Data from: Den site selection, pack composition, and reproductive success in endangered African wild dogs

Habitat quality is often assumed to be directly related to increased consumer density, but such assumptions cannot be made without supporting demographic data that indicate improved fitness. Habitat selection might be especially important for denning species, where vulnerable offspring are confined to a single location for extended periods, but the effect of den choice on the reproductive success of denning species is poorly understood. By combining airborne high-resolution Light Detection and Ranging (LiDAR) measurements with data on pack composition, we investigated den site selection by endangered African wild dogs in Hluhluwe-iMfolozi Park, South Africa, examining whether habitat selection based on ecological factors resulted in increased litter sizes and thus reproductive success compared with social factors known to be important. Although there was selection for den sites in areas of increased terrain ruggedness and vegetation density, only vegetation density was associated with larger litter sizes and translated into increased reproductive success. Moreover, pack size was only influential when a minimum vegetation density around den sites was achieved, indicating that although social variables have a powerful effect on reproductive success, they are mediated by ecological factors defining habitat quality. Our results demonstrate the importance of distinguishing between density- and fitness-based indicators of habitat quality, and how this can affect management actions, particularly for endangered species conservation.生境质量通常被认为与更高的消费者种群密度直接相关，但此类假设若无能够证明种群适合度得以提升的种群统计数据作为支撑，则无法成立。生境选择对穴居物种可能尤为关键——这类物种的脆弱幼崽会长期被限制在单一地点，但目前学界对巢穴选择对穴居物种繁殖成功率的影响仍知之甚少。本研究将机载高分辨率激光雷达（Light Detection and Ranging, LiDAR）测量数据与非洲野犬群组成数据相结合，在南非赫卢赫卢韦-因福洛齐公园（Hluhluwe-iMfolozi Park）内针对濒危非洲野犬的巢穴位点选择展开调查，对比已知具有重要影响的社群因素，探究基于生态因素的生境选择是否能提升窝仔数，进而提高繁殖成功率。尽管研究对象会优先选择地形崎岖度与植被密度更高的区域作为巢穴位点，但仅有植被密度与更大的窝仔数相关，并最终转化为繁殖成功率的提升。此外，仅当巢穴周边达到最低植被密度阈值时，野犬群规模才会对繁殖成功率产生影响，这表明尽管社群变量对繁殖成功率有着显著影响，但这类影响是由定义生境质量的生态因素所介导的。本研究结果证实了区分基于种群密度与基于适合度的生境质量指标的重要性，以及此类区分如何影响管理举措，尤其对濒危物种保护而言意义重大。