Distribution, feeding ecology and habitat association of De Brazza’s monkey (Cercopithecus neglectus) in Mettu district, Illubabor Zone, Southwestern Ethiopia

Abstract

The study was conducted between September 2013 and February 2014 to determine the distribution, feeding ecology and habitat preference of De Brazza’s monkeys in Mettu district, southwestern Ethiopia. The study was designed to cover both wet and dry seasons and both Kola and Woynadega agro-climatic zones. Questionnaire, field survey and focus group discussion were used to gather primary data (qualitative and quantitative data) from the study area. Line transect survey technique was used to study distribution pattern of the monkey. The survey on feeding ecology of the monkey was carried out by direct observation. Average group encounter rate per km was calculated to determine habitat preference of the monkey. The monkey occurred from lowland with altitude of 1312 m up to 1640 m asl in the sampling area. A distance of 16.5 km was surveyed and a total of 49 De Brazza’s monkeys (dry season) and 46 De Brazza’s monkeys (wet season) were counted in 8 localities. Eight groups were identified moving along seven transects. Group size ranged from 1 to 8 with mean 5.8 individuals per group. The average group density of De Brazza’s monkey in the study area was 3.9 per km2. The total population of De Brazza’s monkeys in Mettu district was estimated to be 4939. Riverine forests were the most preferred habitats of the monkey. Fruits, leaves, animal preys and flowers constituted the monkey’s diet listed from the most consumed to the least consumed. The average time spent by De Brazza’s monkeys feeding on fruits was 74.1% (dry) and 54.8% (wet); leaves 8.3% (wet) and 5.5% (dry); animal preys 7.3% (dry) and 4.9% (wet); flowers 1.7% (wet) and 0.7% (dry) and they spent 12.4% and 30.3% of their time feeding on other unidentified items during the dry and wet season, respectively. Thirteen tree species provided the diets of De Brazza’s monkeys, the top five of which were Cordia africana, Albezia gummifera, Sapium ellipticum, Ficus sur and Trichilla dregeana. The population of De Brazza’s monkey is declining and threatened with local extinction due to habitat destruction by anthropogenic activities of the local communities. Urgent governmental and communal conservation measures should be taken.