pers. comm.). HILTY, S. L., AND W. L. BROWN. 1986. A guide to the birds of Colombia. Princeton Univ. Press, LINCOLNS’ SPARROW Princeton, NJ. (MELOSPIZA LINCOLNII) MILLER,W. D., AND L. GRISCOM. 1925. Descriptions of new birds from Nicaragua.Am. Mus. Nat. Hist. I collected an immature female of this species in a Novitates, no. 159. brushy field 0.5 km northeastof Ciudad Universitaria, RIDGELY,R. S. 1981. A guide to the birds of Panama. Prov. San Jose, on 16 November 1985. The specimen 2nd ed. Princeton Univ. Press, Princeton, NJ. (UCR 3238) in fresh plumage with very light fat, is RIDGWAY.R. 1914. The birds of North and Middle the first for Costa Rica following several sight reports America. Part 6. Bull. U.S. Natl. Mus. 50. (Tramer 1979, Stiles and Smith 1980). In addition, G. SLUD,P. 1964. The birds of Costa Rica: distribution Barrantes, A. Pereira, and I banded and released an and ecology. Bull. Am. Mus. Nat. Hist. 128. adult Lincoln’s Sparrow at the same site on 25 No- STILES,F. G., AND A. F. SKUTCH. In press. A guide vember 1985. to the birds of Costa Rica. Cornell Univ. Press, I wish to express my gratitude to the various ob- Ithaca, NY. servers mentioned above for their help and informa- STILES,F. G., AND S. M. SMITH. 1980. Notes on bird tion. In addition, I thank the Organization for Tropical distribution in Costa Rica. Brenesia 17:137-l 56. Studies-Proyecto Zona Norte for logistical support TRAMER,E. J. 1979. First sight records of Lincoln’s during the collection of the Ocellated Poorwill, and Sparrowfor Costa Rica. Wilson Bull. 9 1:469-470. the Vicerrectoria de Investigation, Universidad de WETMORE,A. 1968. The birds of the republic of Pan- Costa Rica, for financial assistance. ama. Part 2. Smithson. Misc. Collect. 150.

The Condor90:933-935 0 The CooperOmithologd Society 1988

FEMALE PAIRING: A REPRODUCTIVE STRATEGY FOR HERRING GULLS? ’

GARY W. SHUGART~ Behavior,Department of PsychologyNI-25, Universityof Washington,Seattle, WA 98195 MARY A. FITCH 5230 16th Ave NE, Seattle, WA 98105

GLEN A. Fox Wildrife Toxicologyand Surveys,Canadian Wildrife Service,Ottawa, Ontario KlA 0E7, Canada

Key words: Larus argentatus;gulls: sex ratio; fe- METHODS male pairs; homosexual. Populationsof color-bandedindividuals at three Great Lakes island colonies were used for this study during Adaptive and nonadaptive explanations have been 1978 to 1986 (Table 1). Female pairs were identified provided for the phenomenonof female pairing in gulls by capturingsupernormal clutch attendantsand by lo- (Hunt and Hunt 1977, Coulson and Thomas 1985). In cating females that we had color-banded in previous this paper we summarize data for Herring Gull (Larus years.We confirmed that the supernormalclutches un- argentatus)female pairs that pertain to these interpre- der study were attended by female pairs and not by tations. one male-multiple female groups (Fitch and Shugart 1983, Fox and Boersma 1983) by observationsof nest attendants.At Lake Michigan colonies (see Shugartet al. 1987for locations),after banding,observations were I Received 8 December 1987. Final acceptance24 donefor a dawn to duskperiod then periodicallythrough June 1988. the breeding season(see Shugart 1980, Shugart et al. 2Present address:Department of Zoology, Univer- 1987). At Lake Ontario. attendantswere observeddur- sity of Oklahoma, Norman, OK 73069. ing nest checks.