Multiple Occurrences of Dark-Bellied Brant (<I>Branta [Bernicla] Bernicla

Multiple Occurrences of Dark-Bellied Brant (<I>Branta [Bernicla] Bernicla

ABSTRACT rate species,using the North American P.A. Buckley The firsttwo North American sight records name "BlackBrant," but eventuallythey [or Branta bernida bernida (known in tooadopted the A.O.U.'s view of onlya sin- U.S.G.S.--PatuxentWildlife Europe as "Dark-bellied Brent Goose"), gle Holarcticspecies of brant. fromNew Yorkand Virginia, and the first With the recentpopularity of the so- ResearchCenter two North Americanspecimens, from New called"Phylogenetic Species Concept" (or Jerseyand Canada,are recorded.The two "PSC";cf. McKitrick and Zmk 1988) advo- Box8 atGraduate School ofOceanography field observations were made in the winter cated strongly by a number of Dutch of 1999-2000, whereas the skins date to researchersand impelled by the increasing UniversityofRhode Island 1846 and 1907, respectively.Recent addi- recognitionof populationsdeemed "diag- tional reports are also at hand from nosable"by moleculartechniques (espe- Bathurst Island (Canada) and Massachu- Narragansett,Rhode Island 02881 cially usingmitochondrial [mt] DNA), a setts; the taxon has occurred at least once split of the brant into three specieshas in Greenland and is now annual in increas- been proposed:Pale-bellied Brent Goose (eraall:[email protected] ing numbers in Iceland,with mostindivid- (B. hrota), Dark-bellied Brent Goose (B. uals there found in flocks of westward- bernicla),and Black Brant (sic: B. nigricans; [email protected]) migrating hrota. It seemslikely that nomi- Sangsteret al. 1997). nate bernida has been overlooked in North Not yet readyto acceptthe PSC unre- Americafor sometime, at least in part servedlyat this stageof development,the S.S. Mitra owing to poor informationon its separa- BritishOrnithologists' Union (B.O.U.) and tion from other brant taxa, especiallyin the A.¸.U. have retained the traditional DepartmentofBiology first-winterplumages. With recentorder- approachto definingspecies known as the of-magnitudeincreases in the European BiologicalSpecies Concept (or "BSC"). population,its occurrencein North Amer- Historically,application of the BSC has CUNY-CollegeofStaten Island ica is likelyto becomemore frequent. involvedthe recognitionof geographical subspecms,most of whichare almost auto- 2800Victory Boulevard INTRODUCTION maticallyelevated to speciesunder •hc The taxonomyof the variousbrant/brent PSC.Although we generallyagree with use StatenIsland, New York 10314 geese(hereafter "brant," the North Ameri- of the BSCin aviantaxonomy, and while canname for thisgroup of geese)has had somerecent biological work on the world's (email:[email protected]) a checkered history and is still in flux. The brant populationsis beginningto suggest AmericanOrnithologists' Union's (A.¸.U.) that there are actuallyseveral biological Check-listof NorthAmerican Birds through speciesof brant,this is not the place[or its fifth edition (1957) treated the two such a discussion. EdwardS. Brinkley North Americanforms nig•icans and hrota The fifth edition of the A.O.U.'s Check- as separate species ("Black Brant" and list, the last to treatsubspecies in detail, 9 RandolphAvenue "Brant,"respectively), but by the sixthedi- recordedonly hrota and nigricansfrom tion (1983) all the world's brant were North America;no subsequentreviews ot CapeCharles, Virginia 23310 lumped in a singlespecies, Brant Branta brantin NorthAmerica (e.g., Palmer 1976; bernicla.Europeans had generally applied Reedet al. 1998) havechanged that status. (eraall:[email protected]) separate names to their two commonand With thesinking of BlackBrant as a sep- readilyidentifiable taxa of "BrentGoose": aratespecies by theA.O.U., interest in field nominate bernicla ("dark-bellied form") identificationof the variousbrant "types" and hrota ("pale-bellied form"). They waned in North America, although it sometimesrecognized ragricans as a sepa- remainedstrong in Europe.This un[ortu- 180 NORTH AMERICAN BIRDS natelyled to a dropin reportsof extralim•- tal hrota on the West Coast south to Cali- fornia and Black Brant in eastern North America(both groups had previously been trackedreasonably well), and to an almost completelack of interestin (or evenaware- nessof) the European"dark-bellied" form (nominatebernicla). Most Europeanfield guides(e.g., Peterson et al. 1954) did not depict its variousage classesor expend much efforton separatingit from the rest of the world's brant until Millingtong (1997) paperand Mullarney et al.'s(1999) fine guide. Consequently,few in North Americawere looking for it or expectingit. In January1986, at JacobRiis Park in Queens,New York City. New York, PAB founda darkadult brain feedingon a golf course with several thousand hrota. It was strikinglydifferent from them but wasalso clearlynot nigricans. Reference to theavail- able but identification-weak literature (especmllyDelacour and Scott 1954) Figure1. Ventral views of adult nominate bernida (Oark-bellied) Brant, from left to right as follows: unsexed, stronglysuggested nominate bernicla, but August1907, Carey Islands, Oavis Straits, Nunavut, Canada (MCZ 576365); female, 9February 1922, UK (AMNH 730855); the bird could not be photographedand female,18 March 1847, Egg Harbor, New Jersey (AMNH 45893); and female, 10 March 191 O, Tring, United Kingdom wasnever relocated; PAB eventually left it AMNH730861). Photograph byP. A. Buckley. formallyunidentified. At the time,this was the first hint that berniclamight be occur- observersthought it mightbe a first-winter whichit wasobscured by the water. ring in North America. nigricans. This bird was strikinglydifferent from Especiallyat a distance,it lookeduni- everyhrota there, and while therewere not RECENTNORTH AMERICAN formlybrownish-gray Its smokyhue and verymany young (perhaps 50 in a flockof BERNICLAOBSERVATIONS uniformlydark flanks renderedit unique 500), all showedpaler and brownerbacks In the late fall and winter of 1999-2000, within its hrota flock. [I was slightly with moreextensive white featheredging, two different sets of observers, in Nassau smallerthan the accompanyinghrota, with distinctbreast/belly color differences obvi- County,Long Island, New York and at thesame neck and body proportions and a ous to the unaided eye, and prominent Cape Charles,Northampton County, Vir- faint trace of a broken neck-ring,visible white crescentson theirflanks. Apar! from ginia, each found oddly plumagedbrant only through telescopes.Compared to appearingsmaller, the bird showedno (First Basic I=HY] in New York, adult accompanyinghrota, it wasslightly darker striking differencesin shape,posture, or [=ASY] in Virginia) that after some and grayer dorsally and considerably carriage.[After thiswas written, composite research wcrc identified as nominate berni- darkerand browner ventrally goodmatches to the NewYork first-winter cla. At the time, we believedthese repre- Thus, the contrastbetween the back and bird were depictedin BirdingWorld 13:3 sentedthe first firm reportsof this taxon the flankswas much lessstriking than in (2000) on twobernicla: one immediately to from North America_ any first-winterhrota in the same flock, the left (even thoughdepicting four rows with onlya barelyperceptible difference in of whiteedging) and one to theright (three ß NEW YORK--The first was found by hnebetween the two areas.This impression rowsof white edging)of the Red-breasted PABand SSM at Zach'sBay, Jones Beach of uniformitywas reinforcedby the com- Goose (Branta ruficollis).In turn, body StatePark, NassauCounty, Long Island, plete absenceof light spotting on the color and tone arc well matchedby an New York on 23 November 1999. It was scapularsand of white crescentson the adult in BirdingWorld 10:14 (Plate 8) only seenswimming but was studiedfor flanks.A few younghrota in the flockdid 1997.1 15+ minutes as close as 75-100 m. havesomewhat dark (juvenal)flanks, but PABand SSM were unable to photograph Detectedindependently by eachobserver, each without exceptionshowed at least it but at the time were not overly con- it waseasily relocated several times with- somedistinctly contrasting and easily visi- cerned,as a brantflock was usually in this out opticsand studiedthrough telescopes ble vertical white crescents. The blackish locationon highertides. Unfortunately, it underdiffnsely overcast sky with mid-day headand upper breast showed a discernible wasnot appreciatedthen that manydiffer- side-lighting.Field notes taken at the time changeto the lighter colorationof the ent. small subsets of the 10,000+ brant by the observerswere later expanded. [I lowerbreast and belly, but unlikethe con- wintering in adjacentsaltmarshes were wasimmediately picked out with binocu- ditionin adjacenthrota, this hne wasnot periodreallycoming into Zachg Bay to larswhile on the wateras a curiously"all- obviousto theunaided eye. Unlike virtually preenand rest.Despite intensive searching darkHY brant"whose juvenal dorsal white all nigricans,though, the line waseasily vis- by manypeople, this HY berniclawas never markingswere restricted to only two ible throughscopes. The belly (seenwell relocated,so il may have still been on covert bars and whose flanks were devoid once, when the bird reared back and southwardmigratmn. of white markings of any kind. Even flapped)was uniformly dark and concolor- thoughan HY bird, it did not associate ouswith theflanks, the darkness extending ß VIRGINIA---On 22 March 2000 from with any adult hrota. At the time, the at least to the mid/lowerbelly, beyond 1730-1745, ESBstudied an adult bernicla VOLUME 58 (2004) NUMBER 2 181 sally,never smoky grayish brown_ Lastly, nigricansis

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