Activity patterns, feeding and ranging ecology of colobus monkey (Colobus guereza) in core and transition zone of kaffa biosphere reserve, saylem district, southwestern ethiopia

Abstract

Understanding of activity pattern, ranging and feeding ecology of primates is essential for caring its behavioral ecology and evaluating the suitability of habitats for the species. Colobus monkey (Colobus guereza) is currently listed as Data Deficient on the IUCN Red list and thus it does not get more conservation attention. With the current increasing habitat loss and degradation across its geographic range, data on the current activity pattern, feeding and ranging ecology are essential to design a management plan as well as it helps to evaluate the UNESCO program under the Man and Biosphere Reserve's objective with respect to colobus monkey conservation. This study, therefore aims at providing data on the activity patterns, day range length, home range size and diets of two different Colobus guereza groups (Group I and Group II) in transitional and core zone of Kaffa biosphere reserve, Saylem District, SNNPR, southwestern Ethiopia. The activity time budget, feeding ecology and ranging behavior were studied in two groups for five minutes with 15 minute interval scan sampling for the 6 month study period. Ranging data were derived from by calculating daily movements and estimating home range. To see the variation of the two-habitat types vegetation studies were carried out by using systematic random sampling. On each transect, five rectangular plots of dimensions 20m by 25m (500m2) were systematically established at 100m interval throughout the home range of the two groups. The overall activity time budgets (n=11861) of the two groups of C. guereza were, (37.67% and 47.60%) of their time spent in resting, (29.7% and 12.52%) moving, (16.2% and 21.79%) feeding, (4.55% and 4.75%) playing, (5.70% and 8.13%) grooming (2.96% and 2.10%) aggression, (0.87% and 1.23%) sexual activities and (2.35% and 1.88%) of their of time spent on other activities in Group I and Group II, respectively. During the course of the study in total they foraged 16 different plant species belonged to 13 families. The individuals of Group I consumed 15 different plant species, while individuals of Group II consumed 12 plant species. The most frequently consumed plant species in Group I were Ilex mitis (21.79 %), Prunus africana (21.56%) and Macaranga capensis (13.32%). In the case of Group II, Prunus africana contributed for (25.07%) Macaranga capensis (16.65%) and Syzigium guineans (15.5%) were mostly consumed species. Colobus guereza in the study area had shown strong preference on young leaves and fruits (47.85% and 30.88%) in Group I and (43.73% and 30.74%) in Group II respectively. Home range size was 63.3 ha for Group I and 67.2 ha for Group II. The average day range length was 558.77m and 495.00m for Group I and Group II. Even though there are some behavioural activity variation in the two groups of Colobus generally, transition zone of Kaffa Biosphere can serve as an equivalent habitat for colobus conservation by planting some preferred diet plants in the area.