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Pacific walrus (Odobenus rosmarus divergens) reproductive capacity changes in three time frames during 1975–2010

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Abstract

Reductions in sea ice and increases in air and seawater temperatures have been documented in the Arctic, making female Pacific walruses (Odobenus rosmarus divergens) vulnerable to changes in foraging, energy budgets, and reproductive fitness. The aim of the present study was to assess how walrus reproductive capacity has changed over a span of 35 years analyzing ovaries from three distinct time frames: 1975, 1994 to 1999 and 2008 to 2010. Ovarian weights and volumes, corpora lutea diameter, total number of corpora lutea and albicantia, and the percent of females ovulating in their current cycle were used to evaluate reproductive capacity. Ovaries were collected from walruses hunted by Alaska Native communities for subsistence purposes. There were no differences in ovarian weights or percent of quiescent females between 1975 and 2008 to 2010. Ovaries from 1994 to 1999 were significantly heavier, exhibited more corpora, and all females from this time frame were ovulating at the time of harvest. Reproductive capacity was limited during 1975, due to known density-dependent stressors; reproductive capacity increased during 1994–1999, as harvests increased and more resources became available, and in 2008–2010, females were as reproductively limited as those of 1975. The cause for this reduction in reproductive capacity is unknown, but maybe a result of multiple factors, including an increase in population size coincident with a decrease in carrying capacity, and cumulative stressors relating to sea ice loss, contaminants, and anthropogenic impacts.

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References

  • Atkinson S, Becker BL, Johanos TC, Pietraszek JR, Kuhn BCS (1994) Reproductive morphology and status of female Hawaiian monk seals. J Reprod Fertil 100:225–230

    CAS  PubMed  Google Scholar 

  • Atkinson S, Crocker D, Houser D, Mashburn K (2015) Stress physiology in marine mammals: how well do they fit the terrestrial model? J Comp Physiol B 185:463–486

    CAS  PubMed  Google Scholar 

  • Atkinson S, Dierauf SA (2018) Stress and marine mammals. In: Gulland F, Dierauf LA, Whitman KL (eds) CRC handbook of marine mammal medicine, 3rd edn. CRC Press, Boca Raton, pp 153–178

    Google Scholar 

  • Atkinson SN, Ramsay MA (1995) The effects of prolonged fasting of the body composition and reproductive success of female polar bears (Ursus maritimus). Funct Ecol 9:559–567

    Google Scholar 

  • Atkinson S, Williamson P, Kang CL, Carson RS (1986) Steroid production and hCG binding by ram-induced ovarian follicles in seasonally anoestrous ewes. J Reprod Fertil 78:403–412

    CAS  PubMed  Google Scholar 

  • Born EW (2001) Reproduction in female Atlantic walruses (Odobenus rosmarus rosmarus) from north-west Greenland. Zool Soc Lond 255:165–174

    Google Scholar 

  • Boyd IL (1984) Development and regression of the corpus luteum in grey seal (Halichoerus grypus) ovaries and its use in determining fertility rates. Can J Zool 62:1095–1100

    CAS  Google Scholar 

  • Braune BM (2007) Temporal trends of organochlorines and mercury in seabird eggs from the Canadian Arctic, 1975–2003. Environ Pollut 148:599–613

    CAS  PubMed  Google Scholar 

  • Brodie EC, Gulland FMD, Greig DJ, Hunter M, Jaakola J, St Leger J, Leighfield TA, Van Dolah FM (2006) Domoic acid causes reproductive failure in California sea lions (Zalophus californianus). Mar Mamm Sci 22:700–707

    Google Scholar 

  • Burek KA, Gulland FMD, O’Hara TM (2008) Effects of climate change on Arctic marine mammal health. Ecol Appl 18:S126–S134

    PubMed  Google Scholar 

  • Burns J, Born E, Fay F, Kingsley M, Lowry L, Stoker S (1990) Working group #6. Reproduction, survival and recruitment. In: Fay FH, Kelly BP, Fay BA (eds) The ecology and management of walrus populations. Seattle, Final report to US Marine Mammal Commission, pp 45–48

    Google Scholar 

  • Cattet M, Caulkett NA, Obbard ME, Stenhouse GB (2002) A body-condition index for ursids. Can J Zool 80:1156–1161

    Google Scholar 

  • Chambellant M, Stirling I, Gough WA, Ferguson SH (2012) Temporal variations in Hudson Bay ringed seals (Phoca hispida) life-history parameters in relation to the environment. J Mammal 93:267–281

    Google Scholar 

  • Colegrove KM, Gulland FMD, Naydan DK, Lowenstine LJ (2009) The normal genital tract of the female California sea lion (Zalophus californianus): cyclic changes in histomorphology and hormone receptor distribution. Anat Rec 292:1801–1817

    Google Scholar 

  • Comiso JC (2012) Large decadal decline of the Arctic multilayer ice cover. J Clim 25:1176–1193

    Google Scholar 

  • Creel S (2005) Dominance, aggression, and glucocorticoid levels in social carnivores. J Mammal 86:255–264

    Google Scholar 

  • Cunningham MK, Granberry WF Jr, Pope KL (2000) Shrinkage of inland silverside larvae preserved in ethanol and formalin. N Am J Fish Manage 20:816–818

    Google Scholar 

  • Dickerson L, Burn D, Garlich-Miller JT, Fishbach T, Rice S, Bouchard J, Howard B (1996) The 1995 walrus harvest monitor project: annual summary. Fish and Wildlife Service, Marine Mammals Management, Anchorage, p 26

    Google Scholar 

  • Eberhardt LL (1977) Optimal policies for conservation of large mammals, with special reference to marine ecosystems. Environ Conserv 4:205–212

    Google Scholar 

  • Eberhardt LL, Siniff DB (1977) Population dynamics and marine mammal management policies. J Fish Res Board Can 34:183–190

    Google Scholar 

  • Ewacha MVA, Roth JD, Anderson WG, Brannen DC, Dupont DLJ (2017) Disturbance and chronic levels of cortisol in boreal woodland caribou. J Wildl Manage 81:1266–1275

    Google Scholar 

  • Fay FH (1982) Ecology and biology of the Pacific walrus, Odobenus rosmarus divergens Illiger. N Am Fauna 74:1–279

    Google Scholar 

  • Fay FH, Eberhardt LL, Kelly BP, Burns JJ, Quakenbush LT (1997) Status of the Pacific walrus population 1950–1989. Mar Mamm Sci 13:537–565

    Google Scholar 

  • Fay FH, Kelly BP, Sease JL (1989) Managing the exploitation of Pacific walruses: a tragedy of delayed response and poor communication. Mar Mamm Sci 5:1–16

    Google Scholar 

  • Fay FH, Stoker SW (1982a) Analysis of reproductive organs and stomach contents from walruses taken in the Alaskan Native harvest, spring 1980. Final report to USFWS, Anchorage, pp 86

  • Fay FH, Stoker SW (1982b) Reproductive success and feeding habits of walruses taken in the 1982 spring harvest, with comparisons from previous years. Final report to Eskimo Walrus Commission, Nome, pp 87

  • Fischbach AS, Kochnev AA, Garlich-Miller JL, Jay CV (2016) Pacific walrus coastal haulout database 1852–2016—background report. US Depart of the Interior, US Geological Survey open-file report 2016–1108

  • Fischbach AS, Monson DH, Jay CV (2009) Enumeration of Pacific walrus carcasses on beaches of the Chukchi Sea in Alaska following a mortality event, September 2009. US Geological Survey open-file report 2009–1291

  • Fraser KW (1985) Effect of storage in formalin on organ weights of rabbits. NZ J Zool 12:169–174

    Google Scholar 

  • Garde E, Hansen SH, Ditlevsen S, Tvermmosegaard KB, Hansen J, Harding KC, Heide-Jorgensen MP (2015) Life history parameters of narwhals (Monodon monoceros) from Greenland. J Mammal 96:866–879

    Google Scholar 

  • Garlich-Miller JL (1997) Age, sex and reproductive status of Pacific walrus harvested in the Bering Strait region, 1994–1996. USFWS Technical Report 97–1. US Fish and Wildlife Service, Marine Mammals Management, Anchorage, pp 26

  • Garlich-Miller J, MacCracken JG, Snyder J, Meehan R, Myers M, Wilder JM, Lance E, Matz A (2011) Status review of the Pacific walrus (Odobenus rosmarus divergens). US Fish and Wildlife Service, Marine Mammal Management, Anchorage, pp 155

  • Garlich-Miller JL, Quakenbush LT, Bromaghin JF (2006) Trends in age structure and productivity of Pacific walrus harvested in the Bering strait regions of Alaska, 1952–2002. Mar Mamm Sci 22:880–896

    Google Scholar 

  • Garlich-Miller JL, Stewart REA (1999) Female reproductive patterns and fetal growth of Atlantic walruses (Odobenus rosmarus rosmarus) in Foxe Basin, Northwest Territories, Canada. Mar Mamm Sci 15:179–191

    Google Scholar 

  • Gastal GD, Hamilton A, Alves BG, de Tarso SG, Feugang JM, Banz WJ, Apgar GA, Nielsen CK, Gastal EL (2017) Ovarian features in white-tailed deer (Odocoileus virginianus) fawns and does. PLoS ONE 12:1–20

    Google Scholar 

  • Gaston GR, Bartlett JHW, McAllister AP, Heard RW (1996) Biomass variations of estuarine macrobenthos preserved in ethanol and formalin. Estuaries 19:674–679

    Google Scholar 

  • Grebmeier JM (2012) Shifting patterns of life in the Pacific arctic and sub-arctic seas. Annu Rev Mar Sci 4:63–78

    Google Scholar 

  • Grebmeier JM, Overland JE, Moore SE, Farley EV, Carmack EC, Cooper LW, Frey KE, Helle JH, McLaughlin FA, McNutt SL (2006) A major ecosystem shift in the northern Bering sea. Science 311:1461–1464

    CAS  PubMed  Google Scholar 

  • Guinet C, Roux JP, Bonnet M, Mison V (1998) Effect of body size, body mass, and body condition on reproduction of female south African fur seals (Arctocephalus pusillus) in Namibia. Can J Zool 76:1418–1424

    Google Scholar 

  • Hamilton LC, Stroeve J (2016) 400 predictions: the SEARCH sea ice outlook 2008–2015. Polar Geog 39:274–287

    Google Scholar 

  • Harwood LA, Smith TG, Melling H (2000) Variation in reproduction and body condition of the ringed seal (Phoca hispida) in western Prince Albert Sound, NT, Canada, as assessed through a harvest-based sampling program. Arctic Inst N Am 53:422–431

    Google Scholar 

  • He L, Wang WX, Li LH, Liu BQ, Liu G, Liu SQ, Qi L, Hu DF (2014) Effects of crowding and sex on fecal cortisol levels of captive forest musk deer. Biol Res 47:1–6

    CAS  Google Scholar 

  • Hutchinson E, Atkinson S, Hoover-Miller A (2016) Growth and reproductive tracts from fetal to adult harbor seals in the Gulf of Alaska. Mar Ecol Prog Ser 557:277–288

    Google Scholar 

  • Hutchinson JD, Simmonds MP (1994) Organochlorine contamination in pinnipeds. Rev Environ Contam Toxicol 136:123–167

    CAS  PubMed  Google Scholar 

  • Iwasa M, Atkinson S (1996) Analysis of corpora lutea to estimate reproductive cycles of wild Hawaiian monk seals (Monachus schauinslandi). Mar Mamm Sci 12:182–198

    Google Scholar 

  • Jay CV, Fischbach AS, Kochnev AA (2012) Walrus areas of use in the Chukchi Sea during sparse sea ice cover. Mar Ecol Prog Ser 468:1–13

    Google Scholar 

  • Kanerva RL, Lefever FR, Alden CL (1983) Comparison of fresh and fixed organ weights of rats. Toxicol Pathol 11:129–131

    CAS  PubMed  Google Scholar 

  • Kavry VI, Boltunov AN, Nikiforov VV (2008) New coastal haulouts of walruses (Odobenus rosmarus)—response to the climate changes. Marine Mammals of the Holarctic V Conference, Odessa, pp 248–251

  • Kelsey TW, Dodwell SK, Wilkinson AG, Greve T, Andersen CY, Anderson RA, Wallace WH (2013) Ovarian volume throughout life: a validated normative model. PLoS ONE 8:1–9

    Google Scholar 

  • Kesselring T, Viquerat S, Brehm R, Siebert U (2017) Coming of age:-Do female harbour porpoises (Phocoena phocoena) from the North Sea and Baltic Sea have sufficient time to reproduce in a human influenced environment? PLoS ONE 12:1–14

    Google Scholar 

  • Factors causing Pacific walrus mortality on the coastal haulouts of Wrangel Island. In: Aristov AA (eds) Marine mammals results of research conducted in 1995–1998. Collection of articles, Moscow pp 191–215

  • Kochnev AA (2004) Warming of eastern Arctic and present status of the Pacific walruses (Odobenus rosmarus divergens) population. Marine Mammals of the Holarctic III Conference, Moscow, pp 284–288

  • Kochnev AA (2010) The haulout of Pacific walruses (Odobenus rosmarus divergens) on Cape Serdtse-Kamen, the Chukchi Sea. Marine Mammals of the Holarctic VI Conference, Kaliningrad, pp 281–285

  • Kochnev AA, Kryukova NV, Pereverzev AA, Ivanov DI (2008) Coastal haulouts of the Pacific walruses (Odobenus rosmarus divergens) in Anadyr Gulf (Being Sea), 2007. Marine Mammals of the Holarctic V Conference, Odessa, pp 267–272

  • Krogman BD, Braham HW, Sontag RM, Punsley RG (1979) Early spring distribution, density, and abundance of the Pacific walrus (Odobenus rosmarus divergens). Final Report, Contract No. R7120804, NOAA Outer Continental Shelf, Environmental Assessment Program, Juneau Project Office, Juneau, pp 47

  • Laws RM (1956) Growth and sexual maturity in aquatic mammals. Nature 178:193–194

    Google Scholar 

  • Lefebvre KA, Quakenbush L, Frame E, Burek Huntington K, Sheffield G, Stimmelmayr R, Bryan A, Kendrick P, Ziel H, Goldstein T, Snyder JA, Gelatt T, Gulland F, Dierson B, Gill V (2016) Prevalence of algal toxins in Alaskan marine mammals foraging in a changing arctic and subarctic environment. Harmful Algae 55:1–24

    Google Scholar 

  • Lowry LF, Fay FH (1984) Seal eating by walruses in the Bering and Chukchi seas. Polar Biol 3:11–18

    Google Scholar 

  • MacCracken JG, Lemons PR III, Garlich-Miller JL, Snyder JA (2014) An index of optimum sustainable population for the Pacific walrus. Ecol Indic 43:36–43

    Google Scholar 

  • Metcalf V, Robards M (2008) Sustaining a healthy human-walrus relationship in a dynamic environment: challenges for co-management. Eco Appl 18:S148–S156

    Google Scholar 

  • Muir DCG, de Wit CA (2010) Trends of legacy and new persistent organic pollutants in the circumpolar arctic: overview, conclusions, and recommendations. Sci Total Environ 408:3044–3051

    CAS  PubMed  Google Scholar 

  • Muir D, Kwan M, Evans M (2006) Temporal trends of persistent organic pollutants and metals in ringed seals from the Canadian Arctic. In: Smith S, Stow J (eds) Synopsis of research conducted under the 2005–2006 Northern Contaminants Program. Indian Affairs and Northern Development, Ottawa, pp 162–169

    Google Scholar 

  • Noren SR, Udevitz MS, Jay CV (2012) Bioenergetics model for estimating food requirements of female Pacific walruses Odobenus rosmarus divergens. Mar Ecol Prog Ser 460:261–275

    Google Scholar 

  • Ovsyanikov NG, Menyushina IE, Bezrukov AV (2008) Unusual Pacific walrus mortality at Wrangel Island in 2007. Marine Mammals of the Holarctic V Conference, Odessa, pp 413–416

  • Pavlik EJ, DePriest PD, Gallion HH, Ueland FR, Reedy MB, Kryscio RJ, van Nagell Jr JR (2000) Ovarian volume related to age. Gynecol Oncol 77:410–412

    CAS  PubMed  Google Scholar 

  • Perrin WF, Reilly SB (1984) Reproductive parameters of dolphins and small whales of the family Delphinidae. Report of the International Whaling Commission (Special Issue 6), pp 97–133

  • Polyak L, Alley RB, Andrews JT, Brigham-Grette J, Cronin TM, Darby DA, Dyke AS, Fitzpatrick JJ, Funder S, Holland M, Jennings AE, Miller GH, O’Regan M, Savelle J, Serreze M, St. John K, White J WC, Wolff E (2010) History of sea ice in the Arctic. Quat Sci Rev 29:1757–1778

    Google Scholar 

  • R Studio Team (2019) RStudio: integrated development for R. RStudio Inc, Boston

    Google Scholar 

  • Ray CG, Hufford GL, Overland JE, Krupnik I, McCormick-Ray J, Frey K, Labunski E (2016) Decadal Bering Sea seascape change: consequences for Pacific walruses and indigenous hunters. Ecol Appl 26:24–41

    PubMed  Google Scholar 

  • Reiner JL, Becker PR, Gribble MO, Lynch JM, Moors AJ, Ness J, Peterson D, Pugh RS, Ragland T, Rimmer C, Rhoderick J, Schantz MM, Trevillian J, Kucklick JR (2016) Organohalogen contaminants and vitamins in northern fur seals (Callorhinus ursinus) collected during subsistence hunts in Alaska. Arch Environ Contam Toxicol 70:96–105

    CAS  PubMed  Google Scholar 

  • Rigét R, Vorkamp K, Bossi R, Sonne C, Letcher RJ, Dietz R (2016) Twenty years of monitoring of persistent organic pollutants in Greenland biota. Rev Environ Poll 217:114–123

    Google Scholar 

  • Rust L, Gulland F, Frame E, Lefebvre K (2014) Domoic acid in milk of free living California marine mammals indicates lactational exposure occurs. Mar Mamm Sci 30:1272–1278

    CAS  Google Scholar 

  • Schell CJ, Young JK, Lonsdorf EV, Santymire RM (2013) Anthropogenic and physiologically induced stress responses in captive coyotes. J Mammal 94:1131–1140

    Google Scholar 

  • Scribner KT, Hills S, Fain SR, Cronin MA (1997) Population genetics studies of the walrus (Odobenus rosmarus): a summary and interpretation of results and research needs. Mol Genet Mar Mammal Spec Publ 3:173–184

    Google Scholar 

  • Semenova VS, Boltunov AN, Nikiforov VV (2010) Coastal haulout of Pacific walruses (Odobenus rosmarus divergens) on Cape Kozhevnikov in 2007–2009. Marine Mammals of the Holarctic VI Conference, Kaliningrad, pp 221–226

  • Serreze MC, Holland MM, Stroeve J (2007) Perspectives on the Arctic’s shrinking sea-ice cover. Science 315:1533–1536

    CAS  PubMed  Google Scholar 

  • Shitova MV, Kochnev AA, Dolnikova OG, Kryukova NV, Malinina TV, Pereverzev AA (2017) Genetic diversity of the Pacific walrus (Odobenus rosmarus divergens) in the western part of the Chukchi Sea. Russ J Genet 53:242–251

    CAS  Google Scholar 

  • Speckman SG, Chernook VI, Burn DM, Udevitz MS, Kochnev AA, Vasilev A, Jay CV, Lisovsky A, Fischbach AS, Benter RB (2011) Results and evaluation of a survey to estimate Pacific walrus population size, 2006. Mar Mamm Sci 27:514–533

    Google Scholar 

  • Steele M, Ermold W, Zhang J (2008) Arctic Ocean surface warming trends over the past 100 years. Geophys Res Lett 35:1–6

    Google Scholar 

  • Steele M, Zhang J, Ermold W (2010) Mechanisms of summertime upper Arctic Ocean warming and the effect on sea ice melt. J Geophys Res 115:1–12

    Google Scholar 

  • Stewart KM, Bowyer RT, Dick BL, Johnson BK, Kie JG (2005) Density-dependent effects on physical condition and reproduction in North American elk: an experimental test. Oecologia 143:85–93

    PubMed  Google Scholar 

  • Stroeve J, Holland MM, Meier W, Scambos T, Serreze M (2007) Arctic sea ice decline: faster than forecast. Geophys Res Lett 34:1–5

    Google Scholar 

  • Stroeve JC, Maslanik J, Serreze MC, Rigor I, Meier W, Fowler C (2011) Sea ice response to an extreme negative phase of the Arctic oscillation during winter 2009/2010. Geophys Res Lett 38:1–6

    Google Scholar 

  • Stroeve J, Notz D (2015) Insights on past and future sea-ice evolution from combining observations and models. Glob Planet Change 135:119–132

    Google Scholar 

  • Stroeve JC, Serreze MC, Holland MM, Kay JE, Malanik J, Barrett A (2012) The Arctic’s rapidly shrinking sea ice cover: a research synthesis. Clim Change 110:1005–1027

    Google Scholar 

  • Tarpley RJ, Hillmann DJ, George JC, Zeh JE, Suydam RS (2016) Morphometric correlates of the ovary and ovulatory corpora in the Bowhead whale, Balaena mysticetus. Anat Rec 299:769–797

    Google Scholar 

  • Taylor RL, Udevitz MS (2015) Demography of the Pacific walrus (Odobenus rosmarus divergens): 1974–2006. Mar Mamm Sci 31:231–254

    Google Scholar 

  • Taylor RL, Udevitz MS, Jay CV, Citta JJ, Quakenbush LT, Lemons PR, Snyder JA (2018) Demography of the Pacific walrus (Odobenus rosmarus divergens) in a changing Arctic. Mar Mamm Sci 34:54–86

    Google Scholar 

  • Tetsuka M, Asada M, Mogoe T, Fukui Y, Ishikawa H, Ohsumi S (2004) The pattern of ovarian development in the prepubertal Antartctic Minke whale (Balaenoptera bonaerensis). J Reprod Dev 50:381–389

    PubMed  Google Scholar 

  • Tollefson TN, Shipley LA, Myers WL, Keisler DH, Dasgupta N (2010) Influence of summer and autumn nutrition on body condition and reproduction in lactating mule deer. J Wildl Manage 74:974–986

    Google Scholar 

  • Towell RG, Ream RR, York AE (2006) Decline in northern fur seal (Callorhinus ursinus) pup production on the Pribilof Islands. Mar Mamm Sci 22:486–491

    Google Scholar 

  • USFWS (U.S. Fish and Wildlife Service) (2014) Pacific Walrus (Odobenus rosmarus divergens) Stock Assessment Report. U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, pp 30

  • Vorkamp K, Rigét FR, Bossi R, Dietz R (2011) Temporal trends of hexabromocyclododecane, polybrominated diphenyl ethers and polychlorinated biphenyls in ringed seals from east Greenland. Environ Sci Technol 45:1243–1249

    CAS  PubMed  Google Scholar 

  • Wasser SK, Davenport B, Ramage ER, Hunt KE, Parker M, Clarke C, Stenhouse G (2004) Scat detection dogs in wildlife research and management: application to grizzly and black bears in the Yellowhead ecosystem, Alberta, Canada. Can J Zool 82:475–492

    Google Scholar 

  • Wetzel MA, Leuchs H, Koop JHE (2005) Preservation effects on wet weight, dry weight, and ash-free dry weight biomass estimates of four common estuarine macro-invertebrates: no difference between ethanol and formalin. Helgol Mar Res 59:206–213

    Google Scholar 

  • Yao HHC, Bahr JM (1998) Ovary, overview. In: Knobil E, Neill JD (eds) Encyclopedia of reproduction, vol 3. Academic Press, San Diego, pp 590–597

    Google Scholar 

  • Zar JH (1974) Biostatistical analysis. Prentice-Hall Inc., Englewood Cliffs

    Google Scholar 

Download references

Acknowledgements

All samples were collected by USFWS in accordance with Federal regulations 50 CFR 18.23(b) (2). This work would not have occurred without the Bering Strait island communities of Diomede, Gambell and Savoonga providing walrus specimens from their subsistence hunts and we thank them. Additional walrus specimens (spanning the 2008–2010 time frame) were graciously provided by Jonathan Snyder of USFWS, Alan Springer, and Suzann Speckman. We thank our collaborators at the University of Alaska Museum of the North, especially Link Olson and Aren Gunderson, USFWS and the Eskimo Walrus Commission. We acknowledge the contributions from colleagues Gordon Kruse, Gay Sheffield and John Burns, as well as Philip Ganz and Wendel Raymond for assistance in statistical analyses and figure preparation, and Anatoloy Kochnev for kindly sharing his research. This manuscript was improved by the helpful comments of R. Stimmelmayr, J. Gilbert and an anonymous reviewer. Funding was provided by the North Pacific Research Board Graduate Research Award, the Resilience and Adaptation Program at the University of Alaska Fairbanks, the Rasmuson Fisheries Science Center, Alaska EPSCoR and the Erich Follman Memorial Student Research Support.

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    Jenell T. Larsen Tempel & Shannon Atkinson

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300_2020_2693_MOESM1_ESM.xlsx

University of Alaska Museum of the North accession numbers of Pacific walrus (Odobenus rosmarus divergens) ovary samples from three time frames: 1975, 1994-99, and 2008–2010. Ages and harvest dates were provided by the Alaska Department of Fish and Game (1975) and US Fish and Wildlife Service (1994–1999 and 2008–2010). Supplementary file1 (XLSX 19 kb)

300_2020_2693_MOESM2_ESM.xlsx

Summary statistics comparing corpora counts in Pacific walrus (Odobenus rosmarus divergens) ovaries sampled in 1994–1999 in the present study with corpora counts conducted in a previous study published by Garlich-Miller 1997. Supplementary file2 (XLSX 10 kb)

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Larsen Tempel, J.T., Atkinson, S. Pacific walrus (Odobenus rosmarus divergens) reproductive capacity changes in three time frames during 1975–2010. Polar Biol 43, 861–875 (2020). https://doi.org/10.1007/s00300-020-02693-4

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