Recent ecological theories propose that species reach their highest abundance and genetic diversity in the center of their ecological niche and decline toward the edges. We assessed whether Lyle's flying fox, Pteropus lylei, abundance and genetic diversity were correlated with niche centroid distance using an ecological niche model as a proxy for fundamental niche (N_F). Alternatively, we assessed whether P. lylei abundance and genetic diversity were correlated with fine‐scale environmental factors as a proxy of the species’ realized niche (N_R). We examined relationships between abundance and environmental factors at coarse and fine scales as proxies of N_F and N_R, respectively. For coarse scale, ecological niche of P. lylei was modeled using all available occurrence records in Thailand, Cambodia, and Vietnam, coupled with climatic data. We conducted field measurements of P. lylei abundance and used genetic structure data across a large portion of the species’ range. We measured Euclidean distances between abundance and genetic data and the niche centroid in environmental dimensions. Spearman’s correlation was estimated between abundance and genetic diversity vs. distance to the niche centroid. Complementarily, for the fine‐scale test, we measured multiple regression models between abundance and genetic diversity versus the normalized difference vegetation index (NDVI), local temperature, percent area of waterbodies, human density, and number of Buddhist temples. We failed to detect relationships between abundance and genetic diversity with the distance to the niche centroid in the coarse‐scale model. When using the fine‐scale, landscape‐level data, we found negative correlation between genetic diversity and number of temples. The data available were unable to support niche centroid hypothesis for the current distribution and abundances of P. lylei. We note that our failure to find an association does not support nor reject the niche centroid hypothesis. Instead, our capacity to test the niche centroid hypothesis may be limited by our ability to use empirical data to accurately reconstruct N_F from field observations only. Future research may require physiology‐based experimental approaches to explore relationships between species abundances and the niche structure.

中文翻译：

---

生态位质心假说的评估：翼龙（鳞翅目）

最近的生态学理论提出，物种在其生态位的中心达到其最高的丰度和遗传多样性，并向边缘下降。我们使用生态位生态模型作为基本生态位（N _F）的替代品，评估了Lyle的果蝇，Pteropus lylei，丰度和遗传多样性是否与生态位质心距离相关。可替换地，我们评估是否P. lylei丰度和遗传多样性用细尺度的环境因素相关的物种的实际生态位（的代理ñ _{- [R} ）。我们以粗略和精细尺度考察了丰度与环境因子之间的关系，作为N _F和Ñ _{- [R} ，分别。对于粗尺度，使用泰国，柬埔寨和越南的所有可用发生记录以及气候数据，对莱利毕生菌的生态位进行建模。我们对莱利体育进行了实地测量该物种很大一部分范围内的丰富度和使用过的遗传结构数据。我们测量了环境数据中丰度和遗传数据与生态位质心之间的欧几里得距离。Spearman的相关性在丰度和遗传多样性与距离利基质心的距离之间进行估算。作为补充，对于精细测试，我们测量了丰度和遗传多样性与归一化植被指数（NDVI），局部温度，水体面积百分比，人的密度和佛教寺庙数量之间的多元回归模型。在粗尺度模型中，我们未能检测到丰富度与遗传多样性之间的关系，即与生态位质心的距离。使用细微的横向数据时，我们发现遗传多样性与寺庙数量之间呈负相关。现有数据无法支持利基质心假说的当前分布和丰度。P. lylei。我们注意到，我们未能找到关联并不支持也不拒绝利基质心假说。相反，我们测试小生境质心假说的能力可能会受到我们使用经验数据仅根据实地观测准确地重建N _F的能力的限制。未来的研究可能需要基于生理的实验方法来探索物种丰度与生态位结构之间的关系。