How environmental factors affect the abundance and distribution of two congeneric species of Amazonian frogs

In this study, we test the hypothesis that, at a fine scale, environmental variables influence differently sister species that live in sympatry and are phylogenetically closely related. We sampled two Amazonian anuran species, Phyzelaphryne miriamae and Phyzelaphryne sp., in 11 permanent sampling modules distributed across ~600 km in the Purus-Madeira Interfluve between 2013 and 2014. Using mixed generalized linear models, we found that the species have distinct environmental associations, which may facilitate their coexistence in sympatry. Phyzelaphryne miriamae was more frequent in environments with low precipitation and low water tables, suggesting this species is better adapted to live in drier places. In contrast, Phyzelaphryne sp. appeared to be a generalist regarding to habitat and resource use. These patterns are in accordance with the hypothesis that environmental variables influence sister species differently on a fine scale. Phyzelaphryne miriamae is larger than Phyzelaphryne...

本研究旨在验证如下假说：在精细尺度下，环境变量对同域分布且系统发育关系紧密的姊妹物种的影响存在差异。我们于2013至2014年间，在跨度约600公里的普鲁斯-马代拉河间地带（Purus-Madeira Interfluve）内设置11个永久性采样单元，对两种亚马逊无尾目物种——米氏滑跖蟾（Phyzelaphryne miriamae）与滑跖蟾未定种（Phyzelaphryne sp.）进行了采样。本研究采用广义线性混合模型（generalized linear mixed models）进行分析，结果显示两种物种的环境关联特征存在显著差异，这或有助于二者在同域环境中共存。米氏滑跖蟾在低降水量、低地下水位的生境中出现频率更高，提示该物种更适应较为干燥的栖息环境。与之相对，滑跖蟾未定种的生境与资源利用模式则表现出泛化特性。上述观测结果与"精细尺度下环境变量对姊妹物种产生差异化影响"的假说相符。米氏滑跖蟾的体型大于滑跖蟾未定种……