Population structure and feeding ecology of Guereza (Colobus guereza) in Borena-Sayint National Park, northern Ethiopia

Djaffa Mountains guereza (Colobus guereza gallarum) abundance in forests of the Ahmar Mountains, Ethiopia

The size and density of a population are essential parameters in primate ecology and conservation. Such information, however, is still scarce for many forest primate species. The Djaffa Mountains guereza (Colobus guereza gallarum) is an endemic Ethiopian taxon for which data about its distribution and population size are missing. Therefore, we aimed to estimate the abundance and population size of the Djaffa Mountains guereza in four forests in the Ahmar Mountains southeast of the Ethiopian Rift Valley. We conducted line-transect surveys in the forests. Within an area of 183 km2 , we sampled 19 transects covering a distance of 75.9 km. We encountered 73 guereza clusters which most likely represent social groups. Since the detection distances and cluster sizes did not differ among the four forests, we applied a conventional distance sampling (CDS) model and estimated a population density of 20.6 clusters per square kilometer, i.e., 109.6 individuals per square kilometer or 20 061 individuals within the complete study area. This abundance is relatively high compared to other C. guereza taxa. However, given that the habitat and population of C . g . gallarum are already highly fragmented, further monitoring of the population and exploration of the possibilities of reconnecting its habitat should be priorities for the conservation of this taxon.

Diurnal activity patterns and feeding ecology of geladas (Theropithecus gelada) in Ankober District at Kundi, North Shewa, Ethiopia

Theropithecus gelada is the primate species endemic to the central and northwestern highlands of Ethiopia and is the only extant species of the genus Theropithecus. Diurnal activity patterns and feeding behavior of geladas were studied at Kundi, Ankober district, Ethiopia from August 2017 to March 2018 to cover both wet and dry seasons. Scan sampling method was employed to study the activity patterns and feeding behavior of geladas in the study area. Activity scans were collected at 15-minutes intervals for up to 5 minutes duration from 0700 to 1730h.  During each scan, individuals were recorded as performing one of the following behaviors: feeding, moving, resting, playing, aggression, grooming, sexual activity and others. Descriptive statistics and Chi-square test were used in data analysis. During the wet season geladas spent grooming 20%, playing 19%,  14%  resting,  feeding 12%,  other activity 11%,  moving 9%  and 3% in aggression. Geladas spent 27% feeding, 21% moving, 13% other activities, 12% aggression, 7% grooming, 7% playing and 4% resting during the dry season. There were significant differences in all activity time budgets between seasons except other activities. The total time spent feeding on grass blades and cereals were 25.5% and 23.5% in the study area, respectively. There was a significant difference between the age and sex classes of geladas in their activity time budgets. Eleven species of plants were recorded as the food of geladas in this study area. This study provides baseline information on the behavioral ecology of geladas outside protected areas.

Activity Budget and Feeding Ecology of Geladas (Theropithecus gelada obscurus) around Abogedam Church West of Debre Berhan Town, Ethiopia

Geladas are the most distinctive of Ethiopian endemic mammals, representing the last extant species of primate genus that have a very restricted distribution in the northern Ethiopian plateau. The activity budget and feeding ecology of geladas (Theropithecus gelada obscurus) were studied around Abogedam Church, Ethiopia, from May to October 2014, encompassing dry and wet seasons. The scan sampling method was applied to collect behavioural data on the identified band. Activity scans were collected at 15-minute intervals for up to five minutes duration from 0700 to 1730 h. The activity recorded for each individual was the first activity that lasts for five seconds. During each scan, individuals were recorded as performing activities: feeding, moving, resting, playing, aggression, grooming, sexual activity, and others. On average, geladas devoted 57.19% feeding, 14.82% resting, 14.92% moving, 4.83% playing, 2.53% aggression, 4.14% grooming, 1.23% sexual activity, and 0.34% other activities such as vocalization, defecation, and urination. Forty-one plant species were consumed by geladas that belonged to 18 families of which 53.66% were grasses. This study provides basic information on further studies and motivates conservationists to plan the management of unprotected areas at the vicinity of agricultural lands where such endemic animals dwell.

The diet and feeding behavior of the black-and-white colobus (Colobus guereza) in the Kalinzu Forest, Uganda

One of the goals for primate feeding ecology is to understand the factors that affect inter- and intra-specific variations. Therefore, a detailed description of basic feeding ecology in as many populations as possible is necessary and warrants further understanding. The black-and-white colobus (Colobus guereza) or guereza is widely distributed in Africa and is one of the well-studied colobines in terms of their feeding; they demonstrate considerable variation in their diets in response to local conditions. We studied the diet of a group of guerezas in the Kalinzu Forest, Uganda, for over 30 consecutive months using behavioral observation (4308 h in total), phenology, and vegetation surveys. A total of 31 plant species were consumed by the study group. This study group was predominantly folivorous; the majority of their feeding time was involved in feeding on young leaves (87%). However, during certain times of the year, fruits and seeds accounted for 45% of monthly feeding time. Young leaves of Celtis durandii were by far the most important food, which constituted 58% of the total feeding records. There was a significant increase in the consumption of fruits and flowers once young leaf availability was low, but their consumption of fruits did not significantly increase even when fruit availability was high. Their monthly dietary diversity increased as the number of available plants with young leaves declined, suggesting that much of the dietary diversity in the study group may be attributable to the young leaf portion of their diet. Our findings may help contribute to a better understanding of the dietary adaptations and feeding ecology of guerezas in response to local environmental conditions.