HISTORICAL AND PRESENT BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN

LORI T. QUAKENBUSH, Schoolof Fisheriesand Ocean Sciences,University of Alaska,Fairbanks, Alaska 99775-7220 (currentaddress Alaska Department of Fish and Game, 1300 CollegeRoad, Fairbanks,Alaska 99701-1599) ROBERT H. DAY and BETTY A. ANDERSON, ABR, Inc.-- Environmental Re- search& Services,P.O. Box 80410, Fairbanks,Alaska 99708-0410 FRANK A. PITELKA, Universityof California,Museum of VertebrateZoology, Berkeley,California 94720-3160 BRIAN J. McCAFFERY,Yukon Delta National Wildlife Refuge, P.O. Box 346, Bethel, Alaska 99559

ABSTRACT: The Alaska breedingpopulation of the Steller'sEider (Polysticta stelleri) occursas two subpopulations,one on the coastalplain of northern Alaska,primarily near Barrow,and the other on the Yukon-KuskokwimDelta of western Alaska. In 1997, the Alaska breedingpopulation was listed under the EndangeredSpecies Act as threatenedbecause the nestingrange and population were thoughtto have decreasedsubstantially. The historical(pre-1970) and recent (1970-present)breeding distribution and abundanceof Steller'sEiders, however, are not well known. We compiledand evaluatedthe historicaland recent recordsof breeding-seasondistribution, confirmed nesting for northernand western Alaska, and foundthat the overallsizes of the breedingranges have not changedsubstantially; however, the frequencyof breeding has decreasedin both regions, except near Barrow.Causes of thisreduction in breedingfrequency of Steller'sEiders in Alaskaare unknown,but changesin predatorpopulations, lead poisoning,and interspecific nestingassociations with Snowy Owls (Nyctea scandiaca)and PomarineJaegers (Stercorariuspomarinus) may be contributingfactors.

Three geographicallydistinct breeding populations of Steller'sEiders (Polystictastelleri) are recognized,two in arcticRussia and one in Alaska, withthe greatestnumbers occurring in the easternRussian Arctic (Nyg&rd et al. 1995; Figure1). The Alaskabreeding population is the smallestof the three and comprisestwo geographicsubpopulations, one on the Arctic coastalplain of northernAlaska, the otheron the Yukon-KuskokwimDelta of westernAlaska. The Alaskabreeding population was listed as threatened underthe EndangeredSpecies Act in 1997 becauseit wasthought that the species'nesting range in Alaskahad decreasedsubstantially and that the overallnumber of birdsnesting in Alaskaprobably had decreasedsubstan- tially as well (U.S. Federal Register62:31748-31757). That decision, however,was basedon little information.In this paper, we summarizeand evaluate the historical(pre-1970) and recent (1970-present) breeding distributionand frequencyof Steller'sEiders in Alaskaand discusspossible reasonsfor changes.

METHODS

We compiledboth positive (presence) and negative (absence) observations on the breeding-seasondistribution and breeding frequency of Steller'sEider in Alaska from publishedand unpublishedliterature, museum records,

WesternBirds 33:99-120, 2002 99 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

RUSSIA

Peninsula - •o'•' •ø•'g' Novaya Zemlya AlaskaBreeding

World Distribution Pa•ficPopulation AtlanticPopulation CurrenlBreeding Distribut•on CurrentWintering Distribu•on

Figure1 The currentbreeding and winteringranges of Steller'sEider. The bar at the mouth of the Khatanga River in Russiamarks the boundarybetween Pacific and Atlantic populations. personal communications,and field notes (also see Boarman and Coe 2000). We useddaily or seasonalbird listswhen they existedbecause study reportsdid not alwaysreport on nonlocalspecies. Positive records included Steller'sEiders seen during the breedingseason (May-September) and only on land or freshwater: known migrantsand moltingconcentrations were excluded.Negative records included visits to a specificlocation within the historicalrange of Steller'sEider. during the breedingseason, in whichno Steller'sEiders or evidenceof nestingwere observed.Because Quakenbush and Suydam(1999) found that Steller'sEiders did not nest annuallynear Barrowin the 1990s, despitebeing present, we madea distinctionbetween sightings("occurrence") and evidenceof nesting("breeding"). We did not includeobservations from aerial surveysbecause these surveys do not yield evidencefor nesting.but we did summarizethe distributionof aerial-survey observationsto compare them with those made from the ground. To comparethe past and presentdata setsfor possibledeclines in either the occurrenceor breedingfrequency of Steller'sEiders, we dividedthe recordsinto historical(pre-1970) and recent (1970-present). We chose

100 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

1970 as the divisionbetween periods because of the increasein multiyear ornithologicalstudies that beganon the Arctic coastalplain in conjunction with oilfielddevelopment and studiesin the Yukon-KuskokwimDelta that expandedand intensifiedabout that time. We tabulatednumbers of site-yearsof occurrenceand breedingduring each period. A site-yearreflects data for one year at a particularlocation (site)during the breedingseason. Observations ranged from single-daysite visitsto multi-monthstudies. Potential problems exist because of the greater effort in a longer-termstudy and becausefew siteshave been visited with equaleffort in both periods.To reducethe effectsof this possiblebias, we comparedpooled data from all siteswith data from a subsetof sitesthat had beenvisited in both periods. A compilationof site data by period allowsa qualitativeestimate of distributionand breedingfrequency of Steller'sEiders in Alaska.Because of the qualitativenature of thesedata, thesefrequencies are not estimatesof absolutechange but revealtrends of occurrenceand breeding.

RESULTS

Northern Alaska

Historicaldata suggest that Steller'sEiders formerly occurred across much of the Arctic coastalplain [Anderson1913, Brooks1915, Bailey 1925, 1948, Bent 1925, Bee 1958, Fiscus1952 in Gabrielsonand Lincoln 1959, Gill et al. 1985, Quakenbushand Cochrane1993; egg collectionsin the WesternFoundation of VertebrateZoology, Camarillo, California (WFVZ), andDenver Museum of NaturalHistory, Denver, Colorado (DMNH; Figure 2)]. They alsowere recordedin northwesternCanada as far east as Cape Bathurst,Northwest Territories, and in four of five pre-1970 site-years betweenKaktovik and Cape Bathurst, Northwest Territories, suggesting that the speciesformerly occurred there regularly(Anderson 1913, Brooks 1915, Dixon 1943). Althoughthe speciesapparently ranged widely over the Arctic coastal plain and into northwesternCanada, unequivocalhistorical evidence of nestingis availableonly from Wainwright to Cape Halkettin Alaska(Bailey 1925, 1948, Stone1900 in Gabrielsonand Lincoln 1959, Bee 1958; egg collectionsin WFVZ, DMNH, and Museumof VertebrateZoology, Univer- siN of California,Berkeley; Figure 2). Verbalaccounts of nestinginclude locationsas far eastas the ColvilleRiver Delta (P. Sovalik in Myres1958) and CollinsonPoint near Kaktovik (W. Patkotak in Quakenbushand Cochrane 1993), but there are no definitivehistorical records of nestingeast of Cape Halkett.Regardless of the easternlimit of nesting,the speciesoccurred and nestedwith greatestfrequency in the vicinity(within 20 km) of Barrow (Myres1958, Gabrielsonand Lincoln 1959, Pitelka1974, Quakenbushand Suydam1999)and, secondarily,elsewhere within the Arcticcoastal plain at leastas far eastas Cape Halkett (Figure2). Recentoccurrence extends from Wainwrightto the SagavanirktokRiver, with one recordfrom HerschelIsland, Yukon Territory,Canada (Talarico and Mossop1986); however,there are no recent sightingsbetween the SagavanirktokRiver and the Alaska-Canadaborder (Figure 3). In addition,

101 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

102 BREEDING SEASON DISTRIBUTION OF STELLER'S IN ALASKA

103 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA aerial surveysflown annuallybetween 1989 and 1999 have accumulated sightingsof 436 Steller'sEiders at 180 locationson the Arcticcoastal plain (Larned et al. 1993, Brackneyand King 1993, 1994, Balogh and Larned 1994, Larnedand Balogh1994, King and Brackney1995, King and Dau 1997). These surveysfound that Steller'sEiders were widely distributed betweenPoint Lay and the SagavanirktokRiver, with only three sightings betweenthe Colvilleand Sagavanirktokrivers and the highestdensities near Barrow. An aerial surveyflown near Barrow, AdmiraltyBay, and Meade River in 1999 and 2000 also found Steller's Eiders to be most common near Barrow (Ritchieand King 2001). Recentunequivocal nesting records range from Barrowto inlandon the ColvilleRiver (Figure3), with the Barrow area still being the center of abundanceand primary nestinglocation in northern Alaska. There is no unequivocalevidence of recent nestingeast of the ColvilleRiver, despite extensivefieldwork in this region. M. M. Johnson(Univ. of Calif., Davis, pers. comm.) saw a flight-capablebrood on Lake Colleen, near the SagavanirktokRiver, and K. Russell[U.S. Fishand Wildlife Service (USFWS), Fairbanks,pers. comm.]saw a flight-capablebrood on ElusiveLake in the BrooksRange; however, these may have flownconsiderable distances from their breedingsites. Occurrenceand breeding status are availablefrom the Arcticcoastal plain for 106 historicaland 151 recentsite-years. Steller's Eiders were recorded during75% of historicalsite-years but only 36% of recentsite-years (Figure 4). Breedingfrequency, based on yearsof occurrence,was 49% of historical site-yearsbut 33% of recent ones (Figure 5). Fourteen sites between

o 60-•

20i

10•I

•JI sites 14 sites Barrow 13,s•tes (wlo I•rrow)

Figure4. Percentageof site-yearsthat Steller'sEiders were presentbefore (shaded bars) and after (white bars) 1970 in northern Alaska. The number of site-years appearsabove bars.

104 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

lOO

9o

80

70

All sites 14 s•tes Barrow 13 sites(w/o Ban'ow)

Figure5. Percentageof site-yearsthat Steller'sEiders were breedingwhen present before (shadedbars) and after (whitebars) 1970 in northernAlaska. The numberof site-yearsappears above bars.

Wainwrightand the SagavanirktokRiver have both historicaland recent data for comparison(Table 1). These data indicatedeclines in occurrence (from 76% of historicalto 52% of recentsite-years; Figure 4) and breeding frequency(from 51% to 39%; Figure 5), as do all recordseast of the SagavanirktokRiver. During 12 yearsof recentstudies on the ColvilleRiver Delta,there was only one recordof occurrenceand no evidenceof breeding. Data on occurrenceand breeding within 10 km of Barrowfor 39 historical and 21 recentsite-years (1881-2000), however,do not suggestdeclines (Figures4 and5). Steller'sEiders were recorded during 97% of historicaland 95% of recentsite-years, and they bred in 55% of historicaland 70% of recentsite-years (Figures 4 and 5). If the Barrow data are omitted from the subset of sites with both historical and recentrecords, the frequencyof occurrencestill declines from 56% to 36% of site-years(Figure 4). The declinein breedingfrequency, however, is much greater--from 43% to 5% (Figure5). These data clearlyindicate a reductionin both occurrenceand breedingfrequency for the Arcticcoastal plain, except near Barrow (Figures4 and 5).

Western Alaska There are only four historicalbreeding records for the westernAlaska subpopulationnorth of the centralYukon-Kuskokwim Delta (Figure6). A broodof three was seenin 1879 at Port Clarence,on the SewardPeninsula (Portenko1972, Kessel1989), five eggswere collectedfrom a nest at St. Michael(WFVZ), and there were two reportsof nestingfor St. Lawrence Island(Nelson 1887, Fay and Cade 1959); however,only the reportby Fay and Cade (1959) was substantiated.

105 BREEDING SEASON DISTRIBUTION OF STELLER'S EIDERS IN ALASKA

Table 1 Distribution of Steller's Observations in Northern Alaska duringthe BreedingSeason (May-September) a

Time Total Site-years Site-years Locationb periodc site-yearsd present breeding

Cape Sabine H 4 3 0 PointLay R 10 0 0 Icy Cape R 1 1 0 Wainwrighte H 10 7 1 R 2 1 0 Kaolak River H 2 0 0 PeardBay • H 1 1 0 R 2 1 0 Barrow • H 39 38 21 R 21 20 15 Meade/ChippRivers e H 6 2 2 R 2 1 0 Meade River R 2 0 0 Atqasuk• H 1 1 0 R 4 1 0 Inaru River H 3 2 0 Meade River Delta • H 2 1 0 R 1 0 0 AdmiraltyBay H 1 1 1 Dease Inlet H 1 1 1 Singiluk R 1 1 0 TopagarukRiver H 1 1 1 ChippRiver H 4 4 2 CapeSimpson H 4 2 2 Pitt Point/Lonely• H 6 4 4 R 1 0 West/EastLong, GooseLakes R 5 1 0 Island Lake R 2 1 0 TeshekpukLake H 1 0 0 SquareLake R 1 0 0 CapeHalkett • H 3 3 2 R 1 1 0 KogruRiver R 1 0 0 Colville River• H 2 0 0 R 1 1 1 Colville River Delta • H 3 3 17 R 12 1 0 Umiat area • H 4 0 0 R 1 0 0 Anaktuvuk Pass H 1 1 0 Milne Point R 1 1 0 Oliktok Point R 5 2 0 SakonowyakRiver R 3 1 0 BeecheyPoint R 2 0 0 KuparukRiver Delta R 1 0 0 Storkersen Point • H 1 1 0 R 8 4 0

(continued) 106 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

Talkie 1 (Continued)

Time Total Site-years Site-years Locationb periodc site-yearsd present breeding

Pt. Mcintyre R 1 0 0 PrudhoeBay e H 1 1 0 R 21 13 SagavanirktokRiver • H 1 0 0 R 2 0 0 Franklin Bluffs R 1 0 0 Elusive Lake R 1 1 Kadleroshilik River R 2 0 0 Shaviovik River Delta R 2 0 0 Bullen Point R 1 0 0 CanningRiver Delta R 6 0 0 TamayariakRiver R 3 0 0 Katakturuk River R 3 0 0 Marsh Creek R 1 0 0 Sadlerochit River R 3 0 0 Collinson Point H 1 1 Hulahula River R 1 0 0 OkpilakRiver Delta R 3 0 0 JagoBitty R 2 0 0 JagoRiver Delta R 2 0 0 Nuguanak R 1 0 0 Barter Island/Kaktovik H 1 1 0 R 1 0 0 HumphreyPoint H 1 1 0 Aichilik River Delta R 2 0 0 NuvagapakPoint R 1 0 0 Demarcation Point H 1 0 0 Totals H 106 80 39 R 151 54 18 HerschelIsland, Yukon R 1 1 0 CapeBathurst, Northwest Territories H 1 1 0

øSurveysthat failedto recordSteller's Eiders are included. bArrangedgeographically, from west to east. OH,historical (before 1970); R, recent (since1970). aA site-yearreflects data for a particularlocation during one year. eOne of 14 sites with both historical and recent data. fLocationof flight-capablebrood, origin unknown.

Southof the Yukon-KuskokwimDelta, three reports,none substantiated, suggestbreeding by Steller'sEiders. Notes from ChaseLitttlejohn, published by Bent (1925) and later by Gabrielsonand Lincoln(1959), indicatedthat a few Steller'sEiders nested at MorzhovoiBay on the AlaskaPeninsula, but no evidenceof nestingwas provided.In 1872, Dall (1873) collectedan egg reportedto be from a Steller'sEider nest in UnalaskaBay. The birdcollected

107 BREEDING SEASON DISTRIBUTION OF STELLER'S EIDERS IN ALASKA

p-re-19•O Present/ Breeding Present/ NotBreeding Not Present Ques'donableBr•i•

Figure6. The occurrenceand breeding distribution of Steller'sEider in westernAlaska (May-September)before 1970.

108 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA with the egg, however,was an adult male Steller'sEider, although it was recordedas a female on the data card (J. Dean, National Museumof Natural History,Washington, D.C., in litt.)and was published that way (Dall1873). The egg'sdimensions are withinthe rangeof Steller'sEider eggs measured near Barrow(Quakenbush et al. 1995, Quakenbush,unpubl. data); unfortu- nately,so are thosefor 10 of 13 speciesof waterfowlthat breedregularly in the Alaska Peninsula/easternAleutian Islandsregion (data from Bellrose 1978). Turner (1886) wrote that the species"breeds sparingly on Island,"according to local Natives.Murie (1959) did not find any nesting alongthe AleutianIslands, and Nativesat Attu did not recognizepictures of Steller'sEiders, saying that they did not occurthere, even in winter.Murie (1959) found no evidenceof breedingon the Alaska Peninsulaor the Aleutiansin 1936 or 1937, and none hasbeen reported since then, despite many visitors. Althoughsuggestive of sporadicbreeding in low numbers,these records shouldnot be regardedas conclusiveevidence that Steller'sEiders were regularbreeders in the Aleutiansor on the Alaska Peninsulain historical times. This regionincludes the major winteringarea for the species,and immatureor nonbreedingbirds could summerthere. Pair formation also occurson the winteringgrounds (Metzner 1993), so courtingbehavior prior to migrationmay havesuggested nesting to earlyobservers, such as Dall and Littlejohn. Historically,the greatestnumber of breedingSteller's Eiders in western Alaskaoccurred on the Yukon-KuskokwimDelta, where they nestedin the outer coastalzone from KokechikBay south to possiblyNelson Island (Conover 1926, Brandt 1943, Gabrielsonand Lincoln 1959, Shepherd 1963, Kertell 1991; Figure6). Steller'sEiders were reported(but were not breeding)as far inland as 150 miles from the coast (Gillham 1941). No historical records are available from the Yukon-Kuskokwim Delta south of , and historical midsummer records from appearto be of Steller'sEiders that were molting,not breeding(Dau 1987). As of 1990, Steller'sEiders were thoughtto have been extirpatedas a breedingspecies from the Yukon-KuskokwimDelta becauseno nestshad been found there since 1975 (Kertell 1991). Between 1991 and 2000, however,six nests were found(Flint and Herzog 1999; M. Herzog,Univ. of Alaska,Fairbanks, pers. comm.), indicating that Steller'sEiders continue to nest there in extremely low numbers.The recent nestingdistribution appearsto be restrictedto the Kashunuk,Tutakoke, and Opagyarakrivers of the centralportion of the delta (Table2, Figure7; Kertell 1991, Flint and Herzog1999, C. J. Lensinkin litt.).Although the speciesnested historically at KokechikBay, it now occursthere only rarely and has not been seen nestingsince 1969 (Table2; Kertell1991). No recentdata are availableto determinewhether Steller's Eiders breed south of NelsonIsland. Away from the Yukon-KuskokwimDelta, recentsurveys for nestingSpectacled Eiders (Somateriafischeri) on St. LawrenceIsland recorded many Steller'sEiders but no evidenceof breeding(S. Stephenson,USFWS, Anchorage,pers. comm.). Overallin westernAlaska, Steller's Eiders were recordedduring 80% of historicalsite-years but only 47% of recentsite-years (Figure 8). Duringyears

109 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

Table 2 Distribution of Steller's Eider Observations in Western Alaska duringthe BreedingSeason (May-September) ø

Time Total Site-years Site-years Locationb periodc site-yearsa present breeding

Cape Lisburne R 2 0 0 Point Hope H 1 1 0 Cape Seppings H 2 2 0 Cape Thompson H 2 0 0 R 2 1 0 Cape Krusenstern R 2 0 0 Kotzebue R 1 0 0 BeringStrait H 1 1 0 Wales/LoppLagoon H 11 11 0 R 1 0 0 Tin City R 1 0 0 Nome H 3 3 0 SledgeIsland H 1 1 0 Port Clarence H 1 1 1 St. LawrenceIs., general H 3 3 1 North side R 1 1 0 South side H 2 1 0 R 1 1 0 Gambell H 15 14 1 R 1 1 0 Savoonga H 3 3 0 Yukon Delta coast H 2 2 0 Yukon-Kuskokwim,general H 2 1 0 St. Michaels/Stebbins H 1 1 1 R 3 1 0 Kolomak River H 5 3 0 KokechikBay • H 2 2 2 R 11 1 0 HooperBay H 2 2 2 Chevak R 1 1 0 Keoklevik River R 1 1 0 Old Chevak e H 2 1 1 R 3 3 0 Kashunuk River• H 12 8 5 R 18 10 3 Punoarat Point R 2 2 0 Tutakoke River R 15 9 2 OpagyarakRiver • H 1 1 1 R 11 5 2 Anerkochik River R 8 1 0 Naskonat Peninsula R 1 1 0 KigigakIsland H 1 1 1f R 8 5 0 Nelson Island H 2 1 If Napakiakarea H 2 0 0 Nunivak Island H 2 2 0

(continued)

110 BREEDING SEASON DISTRIBUTION OF STELLER'S EIDERS IN ALASKA

T•,ble :• (Continued)

Time Total Site-years Site-years Locationb periodc site-yearsd present breeding

GoodnewsBay H 1 1 0 UnknownBering Sea island H 1 1 1 NelsonLagoon H 1 1 0 MorzhovoiBay H 1 1 If AleutianIslands, general H 3 0 0 H 1 1 Island R 1 1 0 AgattuIsland H 1 1 If Totals H 90 72 21 R 95 45 7 aSurveysthat failedto recordSteller's Eiders are included. bArrangedgeographically, from north to south. OH, historical(before 1970); R, recent (since 1970). dAsite-year reflects data for a particularlocation during one year. eOne of four sites with both historical and recent data. fNestingreported at thislocation without substantiation. •Possiblemisidentification of the one egg foundat this location(see text). whenthey were present, breeding frequency declined from 29% of historical site-yearsto 16% of recent ones (Figure9). In the core of the species' westernAlaska breeding range on the centralYukon-Kuskokwim Delta from KokechikBay to NelsonIsland (excluding Nunivak Island), the dataalso indicatethat Steller'sEiders were recordedmore frequentlybefore 1970 (70% of site-years)than more recently(49%; Figure 9). During years of occurrence,breeding frequency declined, from 68% of historicalsite-years to 18% of recentones (Figure 9). Data from four siteswith historicaland recentrecords (Kokechik Bay, Old Chevak,Kashunuk River, and Opagyarak River;Table 2) alsoindicate declines in occurrenceand breedingfrequency (Figures8 and 9), suggestingthat the recent declinesare not causedby greaternumbers of samplesfrom unoccupiedor marginalhabitat.

DISCUSSION

BreedingSeason Distribution and BreedingFrequency This comparisonof historicaland recent sightingsof Steller'sEiders demonstratesa reductionin the breeding-seasondistribution of thisspecies in northernAlaska. Apparently, it formerlyoccurred regularly to the Alaska- Canadaborder, and possiblyinto northwesternCanada. Currently, it occurs only as far eastas the SagavanirktokRiver. Historical and recentnesting recordsof Steller's Eiders in northern Alaska, however, do not indicate a contractionof the breedingrange. The northwesternArctic coastal plain,

111 BREEDING SEASON DISTRIBUTION OF STELLER'S EIDERS IN ALASKA

Figure7. The occurrenceand breeding distribution of Steller'sEider in westernAlaska (May-September)since 1970.

112 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

90

0 All s•tes Central Y-K Delta 4 sites

Figure8. Percentageof site-yearsthat Steller'sEiders were presentbefore (shaded bars)and since (white bars) 1970 in westernAlaska. The numberof site-yearsappears above bars. especiallythe Barrowarea, remainsthe primarynesting area for Steller's Eiders,and historicalrecords do not reflecta broaderbreeding distribution. Oral accounts,however, suggest that breedingwas regular farther east at the ColvilleRiver Delta and near Kaktovik.Breeding frequency has decreased eastof Barrowfrom AdmiraltyBay and itsdrainages to the ColvilleRiver. In

7oi

All s•tes

Figure9. Percentageof site-yearsthat Steller'sEiders were breedingwhen present before(shaded bars) and after (whitebars) 1970 in westernAlaska. The numberof site-yearsappears above bars.

113 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA contrast,occurrence and breedingfrequency at Barrow, the mostimportant nestingarea for the species,are stableor increasing. We foundthat, in historicaltimes, Steller's Eiders probably did not nest regularlyin westernAlaska outside of the centralYukon-Kuskokwim Delta. Both occurrenceand breedingfrequency on the Yukon-KuskokwimDelta have decreasedsince 1970, but nestingcontinues there in low numbers (Flintand Herzog 1999), contra Kertell(1991). We believethat nestingon the SewardPeninsula and St. LawrenceIsland was sporadic and no longer occursthere. We alsobelieve that nestingmay havebeen occasionalin the AleutianIslands-Alaska Peninsula region but emphasizethat there is no conclusive evidence.

Causesfor ReducedBreeding Frequency Causesfor reductionsin the breedingfrequency of Steller'sEiders on the Arcticcoastal plain away from Barrow are not cleanMyres (1958) notedthat Native childrenwere effectiveegg collectorswithin 16 km of Barrow. This area, however,is the one locationwhere the frequencyof occurrencehas beenstable and the frequencyof breedinghas actuallyincreased. Hunting pressureon thisspecies across Alaska has been minimal (Wentworth 1994, Wentworthand Seim 1996, Paige et al. 1996), and sport and subsistence huntingfor Steller'sEiders has been illegalin Alaskasince 1991. Habitat lossfor this speciesacross the statehas alsobeen minimal,although recent housingdevelopments in the Barrow area have resultedin the lossof a few known nest sites. Causesfor reductionin the occurrenceand breeding frequency of Steller's Eidersin westernAlaska are unknown.Kertell (1991) presentedan exten- sive list of possiblereasons, none of which have been discounted.In addition,lead poisoning from ingested lead shot may be a sourceof mortality for Steller'sEiders in both of the Alaskasubpopulations. Lead poisoning has been determinedto be the cause of death in both the Spectacledand Common ($ornateria rnoIIissima)eiders on the Yukon-Kuskokwim Delta (Fransonet al. 1995) and issuspected in the deathof one Steller'sEider from near Barrow (Trustet al. 1997). On the Yukon-KuskokwimDelta, signifi- cant numbers of Spectacled Eiders and Long-tailed (CIangula hyernalis)are exposedto leadduring the breedingseason (Flint et al. 1997), and female eidersexposed to lead surviveat lower rates than unexposed femalesdo (Grand et al. 1998). The slow settlementrate of lead shot in tundrawetlands suggests that leadwill remainaccessible to feedingeiders for manyyears (Flint 1998). Possibleincreases in numbersof predatorssuch as Arctic Foxes(AIopex lagopus),Glaucous Gulls (Larus hyperboreus), and CommonRavens (Cor- vus corax) acrossthe Arctic coastal plain have become a concern as anthropogenicfood sourceshave becomemore availablewith increased communityand industrial development (Day 1998). An increasein predator numbersor distributionmay havedecreased the survivaland/or productivity of Steller's Eiders;on the Yukon-KuskokwimDelta, the removal of Arctic Foxes has been shown to increasethe nestingsuccess of Brant (Branta bernicla;Anthony et al. 1991).

114 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

The breedingfrequency of Steller'sEiders also may be affectedby cycles in small-mammalpopulations, as has been seen elsewhere for arcticnesting birds(e.g., Pehrsson 1986, Summers1986, Underhillet al. 1993, vanImpe 1996, Spaans et al. 1998, Summerset al. 1998, Sittier et al. 2000). Between 1991 and 2001, Steller'sEiders studied near Barrow nestedonly in yearswhen Brown Lemmings (Lemmus trimucronatus) and/or Collared Lemmings(Dicrostonyx groenlandicus) were abundant:1991, 1993, 1995, 1996, 1999, and 2000 (Quakenbush and Suydam 1999, Obritschkewitschet al. 2001). Between 1975 and 1980, other studiesnear Barrowfound a similarpattern of irregularbreeding that correspondedwith yearsof lemmingabundance (Quakenbush and Suydam1999). Pomarine Jaegers(Stercorarius pomarinus) and Snowy Owls (Nyctea scandiaca) also nest at Barrow only during years of lemming abundance(Pitelka et al. 1955a, b). Evidenceincreasingly suggests that Steller'sEiders at Barrow nest within defendednesting territories of PomarineJaegers and Snowy Owls and benefitfrom their protectionagainst predation by Arctic Foxes (Quakenbushand Suydam 1999). The Barrow area is well known for populationcycles of BrownLemmings that are morefrequent and higher in amplitudethan thosefarther south or east(Rausch 1950, Thompson1955, Pitelka 1973, Batzliet al. 1980, Pitelkaand Batzli1993). Other areaswithin the Arctic coastalplain have been studiedbut have not shownlemming or othersmall-mammal cycles similar to thosenear Barrow(Feist 1975; Pitelka and Batzli 1993; D. Troy pers. comm.). If nestingSteller's Eiders are dependenton speciesof birdsthat defendtheir nestsaggressively, such as the PomarineJaeger and SnowyOwl, for protectionagainst Arctic Foxes, Barrowmay be the mostreliable place in northernAlaska for eidersto nest successfully,although not annually. When Steller's Eider nests were found on the Yukon-Kuskokwim Delta in 1924 by Conover(1926), SnowyOwls and all threespecies of jaegersalso were nesting.More than 40 SnowyOwl nestswere found, and extremely high populations were reported for lemmings and voles (Lemmus, Dicrostonyx, Microtus; Brandt 1943). The Steller'sEider nest on St. Lawrence Island in 1954 was found near three nests;two additionalSnowy Owl nestswere foundapproximately 13 km away, and a high in the Vole (Microtus oeconomus)population was reported that year (Fay and Cade 1959). Hence, the relationshipbetween Snowy Owlsand Steller'sEiders observed at Barrowmay be importantfor western Alaska as well. Snowy Owls were formerly uncommonbreeders on the Yukon-KuskokwimDelta (Conover1926), but they are essentiallyabsent now(C. Dau, USFWS,Anchorage, pers. comm.). If Steller'sEiders nest with SnowyOwls and/or jaegerswhenever possible, their breedingdistribution and breedingfrequency would be more similarto thoseof predatorybirds (spatiallyunpredictable and temporally sporadic)than other waterfowl (spatiallypredictable and temporallyregular). Populationgrowth in eidersand other waterfowlwith similarlife-history strategiesappears to be sensitiveto survivalrates of adults(USFWS 1996, Schmutz et al. 1997). Steller's, like other eiders, tends toward late sexual maturity,high annualadult survival (90%; Flintet al. 2000), longevity(20+

115 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA years;Dunning 1997), and low productivityin mostyears (Quakenbush and Suydam1999, Quakenbushunpubl. data). With our currentstate of knowledge,efforts to aid the conservationof the Alaskabreeding population of Steller'sEiders should focus on factorsthat maintainhigh adultsurvival and increaseproductivity and survivalto matu- rity. Furtherinvestigation of the relationshipamong Steller's Eiders, Snowy Owls, and jaegersmay better our understandingof the eider'sbreeding distribution,breeding frequency, and productivityand may provideinsights for its recovery.

ACKNOWLEDGMENTS

NumerousUSFWS and U.S. GeologicalSurvey/Biological Resources Division personneland other researchersprovided unpublished data. Much of this work was conductedfor the USFWSwhile the firstthree authors were writing the draftrecovery plan for Steller'sEider. Data providedby the curatorsof the collectionsof the Denver Museumof Natural History, the Western Foundationof VertebrateZoology, and Cornell University,Ithaca, New York, contributedgreafiy to documentationof the historicaldistribution. Daniel Gibsonof the Universityof AlaskaMuseum provided informationon Alaskaspecimens from severalcollections. Will Lentz, AllisonZusi- Cobb,and Tai Grahamof ABR, Inc., producedthe map figures.An earlydraft of the manuscriptbenefited from reviewsby ChristianDau, RobertSuydam, Paul Flint, and Lynn Dickson;comments from ChristianDau improveda later versionas well.

LITERATURE CITED

Anderson,R. M. 1913. Reporton the naturalhistory collections of the expedition,in My Life with the (V. Stefansson,ed.), pp. 436-527. MacMillan,New York. Anthony, R. M., Flint, P. L., and Sedinger,J. S. 1991. removalimproves nest success of black Brant. Wildlife Soc. Bull. 19:176-184. Bailey, A.M. 1925. A report on the birds of northwesternAlaska and regions adjacentto BeringStrait, part V. Condor 27:197-207. Bailey,A.M. 1948. Birdsof ArcticAlaska. Colo. Mus. Nat. Hist. PopularSer. 8. Bee, J. W. 1958. Birdsfound on the Arctic slopeof northernAlaska. Univ. Kan. Publ., Mus. Nat. Hist. 10:163-211. Bent, A. C. 1925. Life historiesof North Americanwild fowl, part 2. U.S. Natl. Mus. Bull. 130. Balogh,G. R., and Larned,W. W. 1994. Eiderbreeding population survey, Alaska Arcticcoastal plain, 1994. Unpubl.report available from U.S. Fishand Wildlife Service(USFWS), 1011 EastTudor Road, Anchorage,AK 99503-6199. Batzli,G. O., White, R. G., MacLean,S. F., Jr., Pitelka,E A., and Collier,B. D. 1980. The herbivore-basedtrophic system,in An Arctic Ecosystem:The Coastal Tundraat Barrow, Alaska(J. Brown, P. C. Miller, L. L. Tieszen,and F. L. Bunnell, eds.),pp. 335-410. Dowden, Hutchinson,and Ross,Stroudsberg, PA. Bellrose,F. C. 1978. Ducks, Geese and Swans of . Stackpole, Harrisburg,PA. Boarman, W. I., and Coe, S. J. 2000. Finding value in pre-existingdatasets: Ecologicaleffects of ravenpopulations in JoshuaTree NationalPark. Conserva- tion Biologyin Practice1:32-34.

116 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

Brackney,A. W., and King, R. J. 1993. Aerial breedingpair surveyof the Arctic coastalplain of Alaska:Revised estimates of waterbirdabundance, 1986-1992. Unpubl.report available from USFWS, 1011 EastTudor Road, Anchorage, AK 99503-6199. Brackney,A.W., and King, R. J. 1994. Aerial breedingpair surveyof the Arctic coastalplain of Alaska,1993. Unpubl.report available from USFWS, 1011 East Tudor Road, Anchorage,AK 99503-6199. Brooks, W. S. 1915. Notes on birdsfrom east Siberia and arctic Alaska. Bull. Mus. Comp. Zool. 59:361-413. Brandt, H. 1943. Alaska Trails. Bird Res. Found., Cleveland,OH. Conover,H. B. 1926. Game birdsof the Hooper Bay region,Alaska. Auk 43:162- 180. Dall, W. H. 1873. Notes on the avifaunaof the ,especially those west of Unalaska. Proc. Calif. Acad. Sci. (firstseries) 5:270-281. Dau, C. P. 1987. Birdsin nearshorewaters of the Yukon-KuskokwimDelta, Alaska. Murrelet 68:12-23. Day, R. H. 1998. Predatorpopulations and predationintensity on tundra-nesting birdsin relationto humandevelopment. Unpubl. report availablefrom USFWS, 1011 EastTudor Road, Anchorage,AK 99503-6199. Dixon, J. S. 1943. Birds observedbetween Point Barrow and Herschel Islandon the arctic coast of Alaska. Condor 45:49-57. Dunning,J. B., Jr. (ed.).1997. Significantencounters. N. Am. BirdBander 22:133- 138. Fay, F. H., and Cade, T. J. 1959. An ecologicalanalysis of the avifaunaof St. LawrenceIsland, Alaska. Univ. Calif. Publ. Zool. 63:73-150. Feist,D. D. 1975. Populationstudies of lemmingsin the coastaltundra of Prudhoe Bay, Alaska,in Biologicalinvestigations of the tundrabiome in the PrudhoeBay region, Alaska(J. Brown, ed.), pp. 135-143. Biol. Pap. Univ. Alaska, Spec. Rep. 2. Flint, P. L. 1998. Settlementrate of lead shot in tundrawetlands. J. WildlifeMgmt. 62:1099-1102. Flint, P. L., and Herzog,M.P. 1999. Breedingof Steller'sEiders, Polysticta stelleri, on the Yukon-KuskokwimDelta, Alaska. Can. Field-Nat. 113:1-3. Flint, P. L., Petersen,M. R., and Grand, J. B. 1997. Exposureof SpectacledEiders and other divingducks to leadin westernAlaska. Can. J. Zool. 75:439-443. Flint, P. L., Petersen,M. R., Dau, C. P., Hines, J. E., and Nichols,J. D. 2000. Annual survivaland sitefidelity of Steller'sEiders molting along the AlaskaPeninsula. J. WildlifeMgmt. 64:261-268. Franson, J. C., Petersen,M. R., Meteyer, C. U., and Smith, M. R. 1995. Lead poisoningof SpectacledEiders (Sornateriafischeri) and of a (Sornateria mollissirna)in Alaska. J. Wildlife Diseases31:268-271. Gabrielson,I. N., and Lincoln,F. C. 1959. The Birdsof Alaska.Stackpole, Harris- burg, PA. Gill, R., Handel, C., and Connors,P. 1985. Bird utilizationof PeardBay and vicinity, in Environmentalcharacterization and biologicalutilization of Peard Bay (P. J. Kinney, ed.), vol. 35, pp. 244-323. EnvironmentalAssessment of the Alaskan ContinentalShelf, Final Reports(Biological Studies) (available from Minerals ManagementService, 949 E. 36th Ave., Room 300, Anchorage,AK 99508- 4363).

117 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

Gillham,C. E. 1941. Reportof Alaskawildfowl investigations, summer, 1941, lower , Chevak, Hooper Bay. Unpubl. report availablefrom USFWS, 1011 EastTudor Road, Anchorage,AK 99503-6199. Grand, J. B., Flint, P. L., Petersen,M. R., and Moran, C. L. 1998. Effect of lead poisoningon SpectacledEider survival rates. J. WildlifeMgmt. 62:1103-1109. Kerte]l,K. 1991. Disappearanceof the Steller'sEider from the Yukon-Kuskokwim Delta, Alaska. Arctic 44:177-187. Kessel,B. 1989. Birds of the ,Alaska: Their Biogeography, Seasonality,and NaturalHistory. Univ. of AlaskaPress, Fairbanks. King, R. J., and Brackney,A. W. 1995. Expandedaerial searches for Steller'sEider on the Arcticcoastal plain, June 29-July 3, 1995. Unpubl.report available from USFWS, 1011 EastTudor Road, Anchorage,AK 99503-6199. King, R. J., and Dau, C. P. 1997. Expandedaerial searches for Steller'sEiders on the Arctic coastalplain of Alaska, 1997. Unpubl.report availablefrom USFWS, 1011 EastTudor Road, Anchorage,AK 99503-6199. Larned,W. W., and Balogh,G. R. 1994. Eiderbreeding population survey, Alaska Arctic coastalplain, 1993. Unpubl. report availablefrom USFWS, 1011 East TudorRoad, Anchorage,AK 99503-6199. Larned,W. W., Balogh,G. R., Stehn,R. A., and Butler,W. I. 1993. The statusof eider breedingpopulations in Alaska,1992. Unpubl.report available from USFWS, 1011 EastTudor Road, Anchorage,AK 99503-6199. Metzner,K. A. 1993. Ecologicalstrategies and winteringSte]ler's Eiders on Izembek Lagoon and Cold Bay, Alaska.M.S. thesis,Univ. Mo., Columbia. Murie, O. J. 1959. Fauna of the AleutianIslands and AlaskaPeninsula. N. Am. Fauna 61. Myres,M. T. 1958. Preliminarystudies of the behavior,migration, and distributional ecologyof eider ducksin northernAlaska, 1958. Unpubl. interimprogress report prepared for Arctic Instituteof North America, Fairbanks,AK, by Universityof BritishColumbia, Vancouver, BC (availablefrom AINA, Univ. Calgary,2500 UniversityDr. NW, Calgary,Alberta T2N 1N4, Canada). Nelson,E. W. 1887. Birdsof Alaska,in Reporton naturalhistory collections made in Alaskabetween the years1877 and 1881 (H. W. Henshaw,ed.), pp. 19-226. GovernmentPrinting Office, Washington, D.C. Nyggrd,T., Frantzen,B., and•va•as, S. 1995. Steller'sEiders Polysticta stelleri winteringin :Numbers, distribution and origin.Wildlfowl 46:140-155. Obritschkewitsch,T., Martin, P. D., and Suydam,R. S. 2001. Breedingbiology of Steller'sEiders nesting near Barrow,Alaska, 1999-2000. EcologicalServices Fairbanks,AK, U.S. Fish and Wildlife Service,Tech. Rep. NAES-TR-01-04 (availablefrom USFWS, 1011 EastTudor Road, Anchorage, AK 99503-6199). Paige, A. W., Scott, C. L., Andersen,D. B., Georgette,S., and White, R. J. 1996. Subsistenceuse of birdsin the BeringStrait region, Alaska. Alaska Dept. Fish and Game,Div. of Subsistence,Tech. Pap. 239 (availablefrom Alaska Dept. Fishand Game, P.O. Box 25526, Juneau, AK 99802-5526). Pehrsson,O. 1986. Ducklingproduction of the Oldsquawin relation to spring weather and small-rodent fluctuations. Can. J. Zool. 64:1835-1841. Pitelka,E A. 1973. Cyclicpattern in lemmingpopulations near Barrow,Alaska, in AlaskanArctic Tundra (M. E. Britton, ed.), pp. 199-215. Arctic Inst. N. Am. Tech. Pap. 25.

118 BREEDING SEASON DISTRIBUTION OF STELLER'S EIDERS IN ALASKA

Pitelka,F. A. 1974. An avifaunalreview for the Barrowregion and NorthSlope of arcticAlaska. Arctic and Alpine Res. 6:161-184. Pitelka,F. A., and Batzli,G. O. 1993. Distribution,abundance, and habitatuse by lemmingson the North Slope of Alaska,in The Biologyof Lemmings(N. C. Stensethand R. A. Ims, eds.),pp. 213-236. AcademicPress, London. Pitelka,F. A., Tomich,P. Q., andTreichel, G. W. 1955a. Breedingbehavior of jaegers and owlsnear Barrow, Alaska.Condor 57:3-18. Pitelka,F. A., Tomich,P. Q., and Treichel,G. W. 1955b. Ecologicalrelations of jaegersand owls as lemmingpredators near Barrow, Alaska. Ecol. Monogr. 25:85-117. Portenko,L. A. 1972. [Birdsof the ChukchiPeninsula and WrangelIsland], vol. I. Nauka, Leningrad,USSR. (Translatedin 1981 by SmithsonianInstitution and NationalScience Foundation, Washington, D.C.). Quakenbush,L., andCochrane, J. F. 1993. Reporton the conservationstatus of the Steller's Eider (Polysticta stelleri), a candidatethreatened and endangered species.Unpubl. report available from USFWS, 1011 EastTudor Road, Anchor- age, AK 99503-6199. Quakenbush,L., Suydam,R., Fluetsch,K. M., andDonaldson, C. L. 1995. Breeding biologyof Steller'sEiders nesting near Barrow,Alaska, 1991-1994. Unpubl. reportavailable from USFWS, 1011 EastTudor Road, Anchorage, AK 99503- 6199. Quakenbush,L., andSuydam, R. 1999. Periodicnonbreeding of Steller'sEiders near Barrow,Alaska, with speculations on possiblecauses, in Behaviourand ecology of seaducks (R. I. Goudie,M. R. Petersen,and G. J. Robertson,eds.), pp. 34- 40. Can. WildlifeService Occ. Pap. 100. Rausch,R. 1950. Observationson a cyclicdecline of lemmings(Lemmus) on the arcticcoast of Alaskaduring spring of 1949. Arctic 3:166-177. Ritchie,R. J., andKing, J. G. 2001. Resultsof Steller'sEider surveys near Barrow, AdmiraltyBay, and Meade River, Alaska, 1999 and 2000. Unpubl. report availablefrom ABR, Inc., P.O. Box 80410, Fairbanks,AK 99708. Schmutz,J. A., Rockwell,R. F., andPetersen, M. R. 1997. Relativeeffects of survival and reproductionon the populationdynamics of EmperorGeese. J. Wildlife Mgmt. 61:191-201. Sittier,B., Gilg,O., andBerg, T. R. 2000. Low abundanceof KingEider nests during low lemmingyears in northeastGreenland. Arctic 53:53-60. Shepherd,P. E. K. 1963. Nestingecology of BlackBrant in Alaska.Unpubl. report availablefrom AlaskaDept. Fish and Game, P.O. Box 25526, Juneau,AK 99802-5526. Spaans,B., Blijleven,H. J., Popov,I. U., Rykhilova,M. E., andEbbinge, B. S. 1998. Dark-belliedBrent Geese Branta berniclabernicla forego breeding when Arctic FoxesAlopex lagopusare presentduring nest initiation.Ardea 86:11-20. Summers,R. W. 1986. Breedingproduction of dark-belliedBrent Geese Branta berniclabernicla in relationto lemmingcycles. Bird Study33:105-108. Summers,R. W., Underhill,L. G., andSyroechkovski, Jr., E. E. 1998. The breeding productivityof dark-belliedBrent Geeseand CurlewSandpipers in relationto changesin the numberof ArcticFoxes and lemmings on the TaimyrPeninsula, Siberia.Ecography 21:573-580.

119 BREEDING SEASON DISTRIBUTION OF STELLER'S ELDERS IN ALASKA

Talarico,D., andMossop, D. 1986. HerschelIsland avifauna and interpretive report 1986. Unpubl.report by YukonDepartment of RenewableResources, P.O. Box 2703, Whitehorse,Yukon Y1A 2C6, Canada. Thompson,D. Q. 1955. The 1953 lemmingemigration at Point Barrow,Alaska. Arctic 8:37-45. Trust,K. A., Cochrane,J. F., and Stout,J. H. 1997. Environmentalcontaminants in three eiderspecies from Alaskaand Arctic Russia.U.S. Fishand WildlifeService Tech. Rep. WAES-TR-97-03, availablefrom USFWS, 1011 East Tudor Road, Anchorage,AK 99503-6199. Turner,L. M. 1886. Contributionsto the naturalhistory of Alaska.U.S. Army Signal Service,Arctic Ser. Publ. II. Underhill,L. G., Prys-Jones,R. P., Syroechkovski,Jr., E. E., Groen,N. M., Karpov, V., Lappo, H. G., van Roomen, M. W. J., Rybkin, A., Schekkerman,H., Spiekman,H., and Summers,R. W. 1993. Breedingof waders(Charadrii) and Brent Geese Branta bernicla bernicla at PronchishchevaLake, northeastern Taimyr,Russia, in a peak and decreasinglemming year. Ibis 135:277-292. U.S. Fishand Wildlife Service. 1996. SpectacledEider recovery plan (available from USFWS, 1011 EastTudor Road, Anchorage, AK 99503-6199). Van Impe, J. 1996. Long-termreproductive performance in White-frontedGeese Anser a. albifrons and tundra Bean GeeseA. fabalis rossicuswintering in Zeeland(the Netherlands). Bird Study43:280-289. Wentworth, C. 1994. Subsistencemigratory bird harvestsurvey--Saint Lawrence Island:Results, 1993. Unpubl.report available from USFWS, 1011 EastTudor Road,Anchorage, AK 99503-6199. Wentworth,C., and Seim,S. 1996. Subsistencewaterfowl harvest survey--Yukon- KuskokwimDelta: Comprehensivereport, 1985-1995, results1995. Unpubl. ßreport available from USFWS, 1011 EastTudor Road, Anchorage, AK 99503- 6199.

Accepted 17 May 2002

120