ABR: Long-term Studies of African Lions

这一提议将延长对非洲狮子的遗传学、生态学和行为的长期研究。这项研究包括两个截然不同的人群。塞伦盖蒂陨石坑拥有非常大的异种繁殖种群，而恩戈罗陨石坑的种群是15个创建者的后代，已经被遗传隔离了五代。未来的工作将调查为什么中心种群的小卫星DNA具有与塞伦盖蒂类似的变异性，近亲繁殖的陨石坑种群是否由于其MHC基因多样性的丧失而导致免疫受损，以及陨石坑种群的繁殖性能下降是否由于持续的近亲繁殖。由于许多大型哺乳动物物种越来越局限于小型生态“岛屿”，因此近亲交配的程度越来越高，因此这项研究将对评估通常影响这些小种群的遗传和流行病学问题的种类具有价值。生态学研究将集中于调节狮子种群大小的因素，并测试密度依赖是否直接影响种群中的个体数量或群体数量。最后，行为研究将重点放在未成年狮子异常长的依赖期上。幼狮的长期发育在灵长类动物中更为典型，这表明在出生时保持较长时间骄傲的亚成体可能会成为更熟练的觅食者(既作为猎人，也作为食腐动物)。亚成人在保卫领地不受邻近群体攻击方面发挥着积极的作用，本研究将通过回放实验来探索亚成人领地行为的个体发生。

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.