Endangered Grevy's zebra in the Alledeghi Wildlife Reserve, Ethiopia: species distribution modeling for the determination of optimum habitat

摘要

Habitat loss due to human-induced factors is intensifying and is a critical threat to most endangered species. Grevy's zebra Equus grevyi is one of the most endangered mammals in the world. Human encroachment on its natural habitat and poaching are the greatest threats to this species' survival in the wild. Grevy's zebra only occur within a few isolated areas in Ethiopia and Kenya. Effective conservation interventions based on scientific information are needed to safeguard this species from extinction. Wildlife managers need to identify the extent of the remaining suitable habitat and achieve a better understanding of human and wildlife interactions if they are to facilitate appropriate conservation strategies. The present study employed the max- imum entropy model (Maxent), a species distribution modeling approach, to determine the geo-graphic extent of habitat and seasonal distribution of Grevy's zebra in the Alledeghi Wildlife Reserve, Ethiopia, and to use this information to determine the otimum demarcation of conserva-tion boundaries. Field surveys were conducted 4 times annually, twice during the wet season and twice during the dry season, for 2 yr. Field data and predictor variables were separated into 2 sea-sons, and models were generated for each season independently. Seasonal maximum tempera-tures, distance to human settlements and slope were the best predictors for both the dry and wet seasons. Evaluations of model performances were high, with AUC (area under the receiver oper-ating curve) values of 0.96 and 0.97 for the dry and wet seasons, respectively. Our results will be critical for modifying the existing boundaries of the Alledeghi Wildlife Reserve and directing con-servation strategies for the Grevy's zebra.