Jackson Craig R, Power R John, Groom Rosemary J, Masenga Emmanuel H, Mjingo Ernest E, Fyumagwa Robert D, Røskaft Eivin, Davies-Mostert Harriet
Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.
Department of Economic Development, Environment, Conservation and Tourism, North West Provincial Government, Mmabatho, South Africa.
PLoS One. 2014 Jun 11;9(6):e99686. doi: 10.1371/journal.pone.0099686. eCollection 2014.
Compared to their main competitors, African wild dogs (Lycaon pictus) have inferior competitive abilities and interspecific competition is a serious fitness-limiting factor. Lions (Panthera leo) are the dominant large carnivore in African savannah ecosystems and wild dogs avoid them both spatially and temporally. Wild dog young are particularly vulnerable and suffer high rates of mortality from lions. Since lions do not utilize all parts of the landscape with an equal intensity, spatial variation in lion densities can be exploited by wild dogs both during their general ranging behaviour, but more specifically when they are confined to a den with vulnerable young. Since patches of rugged terrain are associated with lower lion densities, we hypothesized that these comparatively safe habitats should be selected by wild dogs for denning. We investigated the relationship between the distribution of 100 wild dog den sites and the occurrence of rugged terrain in four wild dog populations located in Tanzania, Zimbabwe and South Africa. A terrain ruggedness index was derived from a 90 m digital elevation model and used to map terrain ruggedness at each site. We compared characteristics of actual and potential (random) den sites to determine how wild dogs select den sites. The distributions of wild dog dens were strongly associated with rugged terrain and wild dogs actively selected terrain that was more rugged than that available on average. The likelihood of encountering lions is reduced in these habitats, minimizing the risk to both adults and pups. Our findings have important implications for the conservation management of the species, especially when assessing habitat suitability for potential reintroductions. The simple technique used to assess terrain ruggedness may be useful to investigate habitat suitability, and even predict highly suitable denning areas, across large landscapes.
与它们的主要竞争对手相比，非洲野犬（非洲野犬属）的竞争能力较差，种间竞争是一个严重限制其适应性的因素。狮子（豹属）是非洲草原生态系统中的优势大型食肉动物，野犬在空间和时间上都会避开它们。野犬幼崽尤其脆弱，死于狮子的死亡率很高。由于狮子不会以相同强度利用景观的所有区域，野犬在其一般活动范围内，特别是当它们与脆弱的幼崽被困在巢穴中时，可以利用狮子密度的空间变化。由于崎岖地形区域与较低的狮子密度相关，我们推测这些相对安全的栖息地应该会被野犬选作巢穴。我们调查了位于坦桑尼亚、津巴布韦和南非的四个野犬种群中100个野犬巢穴地点的分布与崎岖地形的关系。从90米的数字高程模型中得出地形崎岖度指数，并用于绘制每个地点的地形崎岖度图。我们比较了实际巢穴地点和潜在（随机）巢穴地点的特征，以确定野犬如何选择巢穴地点。野犬巢穴的分布与崎岖地形密切相关，野犬会主动选择比平均可获得地形更崎岖的地形。在这些栖息地遇到狮子的可能性降低，从而将成年野犬和幼崽的风险降至最低。我们的研究结果对该物种的保护管理具有重要意义，特别是在评估潜在重新引入的栖息地适宜性时。用于评估地形崎岖度的简单技术可能有助于调查大面积景观的栖息地适宜性，甚至预测高度适宜的巢穴区域。
