Population size and human-grivet monkeys (Chlorocebus aethiops) conflict in Zegie peninsula, Bahir Dar, Ethiopia.

Background: Human-monkey conflict exists in different forms all over the world and is experienced more in developing countries. The conflict between human and grivet monkey (Chlorocebus aethiops) ranks among the main threats to biodiversity conservation and has become frequent and severe in different parts of Africa. A study on population size and human-grivet monkey conflict in Zegie Peninsula was carried out from August 2019 to March 2020; the study comprised both the wet and dry seasons. The line transect method was used to collect data on the population size of grivet monkeys. Questionnaires and focus group discussions were used to study the human-grivet monkey conflict and its conservation status.
Results: The estimated population of grivets in the study area was 5046. Population structure of grivets indicated that there were 637 adult males, 1246 adult females, 1839 juveniles, and 1324 infants. The number of grivets in different habitat was; 1925 grivets in agricultural area, 1568 in lakeshore, 988 in forest and 565 grivets in shrub. Grivet population estimate between the wet and dry seasons did not show significant differences (χ ²  = 0.941, df = 1, p > 0.05). But there was a significant difference in the population estimate of grivets among the different habitats (χ ²  = 239.135, df = 3, p < 0.05 and among their age/sex (χ ²  = 504.102, df = 3, p < 0.05. Based on the questionnaire result the most problematic crop pests in the area were grivet monkeys (96.4%), bush pigs (52.3%), porcupine (46.3%) and squirrels cover (33.2%). The result of discussions held with focus groups and questionnaires in the study area showed that grivet monkeys damage crops (98.4%), chicken depredation (49.5%), steal and snatch human food (32%), disturbing communities (11.3%) in the area. Most (62%) of the respondents noted that guava is the most vulnerable crop followed by papaya, mango, avocado to be damaged by grivet monkeys.
Conclusion: The total number of grivet monkey in the study area is 5046. The number of grivet monkeys varies based on their sex/age and their habitat type. There is no significant difference in their number according to season since the movement of grivets is restricted to the area (there is no migration in the area). The increasing population number leads the occurrence of human grivet monkey conflict in the area and this inversely affects grivet monkeys. There was a human-grivet monkey conflict in the Peninsula and grivets damaged crops, not only crops but also predating poultry, stealing eggs, and human food. Consequently, grivets were killed in response to the damage they caused to crops. Grivet's habitat in the Peninsula is highly disturbed because the local people cut trees for sale to support their livelihood. Awareness creation of the residents about wildlife and their habitat is necessary, and people should understand the impact of deforestation, illegal hunting, and the role of grivets in the ecosystem at large. Hence there is a need to protect the forest in order to ensure sustainable conservation of biodiversity in general and grivet monkeys in particular.
(© 2021. The Author(s).)