Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-29T11:59:58.264Z Has data issue: false hasContentIssue false

Marine-feeding otters (Lutra lutra) in Norway: seasonal variation in prey and reproductive timing

Published online by Cambridge University Press:  11 May 2009

Thrine Moen Heggberget
Affiliation:
Norwegian Institute for Nature Research, Tungasletta 2, 7005 Trondheim, Norway

Extract

Diet and food resources of marine-feeding otters (Lutra lutra, Mammalia) were studied along the coast of central Norway, where otters breed in all seasons. The fish and crab fauna in the 0–10 m depth zone where otters forage were sampled and otter spraints collected monthly for three years. Results were compared with published data from Shetland where otters breed mainly in summer. Most of the main prey species showed significant seasonal variation in numbers or biomass, which tended to be low in late winter or spring. The variations during the rest of the year were not synchronized between species. The combined density of the main prey species of Shetland otters, which peaked during summer, was low in Norway. This species group, eelpout (Zoarches viviparus), butterfish (Pholis gunnellus) and rocklings (Ciliata sp., Gaidropsarus sp. ), also constituted a smaller fraction of the total catch in Norway than in Shetland.) and bullrout (Myoxocephalus scorpius), constituted a larger fraction of the catch in Norway than in Shetland. Thus the otter's food resources on the Norwegian coast were seasonal, being minimal during the early months of the year, but with no clear maximum season as there is in Shetland. This may explain the differences in reproductive timing in the non-seasonal or autumn and winter species, cod (Gadus morhua.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bekker, D. L. & Nolet, B. A., 1990. The diet of otters Lutra lutra in the Netherlands in winter and early spring. Lutra, 33, 134144.Google Scholar
Brett, J. R., 1967. Swimming performance of sockeye salmon (Oncorhynchus nerka) in relation to fatigue time and temperature. Journal of the Fisheries Research Board of Canada, 24, 17311741.Google Scholar
Bronson, F. H., 1989. Mammalian reproductive biology. University of Chicago Press.Google Scholar
Bye, V. J., 1984. The role of environmental factors in the timing of reproductive cycles. In Fish reproduction: strategies and tactics (ed. Potts, G. W. and Wootton, R. J.), pp. 187205. Harcourt Brace Jovanovich.Google Scholar
Chanin, P., 1985. The natural history of otters. London: Croom Helm.Google Scholar
Conroy, J. W. H. & French, D. D., 1991. Seasonal patterns in sprainting behaviour of otters (Lutra lutra L.) in Shetland. In Proceedings of the Fifth International Otter Colloquium (ed. Reuther, C. and Rochert, R.), pp. 159166. Hankensbuttel.Google Scholar
Coutant, C. C., 1977. Compilation of temperature preference data. Journal of the Fisheries Research Board of Canada, 34, 739745.Google Scholar
Erlinge, S., 1968. Food studies on captive otters Lutra lutra L. Oikos, 19, 259270.CrossRefGoogle Scholar
Gibson, R. N., 1969. The biology and behaviour of littoral fish. Oceanography and Marine Biology. Annual Review. London, 7, 367410.Google Scholar
Gittleman, J. L. & Oftedal, O. T., 1987. Comparative growth and lactation energetics in carnivores. Oceanography and Marine Biology. Annual Review. London, 7. 36–410.Google Scholar
Godø, O. R., 1983. Foreløpige resultater av merkeforsøk på kysttorsk i området Møre-Helgeland. Fisken og Havet.b Bergen, 1983, 1928.Google Scholar
Härkönen, T., 1986. Guide to the otoliths of the bony fishes of the northeast Atlantic. Hellerup, Denmark: Danbiu ApS.Google Scholar
Haro, A. J., 1991. Thermal preferenda and behaviour of Atlantic eels (genus Anguilla) in relation to their spawning migration. Environmental Biology of Fishes, 31, 171184.Google Scholar
He, P., 1991. Swimming endurance of the Atlantic cod, Gadus morhua L., at low temperatures. Fisheries Research, 12, 6573.Google Scholar
He, P. & Wardle, C. S., 1988. Endurance at intermediate swimming speeds of Atlantic mackerel, Scomber scombrus L., herring, Clupea harengus L., and saithe, Pollachius virens L. Journal of Fish Biology, 33, 255266.Google Scholar
Heggberget, T. M., 1988. Reproduction in the female European otter in central and northern Norway. Journal of Mammalogy, 69, 164167.Google Scholar
Ims, R. A., 1990. The ecology and evolution of reproductive synchrony. Trends in Ecology and Evolution, 5(5), 135140.CrossRefGoogle ScholarPubMed
Kruuk, H., Conroy, J. W. H. & Moorhouse, A., 1987. Seasonal reproduction, mortality and food of otters Lutra lutra L. in Shetland. Symposia of the Zoological Society of London, 58, 263278.Google Scholar
Kruuk, H., Conroy, J. W. H. & Moorhouse, A., 1991. Recruitment to a population of otters (Lutra lutra) in Shetland, in relation to fish abundance. Journal of Applied Ecology, 28, 95101.Google Scholar
Kruuk, H. & Moorhouse, A., 1990. Seasonal and spatial differences in food selection by otters (Lutra lutra) in Shetland. Journal of Zoology, 221, 621637.Google Scholar
Kruuk, H. & Moorhouse, A., 1991. The spatial organization of otters (Lutra lutra) in Shetland. Journal of Zoology, 224, 4157.Google Scholar
Kruuk, H., Nolet, B. & French, D., 1988. Fluctuations in numbers and activity of inshore demersal fishes in Shetland. Journal of the Marine Biological Association of the United Kingdom, 68, 601617.Google Scholar
Kruuk, H., Wansink, D. & Moorhouse, A., 1990. Feeding patches and diving success of otters, Lutra lutra, in Shetland. Oikos, 57, 6872.Google Scholar
Lightfoot, A., 1981. Coastal otters in Norway. London: The Vincent Wildlife Trust.Google Scholar
Mason, C. F. & Macdonald, S. M., 1980. The winter diet of otters (Lutra lutra) on a Scottish sea loch. Journal of Zoology, 192, 558561.Google Scholar
Mason, C. F. & Macdonald, S. M., 1986. Otters. Ecology and conservation. Cambridge University Press.Google Scholar
Murphy, K. P. & Fairley, J. S., 1985. Food of otters Lutra lutra on the south shore of Galway Bay. Proceedings of the Royal Irish Academy B, 85, 4755.Google Scholar
Negus, N. C. & Berger, P. J., 1987. Mammalian reproductive physiology. Adaptive responses to changing environments. In Current mammalogy, vol. 1 (ed. Genoways, H. H.), pp. 149173. New York: Plenum Press.Google Scholar
Nolet, B. A. & Kruuk, H., 1989. Grooming and resting of otters Lutra lutra in a marine habitat. Journal of Zoology, 218, 433440.Google Scholar
Oftedal, O. T. & Gittleman, J. L., 1989. Patterns of energy output during reproduction in carnivores. In Carnivore behaviour, ecology and evolution (ed. Gittleman, J. L.), pp. 355378. London: Chapman and Hall.Google Scholar
Pethon, P., 1985. Aschehougs store fiskebok. Oslo: Aschehoug.Google Scholar
Quasim, S. Z., 1957. The biology of Centronotus gunnellus (L.) (Teleostei). Journal of Animal Ecology, 26, 389401.Google Scholar
Sivertsen, K., 1982. Utbredelse og variasjon i kråke-bollenes nedbeiting av tareskogen på vestkysten av Norge. Nordlandsforskning, Rapport 7/82, 131.Google Scholar
Skogland, T., 1989. Comparative social organization of wild reindeer in relation to food, mates and predator avoidance. Advances in Ethology, vol. 29. Berlin: Paul Parey Verlag.Google Scholar
Stott, B., 1970. Some factors affecting the catching power of unbaited fish traps. Journal of Fish Biology, 2, 1522.Google Scholar
Watson, H., 1978. Coastal otters (Lutra lutra L.) in Shetland. London: The Vincent Wildlife Trust.Google Scholar
Westin, L. & Aneer, G., 1987. Locomotor activity patterns of nineteen fish and five crustacean species from the Baltic Sea. Environmental Biology of Fishes, 20, 4965.Google Scholar
Wise, M. H., 1980. The use of fish vertebrae in scats for estimating prey size of otters and mink. Journal of Zoology, 192, 2531.Google Scholar
Wise, M. H., Linn, I. J. & Kennedy, C. R., 1981. A comparison of the feeding biology of mink Mustek vison and otter Lutra lutra. Journal of Zoology, 195, 181213.Google Scholar