Abstract

We investigated habitat selection by grey seals, Halichoerus grypus, around haulouts in the Baltic Sea. Home ranges (95% fixed kernel) varied in size from 1088 to 6400 km(2). Observed habitat use was tested against the circular home range predicted from a simple central-place model. The overlap between the home ranges predicted by this simple model and actually exhibited by the seals was < 70% for 9 of 11 seals. Furthermore, the depth distributions of the utilised areas were significantly different from that available in the circular home range for all 11 seals. Seals selected depths of 11-40 m and avoided areas > 51 m deep. Ten of the 11 seals used areas within a 50-km radius around the haulout site for more than 75% of the time. Thus, in spite of their mobility and the availability of many islands, seals usually remained in the vicinity of a specific haulout site for extended periods. The seals did not use the habitat around the haulout site as predicted by the simple central-place model, but selected habitat according to bathymetric characteristics (e.g., water depth). Detection of these relatively small but heavily used home ranges around haulout sites may be of assistance in management plans in order to reduce the growing number of seal-fisheries conflicts

Published in

Canadian Journal of Zoology
2000, Volume: 78, number: 9, pages: 1661-1667
Publisher: NATL RESEARCH COUNCIL CANADA

SLU Authors

• Sjöberg, mikael

  • Department of Animal Ecology, Swedish University of Agricultural Sciences
    

• Ball, John

  • Department of Animal Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Publication identifier

DOI: https://doi.org/10.1139/cjz-78-9-1661

Permanent link to this page (URI)

https://res.slu.se/id/publ/6308