Body size impacts nearly all aspects of an animal's life and can be subject to considerable variation in response to differences in climate and resource availability. We studied the impact of temperature and resource availability on arid‐living Cape ground squirrels (Xerus inauris), relative to body size and degree of sexual dimorphism, over three locations differing in annual rainfall and temperature to test Bergmann's rule, the resource rule and Rensch's rule. We found that squirrels were the largest where resources were the highest and temperatures were the lowest but squirrels were similar in mass where resources were medium or low and temperatures medium and highest, partially supporting Bergmann's rule and the resource rule. Hind‐feet were the largest where resources were medium and temperatures were medium and similarly small in low and high resource and high‐ and low‐temperature areas. The degree of sexual dimorphism of hind‐foot and mass was constant no matter the resource abundance or temperature, suggesting no impact of resource availability or temperature on the degree of sexual dimorphism, contradicting Rensch's rule. Our findings suggest that, while resource availability and temperature may have an impact on body size, other mechanisms may be important in limiting both body size and degree of sexual dimorphism in this species.

中文翻译：

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不遵守规则：在干旱适应的非洲地松鼠中对生态地理规则的支持不一

体型几乎影响动物生命的方方面面，并可能因气候和资源可利用性的差异而发生很大变化。我们研究了温度和资源供应对干旱活的海角地松鼠（Xerus inauris）（相对于身体大小和性二态化程度），在三个年降雨量和温度不同的位置上，分别测试伯格曼法则，资源法则和伦施法则。我们发现，松鼠在资源最高，温度最低的地方最大，而松鼠在质量上相似，在资源为中或低，温度为中，最高的地方，部分地支持了伯格曼法则和资源法则。后脚是最大的，那里的资源是中度的，而温度是中等的，在高，低资源和高温和低温的地区同样较小。无论资源丰度或温度如何，后脚和肿块的性二态性程度都是恒定的，这表明资源可用性或温度对性二态性程度没有影响，与伦施的规则相矛盾。我们的发现表明，尽管资源的可获得性和温度可能会影响体型，但其他机制可能在限制体型和该物种性二态性的程度方面也很重要。