Data from: Competition between sympatric wolf taxa: an example involving African and Ethiopian Wolves

Carnivore populations are declining globally due to range contraction, persecution and prey depletion. One consequence of these patterns is increased range and niche overlap with other carnivores, and thus an elevated potential for competitive exclusion. Here we document competition between an endangered canid, the Ethiopian wolf (EW), and the newly discovered African wolf (AW) in central Ethiopia. The diet of the ecological specialist EW was dominated by rodents whereas the AW consumed more diverse diet also including insects and non-rodent mammals. EWs used predominantly intact habitat whereas AWs used mostly areas disturbed by humans and their livestock. Still, we observed 82 encounters between the two species, of which 94% were agonistic. The outcomes of agonistic encounters followed a territory-specific dominance pattern, with EWs dominating in intact habitat and AWs in human-disturbed areas. For AWs, the likelihood of winning encounters also increased with group size. Trapping data indicated that rodent species consumed by EWs were also available in the human-disturbed areas, suggesting that these areas could be suitable habitat for EWs if AWs were not territorially dominant there. Increasing human encroachment not only affects the prey base of EWs, but also may impact their survival by intensifying competition with sympatric AWs.受分布范围缩减、人为迫害与猎物枯竭等因素影响，全球食肉动物种群数量呈下降趋势。此类变化带来的后果之一，是不同食肉动物类群间的分布范围与生态位重叠程度加剧，进而提升了竞争排除（competitive exclusion）的发生概率。本研究针对埃塞俄比亚中部的濒危犬科物种展开调查，记录了埃塞俄比亚狼（Ethiopian Wolf, EW）与新发现的非洲狼（African Wolf, AW）之间的种间竞争关系。作为生态特化种（ecological specialist）的埃塞俄比亚狼，其食谱以啮齿类为绝对优势食物类群；而非洲狼的饮食结构更为多样，除啮齿类外还涵盖昆虫与非啮齿类哺乳动物。埃塞俄比亚狼主要依赖未受干扰的原生栖息地，非洲狼则多选择受人类及牲畜活动干扰的区域栖息。尽管如此，本研究仍记录到两个物种间共计82次相遇事件，其中94%呈现出争斗性（agonistic）互动。争斗性互动的结果遵循领地特异性优势（territory-specific dominance）模式：在原生栖息地内埃塞俄比亚狼占据主导地位，而在受人类干扰的区域则由非洲狼掌控优势。对于非洲狼而言，其赢得争斗互动的概率亦随种群群体规模的扩大而升高。诱捕监测数据显示，埃塞俄比亚狼所捕食的啮齿类物种在受人类干扰的区域同样存在，这表明若非洲狼未在这些区域占据领地优势，此类区域本可成为埃塞俄比亚狼的适宜栖息地。日益加剧的人类侵占（human encroachment）活动，不仅会削弱埃塞俄比亚狼的猎物基础，还可能通过加剧与同域分布（sympatric）非洲狼的种间竞争，进一步威胁其种群存续。