Diurnal activity budget and feeding activity of grivet monkeys (Chlorocebus aethiops) in Zegie Peninsula, Northern Ethiopia

Abstract Background Grivet monkeys (Chlorocebus aethiops) are an Old World monkey with long white tufts of hair along the sides of the face. We collected data on the activity patterns of the members of the 2 neighboring focal groups on an average of 4 day per month from August 2021 to March 2022 covering both the wet and dry seasons. Scan sampling method at 15 minutes interval was used to collect data on diurnal activity patterns and feeding ecology of grivet monkeys. Results A total of 16707 individual behavioral scans were recorded for a total of 24 days; 12 days during the wet season (August, September and October) and 12 days during the dry season (January, February and March). Grivet monkeys spent 39.4% of time feeding, 29.6% moving, 19.9% resting, 4.4% grooming, 3.1% social play, 2.4% aggression, and 1% for other activities. The overall diet of grivet monkeys was dominated by fruit (61.2%), while young leaf accounted (22%), young shoot (8%), bark (4.6%), animal prey (2.9%), and others (1.1%). A total of 22 plant species were consumed by grivet monkeys in the study area. The top four plant species namely Mimuscops kummel, Ficus sur, Strychanoss pinosa and Ficus vasta accounted for more than 73% of their plant diet. According to the total percentage contribution of the plant food items eaten, Mimuscops kummel was the most frequently consumed species which accounted about 29%, Ficus sur was 17%, Strychanoss pinosa 16%, and Ficus vasta was 11%. Conclusion Grivet monkeys spent more time for feeding followed by, moving, resting, grooming, social play, aggression and other activities. Grivet monkeys are mostly feed on fruits and they also feed on young leaves, shoots, bark, animal preys and other food items.