Abstract
An isolated female with two pups in the field has occasionally been documented in pinnipeds; this phenomenon may represent twinning, fostering, or adoption. This study presents three cases of female Weddell seals (Leptonychotes weddellii) that attended two pups on Biyu Beach at Fildes Peninsula, King George Island, Antarctica where 16 mother–pup pairs were observed in total during the 2014 breeding season. Each pup in each case exhibited intense association with the female, despite being separated on occasions from the mother. In each case, both pups, at about 3 weeks of age, showed different growth development, which corresponded to the duration of nursing from their mothers; the bigger pup had more opportunity to suckle. Moreover, both pups in each case were female, were born in a low-density colony, and had strong attachment with their mother, showing similarities to other studies of confirmed twinning in pinnipeds. All individuals were in good condition when last seen, which could be due to the possible suitable rearing environment, e.g., low-density colony and flat beach topography.
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References
Altmann J (1974) Observational study of behavior: sampling methods. Behaviour 49:227–267. https://doi.org/10.1163/156853974X00534
Boness DJ (1990) Fostering behavior in Hawaiian monk seals: is there a reproductive cost? Behav Ecol Sociobiol 27:113–122. https://doi.org/10.1007/BF00168454
Boness DJ, Bowen WD, Iverson SJ (1995) Does male harassment of females contribute to reproductive synchrony in the grey seal by affecting maternal performance? Behav Ecol Sociobiol 36:1–10. https://doi.org/10.1007/BF00175722
Boness DJ, Craig MP, Honigman L, Austin S (1998) Fostering behavior and the effect of female density in Hawaiian monk seals, Monachus schauinslandi. J Mammal 79:1060–1069. https://doi.org/10.2307/1383115
Bryden MM (1966) Twin foetuses in the southern elephant seal. Pap proc R Soc Tasmania 100:89–90
Carrick RS, Csordas SE, Ingham SE (1962) Studies on the southern elephant seal, Mirounga leonina (L.). IV. Breeding and development. Wildl Res 7:161–197
Christensen TE, Le Boeuf BJ (1978) Aggression in the female northern elephant seal, Mirounga angustirostris. Behaviour 64:158–172. https://doi.org/10.1163/156853978X00495
Clutton-Brock TH (1988) Reproductive success: studies of individual variation in contrasting breeding systems. University of Chicago Press, Chicago
Dowell SA, Boren LJ, Negro S, Muller CG, Caudron AK, Gemmell NJ (2008) Rearing two New Zealand fur seal (Arctocephalus forsteri) pups to weaning. Aust J Zool 56:33–39. https://doi.org/10.1071/ZO07063
Ellis SL, Bowen WD, Boness DJ, Iverson SJ (2000) Maternal effects on offspring mass and stage of development at birth in the harbor seal, Phoca vitulina. J Mammal 81:1143–1156
Fenwick GD (1973) Breeding biology and population dynamics of the Weddell seals, Leptonychotes weddellii: a review. Mauri Ora 1:29–36
Galimberti F, Boitani L, Marzetti I (2000a) The frequency and costs of harassment in southern elephant seals. Ethol Ecol Evol 12:345–365. https://doi.org/10.1080/08927014.2000.9522792
Galimberti F, Boitani L, Marzetti I (2000b) Harassment during arrival on land and departure to sea in southern elephant seals. Ethol Ecol Evol 12:389–404. https://doi.org/10.1080/08927014.2000.9522794
Gelatt TS, Davis CS, Siniff DB, Strobeck C (2001) Molecular evidence for twinning in Weddell seals (Leptonycotes weddellii). J Mammal 82:491–499
Gentry RL (1970) Social behavior of the Steller sea lion. Dissertation, University of California, California
Haase TJ (2007) Suckling an additional pup to weaning in the New Zealand fur seal. Mar Mammal Sci 23:176–183. https://doi.org/10.1111/j.1748-7692.2006.00078.x
Hoffman HI, Forcada J (2009) Genetic analysis of twinning in Antarctic fur seals (Arctocephalus Gazella). J Mammal 90:621–628. https://doi.org/10.1644/08-MAMM-A-264R1.1
Huber HR, Beckham C, Nisbet J (1991) Effects of the 1982–83 E1 Niño on northern elephant seals on the South Farallon Islands, California. In: Trillmich F, Ono KA (eds) Pinnipeds and E1 Niño: responses to environmental stress. Springer, New York, pp 219–233
Hückstädt L (2015) Leptonychotes weddellii. The IUCN red list of threatened species. www.iucnredlist.org. Accessed 18 Aug 2016
Kaufman GW, Siniff DB, Reichle R (1975) Colony behavior of Weddell seals, Leptonychotes weddellii at Hutton Cliffs, Antarctic. Rapp P V Reun Cons Int Explor 169:228–246
Lake SE, Burton HR, Hindell MA (1997) Influence of time of day and month on Weddell seal haulout patterns at the Vestfold Hills, Antarctica. Polar Biol 18:319–324. https://doi.org/10.1007/s003000050194
Laws RM (1953) The elephant seal (Mirounga leonina Linn.): I. Growth and age. Falkland Isl Depend Surv Sci Rep 8:1–62
Le Boeuf BJ, Morris P, Reiter J (1994) Juvenile survivorship of northern elephant seals. In: Le Boeuf BJ, Laws RM (eds) Elephant seals: population ecology, behavior, and physiology. University of California Press, California, pp 121–136
Lunn NJ (1992) Fostering behavior and milk stealing in Antarctic fur seals. Can J Zool 70:837–839. https://doi.org/10.1139/z92-119
Maniscalco JM, Parker P (2009) A case of twinning and the care of two offspring of different age in Steller sea lions. Mar Mammal Sci 25:206–213. https://doi.org/10.1111/j.1748-7692.2008.00247.x
McCann TS (1981) Aggression and sexual activity of male southern elephant seals, Mirounga leonine. J Zool 195:295–310. https://doi.org/10.1111/j.1469-7998.1981.tb03467.x
McCann TS (1982) Aggressive and maternal activities of female southern elephant seal (Mirounga leonina). Anim Behav 30:268–276. https://doi.org/10.1016/S0003-3472(82)80263-7
McMahon CR, Bradshaw CJA (2004) Harem choice and breeding experience of female southern elephant seals influence offspring survival. Behav Ecol Sociobiol 55:349–362. https://doi.org/10.1007/s00265-003-0721-1
McMahon CR, Hindell MA (2003) Twinning in southern elephant seals: the implications of resource allocation by mothers. Wildl Res 30:35–39. https://doi.org/10.1071/WR01069
Oftedal OT, Boness DJ, Tedman RA (1987) The behavior physiology, and anatomy of lactation in the pinnipedia. Curr Mammal 1:175–245. https://doi.org/10.1007/978-1-4757-9909-5_6
Perry EA, Boness DJ, Fleischer RC (1998) DNA fingerprinting evidence of nonfilial nursing in grey seals. Mol Ecol 7:81–85. https://doi.org/10.1046/j.1365-294x.1998.00313.x
Peter H-U, Buesser C, Mustafa O, Pfeiffer S (2008) Risk assessment for the Fildes Peninsula and Ardley Island, and development of management plans for designation as Antarctic specially protected or managed areas. The Federal Environment Agency, Germany
Plötz J (1986) Summer diet of Weddell seals (Leptonychotes weddelli) in the Eastern and Southern Weddell sea, Antarctica. Polar Biol 6:97–102. https://doi.org/10.1007/BF00258259
Rae BB (1969) Twin seals in Scotland. J Zool 158:243–245
Reijnders PJH, Plötz J, Zegers J, Grafe M (1990) Breeding biology of Weddell seals (Leptonychotes weddellii) at Drescher Inlet, Riiser Larsen Ice Shelf, Antarctica. Polar Biol 10:301–306. https://doi.org/10.1007/BF00238429
Reiter J, Panken KJ, Le Boeuf BJ (1981) Female competition and reproductive success in the northern elephant seals. Anim Behav 29:670–687. https://doi.org/10.1016/S0003-3472(81)80002-4
Riedman ML, Le Boeuf BJ (1982) Mother–pup separation and adoption in northern elephant seals. Behav Ecol Sociobiol 11:203–215. https://doi.org/10.1007/BF00300063
Schaeff CM, Boness DJ, Bowen WD (1999) Female distribution, genetic relatedness, and fostering behavior in harbor seals, Phoca vitulina. Anim Behav 57:427–434. https://doi.org/10.1006/anbe.1998.1001
Schultz JK, Becker BL, Johanos TC, Lopez JU, Kashinsky L (2011) Dizygotic twinning in the Hawaiian monk seal. J Mammal 92:336–341. https://doi.org/10.2307/23260097
Shirihai H, Jarrett B (2006) Whales, dolphins, and other marine mammals of the world. Princeton University Press, New Jersey
Smith MSR (1966) Studies of the Weddell seal in McMurdo Sound, Antarctica. Dissertation, University of Canterbury, Christchurch
Smith EA (1968) Adoptive suckling in the grey seal. Nature 217:762–763. https://doi.org/10.1038/217762a0
Spotte S (1982) The incidence of twins in pinnipeds. Can J Zool 60:2226–2233
Stirling I (1969) Ecology of the Weddell Seal in McMurdo Sound, Antarctica. Ecology 50:573–586. https://doi.org/10.2307/1936247
Stirling I (1975) Adoptive suckling in pinnipeds. J Aust Mammal Soc 1:389–391
Tedman R, Green B (1987) Water and sodium fluxes and lactational energetics in suckling pups of Weddell seal (Leptonychotes weddellii). J Zool 212:29–42. https://doi.org/10.1111/j.1469-7998.1987.tb05112.x
Testa JW, Hill SEB, Siniff DB (1989) Diving behavior and maternal investment in Weddell seals (Leptonychotes weddellii). Mar Mammal Sci 5:399–405. https://doi.org/10.1111/j.1748-7692.1989.tb00354.x
Trillmich F (1981) Mutual mother-pup recognition in Galapagos fur seals and sea lions: cues used and functional significance. Behaviour 78:21–42. https://doi.org/10.1163/156853981X00248
Acknowledgements
The authors are grateful to the Chinese Arctic and Antarctic Administration of the State Oceanic Administration, and the Polar Research Institute of China for logistical support in the field. We also appreciate the members J. J. Cao, J. Xiong, and R. H. Wang of the 30th Chinese Antarctic scientific expedition for their generous help and assistance during field investigation, and the anonymous reviewers for their comments to improve this paper. This research was funded by the Scientific Research Foundation of the Third Institute of Oceanography, State Oceanic Administration of China (TIO2015036), Chinese Polar Environment Comprehensive Investigation and Assessment Program (CHINARE2012-2015-04-03, CHINARE2012-2015-03-05), and State Oceanic Administration of China (SOA, 2011GW13ZS07019).
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Wu, F., Zhang, Z., Miao, X. et al. Three cases of potential twinning in Weddell seals (Leptonychotes weddellii) at Fildes Peninsula, King George Island, Antarctica. Polar Biol 41, 611–617 (2018). https://doi.org/10.1007/s00300-017-2222-0
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DOI: https://doi.org/10.1007/s00300-017-2222-0