S Warbler (<I>Phylloscopus Proregulus</I>)
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First North American recordof Pallas'sWarbler (Phylloscopusproregulus) at Gainbell,Alaska PAULE. LEHMAN ß P.O.BOX 379 ß CAPEMAY, NEW JERSEY 08204 ß (EMAIL:[email protected]) GARYH. ROSENBERGß P.O.BOX 91856 ß TUCSON,ARIZONA 85752 ß (EMAIL:[email protected]) Abstract fromat leastthe pasttwo centurieshave Two of the threeboneyards are located Thefirst record of Pallas'sWarbler (Phyl- revealedimportant records involving near the base of 187-m Sevuokuk Moun- 1oscopusproregulus) for North America bird bones (Friedmann 1934, Murie tain(Figure 5), whichprobably acts as a was documented at Gainbell, Saint 1936). Today,these same midden sites barrierto somelow-flying landbirds that LawrenceIsland, Alaska, on 25-26 Sep- (known collectively as "the bone- mightotherwise continue moving farther tember 2006. The identification and evi- yards")--aswell as other areasof dis- eastward.Other migrants probably arrive dencesupporting the record are present- turbedground--are characterized in late elsewhere on the island and work their edhere and put intocontext with records summerand early fall by relativelylush way to the northwesterntip at Gainbell of otherlandbird vagrants found in au- vegetationdominated by Northern or Many passerinesare not discoveredin tumn at Gainbell since the 1990s. Tall Wormwood (Artemisia tilesii) and theboneyards until theafternoon or ear- ArcticSage or Wormwood(A. arctica), ly evening,which suggests that theyare Introduction which growsto a maximumheight of new arrivals. The Aleutiansand islands of the Bering slightlymore than a halfmeter. The rich Sea in western Alaska are well known to soil and vegetativegrowth, combined Field encounter NorthAmerican birders as places where with the verticalrelief and protection The autumn of 2006 at Gainbell was Asianmigrants and vagrants occur regu- from the wind providedby the digging poor for vagrant Asian passerines larly Attu, Shemya,Buldir, and Adak Is- pits, are magnetsfor passerinesin au- through early September,with none lands in the western and central Aleu- tumn. The list of regularlyoccurring found until 10 September,when three uans,St. Paul (and to a lesserextent St. avianspecies found here includes a num- Bramblings(Fringilla montifringilla) put George)Island in thePribilofs (southern ber with primarilyOld World distribu- in a brief appearance.In contrast,the BeringSea), and the village of Gainbellat tions that also nest on mainland Alaska lastseveral days of Augustand firstten the northwesterntip of SaintLawrence (with a few breedingin smallnumbers daysof Septemberwere goodto excel- Island(northern Bering Sea) (Figure4) on St. Lawrence Island as well), but lent for Asianlandbird strays each year are all sitesthat have producedmany which then return westward in late sum- from 2002 through2005. The Bram- documented records of Asian waterbirds merand early fall to winterin southeast- blings were followed,however, by a and landbirds--some of which have ern Asia or Africa. These "trans- SiberianRubythroat (Luscinia calliope) turned out to be regularmigrants and BeringJan"species include Arctic War- and a PechoraPipit (Anthusgustavi) on some of which have been determined to bler (Phylloscopusborealis), Bluethroat 14 September.But then moderate-to- be true vagrantswith few NorthAmeri- (Luscinia svecica), Northern Wheatear strongnorth winds set in for the follow- can records. (Oenanthe oenanthe), Eastern Yellow ing eight days--through 22 Septem- Gainbell,a villageof some660 Yupik Wagtail( Motacillatschutschensis) , White ber-and againno Asian passerines were peoplelocated at thenorthwestern tip of Wagtail(M. alba),and Red-throated Pip- found(although Alaska's fourth and the St. Lawrence Island, lies 315 km (195 it (Antbus cervinus). Another trans- BeringSea region'sfirst Philadelphia mi) west-southwestof Nome and 74 km BeringJanmigrant, Gray-cheeked Thrush Vireo[Vireo philadelphicus] appeared on (46 mi) fromthe closest point on Russia's (Catharusrainlinus), has nesting popula- 18 September).The windsslackened to ChukotskiyPeninsula (Figure 4). Con- tions in northeastern Russia that in au- lightsouthwesterly and then light north- unuoushuman occupation of the Gain- tumn head eastward,back into North easterlyover the ensuingseveral days, bell area datesback some2000 years. America.The boneyardsare also attrac- with partlycloudy to overcastskies on Middendeposits (burial sites for discard- tiveto mostof thevagrant landbirds from 23-24September, and overcast with light ed marine mammal and bird carcasses) both Asia and mainland North America. rain on 25 September.We discovereda 4 NORTH AM[RICAN BIRDS Pallas'sBunting (Emberiza pallast) on 24 which in turn contrasted with a bold su- Septemberin Gainbell's"Near Bone- perciliumthat wasstrongly tinged with yard," where it remainedthrough 26 deepyellow in frontof theeye, paling to September. an off-whitishbehind the eye, and which Duringthe earlyafternoon of 25 Sep- in turn contrasted with a distinct dark tember,we arrived at the "Circular Bone- eyeline. In all, thehead pattern was very yard,"where Lehman promptly flushed bold and distinct.The upperpartswere a very small passerinewhich flew off, unmarkedolive green, except for a bold low, and droppedback into cover.He medium yellow rump patch that was told Rosenbergthat it lookedinteresting usually coveredby the folded wings and thatthey should try to re-findit. Af- when the bird was at rest but which be- ter sometime, Rosenbergrelocated the came obvious when the bird flicked its bird, gota brieflook at it on the ground wingsor tookflight. The wingsshowed and,based on partialviews, yelled, "Yel- twobold pale yellow wing bars, pale yel- 1ow-browed Warbler!" The bird then lowishedgings to the secondaries,and flushed and both observers were able to distinct whitish edgesto the tertials. see its yellow rump, at which point [The bird's overall small size, distinct Lehmanyelled, "Pallas's Warbler!!" Pan- palesupercilium, and white tertialedges ic quickly ensued,as Rosenbergwas are all charactersshared by Yellow- scheduledto leavethe island in just two browedWarbler (Phylloscopusinorna- hours time and still needed to do some tus).] The underpartswere off-whitish packing.Both observers were well aware and appearedunmarked. The tail was that this bird would constitute a first short and showedno pale patchesor NorthAmerican sighting and that recog- spots.The legswere dusky, not obvious- nizablephotographs would be neededto ly paleor verydark. The birdacted nerv- documentthe record.So, with a high ous,giving regular wing-flicks, much as a level of urgency and nervousness, Ruby-crownedKinglet does. Several Rosenbergand Lehmanbegan the task timesit hover-gleanedfood from plants, of trytngto obtainthe needed documen- oneto two feetoff the groundfor about tation, with digital photographyand one or two secondseach time, but then video,respectively. quicklyreturned to coverout of view.It Figures1-3. These photographs ofthe Gainbell The bird remained faithful to the Cir- calledat leastonce, and gave a clear,up- Pallas'sWarbler were taken 25 September 2006. cular Boneyardfor two days--through slurred su-wee. Togetherthey show almost all the important field 26 Septemberbut, like manymigrant The combination of small overall size, marksof this species, including the distinct pale passerinesoccurring at Gainbellin au- distinctpale median crown stripe, bold mediancrown stripe, bold supercilium with bright tumn, it was very furtive,could easily supercilium with strongly yellow mediumyellow supraloral area, distinct dark eye hidein therelatively thick boneyard veg- supraloralarea, distinctdark eye line, line,olive-green upperparts and off-whitish etation,and proveddifficult to seewell olive-greenupperparts, off-whitish un- underparts,dark tertials with distinct whitish or for longperiods of time.Despite these derparts, dark tertials with distinct edges,and a light-to-medium-yellowrumppatch. PhotorjraphsbyGary tt. Rosenberg. difficulties,excellent photographs (e.g., whitish edges,medium yellow rump Figures1-3) andvideo were obtained. patch,su-wee call, and wing-flicking and The bird was the size of a Ruby- hover-gleaningbehavior clinch the iden- crownedKinglet (Regulus calendula). It tification as Pallas's Warbler. showeda thinbut sharp and distinct pale yellowcentral crown stripe, set off by Discussion dark(very dark olive) sides to thecrown, Pallas'sWarbler, also known as "Pallas's VOLUME 61 (2007) ß NUMBER 1 5 [FIRSTNORTH AMERICAN RECORD OFPAL•'AS'S WARBLER ß Kilometers Barrow Males Chukotsk•y Anadyr Peninsula ALASKA RUSSIA Riverbas•n...• KoryakAnad)•r GRMBELSt Lawr-•r ce I.ß Anchorage Highlands Magadan B, ing gea II 'a• • PRIBILOIS•'c e•l Ok! Attu•Shem• /• Island ,ALEUTIAN / Nofith Pacific Ocean Hr '•' * o JAPAN 71o •a ,7• • •m • 150 Figure4. Mapshowing the Bering Sea region, western Alaska, and eastern Siberia and the Russian FarEast. 6arnbell islocated atthe northwestern tipof St. Lawrence Island andis only 74 krn (46 rni) frorn the closest point on Russia's Chukotskiy Peninsula. Many of the vagrant Asian passefines thatturn up at Gainbell inthe fall breed northeast to theKoryak Highlands orAnadyr River basin ("Anadyrland"). Someindividuals have originated from even rnuch farther away. Pallas's Warbler isnot known to breed any closer thanthe Magadan area bordering thenorth-central Seaof Okhotsk. Map by Vir•Tinia MaynarcL Leaf-Warbler"and (formerly)"Lemon- (south to northern Thailand, northern ganistan(Cramp et al. 1992,Baker 1997, rumpedWarbler," is a distinctivespecies Laos,and northern