VoL1937 ,541J SIPLEAND LINDSEY, Ornithology inthe Antarctic 147

ORNITHOLOGY OF THE SECOND BYRD ANTARCTIC EXPEDITION

BY PAUL A. SIPLE AND ALTON A. LINDSEY

THE secondByrd Antarctic Expedition embarkedfrom Boston on October11, 1933. After passingthrough the PanamaCanal, we touched Easter Island, then crossedthe Pacific to Wellington,New Zealand. A southeastcourse from there brought our vessel into ice-filled antarctic waterseast of the RossSea. A large area of unknownocean was explored by ship and airplaneas far eastas the 116th meridian,where we turned westwardagain. One month after the shiphad first enteredthe pack-ice, it reachedthe southernmostshore of the . The Bay of Whales is thatpoint on the circumference of the antarctic continent where the encroachesfarthest toward the pole. Here at 78ø 34t S. and 163ø 56t W., ßthe basecamp was established on the floatingshelf ice of the RossBarrier. The ice-partyoccupied the Bay of Whalesbase from January17, 1934,until February5, 1935,while the shipswintered in New Zealand. The itinerary of the return voyageincluded Dunedin, New Zealand,Easter Island, Albe- •narle Island of the Galapagosarchipelago, and Panama. The expedition arrivedin the United Stateson May 10, 1935,after an absenceof nineteen months. The presentpaper reports the birdsobserved at seaand on the antarctic continentby the writersduring the secondByrd expedition,when Lindsey studiedthe vertebratesof the Bay of Whalesregion, and Sipleworked for two months in . Observationsin the Bay of Whales made by Siple during the first Byrd expeditionare also includedin the discussions of seasonal occurrence. His collection of skins made in 1929-30 has beenreported on by Dr. R. C. Murphy in 'OceanicBirds of South America' under the biographiesof the speciesin question. The 1933-35collection made by Lindseyis summarizedbelow. The writers are grateful to ProfessorA. A. Allen and Dr. R. C. Murphy for critical readingof the manuscript,and to Dr. Murphy for verifyingand correcting their identifications of the oceanic-bird material collected, which has been placedin the AmericanMuseum of Natural History. Fifty-four speciesof were identified in the courseof the second expedition. Twenty-three of these were non-oceanicbirds which came aboardship from October14 to 30 betweenNew York and Panama. Nine speciesof sparrowsand four speciesof warblerswere amongthe passerine birds. The followinglist includesthe non-passerinebirds identifiedat sea, but not collected. 148 SIPLEAND LINDSEY, O•{tholog• {nl•]• A•7garct{½ [April•Auk

GalapagosPenguin, Spheniscus mendiculus Sundevall SootyAlbatross, Phoebetria fusca (Hilsenberg) Light-mantled Sooty Albatross,Phoebetria palpebrata (Forster) Giant , Macronectesgiganteus (Gmelin) Cape Pigeon,Daption capensis(Linnaeus) ? Bulwer's , Bulweria b•dwerii (Jardine and Selby) White-facedStorm Petrel, Pelagodromamarina, subsp. CaribbeanMan-o'-war Bird, Fregatamagnifcens rothschildi Mathews Man. o'-war Bird, Fregataminor, subsp. Flamingo, Phoenicopterastuber Linnaeus Purple Gallinule, Porphyrula martinica (Linnaeus) Red-billed Gull, Larus novaehollandiaescopulinus J. R. Forster Antarctic Tern, Sternaviitara Gmelin White Tern, Gygisalba, subsp.

The ornithologicalcollection of the secondByrd Antarctic Expedition consistsof one hundred and seventeenskins, chiefly of the larger oceanic birds. Twenty speciesare included,representing ten families, as follows: Emperor Penguin,Aptenodytes forsteri G. R. Gray Ad•lie Penguin,Pygoscelis adeliae (Hombron and Jacquinot) Black-browedAlbatross, Diomedea melanophris Temminck WanderingAlbatross, Diomedea ex•dans ex•dans Linnaeus Sfiver-grayFulmar, Priocellaantarctica (Stephens) , Pogodromanivea (Forster) Antarctic Petrel, Thalasso•caantarctica (Gmelin) Pediunker, Adamastorcinereus (Gme]Jn) GalapagosShearwater, Pu.•nus l'herminierisubularis Ridgway Wilson'sStorm Petrel, Oceaniresoceanicus oceanicus (Kuhl) Red-tailed Tropic-bird, Pha•thonrubricauda, subsp. Blue-lootedBooby, Sula nebouxiiMilne-Edwards Masked Booby,Sula dactylatragranti Rothschild SpottedCprmorant, Phalacrocorax punctatus punctatus (Sparrman) GalapagosMan-o'-war Bird, Fregatamagnificens magnificens Mathews South Polar Skua, Catharactaskua maccormicki(Saunders) Brown Skua, Catharactaskua lOnnbergiMathews Dusky Gull, Larus fuliginosusGould Kelp Gull or SouthernBlack-backed Gull, Larus dominicanusLichtenstein Panama Potoo, Nyctibius griseus ALB•.TROSSES.--Throughoutmost of the year the RossSea is completely shutoff from the openPacific by a bandof driftingice as muchas three hundredmiles in width. This is the antarcticice-pack, a purgatoryfor the navigatorbut a paradisefor the observerof bird and mammallife. Unfor- tunatelyfor the latter, no packice wasencountered on our return voyage. However,this broughta measureof compensationin its effecton the south- ward occurrenceof albatrosses,so that the knownnon-breeding ranges of three specieswere extended. The mostsoutherly wanderer of the Diomedeidaeis the Light-mantled Vol.1937 •4-•J SIPLEAND LINDSEY, Ornithology in the Antarctic 149

SootyAlbatross (Phoebetria palpebrata). The southernmostprior recordof this bird is that of Dr. Edward A. Wilson, who died with Scott's sledging party on the returnfrom the pole. In 1904,Wilson had observedthis bird at 74ø S. At the beginningof our return voyagea Light-mantledSooty Albatrosswas patrollingour wake at 77ø 50• S. Three days later, five Black-browedAlbatrosses (Diomedea melanophris) joined us at a south- ward advanceof 3.5 degreesbeyond its formerrecord. The stately Wan- deringAlbatross (Diomedea exulans exulans) appeared at 68ø 40• S.; its previouslimit had beenset at 67ø S. by the naturalistsaboard the 'Scotia' (Clarke,1915, p. 267). Theseare advancesof 230,210 and 100geographical miles,respectively, for the three .If the albatrosseshad followed a vesselsouthward into thesehigh latitudesthe positionmight not truly representnatural occurrence,but the birds were pickedup on the north- wardvoyage, with oursthe only two shipsinthe entireRoss Sea. On the southwardtrip the first albatrosseswere met at 34ø 3• S. These were the Wandering and the Black-browedAlbatross. In the 'roaring forties'two male WanderingAlbatrosses were collected, the largerweighing 19 poundsand measuring10 feet 9 inchesin extent. SNOWPETREL AND ANTARCTIC PETREL.--We are here concernedprimarily with the nine speciesof antarcticand sub-antarcticbirds whichwere found in summerat the southernlimit of the RossSea, along the Ice Barrier cliff. The Bay of Whalesregion marks the southernmostlimit of eight of these species,a fact whichlends increased interest to'these records. When an experiencedice-pilot in antarcticwaters sights the first Snow Petrel he concludesthat ice is not far away. The first part of its generic name, Pagodroma,means ice, its specificname, ni•ea, meanssnowy, and the bird itself is seldom found far from either ice or snow. This is the most abundantbird in the pack ice. It liveslargely on the shrimp-likereddish crustacean,Euphausia superba, which is also the principal food of the Ad•lie Penguin, the Crab-eater Seal, and other denizensof the antarctic pack. The SnowPetrel's plumage is white with ivory tones;its beak, eyes, tarsl, and feet are black. This would be an altogetherattractive bird were it not for its accuracyand eight-footrange in ejectingthe oily, orange- colored contents of its stomach at the intruder. After four monthsbelow the horizon,the sun reappearsat the Bay of Whaleson August22. The earliestspring migrants are the Snowand the Antarctic . In 1929, a singleAntarctic Petrel was seenOctober 2, but no Snow Petrels appeareduntil October31. In 1934, a lone Snow Petrel and two Antarctic Petrels arrived October 6. In terms of the calen- dar this is analogousto the Bluebirds'delaying their arrival in the north- easternUnited Statesuntil the first week of April. The last SnowPetrel seenin the autumnwas on 1V•arch13, after whichno birdsof any kind were 150 SIPLEAND LINDSEY, Ornitholog•l inthe Antarctic tAprilrAuk

SnowPetrels did not becomecommon in the bay until December,or mid- summer,when they congregatedby thousandson the seariceand barrier cliff near openwater. A few habituallycoursed back and forth alongthe higherridges of pressureice, where it waspossible to collectthem by hiding amongthe ice blocks. A tractor party returningto the basesaw a Snow Petrel flying over the barrenshelf ice forty milesfrom the sea. Though this is the southernmostrecorded individual, several of Scott'ssledging parties saw thesebirds seventymiles inland (Wilson, 1907, p. 90). The breedinghabits have been observed by half a dozendifferent expeditions. No birds breedin the Bay of Whalesregion. The only knownbreeding groundwithin four hundred miles is a rookeryof SnowPetrels discovered by a four-mansledging party which Siple led into the mountainranges of Marie Byrd Land. On the return trip throughKing Edward VII Land an ascentof Mount Helen Washingtonwas made on December19, 1934. A great flock of birds envelopedthe summit of the peak, about one thousand by estimate.Both Snow and Antarctic Petrels were represented, in.approx- imatelyequal numbers, and the presenceof a rookerywas suspected. On the lowerslopes many bleachedpetrel bones were found in the profusematting of lichenscovering the rocks. As the summit was approachedthe bones became more numerous,and fragments of egg-shellswere found. The birds beganswooping at the headsof the two climbers. Finally, at the summit of the peak the rookery was located, where Snow Petrels were sitting on their eggsdeep in crevicesamong the rocks. They defended their nestswith the customarymarksmanship. The eggscollected were found to be in the early stagesof incubation. No nestsof the Antarctic Petrel were found, but from the numbersof the birds it seemslikely that they neston this peakwith the SnowPetrds. A fact of unusualinterest is the distanceof this nestingsite from the nearestwater. Thesebirds nest fifty-oriestatute miles from their nearestpossible source of food. This dis- advantageseems to be counterbalancedby the nature of the peak, where many shelterednesting sites are availableamong the looselyaggregated rocks. Winds of hurricaneforce sweepover the peak and preventlarge accumulationsof snow,while the dark rock contributesby absorbingthe sun'sheat and meltingthe snow. Findingthis rookeryextends the breeding rangeof the SnowPetrel 6ø 36' or 452 statutemiles to the south. In the ice pack in Januaryflocks of hundredsof Antarctic Petrds were seenwheeling in unisonabove the great tabular bergs. About seventeen inchesin length, or three incheslonger than the SnowPetrel, this bird is no lesshandsome. Its chocolate-brownhead, back, and wings furnish a pleasing contrast with the whitenessof the wing coverts and other parts. Our northernmostobservation of it wasat the sa•neposition as that of the Snow Petrel, 63ø 30' S. Both speciesare circumpolarin distributionfrom the northernlimits of the pack to the coastsof . Vol.1937 ,54]J SIPLEXND LINDSEY, Ornithology inthe Antarctic 151

In the Bay of Whalesthe AntarcticPetrel was much more commonin 1929 than in 1934. Large flockswere seenfrequently in the summerof 1929-30, but disappearedafter the middle of January, and from then on even singleindividuals were very rarely seen. In 1934, no flocksof more than fourwere to be foundin the bay, andthe bird wasuncommon through- out our stay there. SILVER-GRAYPETREL (Priocella antarctica).--This is the leastcommon of the birds known to visit the Bay of Whales. In 1930, it occurredrather frequentlyamong the largeflocks of AntarcticPetrels early in January,but has not beenrecorded in the bay sincethat time. Our only specimencol- lected was securedon the antarctic circle and the 150th meridian, at the northern edgeof the pack. CArE PIGEO• (Daptioncapensis).--This petrel has never beenreported in the Bay of Whales. Its southernmostrecord is at DiscoveryInlet, 78ø 30' S., whereit wasobserved December 26, 1928,in the courseof the first Byrd AntarcticExpedition. Apparentlyit had not beenfollowing the ship,for it paid little attentionto it, and soondisappeared from sight. WILSO•'SSTOl•M P•TR•L (Oceaniresoceanlcus oceanicus).--Breedlng only on antarctic and sub-antarctic islands and on shores of the antarctic conti- nent, this speciesmigrates as far north as Labradorduring the southern winter. As for all birds which reach the Bay of Whales,except the South Polar Skua, this station marks its southernmostlimit. Wilson's Storm Petrel is frequenthere in Januaryand February, and may be seenten miles back from the sea, careeningover the fiat bay-ice in a very swallowdike manner. We neversaw them alight on the ice. Scott'sexpedition observed these birds flying over the shelf ice some sixty miles from open water (Wilson, 1907, p. 79). GIANTFULMAR (Macronectes giganteus).--In summer during the second Byrd Expedition,after the seaice at the mouthof the bay beganto break up and float northwardto join the pack,the Giant Fulmar or was frequently seen soaringover the open water. This was not the case in 1928-30, however,for although severalhad appearedat DiscoveryInlet, not one had beenreported at the Bay of Whalesuntil the autumn of 1933. The two stationsare about eighty milesapart. This specieshas two colorphases, a brownand a white,with intermediate conditions. Wilson (1907,p. 96) pointedout that in proceedingsouthward the proportionof whitespecimens greatly increases. From 33 ø S. to 66ø 7' S., he saw only one white bird in five hundred,while southof 66ø 7' eighteen white and sixty dark birdswere counted. Of about ten Giant Fulmarsseen in the Bay of Whales in 1934-35, all were brown birds. None of these was seenat rest on the ice or flying over it, butalways flying a fewfeet aDove the waves. In cruisingalong the barriercliff betweenthe Bay of Whalesand 152 SIPLEAND LINDSEY• Ornithology inthe Antarctic ['Auk[April

DiscoveryInlet, we saw a flock of about fifty which had settled on an ice floe. Only two of theserepresented the white plumagephase. Although thesetwo stationsare at the very southernmostlimit of the range,within the scopeof our observationsthe white birdsconstituted only 3.3 per cent of the sixty individuals,as comparedwith Wilson's23 per cent. SOUTHPOLAR SKUA (Catharactaskua maccormicki).--Thedrama of antarctic bird life is not without its villain. Theft and pillage,murder, cannibalismand infanticide,these crimes are all in the repertory of the South Polar Skua. The Ad41iePenguin rookeries suffer heavily from its depredations.The EmperorPenguins are immune to this plagueonly becausethey nestin the middleof winter, sharingwith no otherbird species the rigor of the polar night. At the afore-mentionedSnow Petrel rookery therewere skuas about. Doubtlessthe petrels'habit of laying their eggsin narrowcrannies serves to protectthe eggsand youngfrom skuas,as well as from the force of frequentsevere blizzards. It was not possiblefor the sledgingparty to remainin the regionuntil the eggshatched, but the bones scatteredaround the rookeryprobably bear witness to the work of skuas,at least in part. At the summitof an unnamedpeak near 1VIt.Saunders, the 1VIarieByrd Land party made a find whichis unusualindeed in theselatitudes. A small unfrozenfresh-water lake in the black sedimentaryrock supportedcon- siderableplant and animallife. The muck bottomwas pinkish in colordue to innumerablered rotifers. There was a profusegrowth of filamentous green algae in the pool, and the water had a stagnant odor. The moss, Grimmiaantarctica, grew along thebank. The tarn servedas the rendezvous of skuas,and a depositof guanoaround it attestedto longuse of thishaunt. A half-dozenskuas loitered about all day, bathingin the lake andresting on the rocks. SnowPetrel feathersand bonesdisgorged in definitepellets were scatteredaround the lake. Sincethis is 180 geographicalmiles from the SnowPetrel rookeryin King Edward VII Land, it seemslikely that the skuashad broughtthe remainsof the youngpetrels here from asyet undis- coveredrookeries on thosehundreds of nearerpeaks along the coast,which have neverbeen visited by man. The date of this observationwas Decem- ber 3. No egg-shellsor other evidencesof nestingwere found, but the abundanceof the skuasin the generalneighborhood suggests the proximity of a rookery. This mountainis thirty geographicalmiles from the coast. A similar 'robbers' roost' of the skuas was found at the summit of 3/It. Saunders,76 ø 47' S., and thirty-fivemiles from the nearestwater. The SouthPolar Skua wanders farther south over the continentthan any other bird. Amundsensaw two of them on the RossShelf Ice at 84ø 26' S., and Dr. Gould,in 1929,photographed one at the Queen1VIaud Range, 85 ø S. On the secondByrd Expedition,the southerngeological party reportedone Vol.1937 541J SIPLEAND LINDSEY, Ornithology in the Antarctic 153 skuaat 81ø 41' S. However,the recordof greatestinterest is an observation madeby this party at 86ø 05' S., thirty milesup the Thorne Glacier,at an altitude over two thousandfeet. The date was December 20, 1934, and the position464 geographicalmiles from the nearestwater and 235 miles from the pole. Here the men saw four skuasflying toward them from up-glacier, i.e., from the polar plateau, presumably. When the birds settled on the snownear the doglines, the tethereddogs went into a frenzy at the sightof them. The birds restedfor a time and finally took off, flying north, con- tinuing the flight downthe glacier. Thesefacts suggest that the skuasmay have been on a flight acrossthe antarctic continent. There is one still more southerlybird record, though the circumstances seemrather lesssuggestive. Captain Scott on his last journeywrote in his diary, January 2, 1912: "One skua gull visited us on the march this after- noon--it was evidently curious,kept alighting on the snow ahead, and flutteringa few yardsas we approached.It seemedto havehad little food-- an extraordinaryvisitor consideringour distancefrom the sea." This was on the plateau,at an altitude of 9,980feet. The positionwas 87 ø 20' S., or 160 geographicalmiles from the , and 560 geographicalor 640 statute miles from the sea. Soonafter the Byrd Expeditionarrived at the Bay of Whales,numbers of Weddell Sealswere beingkilled for dogfood. At the time whenour search for a seal embryowas first rewarded,the specimenwas left lying on the sledgewhile preservative was being prepared. A suddenswift rushof wings, then skua and embryo were making for the horizon. On another occasion the thievingnature of the skuawas accidentallysublimated into usefulness. We wereattempting to collectfish by dynamitingfrom a smallboat in open water. A current from beneaththe ice, however,apparently carried most of the victimsfar out to seabefore they floatedto the surface. After shoot- ing eighty sticksof dynamiteat variousdepths, we had securedonly two small specimensof Pleurogrammaantarctlca. A skua was then seenflying in from seawith a fishin its beak. While it alightedon the ice to devourits find, we rowed ashoreand rushed toward it with wild shouts,so that it flew off, abandoningthe scarcelydamaged . Two other skuas were seen carryingfish ashorethat day, whereasthroughout both expeditionsonly one other caseof a skua with a fish was observed. The only items in the stomachsof skuaswe collectedwere pebbles,the blubber,flesh and hair of seals,flesh and bonesfrom skua carcassesthat we had skinned,and cuttle- fish beaks. The first springtimearrival of skuasin the Bay of Whaleswas on Novem- ber 9, when three appeared. They were commonduring December,Janu- ary, and February. The last autumnrecord for them was1VIareh 13, when the temperature had been dropping to --30 ø F. for a week. Eighteen 154 SIPLEAND LINDSEY, Ornithology in the Antarctic rAuk[April specimenstaken in the middle of Decemberwere equally divided between the sexes,and the gonadsof both evidencedreproductive activity. AD•LIr Pr•iGvl•; (Pygoscelisadeliac).--After twelve days of cruising eastwardthrough pack ice and bergs,we saw the first Ad•lie and Emperor Penguinsat 68ø S. and 124• W. The Ad•lieswere the moreabundant of the two. Both adult and immature birds of each specieswere seen. The immature Ad611esgreatly outnumberedthe adults, and two seenJanuary 2 carriedthe remnantsof their downplumage. This is remarkable,for Wilson (1907,p. 58) foundthat the nestlingdown is moultedat therookery between January 9 and 16. The two white-throated young in questionwere on a large ice-pan 180 miles north of the nearestpossible unknown coast llne. They were not seento enter the water. Perhapsthey were carried away accidentallyfrom the vicinity of the rookery with the break-up of sea ice alongthe shore,and werefinishing the moult on floatingice as the Emperor Penguinchicks do in the springduring their ride north to the pack. Even so,January 2 wouldseem to be unusuallyearly for the last of the downto be shed. This occurrencemay indicatethe presenceof a rookerynear the 115th meridian, and probably to the east of it sincethe oceancurrent is westward-flowingalong thesecoasts. The white-throatedimmature plumageis carried for thirteen months, and is replacedby the black-throated adult plumage in the latter part of February of the bird's secondyear. Only birds in the adult plumagemi- grate southto the rookeriesin the spring. The black-throatedbirds which we find in the packin early Januaryare obviouslynot breeding. Thesemay be third-year birds remainingin the pack for another year after acquiring the adult plumage. If so,as Wilson (1907, p. 58) has suggested,it follows that the penguinsare three yearsold beforethey breed. In the Bay of Whalesthe earliestspring record is a specimentaken No- vember 14, 1934, nine days after the first Emperor had arrived. Both speciesare merelyvisitors in the bay, for their nearestknown rookeries are at , 400 miles to the west. Not another Ad4lie was seenuntil January 5. After this date they appearedoccasionally in the bay in groups of from two to four, but only one suchgroup was seenat a time. In fact, throughoutthe summer'swork in the Bay of Whales•only fourteen Ad4lies wereseen here in all. Yet at DiscoveryInlet, eighty milesto the west,they were numerousafter the middle of January. Someof the latter were pre- sumably from a rookery, for the gonads were enlarged. The relative abundanceat the two stationsalso suggeststhat the birds had come from the rookerleswest of us, and that most of them go ashore at Discovery Inlet, only a few continuingto the Bay of Whales. It alsomay indicatethe absenceof any rookeryalong the equivalentfour hundredmiles of coastto the east, the more stronglybecause the westward-flowingcoastal current Vol.1937 54'1J SIPLEAND LINDSEY, Ornithology in the Antarctic 155 wouldfavor movement of birdstoward the bay fromthe east,while opposing it from the west. With a singleexception, all the DiseoveryInlet spedmenswere in the adult plumage. The oneimmature bird wasin the bleaehedand weathered white-throatedplumage, ready to moult sooninto the black-throatedadult plumage. Suchbirds are not to be found in rookeries,but are met with in the packice. The fact that this year-oldbird, whichhad spentthe previous winter in the pack, was on the continentalcoast in January, suggeststhe possibilitythat some.of the black-throatedbirds collectedwith it were also birds whieh wouldnormally be in the paek at the time, and had comefrom there rather than from any rookery. Thesewould then correspondto tile black-throatednon-breeding Ad41ies whieh we saw in the pack along the antarcticcircle in January. Insteadof remainingin the packto moult with theirfellows, they had wandered perhaps eight hundred miles to the southto moult in the securityof a shelteredbay alongthe Rosslee Barrier. Of the twenty-sevenspecimens taken in January on the coast, ten were femalesand seventeenwere males. The mean total lengthof twelve males was 29.0 inches,and of sevenfemales, 26.9 inches. The weight of twelve malesranged from 7.5 to 10 pounds,averaging 8.5 pounds. Three females averaged8.2 pounds. Wilson (1907,p. 43) statesthat a eolleetionof small pebblesis invariablyfound in the stomach. This doesnot apply to birdsin the moult, which are fasting sincethey dare not enter the water. Most stomachsexamined contained from one to ten pebbleseach, but sixstomachs were completelyempty. In 1929, the white-throatedjuveniles were not uncommonin the flocks of adults. The largestgroup of Ad41ieswe sawat any onetime wasa com- pact flock of 85 adults on the seaice at DiscoveryInlet. EMrEaoa PENGmN(Aptenodytes forsteri).--These largest of living pen- guinswere more frequent visitorsto the Bay of Whales than the Ad•lies in 1934-35, but the reverse was true in 1929-30. Their remarkable habit of breedingduring the extremecold and darknessof the antarcticnight leaves them freein summerto wanderalong the coastand throughthe ice pack. Many Emperorsare to be seenin the packduring December and January, both juvenileand black-throatedbirds. Othersof both groupsseek coastal bay ice, suchas the Bay of Whalesaffords, on which to moult. Althoughco•tspicuous byvirtue of their size, coloration, and loud, reedy, whiningcall note,Emperors are by no meansabundant in •he bay. Through- out the summerof 1934-35, thoughwe were on the bay almostdaily for threemonths, the total numberof Emperorsseen was only thirty-two. The first in the springappeared November 5, after whichnone was seenfor a month. On the first expeditionthey wereeven less commonly found. An Emperor was found starting to moult as early as December5. The 156 SIPL]gAND LINDSEY, Ornithology inthe Antarctic [April[Auk birdsavoid the water and take no foodduring the moult,which lasts nearly one month. Eighteenspecimens taken in Novemberand December,before the moult,ranged from 60 to 84 pounds,while eleven taken after the moult, in February, rangedfrom 39 to 55 pounds. The mean weight beforethe moult was 70.1 pounds,and after the moult, 49.8 pounds. Sometaken in the latter part of Decemberhad already completedthe moult and were feeding. Their stomachscontained fish and Euphausiaremains, and usually pebbles,though not invariably. The pebbleshad undoubtedlybeen secured elsewhere,for no land is exposedwithin one hundredmiles and the sea is 1800 feet deepbeneath the bay ice. Sixty-eightgrams was the maximum weight of pebblesfound in one stomach;the largestpebble weighed six grams. Sclater (1888, p. 325) reportedpebble massesfrom two to ten poundsin weight. They restremarkably far down,since the lowestpart of the greatlyelongated stomach reaches nearly to the baseof the bodycavity. The weight of pebblesat this point lowersthe penguin'scenter of gravity and possiblyhelps it to someextent to maintainits upright postureon the ice. This may alsoserve as ballastwhen diving, as Murphy (1936,p. 364) has suggested. Only two of the Bay of Whales Emperorswere in juvenile plumage. These individuals were about seventeen months old and soon to assume the adult coat. Four suchbirds caught at DiscoveryInlet moultedinto the adult plumagewhile in captivity. All of the juvenileEmperors seen along the coastwere over one year old. The pupil of the eye is capableof great changein sizein relation to light intensity. In the bright sunlightof the antarctic summerthe pupil is less than a millimeter in diameter. The iris is dark rufousin color. The shapes which the pupil assumesat differentapertures are similar to thoseof the King Penguin(Aptenodytes patagonica) as describedby Murphy (1936,p. 343). At a moderatelysmall aperturethe Emperor'spupil is distinctly square,and in dosing further the cornersbecome more sharply defined. Finally, when less than three or four millimetersin diameter, the pupil showsvery sharplyattenuated corners, since the iris bowsinward from the four sides. The characteristiccall note is givenby both sexes. A dog-teamdriver on the trail eastof the basesaw an Emperor'stracks fifteen milessouth of the coastin the first week of January. The penguin washeading south, on the highshelf ice. Suchwanderings are typicalof the moultingperiod. It is not probablethat thisbird waslost, for we foundthat captivepenguins released on the barriersurface were able to head accurately in the directionof the nearestwater, possiblyby a reaction to the dark band of 'water-sky.' Thesepenguins displayed apparently intelligent behavior when a group of them skirtedthe edgeof the high barriercliff in an effortto find a way Vol.1937 54]J SlPLEAND LINDSEY, Ornithology in the Antarctic 157 down into the water. One or two of the flock would drop down on their belliesand toboggan up to the edge. Afterpeering. over and finding a precipitoussixty-foot drop, this advanceguard would turn directly about and slideback to the flockwhich had remainedat a distanceof twenty feet from the edge. Here the birdswould again stand up on their feet and the wholegroup would waddle along parallel to the edgeforty feet or so,when the wholeperformance would be repeated. This continuedfor miles,and wasobserved with differentgroups of EmperorPenguins. Thosewho have seenthe barrieredge calve off into the seaunder the slightweight of man or dogsmight be proneto attributeto the penguinsa realizationof this danger. This anthropomorphicinterpretation fits well with the popularidea of the birds' cleverness. The ornithologist,however, might reach either of two conclusions.Since antarctic seasare filled with great tabular icebergs, merely loosepieces of shelf ice derived from the Ross Barrier or similar formations,it would seemprobable that penguinsfind slopingedges and make their way to the top, later followingalong the steepedge in search of the same or anotherroute back down. An instinctivefear of high and steepplaces would have survival value and be implantedin the race througha long periodof selection. Or, again,it might be concludedthat someor all of thesebirds had beenconditioned by personalexperience with unstableoverhanging snow cornices on a smallerscale, or had been blown by high winds off the edgesof ice cakes,particularly when walking or standingerect. Thesepossible explanations, however, seem unnecessarily elaborate. Considerthe approachof a flockof Emperorstoward a man or a dogteam. They comeup to within fifty or sixtyfeet, some walking, others tobogganing.Then they standerect in a curiousyet cautiousgroup while oneof them slidesalong on its belly to investigate,approaching to within ten feet or lessof the strangeobject. After sometrumpeting, bowing and scraping,it returnsto the group. Anotherbird may then carry out the sameprocedure, or its curiositysatisfied, the flock may resumeits leisurely walk. If man or dog advancesmenacingly, however, all the birds at once dropto their belliesand skitter off at sucha pacethat a man runningfull tilt ishard put to overtakethem. It seems,then, that the EmperorPenguin whenout of water reactsin the sameway towardany objectof curiosity and potentialdanger, such as man, tractor, or the more usual problemof the steepedge of the ice. Their habit of approachingsuch situations on their belliesshows an apprehensivestate of 'mind'. They are preparedfor a quickretreat if the edgeof the icebegins to crumbleor in case of attack by naturalenemies such as the Sea-leopard(Hydrurga leptonyx). Danger fromthe latter is confinedlargely to the water,however (Levick, 1914, p. 84). Afteran unsuccessfulattempt on the firstByrd Expeditionto bringback 158 SlPLEAND LINDSEY, Ornithology in the Antarctic tApri!fAuk

living antarctic penguinsfor Americanzoos, another attempt was made on the secondtrip. The captiveswere kept at the basecamp, where an areaof about 5000 squarefeet of snowwas enclosedby a wire netting. The first birds caughtwere kept here for two monthsbefore being transferred to the ship. Frozen fish had been purchasedin New Zealand for feedingthem. This was thawed in water and cut into strips of convenientsize with the largerbones removed. The birds were fed oncea day, and care was taken not to overfeedthem, sincesome were moulting. Becausethe penguins wereunable to recognizedead material as food,and wereunwilling to accept the hospitality of their captors,forcible feedingwas necessary. This re- quired two men, ohe to catch the bird, overpowerit and hold it down, anotherto pry openits beak and administerthe food, pieceby piece. At the end of two monthsone of the flock, an Emperor,had becomereconciled to eating,and wouldopen its beak for food. On leavingthe Antarctic we had twenty-onecaptive Ad•lies and nine- teen Emperorshoused amidships in an air-conditioned,refrigerated, cork- insulatedroom forty feet long, six feet wide, and sevenhigh. Half its length was given over to a concretetank of cooledsea water three feet deep. Air was pumpeddown from the mastheadand cooledby passing througha large honeycombcoil of ammoniaveins. On the coolerdays the bird• were taken out to a canopy-coveredenclosure on deckfor a chanceto dry their feathers, since the necessityof continually washingdown the room kept it too humid and the penguinswere sometimesunable properly to dry themselves.After threeweeks at sea,when the birdshad beenkept for two or three months in captivity, most of the Emperors no longer requiredforcible feeding. On the contrary,they had becomevery tame and friendly, since a new associationhad finally been formed and man now symbolizedfood. The task of feedingthem was scarcelylightened on this account,for their greedy shovingand squabblingover each piece of fish creatednew difficulties. The fact that a very few of the adult birds ulti- mately learnedto pick up food from water in a pan did not facilitatethe feeding,because of their clumsinessand slownessin trying to feed them- selves. The youngEmperors were far behindthe adultsin their condition- ing to hand feeding,and weremore vicious in defendingthemselves against beingfed. The Ad•lies showedstill lessadaptability and more pugnacity. Their stouthooked beaks proved much more formidable weapons than the long,curved bills of the Emperors. If the powerfulEmperors had foughtas strenuouslyin proportionto size,keeping them alive wouldhave been quite impossible. Unfortunatelyfor the captives,the return voyageto Americatook more than three monthsdue to the slowpace of the shipsand an extendedstay in New Zealand,where many of the Ad•llesdied. By the time the expedition' Vol.1937 ,541] SIPLEAND LINDSEY, Ornithology in the Antarctic 159 had crossedthe tropics,nine of the Emperorshad died from a heavymycosis infection of the lungs, tracheae,and air sacs. Ten Emperorsand one Ad41iePenguin reached the United States alive and were deliveredto the ChicagoZoological Society. The last of thesedied about two monthslater of the same disease. The Society transferred these birds to the Field Museumof NaturalHistory, where they are now on displayas a habitat group.

LITERATURE CITED CLARKE,W. EACLE 1915. On the birds of the Weddell and adjacent seas,Antarctic Ocean. Rept. Sci. ResultsVoyage of S. Y. "Scotia," ScottishNat. AntarcticExp., vol. 4, pt. 14, pp. 255-270; Edinburgh. (Reprintedwith slight verbal changes from Ibis, ser. 9, vol. 1, pp. 325-349, 1907.) LEvies:, G. MURRAY 1914. Antarctic penguins:a study of their socialhabits. 8vo, New York, ix q- 140 pp., illustr. MURPHY,]ROBERT CUSHMAN 1936. Oceanicbirds of South America. 8vo, Amer. Mus. Nat. Hist., New York, 2 vols., illustr. SCnATER,P. L. 1888. Notes on the Emperor Penguin (Aptenodytesforsteri). Ibis, ser. 5, vol. 6, pp. 325-334, 4 figs. WILSON,EDWARD A. 1907.Aves. National Antarctic Exped., 'Natural History, vol. 2, Vertebrata, pt. 2, pp. 1-21, pls. 1-13; London. Clark University,Worcester, Mass. CornellUniversity, Ithaca, N.Y.