BEHAVIOR

An appreciation of

Olin Sewall Pettingill, Jr.

MagellanicOystercatcher. Photo/O. S. Pettingill.Jr. BlackishOystercatcher. PhotolO. S. Pettingill, Jr

YSTERCATCHERSare big, robust, Oystercatchersare so distinct from Mage!lanicOystercatcher (H. !eucopo- boldly markedshorebirds that inhab- othershorebirds that ornithologistshave dus, southern South America and the it long stretchesof the world's oceanic placedthem in a family by themselves; Falkland Islands). The other three are coasts.They are black and white or black and becausethey are so much alike blackor brownishblack: the Black Oys- all over. Their bills are twice the length throughouttheir worldwiderange, orni- tercatcher (H. bachmani, western North of theirheads, and red. Uponsuch pow- thologistshave groupedthem in the sin- America and the Aleutian Islands); the erful and wonderfullydesigned bills do gle Haematopus. Within their Sooty (H. fuliginosus, the lives of oystercatchersdepend. range,however, oystercatchers differ re- Australia and New Zealand); and the Viewedfrom abovethe oystercatcher gionally in coloration and habitat selec- BlackishOystercatcher (H. ater, south- bill is sharplytipped, but viewed from the tion in sucha way that ornithologists ern South America and the Falkland Is- side, the bill tip is squaredoff; thusthe havebeen confounded as to how many lands).In all the speciesthe sexeslook bill is like an oysterknife,suited to open- speciesthere are. alike. ing bivalvemo!lusks-•, , Without reviewing here the lines of Along the Atlantic coast of North andclams--or like a wedge,for prying scientificreasoning and conflicting opin- America as well as in Iceland and New off rocky surfaces. Since the ions, I will state categoricallythat the ZealandI have watchedoystercatchers mandiblesare of equal length, meeting consensusamong most American and occasionally,but neverfor any lengthof firmly at their tips, the bill can pick up Britishornithologists is that thereare six time. So often they were shy and flew foodfrom any flat surface.Furthermore, species.Three are conspicuouslyblack fartheraway whenever I attempted to get thebill, longas it is andrelatively inflexi- and white: the AmericanOystercatcher near them. It was only in the Falkland ble, can probedeeply into sandor soft (Haematopuspalliatus, southeasternand Islandsthat I really becameacquainted soil for wormsand insects.Quite apart southwesternNorth America, the Carib- with oystercatchers. from its capabilitiesfor securinga wide bean, and northern South America); the This archipelagoin the SouthAtlantic, varietyof food, the bill is alsoa formida- EurasianOystercatcher (H. ostralegus, 300 milesnortheast of thesouthern tip of ble weaponfor discouragingpotential Eurasiaincluding Iceland, southernAfri- South America, has two oystercatcher predatorsby painfuljabs. ca, Australia, and New Zealand); and the species,the Magellanicand the Blackish.

Volume 39, Number I 3 Both speciesalso inhabitthe coastsof Unlikethe MageilanicOystercatchers, queee, weee, weee, wee, we. When two southern South America. For six months the Blackishfed almostentirely on mol- or morebirds together gave the series, the in the late springand summer of 1953- lusks that they found in abundanceon resultwas a remarkablemedley. Each 1954 and again for five month,in the rocksand ledgesbetween high and low . when utteringthe seriesin flight, same austrai seasonsof 1971-1972, my tidelines.Occasionally they flew beyond alternatedmoments of flappingits wings wife Eleanor and 1 were in the Falklands sightof theirhome shores to musselbeds. more slowly. butterfly-like with mo- for b•rd studyand photography.During also frequentedby Mageilanics. When mentsof settingits wingsand gliding. the latter stay we were accompaniedby both specieswere presentat the same My appreciationof each of the two Maurice A. E. Rumboil, my assistant. time--not uncommonly--I never saw Falkland oystercatcherswas attained in Inevitablywe gave both speciesconsid- anyevidence of hostility,but rathertotal separate stages. erable attention, as they were equally disregardof one another. MAGELLANIC OYSTERCATCHERS common, and. becausethey were insu- Boththe Magellanicand Blackishoys- lar, non-migratorybirds more or lessiso- tercatcherswere noisy. The most com- YFroST opportunity towatch these latedin an areawith a sparsehuman pop- moncall of the Mageilanicwas a piping strikinglyhandsome shorebirds for ulation and not subjectto predationby kleee-eeeee,loud and piercingwith a ris- any lengthof time was on December landmammals, they were muchless shy- ing inflection, uttered when flying or 1953, at CarcassIsland. Here, only a --hence more approachable--thanany standing.The call had great carrying shortdistance away on a beach,two for- oystercatchersI had observed elsewhere. power;we could hear it despitewind and agingMageilanics were suddenlyjoined The Mageilanic Oystercatcherswere surf.Among a varietyof othercalls was a by twoothers flying in from afar. At once mostlyresidents of the extensivesandy prolonged,plaintive I,ee-kee-kee-kee of- all fourbegan piping loudly as they drew beachesalong the two big islands, East ten given in flight, somtimesbutterfly- closertogether. What followeddefies co- Falkland and West Falkland, and some of like. Many timesour attentionwas drawn herentdescription. They quick-stepped the largeroutlying islands. The Blackish to a flock of several by hearing forward one beside another and occasion- Oystercatchers,on the other hand, re- themas they passedfar out from shore. allybobbed -like; they stopped and sided along the many rocky shores The most common vocalization of the faced one another, then turned away, throughoutthe archipelago.Thus, in an Blackish.given when flying or standing, sometimescompletely around to faceone ecologicalsense, the two specieswere was a piping quee-ee, clear and ascend- anotheragain. All this they did with separated,each occupying its own niche. ing but shorterand lesspiercing than the shouldershumped, necks arched, heads Although both specieswere equally Mageilanic's.An additionalvocalization occasionallyjerked up but bills always common,I first thoughtthat the Magei- that I never heard from the Mageilanic pointedstraight down, primariesslightly !anic was more numerous,chiefly be- was a series of loud, ringing, musical lowered,and tails lifted straightup, un- causeat the outsetwe spentmore time on sounds,ascending in a rapid, trill-like fanned. yet clearly showingthe white beacheswhere it wasconspicuous by vir- purrrrrr. followedby high-pitchedqueee basalportions. The entire performance, tue of its black and white plumageand notes. then by slower and descending accompaniedthroughout by pipingcalls orange-redbill. But later. aswe explored •'eee notes that gradually faded from that were variouslysharp, high-pitched. the shoresof rocky headlandsand many hearing. The sequencewas roughly: and discordant, was over in a minute or of the smallerislands with shoreslargely purrrrrr queee, queee, queee, queee, so. The visitingpair movedaway, then of rock, I soon realized that the Blackish Oystercatcherwas probably as numer- ous. My early misconceptionwas due to the bird's uniformly brownish black plumage,which blendedso effectively with thegrayish black rock strata,ledges, and bouldersthat a bird could be easily overlookedunless it moved or unlessby chanceI caughtsight of its scarletbill and stout, pinkishwhite Cuntanned") legs. Mageilanic Oystercatcherssought a w•devariety of foods.On the beachesat ebbingtide they probedfor sandworms andpicked up strandedjellyfish. If there were exposedrocky reefs, they foraged for musselsand limpets. Farther up on the beaches,beyond the normal tides. theyflipped over pebbles and small heaps of washed-upkelp and seaweed to uncov- er and catch whatever insects and crusta- ceansthere might bc underneath.Some- times they moved inland from the beachesto low, grassy wet areas near streams,where they probed, presumably for . BlackishOystercatcher opening still attached to rock.PhotolO. S. PettingillJr.

4 AmericanBirds, Spring 1985 returned,and all four repeatedthe com- plex d•splay. Again the pair moved away, againthe pair returned,and so on for six separateperformances that were essentiallythe same. Not once did one bird chase another or show the least incli- nationto attack.After the last perform- ance,the visitingpair simplytook off in the direction l¾om whence they had come. I realizedthat I hadwitnessed the "pip- ing ceremony"that Europeanornitholo- gists have frequentlyobserved in their native EurasianOystercatcher and have describedin their publicationswhile ad- vancingtheir ideasof its function. I had neverseen any suchperformance in our AmericanOystercatcher. Again later in January,I watchedMa- gellanicspiping, this time when they were in smallgroups on a beachat New Island.Piping in eachcase was triggered MagellanicOystercatchers performing piping ceremony. Photo/O. S. Pettingill,Jr. as more Magellanicsjoined them. Both the arrivalsand the birdsalready present pipedloudly with billsdown and tails up; a close acquaintancewith Magellanics. the ground(displacement feeding), dab- therewas little moving or turningabout. Within easywalking distance of the little bingat the feathers(displacement preen- In a minuteor so the performancewas farm settlement were two nests about 50 ing), and then standingat intervalswith over. The newcomersstayed, apparently feet aparton a grassyflat ("sheeppas- bills slippedunder the shoulderfeathers acceptedin the group. ture")roughly 100-150 feet from a sandy but eyes kept open "shamsleeping," After we returned to the Falklands in beach.Both nests, without lining, were notedin the EurasianOystercatcher and 1971,Eleanor found our first Magellanic in shallow, grassy depressionsin the so called by K. Williamson (1953). As neston December3. High up on Volun- middle of moundshigh enoughto give soonas I withdrewfrom the nestingarea, teer Beach, it was a mere scrapein the the birds sittingon them a wide view in the same birds (or so I assumed)that had sandwith oneegg betweenhummocks of all directions. One nest contained two beenon the nests when I arrivedpromptly old kelp roots washedup from the sea. that hatchedon January 5 and 6, returned to the nests, and the other two The occupantpair, greatly disturbed. respectively;the other held one that left for the beach before I was out of took to the air and circled her in a slow, hatchedon January 15. sight. butterfly-likeflight, piping loudly and When I approachedthe two nestson The reactionsof the birds to my visits rapidly. January3, the birdson them, seeingme in the next two days were similar. The On December 7, Alan Miller drove El- coming,stepped off and walked slowly sittingbirds startedwalking toward me eanorin hisLand-Rover the full lengthof toward me. As I drew nearer, the birds andbegan to pipe, bringing their partners PalomaBeach, passing the territoriesof steppedaside and began piping, bringing up from the beach,whereupon a piping 15 pairsof protestingMagellanics in the up from the beach two more - ceremonyinvolving all four ensued.On course of two and a half miles. Presum- catchers,probably their mates. Then, one occasion a fifth bird flew in from ablytheir nests, like the oneat Volunteer seemingto •gnoreme, all four came to- somewhereand joined the ceremony Beach,were far up on the beach.While getherfacing one another and joined in a briefly. Miller and Eleanor took the drive, I seriesof pipingceremonies such as I had By January6, one of the chicks from stayedwith the first pairthey had encoun- seen years before at Carcass Island. the nestwith two eggswas high up on tered.Both birds walked up to within 20 WhenI movedup to one of the nestsand the beach in the care of both parents. feet of me and proceededto posturere- bent over to examine it, two of the birds Whateverhappened to the other chick, 1 peatedly,bills down, tails up, and pip- instantlybroke away from the ceremo- neverknew. At my approachthe chick ing. When I stoppedand stoodmotion- nies and hurried toward me within a few crouchedmotionless under a leafy plant less,they ceasedposturing and piping; feet, veeredaround me in a slouching while the parentsshowed their concern insteadthey walkedcalmly aroundme in gait, shouldershumped, bills directed with pipingand displacementbehaviors. wide circles, meanwhiletouching the down, and tails up. Now and then they From a distance, when the tide was sandwith their bill tipsas though picking stoppedand crouched(displacement in- low, I watchedthe parentsforaging for upfood--an example of whatethologists cubating)while lifting and lowering their sandworms.Their technique was not a wouldcall displacementfeeding. After a unfannedtails. All thiswas accompanied matterof randomprobing in thesand, but shortwhile they becameaccustomed to by a low, somewhatmuffled purring, but wasrather to locatethe "breathingholes" my motionlesspresence and did nothing therewas no piping. Their behaviorsug- of the sandwormsand then poke into but stand and watch me. gestedinjury-feigning. While I stayed them, sometimes with success, some- At New Islandfrom January3 through near the nest, injury-feigningwas soon timesnot. If a parentwas successful,it January18 1 hadan idealopportunity for replacedby other behaviors--pecking carriedits quarryto the chick, which ac-

Volume 39, Number 1 5 In orderto cut out and devourthe fleshy parts,each bird first priedthe limpetsoff by wedgingthe bill betweenthe ledge and the shells,then lifting them off and turningthem over. For sundryreasons we were distracted from further observationson the nesting pair at OystercatcherRock (our namefor the site)until our thirdperiod on Kidney Island in late February.One chick had survived;it waspractically full grown, in juvenal plumagewith a yellowish pink, nearly full-length bill. Neverthelessit wasstill dependenton its parents,which continueddiligent in obtaininga suffi- cientsupply of mollusksfrom the mussel x bedbelow. Once we thoughtthat the par- ents would be unable to reach the mussel bed when, for four days in succession, KidneyIsland was battered by winds that attainedgale force, keepingthe sea well Mage!!anicOystercatcher chick freezing. Photo/O. S. Pettingill, Jr. abovethe normalhigh tide line and the mussel bed inundated. But that did not discouragethe parents. Out to the bed ceptedit with gustounless already well tions did we hear them that I soon be- they went, first wading, finally swim- fed. lieved BlackishOystercatchers to be as ming. Once over the bed they plunged Both parentswere alert to other bird activeat night as duringthe day. deeply,just about disappearing;and up species,especially ones their sizeor larg- On November4, 1953, at the begin- theycame with mussels,which they car- er, that came close to their beach area. ningof ourfirst periodon KidneyIsland, ried back to the ledge before extracting They drove away Black-crownedNight- my wife andI founda nestwith two eggs the contents. Herons (Nycticorax nycticorax) that on pebblesin a wide crevicein the top of When I returnedto Kidney Island with stoppedto stalk food at the water'sedge a broad ledge well above the tide. The Maurice Rumboll for the two periods, I and noisily pursuedKelp Gulls (Larus eggslooked fresh but they were cold. The vowednot to be distractedfrom watching dominicanus)and Great Skuas (Catbar- pair to whichthey belonged were 20 feet the BlackishOystercatchers as my wife acta skua) passingoverhead or just off- from us. They pipeda few times, moved and 1 had been in 1953-1954. shore.One parentactually flew up under about casually, or simply stood and Before Maurice and I had left for the a passingskua and delivereda jab effec- lookedat us. Obviouslythey had not got- firstperiod in November,Stuart Booth, a tive enoughto make the big bird flinch ten down to the businessof incubating longtimeresident in the Falklands'cap- and changecourse. their eggs. ital and an accomplishedbird watcher, The ledgewith the nestsloped down told us abouthis annualvisits to Kidney BLACKISH OYSTERCATCHERS and into the sea and was encrusted be- Islandduring the breedingseason and of tween the tidelines with mussels and lim- how he alwaysfound a pair of Blackish IDNEYISLAND, its 80 acresmainly petsupon which the pair fed commonly. Oystercatchersnesting high up on a par- covered with tussock grass, was We watchedthem foraging. They chose ticular ledge. From his description,the rimmed, exceptfor a small beach, by to feed on the mussels that were still un- ledgehad to be "our"Oystercatcher Rock ledgesthat providednesting habitat for der water with their two shells not entire- of 1953-1954. severalpairs of BlackishOystercatchers. ly closed.Each bird's techniquewas to Sure enough, it was! On November Thanksto a hut high on the island, my insertthe bill betweenthe shells,opening 12, Maurice and I found the nest. There wife andI wereable to staythere for three them wider after severingthe muscles wasone egg in virtuallythe samespot as differentperiods in 1953-1954and Mau- thatheld the shellstogether, then remov- theone we hadvisited ! 8 yearsbefore. A rice Rumboll and I for two periodsin ing and swallowingthe soft contents.In pair of oystercatcherswas in attendance; 1971-1972. Thus we lived close to the someinstances, rather than performing they were near the nestand beganquee- oystercatchersaround the clock. thewhole operation while the mussel was eepingin protestas we approached.The However obscure Blackish Oyster- still attachedto the ledge,the bird insert• eggwas cold. While I examinedit, one of catchersmay be in their environment, ed the bill betweenthe shellsand, grip- the pair walkedup to within threefeet of they made up for it with vocalizations, ping the contentswithin, tore the mussel me. The otherbird, a little fartheraway, especiallywhen flying. Not only during loose and carried it out of the water. tucked its bill under its shoulder feathers the day but at night, whetherit wascalm Whenfeeding on limpets,whose single, --sham sleepingwith eyeswide open. or moonlit, windy or stormy, we could tent-shapedshells were firmly clamped The nest,I mustmention, was so high hear them from our hut as they passed on theledge by a musclethat resembled a up on OystercatcherRock and down in a below us over the water. So frequently suctioncup, the pair usually chosethe creviceas to preventthe sittingbird from and under such varying weathercondi- timewhen the limpetswere above water. viewing the shore from which we ap-

6 American Birds, Spring 1985 proached.But neverdid we catchthe bird unawareof our coming, for its mate was always, it seemed,on a nearbyvantage, ready to give warning. Such was the case on November 15 when I climbed OystercatcherRock. l was "pipedaboard" by the oystercatcher on watch, and this instantlybrought its mate up from the nestingcrevice. Both birds first walked toward me, then turned aside.There were now two eggsand they were warm. Maurice had reportedonly one egg the day before. Incubationwas obviouslyunder way and with it a change in the pair's behavior. One crouched three feet from me, droopedits primar- ies, then movedaway in a slouch,while its partnerstrode back and forth farther away, now and then poking its bill into ledge cracks. Returningto Kidney Island on Febru- ary 12, we fully expecteda family with Pair of Blackish Ovstercatcherspiping. Photo/O. S. Pettingill, Jr. full grownyoung on OystercatcherRock. To our astonishment there were two adultswith two downy young not older small area, for it was strewnwith empty THE FALKLAND OYSTER- than 10 days! The first set of eggs must mollusk shells. Sometimes when one CATCHERS IN RETROSPECT havebeen destroyed and the chickspres- parentforaged, the chicksought warmth IKENEARLY ALL of the fifty or so bird ent had comefrom a secondlaying. This underthe other parent. If the weatherwas speciesbreeding in the Falklands, was true, as we later learned from a Falk- warm and sunny, the chicks wandered the Magellanic and Blackish oyster- lander, John Smith, who had visited the overthe ledge,exploring cracks, pecking catcherswere remarkablyapproachable, islandon January9 and rememberedsee- at emptyshells, and occasionallypicking a trait in keepingwith birds isolatedand ing two eggson OystercatcherRock. up an insect,but they rarely followed a breedingon oceanic islands. In contrast, We kept the family undersurveillance parentdown the ledgeto the water. For- our American Oystercatcherthroughout during the next seven days. They were agingfor themwould be futile sincetheir its rangeis "one of the shyestand wildest always on the Rock. Without fail, the bills were not well enough developed. of our shorebirds, seemingever on the parentswalked from their chicks in our Now and then the two parentspiped alertto escapedanger" (Murphy 1936, p. direction,protested with quee-eeps.then beforeeach other, usually after one of 977). In his detailed study of the Black with purring as they turned away with themhad been out of sightof the otherfor Oystercatcheron Kayak Island, two head and bill down and wings drooped quite a while and then returned.A more miles off the coast of Sitka, Alaska, J. D. just a few feet ahead of us. The two elaborateand animatedpiping perform- Webster(1941) requireda blind for close chickshad already flattenedthemselves ance-indeed a classic piping cere- observations. and "frozen," presumably when their mony-resulted when three adult Black- The fact that the Falkland oyster- parentshad first voiced alarm. One was ish Oystercatchersfrom some distant catcherswere so approachablemay well in a little crevice, the other under an over- area alightedon the Rock near the par- accountfor certainbehavioral responses. hangingledge. If I stoodmotionless or ents. Instantlyall five began piping. All For example,the incubatingbirds delib- satdown and remainedstill, both parents the time they postured, bills pointed erately walking toward me from their resortedto standingon onefoot and sham straightdown as they raisedand lowered nests. I would have expected oyster- sleeping•as thoughto wait me out. their headsand humpedtheir shoulders. catchers, like most shorebirds, to sneak For a periodof severalhours on three Their tails were not lifted nor were their off theirnests away from me, or to fly up differentdays I watchedand filmed the primaries drooped. Mainly they stood in alarm and circle above me. For another family, carefulto keep far enoughaway facingone another,moving around very example, sham sleeping. Although no sothat they would pay no attentionto me. little. The ceremonylasted no more than accountsthat I have read report injury- While one parentstayed near the chicks, two or three minutes, gradually decreas- feigning to the extent of wing-dragging the other often soughtmussels. Tearing ing in sound and animation until it or spreadingand dragging the tail, as per- one loose,the bird boreit up to the ledge, stopped.Shortly thereafter the strangers formed by many shorebirdswhen their pushed it into a crack for holding, flew off. nests and young are suddenly ap- and proceededto remove the contents. The parentoystercatchers chased any proached,nevertheless the accountsdo The chicks,seeing this happening,drew otherlarge bird that attemptedto land on indicategreater alarm and animationthan close, and watched with anticipation, theirledge. Gulls andskuas passing over- shown by the Falkland oystercatchers readyto take the food directly from the headevoked piping. No Black-crowned whose reactionsI consideredlow-key. parent'sbill. Feedingsof this sort had Night-Heronwas ever allowed to stopon Surely no reactionto intrusion could be obviouslyoccurred many times in this the nearby mussel bed. lower-key than sham sleeping.

Volume 39. Number I 7 MagellamcOystercatchers •n southern thoughhe d•dnot describe them •n detail, the same •nd•v•duals that were there •n South America apparently show far he notedthat they werevery muchhke 1953-1954, or even that one •nd•wdual greateranimation in their behavior,if I thosein the EurasianOystercatcher, as might have been the same with a new judge correctlyfrom a recent study of describedby "Europeannaturalists," and mate,the facts nonetheless lend support their displayson the Argentine coastby believedthat the displays served "in the to thereputation of oystercatchersfor re- E H. Miller and A. J. Baker (1980). dualcapacity of courtshipand territory turningto the samenest site year after Theyillustrated their observations with defense."Webster (1941, p. 155), in year and for living an unusuallylong many drawingsfrom still photographs summarizinghis studyof the BlackOys- time. and frames selected from their motion tercatcher,wrote: "The piping ceremony I am aware that my appreciationof p•ctures.Typical amongthe Magellan- variouslyexpresses sexual excitement, oystercatcherswould neverhave been at- m's distractiondisplays when disturbed territorialjealousy, or socialexcitement. tained had my sole acquaintancew•th nearthe nestwas exposing the underside Peckingat the groundand bowingindi- Haematopusgone no further than w•th of the tail toward the authors "while cate nervous emotion." In the literature the .But now erectingand spreading the under-tailcov- onthe in , that I have observed the two Falkland ers" Other less strikingdistraction dis- wherethe species has a largepopulation speciesclose by in a varietyof situations, playsincluded "crouching with sleeked in theBritish Isles and on the continent,I oystercatchersare muchmore to me than plumage,slight drooping, fanning or ro- foundalmost as many explanationsfor simplylarge, strikingly handsome shore- tationof the tail, and loweredwings kept pipingas there were authors. Among all birds,always a joy to see,though so of- fmrly closeto the body.... Theselow theexplanations given, the most logical, tenfrom afar--and always ready to take •ntensitypostures sometimes merged into it seemedto me, wasby P. B. Heppleston flight. sequencesof false-brooding ... or (1970)who concluded, after a studyof croucheswith the tail depressedand pipingdisplays, that piping in the breed- LITERATURE CITED fanned." During pausesin "aggressive ing season"represents the mainterritorial p•ping performances," displacement responseto intruders," and in the winter CONDER, P. J. 1949. Individual distance feedingwas common and "characterized monthspiping is "evidentlystill aggres- Ibis 91: 649-655. by unusuallyvigorous insertion of thebill sivein nature"and possibly operates "in HEPPLESTON, P. B. 1970. The function of the maintenance of 'individual distance' Oystercatcherpiping behaviour.Brtttsh •nto the ground and twisting move- Birds 63: 133-135. ments." In most other respects the whilstfeeding" as first suggested by P. J. MILLER, E. H. and A. J. BAKER. 1980 behaviorof the Argentine Magellanics Conder(1949). But I couldfind no expla- Displaysof the MagellanicOystercatcher correspondedto my observations,photo- nationfor thepiping ceremony I watched (Haematopusleucopodus). Wilson Bull graphs,and films of the Falklandbirds. at CarcassIsland that wastriggered by 92: 149-168. Pipingby the FalklandMagellanic and two birds suddenlyjoining two others MURPHY, R. C. 1936. Oceanic birds of South America. 2 vols. American Muse- Blackishoystercatchers differed marked- foragingon the beach. Apparently piping um of Natural History, New York, 1245 ly •n onedetail. Whereasthe Magellanics behavioris a responsenot to one but to PP. hfted their tails straightup, displaying numerous situations. Just what the cues NETHERSOLE-THOMPSON, D. 1961 thewhite basal portion, the Blackishnev- are that release the behavior remains un- Oystercatcher:breeding behaviourand er lifted theirall-black tails vertically, an determined. breedingbiology. Pp. 310-318in Banner- actionthat would have little if anydisplay Oystercatchersare notoriouslynest- man, D. A., The birdsof the BritishIsles, value. In his descriptionof the piping sitetenacious and long-lived,if what the vol. 10. Oliverand Boyd, Edinburgh and London,320 pp. ceremoniesin the Black Oystercatchers, Britishand European ornithologists have NICE, M. M. 1966. Territo•3•defense in the J D. Webster (1941) does not mention foundin the EurasianOystercatcher is Oystercatcher.Bird-Banding 37:132 the birdselevating their tails. applicableto the otherspecies. (See D. TOMKINS, 1. R. 1954.Life historynotes on Franklypuzzled by the functionof the Nethersole-Thompson1961, for a dis- the AmericanOyster-catcher. Oriole 19 p•pingceremony in differentsituations, I cussionof the subject.)Pairs mate and 37-45. reviewed much of the literature on the remainmated, and they return year after WEBSTER,J. D. 1941.The breedingof the .Wilson Bull. 53 subjectin otheroystercatcher species. I yearto the samenest sites. Marked indi- 141-156. foundvery little informationon pipingin viduals are known to have lived for two WILLIAMSON, K. 1953. Flockingbehav- the AmericanOystercatcher, which has or three decadesor even longer. One iour of Oystercatchers.British Birds 46 been seldomstudied due to its shyness bandedEurasian Oystercatcher,when 108-110. and generally sparse population. In last recorded,was 36 years old (Nice watchingthe specieson the SouthCaroli- 1966). While I make no claim that the na-Georgiacoast, I. R. Tomkins(1954) two BlackishOystercatchers nesting on --P.O. Box 97, observeda few piping displays. AI- OystercatcherRock in 1971-1972 were Wayne,ME 04284

8 AmericanB•rds, Spnng 1985