Foraging in a 3-D world: The Influence of Body Size and Sex on Vertical and horizontal foraging Behaviour of Yellow Baboons

Abstract

Foraging is among complex animal behaviours, which involve making decisions on what and where to forage, so as to maximize nutritional gain and reduce predation risk. In ungulates, it is known to also be influenced by sexual size dimorphism, however, this is not clear in sexually size dimorphic yellow baboon. Using focal animal sampling techniques, we collected data from habituated troops of yellow baboons to test whether body size and/or sex has influence on their use of vertical and horizontal strata when foraging. Results showed that, yellow baboons foraged more frequently on the ground up to 1 m than beyond this height. However, adult females foraged on the ground significantly more frequently than adult and subadult males. While, adult and subadult males used higher canopy beyond 2 m, more frequently than adult females. Moreover, adult females and subadult males foraged more frequently at the troop centre than adult males. This study concludes that sex and to some extent body size significantly influence foraging decisions of yellow baboon in the use of vertical and horizontal strata. Detailed understanding of spacing behaviour of baboons is recommended as it is important towards better understanding of their complex social life.