Professor emeritus, Animal Ecology
Tel: 46 (0)31-773 36 95 | email@example.com
I head the Selection and Social Evolution group, which also includes Sofia Anderholm (PhD student) and Peter Waldeck (PhD, now at Gotland University).
Social relations between individuals can give rise to strong natural and sexual selection, affecting reproductive tactics, breeding systems, sex roles and sex differences. We study these aspects theoretically by mathematical modelling, and empirically by field observations and experiments, comparative analyses and molecular ecological methods. Our current field projects focus on ecology and evolution of breeding systems, for example in the highly variable shorebirds, and on brood parasitism and social evolution in waterfowl and other birds:
Patterns of mating and parental care in the two sexes vary greatly among animals, from polygynous lekking males to emancipated, socially polyandrous females, for reasons that in many cases are unknown. We study social and genetic patterns of parentage and tactical and ecological aspects of mating systems, aiming to understand their evolution. We do so in a group of animals that offers wide contrasts in breeding system and sexual selection, shorebirds (Charadriiformes), in particular several closely related sandpipers in the tribe Tringini. In a test of adaptive seasonal trends in brood sex ratios of monogamous Common and polyandrous Spotted sandpipers, the trends differed between the two species as predicted by theory involving their contrasting breeding systems. In Common sandpiper and two other waders, genetic similarity between the social mates was higher in pairs with extra-pair parentage in their brood than in pairs with perfect genetic monogamy. This suggests that an individual is more likely to cuckold its social mate if their genetic similarity is high.
In conspecific brood parasitism (CBP), parasitic females lay eggs in the nests of other females of the same species, who care for the offspring. CBP is particularly common in ducks and other waterfowl, which differ from most birds in that females, not males, return and breed in their birth area. The local females may therefore be related, creating scope for cooperation and kin selection among related hosts and parasites. Theory suggests that this may be a contributing reason why CBP is particularly common in waterfowl. For testing of this and other tactical aspects of CBP, we have developed protein fingerprinting of eggs, a non-destructive technique of albumen sampling combined with sensitive protein electrophoresis (isoelectric focussing). We found that host-parasite pairs in goldeneyes are more closely related than other females, that individual recognition is probably involved, and that females combining parasitism with normal nesting can greatly increase their reproductive success. To gain further insight into this and other reproductive tactics, we now use these approaches in ongoing work on eiders, geese and other birds.