Pc. Lee et Md. Hauser, LONG-TERM CONSEQUENCES OF CHANGES IN TERRITORY QUALITY ON FEEDING ANDREPRODUCTIVE STRATEGIES OF VERVET MONKEYS, Journal of Animal Ecology, 67(3), 1998, pp. 347-358
1. Food availability and quality are important determinants of mammali
an reproductive success, and long-term changes in food availability we
re assessed for their impact on diets and reproduction of three adjace
nt groups of vervet monkeys in Amboseli, Kenya in two periods spanning
an interval of 9 years. 2. Diets were largely restricted to the produ
cts of two species of acacia trees (Acacia xanthophloea and Acacia tor
tilis), with food selection primarily determined by availability (tree
density, size and seasonal production of foods).3. Over this period t
he overall abundance of major foods, measured through absolute species
density, declined while territory size increased. 4. Despite signific
ant changes in food plant densities, diets remained relatively stable,
suggesting a component of consistency in diet choice. Limited options
or high costs for incorporation of novel foods are suggested as facto
rs maintaining this stability, with deleterious consequences in the fa
ce of very long-term habitat changes. 5. This study suggests that the
habitat deterioration, assessed by reduction in food densities, initia
ted local group extinction. An increased energy expenditure in foragin
g, high mortality and low reproductive rates ultimately led to a popul
ation crash under conditions of reduced food availability.