Demography, population dynamics, and the human-lion conflicts: Lions in the Ngorongoro Crater and the Maasai steppe, Tanzania

I examined factors limiting lion population growth, and looked at how landscape, demography and anthropogenic factors affected the persistence of lion prides in the Ngorongoro Crater, and investigated how livestock prey selection, location and timing of predation contributed to vulnerability of lions, leopards and spotted hyenas to retaliatory killing in the Maasai steppe, Tanzania. The Ngorongoro Crater lion population, showed strong evidence of density dependent regulation at 100-120 individuals but remained below 60 for the past decade despite consistently high prey abundance. Lions enjoyed higher per-capita food intake rate and higher cub recruitment at low population density, and inter-specific competition has not increased in recent years. These animals have suffered from a number of severe disease outbreaks over the past 40 years, but whereas the population recovered exponentially from a severe epizootic in 1963, three outbreaks between 1994 and 2001 have occurred in rapid succession that the population has been unable to return to the carrying capacity. Limitation to population growth is largely driven by top-down processes associated with frequent disease outbreaks.;The persistence of lion prides to 10 years in the Ngorongoro Crater depended on adult female density (pride size), cub productivity (ultimate source of new females), and proximity to rivers. In addition to these factors, short term pride persistence (5 years) was influenced by frequency of male takeovers, disease epidemics and the amount of vegetative cover. Prides closest to rivers had higher adult female density and fewer male takeovers. Adult female mortality increased with disease epidemics, but was lower closest to rivers. Cub productivity was highest in prides closest to rivers and in areas with higher vegetative cover. The intensity of use of the Crater by Maasai pastoralists did not appear to influence pride persistence.;Lions preyed upon adult cattle and donkeys, but hyenas and leopards killed goat, sheep, calves and dogs. Hyenas and leopards attacked livestock at night, whereas lions attacked grazing livestock during the daytime. These behaviors differences made lions more vulnerable to direct retaliatory killing, although hyenas are high risk with poisoning. Cultural and traditions of Maasai pastoralists might also exacerbate retaliatory killing of lions.