He Jiekun, Tu Jiahao, Yu Jiehua, Jiang Haisheng
Spatial Ecology Lab, School of Life Sciences, South China Normal University, Guangzhou, China.
Glob Chang Biol. 2023 Sep;29(18):5199-5210. doi: 10.1111/gcb.16860. Epub 2023 Jul 10.
Bergmann's rule states that endotherms have a large body size in high latitudes and cold climates. However, previous empirical studies have reported mixed evidence on the relationships between body size and latitude, raising the question of why some clades of endotherms follow Bergmann's rule, whereas others do not. Here, we synthesized the interspecific relationships between body size and latitude among 16,187 endothermic species (5422 mammals and 10,765 birds) using Bayesian phylogenetic generalized linear mixed models to examine the strength and magnitude of Bergmann's rule. We further assessed the effect of biological and ecological factors (i.e., body mass categories, dietary guild, winter activity, habitat openness, and climate zone) on the variations in the body mass-latitude relationships by adding an interaction term in the models. Our results revealed a generally weak but significant adherence to Bergmann's rule among all endotherms at the global scale. Despite taxonomic variation in the strength of Bergmann's rule, the body mass of species within most animal orders showed an increasing trend toward high latitudes. Generally, large-bodied, temperate species, non-hibernating mammals, and migratory and open-habitat birds tend to conform to Bergmann's rule more than their relatives do. Our results suggest that whether Bergmann's rule applies to a particular taxon is mediated by not only geographic and biological features, but also potential alternate strategies that species might have for thermoregulation. Future studies could explore the potential of integrating comprehensive trait data into phylogenetic comparative analysis to re-assess the classic ecogeographic rules on a global scale.
伯格曼法则指出，恒温动物在高纬度地区和寒冷气候下体型较大。然而，先前的实证研究报告了关于体型与纬度之间关系的混合证据，这就引发了一个问题：为什么有些恒温动物类群遵循伯格曼法则，而其他类群则不然。在这里，我们使用贝叶斯系统发育广义线性混合模型，综合分析了16187个恒温动物物种（5422种哺乳动物和10765种鸟类）之间体型与纬度的种间关系，以检验伯格曼法则的强度和幅度。我们还通过在模型中添加交互项，进一步评估了生物和生态因素（即体重类别、食性 guild、冬季活动、栖息地开放性和气候带）对体重-纬度关系变化的影响。我们的研究结果表明，在全球范围内，所有恒温动物普遍对伯格曼法则的遵循程度较弱但显著。尽管伯格曼法则的强度存在分类学差异，但大多数动物目内物种的体重呈现出向高纬度地区增加的趋势。一般来说，体型较大的温带物种、非冬眠哺乳动物以及迁徙和栖息于开阔栖息地的鸟类，比它们的亲属更倾向于遵循伯格曼法则。我们的研究结果表明，伯格曼法则是否适用于特定分类群，不仅受到地理和生物特征的影响，还受到物种可能具有的潜在替代体温调节策略的影响。未来的研究可以探索将综合性状数据整合到系统发育比较分析中的潜力，以便在全球范围内重新评估经典的生态地理规则。
