Dietary composition and feeding preference of Mantled guereza Colobus guereza (Rüppell, 1835), in Maze National Park, Ethiopia.

Abstract

Knowledge of feeding ecology is essential for effective management of a primate and its habitat. The Mantled guereza Colobus guereza is a predominantly folivorous monkey that occurs in different parts of eastern Africa, including the Maze National Park in Ethiopia. Despite many studies conducted in the area, there is no up-to-date data that was carried out on feeding ecology of the Colobus guereza. The aim of this study is to determine the dietary composition and feeding preference of the Colobus guereza in the park. To better understand this, we randomly selected three study groups along the Maze River. We used instantaneous scan sampling method to collect feeding data from September 2021-August 2022. We followed guerezas from 6:30 to 10:30 in the morning and 13:30 to 17:25 in the afternoon collecting feeding activity data between 5 min intervals during 10-min scan duration. Overall, guerezas were observed to eat eight plant species and unidentified invertebrates in the park. Of these, Trichilia emetica contributed the highest proportion accounted 53.36% and 27.83% in the wet and dry season respectively, while unidentified invertebrates were rarely utilized over the course of this study. We also found that young leaves were consumed more (n = 1,794, 75.31%) in the wet while mature leaves were eaten more (n = 1,215, 43.61%) over the other diet components in the dry season. These results suggest that the guerezas in the park exhibit temporal dietary flexibility. The observed dietary flexibility may be partly due to seasonal changes in availability of food plant parts in the groups' home ranges in the park. Our results suggest that maintaining the park is critical to protect food plant species for this primate, which at present constitutes only a few.