Abstract
This study examined seasonal changes in blubber distribution and body morphology of 61 male hooded seals, 4 years of age and older, caught in Skjalfandi-Bay in northeast Iceland in May, August and October during 1998 and 1999. Seasonal changes were found in girth, blubber depth and the ratio of blubber depth to body radius (d/r ratio). The seals lost 16% of their total mass between May and August, during moulting, but d/r ratios did not drop significantly. Hooded seals caught in October were 10% heavier than seals caught in August mostly due to greater sculp mass but were not as heavy as seals caught in May that had a higher core mass (mass–sculp). Core mass decreased by 14% between May and August or almost proportionally to total mass but increased much more slowly than total and sculp mass between August and October. Furthermore, this study found that commonly used condition indices are misleading when comparing condition of adult male hooded seals between seasons.
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References
American Society of Mammalogists (1967) Standard measurements of seals. J Mammal 48:459–462
Beck GG, Smith TG (1995) Distribution of blubber in the northwest Atlantic harp seal, Phoca groenlandica. Can J Zool 73:1991–1998
Bowen WD, Sergeant DE, Øritsland NA (1983) Validation of age estimation in the harp seal, Phoca groenlandica, using dental annuli. Can J Fish Aquat Sci 40:1430–1440
Bryden MM (1968) Growth and function of the subcutaneous fat of the elephant seal. Nature 220:597–599
Castellini MA, Calkins DG (1993) Mass estimates using body morphology in Steller sea lions. Mar Mamm Sci 9:48–54
Chabot D, Stenson GB, Cadigan NG (1996) Short- and long-term fluctuations in the size and condition of harp seal (Phoca groenlandica) in the northwest Atlantic. NAFO Sci Counc Stud 26:15–32
Chabot D, Stenson GB (2002) Growth and seasonal fluctuations in size and condition of male northwest Atlantic harp seals Phoca groenlandica: an analysis using sequential growth curves. Mar Ecol Prog Ser 227:25–42
Cherel Y, Leloup J, Le Maho Y (1988) Fasting in king penguin II. Hormonal and metabolic changes during molt. Am J Physiol 254:R178–R184
Gales NJ, Burton HR (1987) Ultrasonic measurements of blubber thickness of the southern elephant seal, Mirounga leonia (Linn.). Aust J Zool 35:207–217
Lavigne DM, Kovacs KM (1988) Harps and hoods. Ice-breeding seals of the northwest Atlantic. University of Waterloo Press, Waterloo
Lockyer CH, McConnell LC, Waters TD (1985) Body condition in terms of anatomical and biochemical assessment of body fat in north Atlantic fin and sei whales. Can J Zool 63:2328–2338
Lockyer CH, Waters TD (1986) Weights and anatomical measurements of northeastern Atlantic fin (Balaenoptera physalus, Linneaus) and sei (B. borealis) whales. Mar Mamm Sci 2:169–185
Nordøy ES, Blix AS (1991) Glucose and ketone body turnover in fasting grey seal pups. Acta Physiol Scand 4:565–571
Noren DP, Mangel M (2004) Energy reserve allocation in fasting northern elephant seal pups: inter-relationships between body condition and fasting duration. Funct Ecol 18:233–242
Øritsland NA, Pasche AJ, Markussen NH, Ronald K (1985) Weight loss and catabolic adaptations to starvations in grey seal pups. Comp Biochem Physiol A 82:931–933
Pond CM (1978) Morphological aspects and the ecological consequences of fat deposition in wild vertebrates. Annu Rev Ecol Syst 9:519–570
Pond CM, Ramsey MA (1992) Allometry of the distribution of adipose tissue in Carnivora. Can J Zool 70:342–347
Rosen DAS, Renouf D (1997) Seasonal changes in blubber distribution in Atlantic harbor seals: indications of thermodynamic considerations. Mar Mamm Sci 13:229–240
Ryg M, Smith TG, Øritsland NA (1988) Thermal significance of the topographical distribution of blubber in ringed seals (Phoca hispedia). Can J Fish Aquat Sci 45:985–992
Ryg M, Lydersen C, Markussen NH (1990) Estimating the blubber content of phocid seals. Can J Fish Aquat Sci 47:1223–1227
Sergeant DE (1973) Feeding, growth and productivity of northwest Atlantic harp seals (Phagophilus groenlandicus). J Fish Res Board Can 30:17–29
Sergeant DE (1991) Harp seals, man and ice. Department of Fisheries and Oceans. Ottawa, Canada
Sivertsen E (1941) On the biology of the harp seal Phoca groenlandica Erxl. Investigations carried out in the White Sea 1925–1937. Hvalrådets Skrifter 26:1–166
Slip DJ, Gales NJ, Burton HR (1992) Body mass loss, utilisation of blubber and fat, and energetic requirements of male southern elephant seals, Mirounga leonia, during the moulting fast. Aust J Zool 40:235–243
Stewart REA, Lavigne DM (1980) Neonatal growth of northwest Atlantic harp seals Phagophilus groenlandica. J Mammal 61:670–680
Trites WA, Bigg MA (1992) Changes in body growth of northern fur seals from 1958 to 1974: density effects or changes in the ecosystem? Fish Oceanogr 1:127–136
Vikingsson GA (1995) Body condition of fin whales during summer off Iceland. In: Blix AS, Ulltang Ø (eds) Whales, seals, fish and man. Elsevier Science B.V., Amsterdam, pp 361–369
Worthy GAJ, Morris PA, Costa DP, Le Boeuf BJ (1992) Moult energetics of the northern elephant seal (Mirounga angustirostris). J Zool Lond 227:257–265
Worthy GAJ, Lavigne DM (1983) Energetics of fasting and subsequent growth in weaned harp seals pups, Phoca groenlandica. Can J Zool 61:447–456
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The assistance of many fieldworkers, particularly of Thordur Peturson, is gratefully acknowledged. We also wish to thank the two anonymous reviewers for their helpful comments on the manuscript.
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Thordarson, G., Vikingsson, G.A. & Hersteinsson, P. Seasonal variation in body condition of adult male hooded seals (Cystophora cristata) in Skjalfandi-Bay, northeast Iceland. Polar Biol 30, 379–386 (2007). https://doi.org/10.1007/s00300-006-0194-6
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DOI: https://doi.org/10.1007/s00300-006-0194-6