Modelling on the Distribution, Habitat Ecology, Suitability and Abundance of Djaffa Mountains Guereza (Colobus Guereza Gallarum, Neumann, 1902) from Ahmar Mountains, Eastern Ethiopia
No Thumbnail Available
Date
2024-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Understanding the distribution, abundance, niche use and habitat suitability of little-known primate species in the human dominated landscape is key to guide the conservation and management efforts. Djaffa Mountains guereza (C. g. gallarum) is endemic primate of Ethiopia with little information on its ecology and distribution. This study aims to provide the most basic ecological aspects of C. g. gallarum focusing on its distribution pattern, population size, habitat suitability and conservation risks. The field study was conducted between 2020 and 2021 both during wet and dry seasons. Population estimate was carried out using line transects method covering a distance of 75.9 km in four forests with varied ecologies. Ecological niche modelling was developed by multiple algorithms. Projected climate of the Representative Concentration Pathways in two scenarios and periods was used. The potential suitable habitats for C. g. guereza and C. g. gallarum were modelled, identified anthropogenic refugia, analyzed protected anthropogenic refugia, and computed niche overlap. During the surveys, 73 guereza clusters were encountered, resulting in 20,061 individuals (109.6 individuals/km2). The habitat suitability modelled using MaxEnt for C. g. gallarum predicted about 1,336 km2 within its range. The predicted climate niche for C. g. guereza was 168,731 km2, and for C. g. gallarum, it was, 69,542 km2 as predicted using weighted mean ensemble models. However, closely related taxa of Ethiopia‘s Guereza exhibit divergent niches. Of the anthropogenic refugia calculated, 53.70% and 39.76% were found within Ethiopia‘s protected area network for C. g. gallarum and C. g. guereza, respectively. Habitat ecology analysis showed that height of the trees, variation of tree height and importance value influenced C. g. gallarum occupancy. The conservation of C. g. gallarum is crucial due to its fragmented habitat and population, necessitating further monitoring and habitat restoration efforts. The study suggests determining C. g. gallarum's geographic distribution and collecting data along the common distribution border between it and other Guereza taxa to check for sympatry and hybridization.
Description
Keywords
Anthropocene, Climate Change, Ecological Niche, Ethiopian Highlands, Guereza, Population Estimate, Relict forest, Species Distribution Modelling