TIME, GENDER, AND SEASONALITY IN VERVET ACTIVITY - A CHRONOBIOLOGICALAPPROACH

A chronobiological approach has been used to highlight the issue of ho w climatic factors and breeding seasonality may affect male and female diurnal activity budget. We investigated gender differences for verve t monkeys in the diurnal distribution of feeding, locomotion, inactivi ty, and social grooming within and between birth, pre-mating, and mati ng seasons. The main climatic traits were that days were shorter, drie r, and cooler in the mating season. Non-parametric statistics showed t hat female activities changed with time of day to a greater extent tha n did male activities. When the constraints imposed by climatic factor s and mate competition increased, from the birth to the mating season, male maintenance activities were more independent of the time of day whereas females continued to vary. Gender differences in timing were t herefore greater in the mating season, except for social grooming; mal es and females were more coordinated in diurnal timing of their groomi ng in the mating season. It is argued that these changes may result in reduced levels of male-female contest competition, and may be related to higher levels of male-female socialization in the mating season. F inally, it is inferred that an out-of-phase synchronization between in activity and feeding for males in the birth season, and for females in the mating season, may result from each sex investing more time feedi ng at the expense of resting in those periods.