NO EVIDENCE OF INBREEDING AVOIDANCE OR INBREEDING DEPRESSION IN A SOCIAL CARNIVORE

Dispersal by young mammals away from their natal site is generally tho ught to reduce inbreeding, with its attendant negative fitness consequ ences. Genetic data from the dwarf mongoose, a pack-living carnivore c ommon in African savannas, indicate that there are exceptions to this generalization. In dwarf mongoose populations in the Serengeti Nationa l Park, Tanzania, breeding pairs are commonly related, and close inbre eding has no measurable effect on offspring production or adult surviv al. Inbreeding occurs because average relatedness among potential mate s within a pack is high, because mating patterns within the pack are r andom with respect to the relatedness of mates, and because dispersal does little to decrease the relatedness among mates. Young females are more likely to leave a pack when the dominant male is a close relativ e but are relatively infrequent dispersers. Young males emigrate at ra ndom with respect to the relatedness of the dominant female and tend t o disperse to packs that contain genetically similar individuals.