The Effect of Habitat on Density, Feeding Behaviour and Activity of Heller’s Vervet Monkey ( Chlorocebus pygerythrus arenarius ): A Case Study in Arba Minch Forest, Ethiopia

Abstract

Heller’s vervet monkey (Chlorocebus pygerythrus arenarius) is one of the African savannah monkeys found in East Africa including Ethiopia. This study was carried out from September 2012 to April 2013 to provide data on the effect of habitat on density, feeding and activity of the Heller’s vervet monkey in Nech Sar National Park and its adjacent areas, in Ethiopia. The study area constituted underground water forest, riverine forest, savannah bushland, bush with Eucalyptus plantation and tree dominated bushland. Five line transects of 3-4 km were made in all habitats to estimate the population density of Heller’s vervet monkey. Five selected troops were also followed using focal animal sampling to study the activity patterns and feeding behaviour. The highest population density of Heller’s vervet monkey was recorded in underground water forest and riverine forest habitats. The overall diet composition of Heller’s vervet monkey was dominated by leaves, which accounted for 37.87%. Foraging on bark, fruit and flowers constituted 21.19%, 19.56% and 13.90%, respectively. They also fed on shoots (4.70%) and unknown food items (2.78%). The activity in different troops showed significant variations in resting behaviour, whereas active behaviours did not show significant variations between the troops.