Feral Donkey Distribution and Ecological Impacts in a Hyper-Arid Region

SIMPLE SUMMARY: We estimated the population density and the population size of feral donkeys in northwest Saudi Arabia. The estimated overall population density was 1.03 (0.19 SE) donkey/km(2) and an abundance at ~1135 individuals. The negative impact of feral donkeys on natural resources included overgrazing, habitat fragmentation, and competition for resources with native species. Our study adds evidence to the detrimental impacts of feral donkeys and calls for urgent actions to control the presence of feral donkeys in the region. We recommend humane eradication for controlling the feral donkeys as it would be the most efficient and applicable action that can significantly abate the feral donkeys’ negative impacts. ABSTRACT: The feral donkey (Equus asinus L.) is an invasive species in Saudi Arabia and can cause severe damage to natural and cultural heritage. Over the last 30 years, feral donkeys have become a serious problem, as their abundance and geographic distribution has increased drastically. The impacts of feral donkeys are not well documented, and information about their abundance and distribution is lacking, certainly in Saudi Arabia, which hampers the implementation of effective management plans. Accordingly, we used the minimum population number approach (MPN) to determine the number of feral donkeys in this part of northwest Saudi Arabia. A total of 1135 feral donkeys were encountered in the region. The area around Khaybar harbors ~25% (n = 338) of the feral donkey population, whereas Tayma and AlGhrameel nature reserves were the least-inhabited sites (almost absent). The average population density of feral donkeys was estimated as 1.03 (0.19 SE) donkey/km(2). We documented the negative ecological impact of feral donkeys on natural resources, which constituted overgrazing that resulted in habitat fragmentation and competition for resources with native species. We propose urgent actions to control the presence of feral donkeys in the region and suggest humane eradication as the most efficient and applicable to significantly reduce the negative impacts of feral donkeys.