Female distribution, genetic relatedness, and fostering behaviour in harbour seals, Phoca vitulina

Although harbour seals may not recognize their relatives, relatives could b e chosen preferentially for fostering (i.e. kin selection) if harbour seals display natal philopatry coupled with breeding site fidelity, and thus kin are clustered within the colony. We used behavioural and genetic data to i nvestigate population structure within the Sable Island breeding colony and to test whether harbour seals tend to foster related pups. Adult females o n Sable Island showed a high level of breeding-colony site fidelity but low levels of within-colony site fidelity both within and between years. Simil arly, although lactating females showed a clumped distribution, group compo sition was highly variable, suggesting that this study colony was not compo sed of groups of related animals, DNA fingerprint data supported the hypoth esis that female distribution within the colony was not correlated with gen etic relatedness. Furthermore, the mean DNA band sharing among foster dyads did not differ significantly from that for unrelated animals. These result s indicate that among harbour seals, related pups are not usually chosen pr eferentially for fostering and hence, kin selection is not likely to be inf luencing the occurrence of this behaviour. (C) 1999 The Association for the Study of Animal Behaviour.