Activity budgets of Angola Black-and-White Colobus (Colobus angolensis palliatus) in an East African coastal forest

Abstract

Activity budgets of primates are commonly associated with strategies of energy conservation and are affected by a range of variables. In order to establish a solid basis for studies of colobine monkey food preference, food availability, group size, competition and movement, and also to aid conservation efforts, we studied activity of individuals from social groups of Colobus angolensis palliatus in a coastal forest patch in southeastern Kenya. Our observations (N = 461 hours) were conducted year-round, over a period of three years. In our Colobus angolensis palliatus study population, there was a relatively low mean group size of 5.6 ± SD 2.7. Resting, feeding, moving and socializing took up 64%, 22%, 3% and 4% of their time, respectively. In the dry season, as opposed to the wet season, the colobus increased the time they spent feeding, traveling, and being alert, and decreased the time they spent resting. General activity levels and group sizes are low compared to those for other populations of Colobus spp. We suggest that Peters’ Angola black-and-white colobus often live (including at our study site) under low preferred-food availability conditions and, as a result, are adapted to lower activity levels. With East African coastal forest declining rapidly, comparative studies focusing on C. a. palliatus feeding ecology, dietary flexibility and behavioral plasticity will be essential for in-situ conservation of the species.