Vol.•94o•7'] a IIowam),Wintering o! GreaterSnow Geese 523

WINTERING OF THE GREATER SNOW GEESE

BY WILLIAM JOHNSTON HOWARD D•ARTHOf literature on the life historyand ecologyof the Greater SnowGoose (Chen hyperboreaatlantica) prompts recording the fol- lowingobservations made on visitsto the coastof North Carolinaand in December1937, January 1938, and January1939, and of information supplied by the men in chargeof the United States BiologicalSurvey waterfowl refugesat , North Carolina, and Back Bay, Virginia. The A. O. U. 'Check-list'(1931) gives the winter range of the Greater Snow Goose as "Atlantic Coast of Maryland, Virginia, and North Carolina, from ChesapeakeBay (sometimesDelaware Bay) to ." In recentyears a substantialpercentage of the entire popu- lation of Greater SnowGeese has wintered along the sandyshoreline of Virginiaand the peninsulaand the stringof North Carolinaislands and sandspits known as the OuterBanks. This coastis chieflywind- sweptdune landswhich start at Cape Henry, Virginia, and extend three hundred miles or more south and west, almost joining the North Carolinamainland near CapeFear. They are narrow,ranging in width from a few hundred yards to about three miles at , but averagingless than three-quartersof a mile. On the east is the Atlantic Ocean and on the west a series of broad shallow sounds;the northern ones, Back Bay and Gurrituck, are fresh or slightlybrackish and the southern,Albemarle, Croatan, and Pamlico, are about as salty as the sea. The barrier islands.have been formed by action of the waves,and much of their surfaceis but a few feet abovesea level although there are many high shifting . The low elevation, abundanceof winter rainfall, extremelyhigh tides,and occasionalpartial inunda- tion when strongwinds continue from the west,produce many tem- porary pondsand wet meadowsthat are favorablefeeding areas for the wintering Greater SnowGeese, Canada Geese (Branta cana- densiscanadensis), and severalspecies of ducks. The formerinaccessi- bility of the islandsand the difficultiesand expenseincident to the buildingand maintenanceof surfacedroads in a soil of nearlypure sand have tended to discourageextensive human developmentand to preservea greatdeal of the wild and primitivecharacter of the region. An importantconsequence has beenthat the habitatfor migratorywaterfowl here hasnot diminishedto the extentof other Atlantic coastalwintering grounds. 52'• HOWARD,Wintering o! GreaterSnow Geese L[ AukOct.

ARRIVAL AND DEPARTURE Temperatureappears to be an importantfactor in the time and rate of arrivalof SnowGeese on the Banks,according to SamuelA. Walker of the Pea Island Migratory Waterfowl Refuge. If cold weather prevailsduring the fall, the geesegenerally arrive in large groups within the spaceof a few days;warm weather seems to causethem to linger along the way, so that they arrive in small flocksover a con- siderablelength of time. Mcllhenny (1932) makesno mention of temperatureas a factor affectingthe arrival of Blue Geese (Chen caerulescens)on their wintering groundsin Louisiana,but statesthat he hasseen small flocks on the Gulf Coastas early asAugust, and that heavymigration occurs in late Octoberand early November. The dates of arrival and departure of Blue Geesein Louisiana and of Greater Snow Geese in North Carolina are about the same, despitethe markeddifference in latitudeof thesetwo places. During the rather mild fall of 1937, ten Snow Geese and two Blue Geese were notedat Pea Island on November4, and fifteendays later only 200 Snow Geeseand sevenBlue Geesewere present. By December14 the number of Snow Geese had increased to about 5,000, and another flock of about 2,000 had been discovered near the small settlement of Corolla,some sixty milesto the north. This smallergroup seemed to be in no hurry to reach Pea Island, as it was seenflying north of Currituck Beach Lighthouse on December 16, finally joining the Pea Island flock later in the month. If the temperatureis low late in winter, the birds stayon the coast,but when a few warm dayscome early in Februarythey are awayin a hurry; not as the CanadaGeese go, in small groupsover a period of severalweeks, but in two or three large flocks. In the winter of 1937-38,the maximumnumber of SnowGeese at Pea Islandapproximated 8,000. All were goneby February15. Harry A. Baileyof the BackBay MigratoryWaterfowl Refugestated that in 1939about 2,500 Greater Snow Geese remained at that refugeuntil March5. Statementsby otherobservers indicate that the largeflocks disintegrate into groupsof a hundredbirds or less while in migration (Eynon,1937; Shelley, 1937), but that they ap- parentlycome together again in largeflocks at selectedresting places (White and Lewis,1937).

NUMBERS ApparentlySnow Geese have never attained great numbers on the Atlanticcoast. Bent (1925)states that H. H. Baileytold him they were formerlynot numerousin Virginia. Forbush(19.25) records Vol.194o•7] a HOWAp,I•, Wintering o! GreaterSnow Geese 525 this speciesas an "abundant migrant coastwiseduring settlement of the country;now very rare straggler." Accordingto White and Lewis (1937),2,000 to 3,000Snow Geese stopped at St. Joachim,Que- bec, about 35 yearsago, while approximately10,000 are now seen there eachfall; this number,they think, includespractically all the Greater Snow Geese in existence. Local observers on the North CarolinaBanks believe that the geesehave probablybeen increasing in numberswithin the last few years. This apparentincrease might be attributed to a shifting of the wintering range from farther north along the coast,as it is known that the geesedo not selectthe same location every year. Observersfamiliar with conditionsalong the entire coast,however, do believe there is a definite upward trend in the number of Snow Geesewintering in Statesbordering the Atlantic Ocean. SHIFTING OF FEEDING GROUNDS A characteristicof GreaterSnow Geese on their winter rangeis their habit of stayingin large,compact flocks which move from placeto place to changetheir feedingsites. Althoughthis pattern of behaviorseems very firmly fixed, deviationsfrom it do occur. Two SnowGeese were seen at Lake Mattamuskeet, on the west side of , dur- ing the first weekin January1939, and accordingto Dr. MaynardS. Johnson,Refuge Manager at Mattamuskeet,they stayedall winter. Judgingby their preferencefor grassymeadows and marshhabitats along the Atlantic coast,one would not expect to find Snow Geese in the Lake Mattamuskeetlocality, which is situatedin farm land carved out of poorly drained œorest. Careful examination of a large flock reveals that it consistsof small units that probablyare families,as noted by McIlhenny in flocksof Blue Geese. Greater Snow Geeseat rest crowd closetogether in a large oval or elliptical massand maintain this formationwhile feeding, although they spreadout to a greater degree. In recentyears there have been two main flocksin the regionunder discussion. One winters south of on Pea Island or north of the Inlet on Bodie 'Island,' which is no longer an island but a peninsula. This flock is usuallyreferred to in the literature as the one that winters"in the vicinity of Cape Hatteras,"some forty miles south of Pea Island. Another flock winters near the head of Back Bay in Virginia. Back Bay is not alwaysused as a wintering range, accordingto CharlesO. Hahalley,who reportsthat during somewinters there are no SnowGeese on the landsbordering this freshwatersound. Largeflocks maintain neither size nor rangeduring an entirewinter, 526 HOWARD,Wintering o! GreaterSnow Geese LI' Auk Oct. as thereis likely to be tradingback and forth, and theymay change feeding groundsone or more times during the season. The Pea Island birds spent part of the winter of 1936-37 at the lower end of Bodie Island, on the tidal meadows and the artificial freshwater pond near the lighthouse. They movedto Pea Island, but returned to Bodie Island about the middle of December. Gunning was un- usuallyheavy at Pea Island, and this disturbancemight have caused them to seeka quieter location. There alsowas considerablehunt- ing there the next year,but despitethis the geesechose Pea Island as their winteringground, and did not occupythe tip of Bodie Island. Having been declared a Federal migratory-waterfowlrefuge in the springof 1938,Pea Island was dosed to huntingthe succeedingwinter, 1938-39. That year the maximum number of Greater Snow Geese there was about 2,000, while a total of about 2,500 birds was reached in Januaryon Bodie Island, lessthan fifteen miles to the north. In January 1938,a coastguardsman at the Pea Island Stationstated that he had not known of SnowGeese being at Pea Island until about five yearspreviously. He believedthat their numbersin that vicinity had been increasingand that they were then more numerousthan ever before. Cottam,Nelson and Williams (1957),in writing of the Pea Island and Bodie Island birds said "... during the last five years, their numbers have increasedfrom approximately a thousand to fully four timesthat number." For the birds at Pea Island in Janu- ary, Walker estimates3,000 in 1936,4,000 in 1937,8,000 in 1938,and 2,000 in 1939. The number at Pea Island doesnot necessarilygive a true index to the total number wintering on the Atlantic coast,but merelyindicates a shiftingof winter rangefrom year to year.

FEEDING HABITS The feedinghabits of Greater Snow Gccscarc probablylargely responsiblefor their shiftingfrom one feedinglocation to another up and down the coast. On land they fccd in the marshes,rarely in the sounds,but whenthey do go to openwater, it is usuallyto rest or to escapemolestation. When œccding,they head directly into the wind, and there is a continual'leap-frog' movement as small groupsfly forward from the rear to the front of the flock. Mc- Ilhcnny'sdescription of the feedingof Bluc Gccscalso applies to the behaviorof the Greater SnowGccsc. Feedingis done usuallycarly in the morningor late in the aœtcrnoon,but the refugemanagers at PeaIsland and BackBay said that it wasnot uncommonfor the birds to fccdalso on bright moonlightnights. Vol..•7]•94o a How•a•l•,Wintering o!Greater Snow Geese 527

The diet of the GreaterSnow Geeseseems limited to fewer items thanthat of theBlue Geese in Louisiana.Cottam (1955) states, "In theareas along the [Atlantic]coast where feeding observations were made,marsh grass (Spartina patens and S. alterniflora),with lesser quantitiesof saltgrass (DistichIfs spicata) and rushes (Scirpus ro- bustusand S. species)were being consumed. Some segments of the alkaliweed (Salicornia sp.) also were being taken." The geeseselect a localitywhere, to quote the natives, the cord grass is "belly deep on a cow." Preferredspots seem to be wherethe grassis standingin a fewinches of brackishor saltwater. If heavyrains or strongwinds or tidescause the waterto deepen,the birdsleave until morefavorable conditionsprevail. SnowGeese do not graze,but drive their bills into thesand at thebase of thegrass or sedgeand pull it outby the roots. After a few weeksof feedingin this mannerwhat was once a grassymeadow becomes a shallowfoul pool, completelydevoid of vegetation. As the meadowchanges to open shallowwater, a new habitatis createdthat is frequentedby ducksand shorebirds. During the winter of 1937-38, Snow Geesedenuded an area of approximately300 acres on PeaIsland. How manyyears must elapse beforethese bare flats will againbe clothedwith sufficientvegetation to be usedas feedinggrounds depends upon a number of factors- the soil, wind erosion, and water action. Plant successionis slow, as cord grassdoes not stolonizereadily and good seedyears seem to be far apart. During the vegetativesuccession the geeseare forced to changetheir feedinggrounds, so that a constantrotation of pastures takesplace. On BodieIsland there are wide,bare, windswept patches of sandwhere the geesehave fed in pastyears. Someof thesebarrens are knownto be four or five yearsold and yet showlittle or no sign of revegetation. Althougha flockof GreaterSnow Geese uses only a relativelysmall part of its range for feedingeach year, it seemsapparent that many thousandsof acresare necessaryto maintain the birds. Not only are feedingand restinggrounds necessary, but a certain amountof buffer area is essentialto protect them from the disturbanceof vehicular trafficand other annoyances. Bent (1925) quotesDr. Elliot as stating that sometimeprior to 1898 flocksof considerablesize occasionallyfrequented the inner beachof CurrituckSound where the waterwas brackish, but that they did not staylong in suchplaces. Walker told the writer that between 1915 and 1920 the birds winteredregularly in that location. He saidthey stayed in the marshesand alongthe beachesand did notfeed 528 Howx•a•,Wintering of GreaterSnow Geese L[' AukOct. in the sounds.A largenumber of hogswere kept by the 'Bankers' about that time, and the SnowGeese picked up considerablefood by eating rootsof grassesand sedgesturned up by the swine. An- other sourceof food wasgrain left by huntersas bait for other kinds of waterfowl. Baiting is now illegal, and grain has thereforeceased to be an item in the diet of Greater Snow Geese. In the West, Lesser Snow Geese (Chen h. hyperborea)feed in grain and stubble fields, but as small grains are grown to a very limited extent near the east coast,Greater Snow Geese have little or no accessto this type of food. Bent believesthis may be why their winter range is restrictedto the coastal marshes and beaches. From Back Bay to Pea Island is a stretchof open water that ranges from freshor slightlybrackish to salt. At varioustimes in the past the SnowGeese have been reportedas winteringadjacent to these waters. At Pea Island the birds feed in water that is more or less constantlychanging in degreeof salinityowing to inundationof the feedinggrounds by hightides and heavyrains. The irregularflights of the flockfrom Pea Island north to the freshwaterpond on Bodie Islandmay be causedby a desireor needfor a changein water. A freshwaterpond has been recently created on PeaIsland by the Bio- logicalSurvey in its refuge-developmentprogram, and its useby the SnowGeese will be interestingto study.

ADULT--IMMATURE P-•.T I o The proportionof immatureto adultbirds apparently varies widely fromyear to year. Cottam,Nelson and Williamsstate that, when theyvisited Pea Island and Bodie Island in January1957, from 15 to 20 percent of thebirds were in immatureplumage. On January 26, 1958,the writerdrove his car to within a hundredyards of a large feedingflock at PeaIsland. Assmall units flew from the rear to the front of the flockthe individualsin 78 groupswere counted. A total of $80 birds was tallied; of this number 257, or 65.8 plus per cent, werein the grayplumage of the young,and 155,or $4.1plus per cent,were white. Of these78 units,61 had oneor two adultsand oneor morejuveniles, five had no juveniles, and nine had more than twoadults. The averagesize of a unit wasa little overfive birds. The followingwinter there were rumors that there were very few birdsin thejuvenile plumage at PeaIsland or BackBay. On Janu- ary6 and7, thewriter with the aid of a binocularmade counts while the flockwas on the groundand in the water. Suchenumerations are much lesssatisfactory than when the birds are in the air in small Vol.194o57] a I-IowAR9,Wintering of GreaterSnow Geese 529 bunches,as the geesestay so closetogether that countingis difficult. The mostsatisfactory method when they are on the groundis to note the birds at eachend of the flock where they spreadout more than they do nearerthe center. Of 290 birds counted,36, or 12.4 plus per cent, were in juvenile plumageand 254, or 87.5 plus per cent, werein the white plumageof the adult. Countsof suchsmall num- bersprobably do not revealthe true percentages,but they do give a good enoughapproximation to indicate considerablevariation in the ratio of youngto adultsfrom year to year.

BLUE G,•ES•. The appearanceof Blue Geesein the flocksof Greater SnowGeese in North Carolinaand Virginia seemsto be a phenomenonof recent years. Recordsof this bird'soccurrence in the Eastwere compara- tively rare until the winter of 1954-$5. Sincethen there has been a generalincrease in numbersin the Statesalong the Atlantic coast. The causeof this suddenand continuedappearance is not known, but Cottam (1955)advances the suggestionthat it may be due to a combinationof factors,including strongnorth and northwestwinds during migration,increase in populationforcing dispersion, disturb- anceon winteringgrounds causing wandering, and droughtalong the migratory lane. Cottam, Nelson, and Williams noted small flocks of Blue Geeseon PeaIsland and BodieIsland for the threeyears prior to 1957. On January 14, 1958,James O. Stevensonand the writer observedseven adult and nine immature Blue Geeseamong the flock of Greater Snow Geeseon Pea Island, and January 7, he noted four Blue Geeseand one White-fronted Goose (Anseralbifrons) at Back Bay, Virginia. PREDATORS From informationat hand, prcdatorsdo not sccmto bc of great importanceto the wintering Greater Snow Gccsc. While at Pea Island they arc saœcfrom molestationby foxesand roving dogs,as there is no way for thesemammals to reachthe island. At Back Bay the situationis different,foxes being present. During the winter of 1958-$9, evidence disclosed that eleven Snow Gccsc had bccn caren by foxes. Sufficientproof to convictthe fox as a seriousprcdator in this area is lacking,and it is thoughtthat the evidenceprobably repre- sentsprcdation on crippledor sickbirds, and is of little importance. Likewise,from presentinformation, the Eagleand Duck Hawk can- not be consideredas doing much damage. At varioustimes the writer has seena Bald Eagle (Haliaegtusleucocephalus) or a Duck Hawk 530 HowAlto,Wintering o[ GreaterSnow Geese L[ AukOct.

(Falco peregrinusanatum) fly over a flock of Greater Snow Geese. The birdsbecame alarmed and left the groundin a body,but their fright seemedof shortduration, as theysoon settled to earthafter the raptors had left. The same behavior resulted when a Great Blue Heron (Ardea herodiasherodias) or an airplaneflew over them. When a Duck Hawk or a Bald Eaglewas on the ground,the geese paid it little attention. Evenone of thesebirds feeding upon a goose in the midstof a flockoccasioned little notice;the geesecontinued to feed as thoughthe occurrencewas a perfectlynatural one. Inquiry amonglocal observers failed to revealany records of geesebeing struck on the wing by an Eagle or a Duck Hawk, but Jameso. Stevenson reported seeinga Duck Hawk make a few swoopsat geeseon Pea Island. He thought the hawk was playing, since its attemptsat capturedid not seemserious. Mcllhenny describesEagles and Duck Hawks killing Blue Geese,and Bent quotesAudubon as mentioning "White-headedEagles and other rapaciousbirds" attacking Greater Snow Geese. Flocksof Greater Snow Geese,while restingand feeding,are oc- casionallyintermingled with small groupsof Canada Geese,but the two speciesrarely fly together. Blue Geeseand GreaterSnow Geese mingle, but as Cottam, Nelson, and Williams have observed,there is a tendencyfor the former to maintain their positionas small units of the larger group. This is true at least while the birds are on the ground. PROTECTION AND MANAGEMENT Hunting of all SnowGeese in the Statesbordering the Atlantic Oceanhas been prohibitedsince the Migratory Bird Treaty Act was passedin 1918. Accordingto statementsof an old-timemarket hunter,they were neverheld in high reputeas a gamebirdalong the North Carolina coast. Pearson,Brimley, and Brimley (1919) state that "the White Brant'sflesh is not very palatable,and the birds are seldom,if ever, hunted in this State." These large white geeseused to be considereda nuisancebecause they ate the grain setout for other waterfowl. If a few of them happenedto fly over a blind they werelikely to bekilled, but apparently tt/ey were never subjected to heavyhunting pressure by sportsmen.They were,however, a favor- ite objectof 'fire-lighting'by localpot hunters. Now, of course,they enjoythe protectiveefforts of both Federaland StateGovernments. The BiologicalSurvey is taking definite stepsto preservesome oœ the winter range for the Atlantic Coast flock of Snow Geeseand has establishedwaterfowl refugesalong the coastin severalStates. From Vol.1940•7] a HOWARD,Wintering o! GreaterSnow Geese 531 early indications,the protectiveand restorativemeasures taken at the waterfowlrefuges at Pea Islandand BackBay will be of considerable benefitto this speciesas well as to othermigratory waterfowl. Kes- rotation work by CCC campsat both theserefuges includes such activitiesas control of wind erosion,building of freshwaterponds and experiments'in food planting. Becausethe placeswhere the geesefeed revegetatevery slowly,experiments to renew the denuded standsof cord grassare being undertaken in connectionwith other phasesof management. Stepsare under way at the presenttime to createthe Cape Hatteras National Seashore, which will embrace most of the North Carolina coastfrom near the Virginia-North Carolina state-lineto the lower tip of OcracokeIsland. When established,the National Seashorewill be under the jurisdictionof the National Park Service,of the Depart- ment of the Interior, and thus a large part of the winteringgrounds of the SnowGeese along the Atlantic coastwill be in Federal owner- ship. Encroachmenton the winteringgrounds of the Greater Snow Geeseseems to be definitelyhalted.

LITERATURE CITED

AMERXCAN ORNXTHOLOaISTS' UNXON 1931. Check-listof North Americanbirds. 4th ed., 526 pp. BENT, ARTHUR CLEVELAND 1925. Life histories of North American wild fowl. Bull. U.S. Nat. Mus., no. 130, 376 pp., 60 pls. COTTAM, CLARENCE 1935. Blue and Snow Geese in eastern United States in the winter of 1934-35 with notes on their food habits. Auk, 52: 432-443. COTTAM, CLARENCE,NEI•ON, A. L., AND WILLIAMS, C. S. 1937. Uncommon winter birds in coastal North Carolina. Auk, 54: 548-549. EYNON, ALFREDE. 1937. Migrating Snow Geesein northern New Jersey. Auk, 54: 532. FORBUSH,EDWARD H. 1925. Birds of Massachusettsand other New EnglandStates. VoL I (1929re- print), 481 pp. MCILHENNY, ]E. A. 1932. The Bluc Goose in its winter home. Auk, 49: 279-306. PEARSON,T. GILBERT,BRIMLEY, C. S., ANDBRIMLEY, H. H. 1919. Birdsof North Carolina. 380 pp. SHELLEY, LEWIS O. 1937. GreaterSnow Goose in New Hampshire. Auk, 54: 532. WHITE, E. F. G., ANDLEWIS, HARRISONF. 1937. The Greater Snow Goose in Canada. Auk, 54: 440-444. U.S. BiologicalSurvey Washington,D.C.