Suitable habitat prediction for African Wild Ass (Equus africanus) in the Danakil Desert of Afar Region, Ethiopia

Redwan Mohammed Yimer^1*Redae Teclai Tesfai²Patricia D Moehlman^3,4Fanuel Kebede⁵Afework Bekele⁶Nicholas E Young²Paul H Evangelista²

• ¹Wollo University, Dessie, Amhara, Ethiopia
• ²Colorado State University, Fort Collins, Colorado, United States
• ³IUCN/SSC Equid Specialist Group, New York, United States
• ⁴Eco-Health Alliance, New York, United States
• ⁵Ethiopian Wildlife Conservation Authority, Addis Ababa, Addis Ababa, Ethiopia
• ⁶Addis Ababa University, Addis Ababa, Addis Ababa, Ethiopia

The African wild ass (Equus africanus) is listed on the IUCN Red List as Critically Endangered. They are found in low population densities and there may be as few as 600 individuals in the Danakil Desert of Ethiopia and Eritrea. The maximum entropy (Maxent) model is used to determine suitable habitat for the African wild ass in the Danakil Desert of Ethiopia. An understanding of suitable habitats is important for prioritizing the conservation and management of African wild ass. African wild ass presence location data were collected quarterly from December 2017 through February 2020 in both the wet and dry seasons. The designed surveys covered about 57 % of the study area (12,300 km²) defined based on the potential range of the species. The sample size (116 and 87) was determined by the number of occurrence points after removing duplicates for dry and wet seasons, respectively. Habitat suitability determinant covariates (bioclimatic (www.chelsa-climate.org) and topographic (https://esa-worldcover.org)) were prepared separately for each season and independently analyzed using Maxent model. Precipitation, temperature and distance from water sources were vital variables for the wet season while distance from water sources and distance from the settlements were important determinant covariates for the dry season. Distance from settlement had a lower contribution to the wet season model than the dry season model while precipitation contributed lower to the dry season model. Moreover, herbaceous grassland vegetation cover and slope had a lower percentage contribution to both season modeling. Model performances were high, with the area under the curve (AUC) values of 0.927 and 0.950 for wet and dry seasons, respectively. The predicted moderately suitable habitat area extent was greater during the wet season (15,223 km2) than during the dry season (6,052 km2). Similarly, the optimal habitat coverage was slightly greater during the wet (294 km2) than dry (207 km2) season. This information prioritizes where protected areas should be established for African wild ass conservation and also indicates potential new undocumented locations to guide surveys in the Danakil Desert of Afar Region, Ethiopia.