Population structure and distribution of geladas (Theropithicus gelada, Ruppell 1835) in Kotu forest, Northern Ethiopia

Abstract

Endemic gelada populations outside protected areas are less investigated, and population census data are not available. As a result, a study was conducted to investigate the population size, structure, and distribution of geladas in Kotu forest and associated grasslands, in northern Ethiopia. The study area was stratified into five dominant habitat types namely, grassland, wooded grassland, plantation forest, natural forest, and bushland based on dominant vegetation type. Each habitat type was further divided into blocks, and a total counting technique was used to count the individuals of gelada. The total mean population size of gelada in Kotu forest was 229 ± 6.11. The mean ratio of male to female was 1:1.178. The gelada age composition comprised is as follows: 113 (49.34%) adults, 77 (33.62%) sub‐adults, and 39 (17.03%) juveniles. The mean number of group one‐male unit ranged from 1.5 ± 0.2 in the plantation forest to 4.5 ± 0.7 in the grassland habitat. On the other hand, all‐male unit social system group was recorded only from grassland (1.5) and plantation forest (1) habitats. The average band size (number of individuals per band) was 45.0 ± 2.53. The largest number of geladas was recorded from grassland habitat 68 (29.87%), and the lowest was recorded from plantation forest habitat 34 (14.74%). Even though, the sex ratio was female biased, the proportion of juveniles to other age classes was very low compared with geladas in relatively well‐protected areas, indicating negative consequences for the future viability of the gelada populations in the area. Geladas were widely distributed over open grassland habitat. Therefore, for sustainable conservation of the geladas in the area, there is a need for integrated management of the area with special attention on the conservation of the grassland habitat.

Population size and structure of beisa oryx and gerenuk in Geralle National Park, southeastern Ethiopia

“…The knowledge of the sex ratio and age distribution of individual mammals is vital for evaluating the viability of a species because these variables reflect the structure and dynamics of the population (Butka & Freedberg, 2019;Mamo et al, 2010;Wilson et al, 1996). Understanding sex and age population structure is important for evaluating the viability of the species, as these variables reflect the structure and dynamics of a species population (Abate & Girma, 2023;Groves, 2005). The sex ratio for both species was biased or skewed toward females.…”

Feeding habits and preferences of southern gelada (Theropithecus gelada obscurus, Heuglin 1863) in Abune Yoesf Zigit Community Conservation Area, northern Ethiopia

“…Geladas are brown and grey-colored old-world primates endemic to Ethiopia that commonly distinguished by red hourglass-shaped, bald patches of skin on their chests; they are named after it as bleeding-heart primate [1]. There are three sub-species of gelada, namely; Theropithecus gelada gelada (northern gelada), Theropithecus gelada obscure (southern gelada) and Theropithecus gelada arsi (arsi gelada) Theropithecus gelada gelada occurs in Gondar and Tigray provinces [1,2,3], whereas Theropithecus gelada obscure inhabits Wollo and Showa provinces [4,5].…”