ABR: Long-term Studies of African Lions

This proposal will extend the long-term studies of genetics, ecology and behavior of African lions. The study includes two contrasting populations. The Serengeti contains a very large outbred population whereas the population in Ngorongoro Crater is descended from 15 founders and has been genetically isolated for five generations. Future work will investigate why the Center population has comparable variability in minisatellite DNA to the Serengeti, whether the inbred Crater population is immunologically impaired as a result of its loss of diversity in MHC genes, and whether declining reproductive performance in the Crater population is due to persistent inbreeding. Because many species of large mammals are increasingly restricted to small ecological 'islands' and are hence subject to increasing levels of inbreeding, this research will be valuable in assessing the kinds of genetic and epidemiological problems that may commonly affect such small populations. Ecological studies will focus on the factors that regulate lion population size and test whether density dependence directly operates on the number of individuals in the population or on the number of groups. Finally, behavioral studies will focus on the unusually long period of dependency of subadult lions. The protracted development of young lions is more typical of primates and suggests that subadults which remain in their natal prides for longer periods may become more proficient foragers (both as hunters and as scavengers). Subadults play an active role in defending the pride territory against neighboring groups, and this proposal will explore the ontogeny of territorial behavior of subadults with playback experiments.