Borries, C.C.BorriesKoenig, A.A.KoenigWinkler, P.P.Winkler2018-11-072018-11-072001https://resolver.sub.uni-goettingen.de/purl?gro-2/17651To determine nutritional and social influences on life history traits and mating behavior in female langur monkeys, new long-term data for a feral population living in mufti-male groups under poor nutritional conditions are presented and compared with published longterm data for the same species living in one-male groups under excellent nutritional conditions. Under poor nutritional conditions, conceptions were confined to 5 months per year, coinciding with the period of the highest mating activity. Age at first parturition, gestation periods, lactation periods, and interbirth intervals were all significantly increased resulting in a more than 50% reduced reproductive rate under poor conditions. The pattern of sexual behavior during gestation was influenced by neither nutritional nor social conditions but the frequency was higher in mufti-male groups. Furthermore, estrus length was significantly increased in mufti-male groups where females tended to mate with as many resident males as available. Both phenomena, together with a high percentage of sexual behavior occurring outside the mid-cycle estrus, are interpreted in the light of paternity confusion in mufti-male groups in a species where infanticide by males is regularly observed. The extreme variation in life history traits and mating patterns disclosed here in one species suggests that future cross-species comparisons should strictly select datasets based on local ecological and social conditions.journal_article10.1007/s002650100391000171706600001