NOTES

FIRST RECORD OF YELLOW-BROWF-r WARBLER (PHYLLO$COPU$ INORNATUS) IN NORTH AMFJ!iCA

PAUL LEHMAN, P.O. Box 379, Cape May, New Jersey08204

For many yearsI have had an interestin the autumnmigration in westernAlaska's islands.In additionto a singlefall visit to Attu Island,in the westernAleutians, in 1993, I havebeen able to visitGambell, Saint Lawrence Island, in earlyfall 1992 (sixdays in late August), 1997 (sevendays in late August), 1998 (16 days, through early September),and 1999 (45 days,20 Augustto 3 October).Fay and Cade (1959) and Sealy et al. (1971) made detailedcensuses on Saint LawrenceIsland, primarily in summer,during the 1950s and 1960s. Birdershave visited Gambell regularly during the late spring(late May and early June)since the mid-1970s. My extendedstay in 1999 was highlightedby the discoveryof a numberof Asian strays,including the Long-toed (Calidris subminuta) and Temminck's(C. temminckii) stints, multiple Common Ringed(Charadrius hiaticula) and Mongolian(C. mongolus)plovers, a Cuculus cuckoo(probably the Oriental, C. saturatus),Siberian (Prunella montanella),and Little (Ernberiza pusilia). ! alsonoted a moderatenumber of straysfrom mainlandAlaska, a numberof latedeparture dates for the westernpart of the state,and a few recordhigh counts,particularly of severalseabirds. The mostunusual I foundin 1999 wasNorth America'sfirst Yellow-browed Warbler(Phylloscopus inornatus), which was present23-24 September.The frequentedtwo of Gambell'sthree "boneyards,"a habitatcharacterized by disturbed nutrient-richground that supportsa lushgrowth of a mintlikevegetation, which, by latesummer, grows to a heightof up to a footor so.In contrastto thevery short tundra vegetationand extensivegravel found elsewherearound Gambell,this boneyard vegetationacts as a magnetto manyspecies of ,both regular migrants and vagrants. The followingdescription of the Yellow-browedWarbler is copiedfrom my field notes,written both daysthe bird was present.On 23 September:"First seen hover- gleaningfood off dense,low mint vegetationin 'far boneyard,'then quicklydisap- peared,and then flushedand doveback into cover.My firstimpression was of either a large kingletor a smallishPhylloscopus. The bird also seemeda bit brighterand more contrastyabove, and smalleroverall, than a typicalArctic Warbler would look. Then began a 3-hour sessionas I chasedthe bird aroundthe north end of the boneyard,getting many looks at it in flightand quick looks of it on the groundbetween long periodswhen it wasburied in the vegetation.Or there wouldbe periodsof up to 30 minutesduring which I couldnot refindit at all or wouldleave it alone so that it wouldfilter back into its favoredarea before I wouldflush it again.Managed to take one mediocre[poor] photo of it today.Did not hear it call. A smallish?h ylloscopus, clearly smaller than a typicalArctic Warbler (P. boreal is), butjust slightly longer looking (but slimmer bodied) than a kinglet,with a shorter,finer bill than an Arctic Warbler,with a pale baseto the lower mandible.Crown a gray- green,with the rear crownand upper nape showinga pale (dirtywhitish or grayish white)skinny line--a partialmedian crown stripe. Back and rump a prettyunmarked medium pure greenish,almost a "mossgreen"; the back and rump were the same color,showing no contrast[contra Pallas' Warbler, P. proregulus].Upperside of tail tingedgreenish but duller than rump. Bold straight pale supercilium tinged pale yellow (not strongyellow) and borderedbelow by a thin dark eyeline.Wings showed two

Western 31:57-60, 2000 57 NOTES wingbars,a boldlower bar (formedby tipsto greatercoverts) that waswhitish tinged yellowand a shorterand narrower upper bar that looked whitish. There were distinct broadwhitish edges to thetertials--at least three--repeatedly seen. These edges were accentuatedby the darknessof the tertial feather centers,which were the darkest featherson the wing.Overall the wingwas rather contrasty looking--more so than in the Arctic Warbler--and this effect was visible a number of times even when the bird was in flight.The underpartswere a whitishcolor throughout, perhaps with a faint duskycolor on the sidesof the breast.The legsand feet were a duskycolor of some sortthroughout, not blackand not distinctlypale (i. e., not yellowor fleshy).The bird acted quite nervousat times, and was seen severaltimes to flick its wings,kinglet fashion." Additionaldetails from 24 September:"Bird still present. Many repeatedbrief but goodviews again in far boneyard.Light becamegood at timesas well. TodayI was ableto getsome 20 photosof the bird(Figure 1). Paleyellow of superciliumeasier to seein somelights than in others.Bird seen flicking its wings on numerousoccasions. Incredibly,a Ruby-crownedKinglet (Regulus ½alendula) [casual on the island]ap- peared30-100 feetaway for about5 minutesor so.Overall size of the Yellow-browed Warblerand kingletalmost the same, the Yellow-browedbeing possibly just a tad longer,if any, and bodysleeker, not as pot-belliedas the kinglet(which appeared slightlypuffed up in the 37 øF temperatures).Then, hadstunning views of the warbler in the evening,when it moveda relativelyshort distance to the "circularboneyard." A coupleof fine detailsnow noted:the pale yellowsupercilium pales at the rearmost sectionto an off whiteand appears either to staystraight or to curveupward slightly. And, the flightfeathers (secondaries and baseof primaries)are thinlyedged with dull yellowish,as are the tail feathers." I identifiedthe bird as a Yellow-browedWarbler after my first goodview of it (a minuteor two afterfirst glimpsing it). I hadseen numbers of the speciespreviously in Asia (China, Malaysia),as well as numbersof Hume's Leaf-Warblers(P. huraei) (in China, plussingle individuals in Hollandand Israel)and a singlePallas' Leaf-Warbler in China. Hume'sand Pallas'leaf-warblers are the mostsimilar species, sharing the smallsize and distinctwhite tertial edges.Pallas' is eliminatedby its head pattern (bolderoverall, with a muchmore distinctive median crown stripe) and by itsshowing a contrastingyellowish rump. Hume's is eliminatedby the Gambellbird's brighter and morecontrasty , moss-green upperparts, distinct upper wingbar, pale yellow rather than dull buff supercilium,and very blackishtertials. Hume's was formerly considereda subspeciesof the Yellow~browedbut was recentlysplit as a separate species (see Alstrom and Olsson 1988). Other species of olive wing-barred Phyllos½opusthat breed in northeasternAsia, including the ArcticWarbler, (P. trochiloides),Pale-legged Leaf-Warbler (P. tenellipes),and Eastern CrownedLeaf-Warbler (P. coronatus),are eliminatedby their largersize, details of headpattern, and. especially,by their lackof whiteedges to the tertials(Vaurie 1959, Baker 1997, Mullarneyet al. 1999). The Yellow-browedWarbler has a hugebreeding range in Russia,where it is "one of the commonest Siberian birds" (Dement'ev and Gladkov 1954). It breeds in coniferous,mixed, and low , , and poplar woodlandsfrom the Ural Mountainseast all the wayto the westernAnadyr Basin, the northernSea of Okhotsk, and Ussurilandin eastern , south to Mongolia, northern Manchuria,and (probably)northern Korea. It wintersmostly in southeastAsia, from eastto southeastChina and the Malay Peninsula(Dement'ev and Gladkov 1954, Vaurie 1959, Baker1997). Hume'sLeaf-Warbler has a moresoutherly breeding distribution, in southernand centralAsia east to central China (Dement'evand Gladkov 1954, Vaurie 1959, Baker 1997). The Yellow-browedWarbler has been anticipatedin Alaska(e.g., Balch 1980, R•berson 1988). It is a regularlyoccurring vagrant from Siberia to Britain and

58 NOTES

Figure 1. 's first Yellow-browedWarbler (Phylloscopusinornatus) at Gambell,St. LawrenceIsland. Alaska. 23-24 September1999. Note the pale yellow washto the supercilium,greenish upperparts, grayer green crown. yellowishedgings to the flight feathers,and, especially,the bold white edgesto the blackishtertials. Photo by Paul Lehman

elsewherein westernEurope in the late fall. Cottridgeand Vinicombe(1996) termed it "thecommonest Siberian vagrant to westernEurope," and notedthat an averageof justunder 100 individualsoccur there annually, with at least615 birdsfound in 1985. That thisspecies had not been foundin Alaskauntil now may be at leastpartly the resultof the limitedautumn coverage of the islandsof the BeringSea. Some vagrant species,such as the Middendorff'sGrasshopper-Warbler (Locustella ochotensis) and LittleBunting. are more likelyto occurin Alaskaduring the fall than duringthe spring. The Yellow-browedWarbler may be anotherexample. This recordof the Yellow-browedWarbler has beenaccepted by Alaskaauthorities as the 457th speciesknown to have occurredin that state (D. D. Gibson, in litt., 1 November 1999).

LITERATURE CITED

Alstr6m. P., and Olsson.U. 1988. Taxonomyof Yellow-browedWarblers. Br. Birds 81:656-657. Baker,K. 1997. Warblersof ,Asia. and North Africa. PrincetonUniv. Press, Princeton, N.J. Balch, L. G. 1980. A brief guideto the identificationand statusof Asian speciesin Alaska. Birding 12:12-22. Cottridge, D., and Vinicombe. K. 1996. Rare Birds in Britain and Ireland: A PhotographicRecord. HarperCollins Publishers, London.

59 NOTES

Dement'ev, G. P., and Gladkov, N. A. (eds.). 1954. Birdsof the Soviet Union. Vol. VI. 1968 translationby IsraelProgram for ScientificTranslations, Jerusalem. Fay, F. H., and Cade, T. J. 1959. An ecologicalanalysis of the avifaunaof St. Lawrence Island,Alaska. Univ. Calif. Publ. Zool. 63:73-150. Mullarney,K., Svensson,L., Zetterstr6m,D., and Grant, P. J. 1999. CollinsBird Guide. HarperCollins,London. Roberson,D. 1988. The ten most likelyadditions to the ABA Checklist.Birding 20:353-363. Sealy,S. G., Bedard,J., Udvardy,M.D. E, and Fay, F. H. 1971. New recordsand zoogeographicnotes on the birdsof St. LawrenceIsland, Bering Sea. Condor 73:322-336. Vaurie, C. 1959. The Birds of the Palearctic Fauna: Passeriformes.H. F. & G. Witherby,London.

Accepted 10 December 1999

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