advocatedan appreciationof the KennKaufman commonbirds. Belatedly, and a bit sheepishly,I took some time to study THEPRACTICED EYE andsketch these abundant gulls. 7•xtand Illustrations byKenn Kaufman What wasironic about my previ- ousneglect of themwas that I had spentmany an hour looking for this very species--inNorth America, where it is an uncommon visitor in most areas.Back in North America, I hadcombed through flocks of Bona- Identif-yingtheCommon parte'sGulls, ignoringthe Bona- parte'sthemselves while hoping for a Black-headedGull Black-headed.So it oftengoes with birders,seduced by the lure of rarity, failingto takenote of thewonderful birdsthat happen to becommon. Over most of North America, the Common Black-headedGull (Larus ridibundus)is definitelynot a com- ...I think of the companies other words, I had failed to heed the monbird. As a stragglerfrom Europe, influenceof thegreat scholar-natu- it was first recordedin •93o at that of black-headedgulls ralistLouis Halle, who had always remarkablegull-watching center of that flow overthe housetops of Geneva,dipping and risingtogether, their wings movingto the rhythm of a dance.By comparison, the spectacleof the ballet-dancers at the Grand Theatreof Geneva, tryingto take off like birds, is awkwardand pitiful.

--Louis J. Halle, from TheAppreciation of Birds

NOT LONG AGO I SPENT A MONTH watchingbirds at Beidaihe,on the coast of China. One of the most nu- merous birds there was the Common Black-headedGull. Almost every day I wouldsearch through the flocks of Black-headeds,looking for theodd raritylike RelictGull or Saunders'sFigure 1. AdultBonaparte's and Common Black-headed Gulls in summer. Which one is the Black- Gull. But after some two weeks, I headedGull? The one with the brownhead (upper r'•oht). It wasnamed by the Britishin a simplerera, realized that I had not even looked at whenthey had to consideronly that this was the one gull in Britainthat did not have a whitehead in summer--andnever mind the fact that various other gulls around the worldreally do have blackish the Black-headed Gulls themselves-- heads,like the Bonaparte's Gull (lower left). Either species will look like it hasa Mackhead at a distance,but the shape of the dark hood is consistently different, with the white extending up to the I hadlooked through them, in a sense, rearedge of the crown on Black-keaded Gull. Bill color also differs; but on some Common Black- whilelooking through the flocks. In headedsin summer,the billis such a darkred that it looksMack at a distance.

1156. American Birds, Winter 1993 Figure2. Adultgulls in Basic (winter) plumage, toshow flight pattern. Left: Common Black-headed Gull. Right: Bonaparte's Gull. The difference inunder- wingpatterns isobvious with any reasonably good view, as the dark inner primaries ofthe Black-headed stand out in contrast to the rest of the wing and the restof the bird, while Bonaparte's looks very white-winged below. However, the appearance ofthe upperside ofthe birds is also different, inmore subtle ways.The gray of the upperparts isa shadepaler on Black-headed than on Bonaparte's, making a little less contrast to the white triangle on the outer edge ofthe wing. The slightly darker gray of the Bonaparte's extends forward farther onto the nape, helping to emphasize itssmaller-headed proportions. Newburyport,Massachusetts. In re- The Common Black-headed Gull headedis a bit morestocky, with centyears it hasbeen found breeding isdistinctly larger than Bonaparte's slightly wider wings. It usuallylooks verylocally in Newfoundlandand Gull,perhaps halfway between Bona- longer-necked,and when standing it NewEngland, and it becomesrather parte'sand Ring-billed(L. dela- lookslonger-legged. Flight behavior numerous in winter around the har- warensis).(It is thus only slightly differs as well. A Black-headed in bor in Halifax, Nova Scotia. Still, smallerthan Laughing Gull [L. atri- flightlooks like a scaled-downver- most North American birders can cilla],although the heavybill and sionof a medium-sizedgull, such as regardthe Black-headed Gull as a rar- Ring-billed.Bonaparte's has more ity, somethingto be underlinedin delicateand fluttery wingbeats, some- ourdaily notes. timessuggesting a tern more than a In itshabitat preference and gen- As withother dark- gull. eral behavior, the Common Black- hoodedgulls, these There are two main elements of headedis more like Bonaparte's Gull patternthat adults of thetwo species (L. philadelphia)than any other two turn mostlywhite- have in common: both wear dark North Americanspecies, and stray headed in winter. hoods in summer, and both have a Black-hcadeds are most often found narrowwhite triangle along the ltead - associatingwith flocks of Bonaparte's. ingouter edge of each wing. (Other- ThisPracticed Eye compares these two longerlegs of LaughingGull can wisethey merely look like most other smalland beautiful gulls. makea lone individual of thatspecies gullsin theworld, white below, gray Bonaparte'sand Common Black- seemlarger than it reallyis.) There- above,with white tails.) The dark headedgulls are often discussed asif fore, with a careful scan, a Black- summer hood of the "Black-headed" theywere very similar, differing in headedcan be pickedout amonga is actuallydark brown (although it onlya fewfield marks. Actually, they flockof Bonaparte'sbysize alone. looksblackish at a distance),and it differin manyways. The moreyou Becauseflying birds are molded, in does not cover the entire head: The know about their distinguishingan evolutionary sense, by the laws of whiteof thenape extends all the way marks,or thebetter you know your aerodynamics,notwo birds of differ- upto the rear edge of the crown. The localBonaparte's Gulls, the easier it ent sizescan ever have exactly the hood of Bonaparte'sin summeris will befor you to spota strayBlack- sameshape. In additionto being dark charcoal-gray,looking deep headed. largerthan Bonaparte's, the Black- blackat a distance.It extendsslightly

Volume 47, Number 5-1157 Figure3. FirstBasic plumage (first-winter plumage) of Bonaparte'sGull (left) and Common Black-headed Gull (right). Both species at thisstage show more complexityof patternthan adults. The diagonal bar across the wing, or "carpalbar," is usuallybrowner and less contrasty on Black-beaded Gull, and that speciesmore often seems to retaintracesof warm brown elsewhere on the plumage.Bonaparte's generally looks neater or cleaneron the wings, lacking all the smearygray on the innerprimaries shown by Black-beaded, although It basmore black marking to breakup the whitein the areaof the outerprimary coverts.The base of the billon young Black-beaded is oftenpink, as shown, but sometimes it maybe yellowish-pink or justdull yellow. fartherdown the nape than on Black- gullshave this mark (although it is headed, and because the neck is sharedby some species elsewhere in shorter,the hood seemsto coverthe Bird e rs seekingthe world). On theBonaparte's Gull, headmuch more thoroughly. The Black-headeds in thiswhite triangle is strikingly obvi- differencein headpattern on sum- ousat any distance. It is usually obvi- meradults can be seen from a surpris- winter (the most likely ous on the Black-headedas well; but ing distanceon standingor swim- season to find them onthat species the gray of theupper- mingbirds. partsis slightly paler, so the contrast Aswith otherdark-hooded gulls, in most areas) have to isa bitless. Especially in glaringsun- thesetwo turn mostly white-headed light,I sometimesfind that distant in winter.Each shows a blackishspot deal with onlytwo Black-headedssimply look very pale behindthe eye, centered on theear- possiblepatterns per grayabove, with the white wing tri- coverts.On Bonaparte's,the gray of anglewashed into obscurity.How- the upper back extendsforward species,the first- ever,no amount of glare can wash out somewhatonto the nape. On Com- winter (or First Basic) theunderwing pattern. The black on mon Black-headed, however, the theunderside of theinner primaries napeis white, and shades gradually plumageand adult is alwaysobvious on Common into the palergray back. This very winter (or Definitive Black-headedGull, contrasting with whiteneck area may help to empha- thepaleness of therest of thewing. sizethe large-headed or long-necked Basic) plumage. Bonaparte'sGull alwayslooks very look o f Black-headed Gull. whiteon the underwing, with a con- On the uppersideof the wing, mariesand primary covertsand trastingnarrow black trailing edge. bothspecies show a triangle or wedge extendingas a n•trrowpoint to the Whilelarger gulls may take three of white, coveringthe outer pri- wrist. No other North American or fouryears to reachadult plumage,

1158- AmericanBirds, Winter 1993 Figure4. Gullsoverhead, i. First Basic (first-wi.ter) plumage. Left: Commo. Black-headed Gull.The white that shows through o.the outer primaries is evenless exte.sive than o. theadults. At a gla.ceor at somea.gles, the bird may simply look dark-wiuged from below. Right: Bo.aparte's Gull. The underwi.gis largely white, bordered by a neatblack or duskytraili.g edge. thesetwo small species are essentially more extensive dark gray on the inner underwing,with a narrowdark trail- all adult-likeafter only a yearand a primariesand secondaries, creating ingedge. The young Black-headed half. Therefore,birders seeking anoverall effect that is quite different haseven more dark marking on the Black-headedsin winter (the most (seeFigure 3)- underwingthan the adult; in fact,the likelyseason to find themin most narrowwhite triangle on the outer- areas)have to dealwith only two pos- mostprimaries may be hardto see siblepatterns per species, the first- Althoughit will from below on some birds, so that winter(or FirstBasic) plumage and theysuggest anything but a Bona- adult winter (or Definitive Basic) helpto studypictures parte's. plumage. such as the ones in this Althoughit willhelp to studypic- First-winterBonaparte's and tures such asthe ones in this article, Black-headedgulls differ from adults article, the bestway to thebest way to preparefor recogniz- in a numberof thesame ways. Each preparefor recognizing ingthe Common Black-headed Gull hasa narrowblack band at thetip of is to studyBonaparte's Gull when- thetail, and more black surrounding the Common Black- ever you have the opportunity. the white in the outerpart of the headedGull is to study Familiaritywith the common birds is wing.Each has a diagonaldark bar the hallmarkof the experienced ("carpalbar") across the wing coverts. Bonaparte'sGull birder.Besides, Bonaparte's Gull is a However,this bar isblacker and more wheneveryou havethe beautifulbird in its ownright, and stronglycontrasted on Bonaparte's wellworth getting to know.If our Gull; and this,combined with a nar- opportunity. searchfor a rarityamong the flocks rowerblack trailing edge on the flight leadsus to appreciateour local Bona- feathers,helps to giveBonaparte's a Seenoverhead, first-winter Bona- parte'sGulls a littlemore, so much neateror cleaner appearance overall. parte'sand Black-headed gulls are the better. Common Black-headed Gull has a easily distinguished.The young palerand browner carpal bar, and Bonaparte'sis verywhite on the

Volume 47, Number 5' 1159