20 March 2006
Do extra-pack copulations reduce inbreeding in Ethiopian wolves?
Previous research showed that despite social monogamy in Ethiopian wolves, females engage in high levels of extra-pack copulations (EPCs). Like other pack living canids, the dominant female monopolizes breeding, producing a litter of up to seven pups, but all group members contribute to parental care. Philopatric males remain in their natal pack apparently for life and roughly half of all females disperse around two years of age. Dispersal is constrained by lack of unoccupied habitat, and females that remain in their natal pack can ascend to breeding status when the incumbent dies, resulting in the potential for incest within groups. However, 70% of observed copulations were between females in one pack and males in neighbouring packs and there is some evidence for multiple-paternity within litters. It has therefore been argued that EPCs are an inbreeding avoidance strategy whereby females gain access to genetically unrelated mates outside their own social group.
In this study, I am using microsatellite markers to determine the paternity of offspring and the extent of multiple and extra-pack paternity (EPP) in litters. I am also examining the relationship between EPP, relatedness, and heterozygosity to determine if there are genetic benefits to polyandry and EPCs. I am testing the hypothesis that females avoid inbreeding by selecting unrelated males or, failing kin recognition, by mating with males outside their own pack. In the latter instance, females may not be able to distinguish the degree of relatedness between themselves and potential mates; but if males outside their social group are on average less related to themselves than the males in their own pack females may avoid inbreeding by gaining EPCs. I am also testing whether EPCs produce young with increased heterozygosity.
In this study, I am using microsatellite markers to determine the paternity of offspring and the extent of multiple and extra-pack paternity (EPP) in litters. I am also examining the relationship between EPP, relatedness, and heterozygosity to determine if there are genetic benefits to polyandry and EPCs. I am testing the hypothesis that females avoid inbreeding by selecting unrelated males or, failing kin recognition, by mating with males outside their own pack. In the latter instance, females may not be able to distinguish the degree of relatedness between themselves and potential mates; but if males outside their social group are on average less related to themselves than the males in their own pack females may avoid inbreeding by gaining EPCs. I am also testing whether EPCs produce young with increased heterozygosity.
# posted by Anonymous @ 20.3.06 
