AStreaked 5hearwater (½ ct leucamelas)record for Wyoming

DOUGFRULKNER ß DEPARTMENT OFZOOLOGY AND PHYSIOLOGY ß UNIVERSITY OFWYOMING ß LARAMIE, WYOMING ß (EMAIL: [email protected])

Abstract his opinionon the identification.McDonald plumage,Figure 1 clearlyshows these features. This paper examinesthe discoveryof a tookphotographs of thecarcass (Figures 1-4) Similar Pacific could include StreakedShearwater ( leucornelas) and forwarded them to the author for an ad- Buller's( bulleri), Wedge-tailed (P paci- carcassnear Medicine Bow, Wyoming, on 13 ditionalopinion. ficus),and Pink-footed(P creatopus).Bullerg June 2006 and criteria for its identification. Shearwateris easilyeliminated by the lackof The largercontext for thisrecord in partic- Identification boldlypatterned upperwings (Figure 2). Addi- ular,other records of pelagic from The bird canbe readilyidentified as a mem- tionally'Buller's shows a dark bill and clean the western interior United States and their ber of the seabirdorder b) whiteunderwing primary coverts. whereas the displacementby weatherfeatures--is also the naricornsat the baseof the maxilla(Fig- Vv•omingbi•d hasa light-colored bill anddark considered herein. ure 1); these are structuresthat encasethe underwingprimary coverts. These latter atmb- nostrilsand are used in divertingsalt excret- utesalso help eliminate Wedge-tailed Shearwa- Field encounter ed fromthe saltglands away from the birdg ter.In additionto billcolor and underwing pri- On 13 June 2006, Frank Mauer and Marji face(and probably in o/factionas well). The marypattern, light-morph Wedge-tailed Shear- Patz (USDA-NRCS) were on a field review on bill is alsocomposed of multipleplates, rather watercan be ruled out based on the long, white the CassidyRiver Ranch, Albany County than as a singlepiece, typical of procellari- undertailcoverts, which extendwell beyond (41.99ø N, 106.08ø W), northeastof Medicine iforms. Fused naricorns are found in the fam- the feet(never so in Wedge-tailed).Examina- Bow,Wyoming, when Mauer observed a bird ilies (shearwaters and ) tionof theWyoming bird showed that the legs carcasson the muddyshore of a smallreser- and Hydrobatidae(storm-petrels); the latter were nearlyfully extended(Figure 3). The lightestPink-footed Shearwaters could appearrather similarto StreakedShearwater, particular- ly individualswith abnormal15 palefaces or napes.Hnk-footed also shares the attributes of a light-coloredbill and pink legs with the Wyomingbird (Figure 4). Furthermore, Pink-footed hasextensive dark pigmentation In underunngcoverts, although usuallythis is moreextensive than in Streaked. However, in contrastto the Wyomingbird (Figure3), Pmk-footedhas dark undertail coverts and a shorter tail, so that the legsextend to nearlythe tail tip. The size of the specimenrules out the larger Cory'sShearwater (Calonectris cliomedea)of the Atlantic, and Figure1. StreakedShearwater carcass found in Albany County near Medicine Bow, Carbon County, Wyoming, on13 June 2006. Note the white facial as- while the recentlysplit Cape pectand extensive streaking o• the crown and nape, all typical of thisspecies and not present inother shearwaters, although rare leucistic individuals of Verde (C. edwardsii) otherspecies may show somewhat similar patterns. I•l•otograph by•virlAtcl)onalrl. issimilar in sizeto theWyoming voiraway from the water's edge. Mauer quick- canbe ruledout by the bird'sbody length as specimen,it is darkerabove and lackspale ly recognizedthe bird'sfeatures (e.g., nari- comparedto thelength of a standardsheet of plumagein thehead and nape. corns)as indicatingan oceanicspecies and paper(27.9 cm; Figures 2, 3), whichexceeds thusits importanceas a speciesuncharacter- thatof all storm-petrels. Discussion isticof Wyoming.Later that day,Patz stored Accordingto Harrison(1985), the only pro- How this arrived in the carcassm a freezerfor deliveryto Bob cellariid with a combination of white facial as- Wyoming remainsa mystery.The natural Lanka (WyomingGame and Depart- peet and streakedhindcrown and nape is occurrenceof this speciesinland has been ment), who subsequentlycontacted David StreakedShearwater (Caloncctris leucomelas). debatedpreviously (California Bird Records McDonald(University of Wyoming)to ask Despite the poor condition of this bird's Committee,in prep.), but it is inconceiv-

324 NORTH AMERICAN REASSESSMENTOFA FRIGATEBIRD RECORD FORWYOMING

able,if implausible,that thisbird arrivedin Wyomingwith humanassistance. Streaked Shearwater,a speciesof the westernNorth Pacific,is considered a fall vagrant along the North American Pacific coast, with the ma- jorityof acceptedrecords (13) fromCalifor- nia and all North American records from the period5 August-9October, including one inlandat RedBluff, California 5 August 1993,about 1360 km fromthe Wyoming lo- cation (Marshall et al. 2003; Garrett and Singer1998). The actualdate of the bird's occurrencein Wyoming,however, appears to havebeen within a week of discovery.A necropsyof the carcassfound the viscera still moistand maggot-ridden--acondition that could applyonly if it was recentlyde- ceased.The bird wasclearly emaciated and had succumbed to starvation, as no visceral fat was evident,the pectoralmuscles were atrophied,and there was no evidenceof ex- ternal trauma. In addition, neither the esophagusnor stomachhad any contents (CynthiaTate, pers. comm.). Recordsof pelagicspecies in the interior West (defined here as North Dakota, South Figure2. StreakedShearwater carcass found in Albany County near Medicine Bow, (:arbon (:ounty, Wyoming on13 June 2006. The fairly Dakota, Nebraska, Kansas,Colorado, Utah, uniformupperparts helpto rule out similar Pacific shearwater species, particularly Buller's Shearwater. Photograph byDawdMcDonald. Wyoming,Montana, and Idaho) are few, particularlyin the summerseason. All of these states but North Dakota have autumn recordsof AncientMurrelet (Synthliboram- phusantiquus), and Colorado and Wyoming have autumnrecords of Long-billedMur- relet(Brachyramphus perdix) (Sibley 2000). Wyominghas a summerrecord of Lesser Frigatebird(Fregata ariel; 11 July 2003;see article, this issue),Montana a late-spring recordof Manx Shearwater(Puffinus puffi- nus; 30 May 2004; Trochlell 2004), and North Dakota a summer record of South Po- lar Skua (Stercorariusmaccormicki; 13 July 1989;Berkey 1989). Colorado, Kansas, and Utah haveone or more recordsof Magnifi- cent Frigatebird(E magnificens),mostly from the warmer months,as doesOklahoma and as do most interior states farther east (Sibley2000). Oklahomaalso has a record of a GreatFrigatebird (E minor;3 November 1975;Heller and Barclay 1977). Someof the frigatebirdrecords, but by no meansall, can be tied to discrete weather events such as tropicalstorms; the absenceof clear evi- dencelinking the recordsof the skua and the shearwatersto storm systemssuggests that otherfactors may have resulted in their disorientation_ It is conceivable that off- coursebirds such as these travel along major waterwayslike the Colorado,Columbia, or MississippiRiver systems,for instance,or Figure3. StreakedShearwater carcass found in Albany (:ounty near Medicine Bow, Carbon (:ounty, Wyoming, on13 June 2006. that they simply have faulty navigational Thefacial streaking isbetter evident inthis photograph than in Figure 1.The dark primary coverts and long, white undertail coverts systems. extendingbeyond the feet eliminate Pink-footed andWedge-tailed Shearwaters. Photograph hyDavid McDonald.

VOtUME 60 (2006) NUMBER 3 325 ,REASSESSMENT O'F•FI•IGAT•RD RECORD FORWYOMING

Literature cited Berkey,G. 1989.The NestingSeason: North- ernGreat Plains region. American Bi•ls 43: 1332-1334. California Bird Records Committee. Rare Birdsof California,in prep.Western Field Ornithologists,Camarillo, California. Garrett,K. L., andD. S. Singer.1998. Report of the California Bird Records Committee: 1995 records. Western Bi•is 29: 133-156. Harrison,P 1985.: An Identification Guide.Houghton Mifflin, Boston. Heller,V. J., and J. S. Barclay.1977. Third specimenof frigatebirdfor Oklahoma.Bul- letinof theOklahoma Ornithological Society 10.2: 9-10. Marshall, D. B., M. G. Hunter, and A. L. Con- treras,eds. 2003. Birds of Oregon:A Gener- Figure4. StreakedShearwater carcass found in Albany County near Medicine Bow, Carbon County, Wyoming, on13 June 2006. Along withsome plumage features, the bird's pink legs superficially suggest Pink-footed Shearwater. Photograph byDavidAtcDonald. al Reference.Oregon State University Press Corvallis,Oregon. Sibley,D. A. 2000. TheSibley Guide to Birds Acknowledgments thiaTare for thenecropsy information; and to Knopf,New York. My thanksto Frank Mauerfor recognizing George L. Armistead, David McDonald, Trochlell,D. 2004.The Spring Migration: Ida- thevalue of thecarcass; to Marji Patzand Bob Michael A. Patten, and Brian L. Sullivan for ho & Western Montana. North American Lankafor preservingthe specimen:to Cyn- theircontributions to themanuscript. Bi•ds58: 403-404. •

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