Competition with livestock over forage resources has been identified as a potential threat to the survival of the African wild ass (Equus africanus) in the Danakil ecosystem (Eritrea). The Messir Plateau is an important breeding area for the African wild ass but also hosts cattle, sheep, goats, donkeys, and camels. Locations and fecal samples of African wild ass and livestock were collected in dry and rainfall months. Stable carbon isotopes [δ 13C ‰] in fecal samples were used to assess diet composition and overlaps with domestic herbivores. Fecal samples also were used to assess the nutritional quality of African wild ass and domestic donkey diets. During the dry months, African wild ass were concentrated in the northern section of the Messir Plateau, approximately 9 km from the permanent water source, and overlapped spatially with local livestock. During the rainfall months, African wild ass dispersed throughout the Messir Plateau (124 km2) when a high number of livestock, particularly cattle from the highlands with herders, were concentrated in the northern section. During the rainfall months, the northern section had relatively better vegetation cover and access to seasonal water. The grass contribution to the diet of the African wild ass in both dry and rainfall months overlapped significantly with that of domestic donkeys and cattle. In rainfall months, the percent fecal nitrogen and phosphorus contents of African wild ass were significantly lower than those of domestic donkey samples. The lower nutrient levels in fecal samples of African wild ass during rainfall months may be due to their displacement from the northern sector by the high number of immigrant highland cattle with people. Our work provides evidence as to how the presence of domestic herbivores, particularly cattle, may negatively impact the nutrient level of wild equids and threaten the survival of the critically endangered African wild ass.

中文翻译：

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与家畜的空间和饮食重叠如何影响梅西尔高原（厄立特里亚）的非洲野驴营养

与牲畜争夺草料资源的竞争已被确定为对达纳基尔生态系统（厄立特里亚）中非洲野驴（非洲野驴）生存的潜在威胁。梅西尔高原是非洲野驴的重要繁殖区，但也有牛、绵羊、山羊、驴和骆驼。在干旱和降雨月份收集了非洲野驴和牲畜的位置和粪便样本。粪便样本中的稳定碳同位素 [δ 13C ‰] 用于评估饮食组成和与家养食草动物的重叠。粪便样本也被用来评估非洲野驴和家驴饮食的营养质量。在旱季，非洲野驴集中在距离永久水源约 9 公里的梅西尔高原北部，并与当地牲畜在空间上重叠。在降雨月份，当大量牲畜，特别是来自高地牧民的牛群集中在北部地区时，非洲野驴分散在整个梅西尔高原（124 平方公里）。在降雨月份，北部地区的植被覆盖率和季节性水源相对较好。在干旱和降雨月份，草对非洲野驴饮食的贡献与家养驴和牛的显着重叠。在降雨月份，非洲野驴的粪便氮磷含量百分比显着低于家驴样本。在降雨月份，非洲野驴粪便样本中的营养水平较低，这可能是由于大量移民高地牛与人从北部地区迁移所致。我们的工作提供了证据，证明家养食草动物，特别是牛的存在如何对野生马科动物的营养水平产生负面影响，并威胁到极度濒危的非洲野驴的生存。