Differential resource selection within shared habitat types across spatial scales in sympatric toads
Differential resource selection within shared habitat types across spatial scales in sympatric toads
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DOI：
10.1890/08-0886.1
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发表时间：
2009-12-01
期刊：
影响因子：
4.8
通讯作者：
Schaub, Michael
中科院分区：
文献类型：
--
作者：
Indermaur, Lukas;Winzeler, Thomas;Schaub, Michael
不同的栖息地选择是物种进化的一个核心组成部分，但它很少被量化的同域物种在动物活动的空间尺度上的资源的多重影响。我们的主要目标是量化的选择陆地夏季栖息地在自然洪泛平原在意大利的两个同域两栖动物（蟾蜍bufo spinosus和B。viridis）作为栖息地类型、猎物密度和温度的函数。我们在三个空间尺度上应用贝叶斯资源选择模型：（1）洪泛平原内的家域布局，（2）95%家域内的空间利用，以及（3）50%核心区域内的空间利用。利用这些数据，我们探讨了在大尺度上的过程是否会导致在小尺度上的空间利用模式，以及这两个物种是否使用相同的栖息地类型的方式，这将有利于共存。栖息地的选择是由栖息地类型，猎物密度，和温度在所有的空间尺度，导致略高的猎物密度和显着较低的温度内比外的家庭范围。我们的结论是，两栖动物感知的栖息地类型的分布，以及猎物密度和温度在所有空间尺度的梯度。栖息地类型的影响占主导地位的家域安置，而猎物密度和温度最强烈地影响空间利用内的家域。我们的研究结果表明，家域的位置依赖于广泛的栖息地功能，表明资源的可用性在小的空间尺度。在最小的空间尺度上，猎物和避难所的选择是最有可能促进由于环境信息的积累，动物可能会采样整个area.Both物种在很大程度上喜欢相同的栖息地类型，但使用它们不同的资源在三个空间尺度。例如，当一个物种使用相同的栖息地类型进行觅食时，另一个物种将其用于休息或休息和觅食。因此，生态位分化，通过不同的资源选择在所有的空间尺度上共享的栖息地类型内，可能会促进这两个物种在陆地夏季栖息地的共存。
Differential habitat selection is a central component in the evolution of species, but it has been quantified rarely for sympatric species in relation to the multiple impacts of resources at the spatial scales at which animals operate. Our main goal was to quantify the selection of terrestrial summer habitats in a natural floodplain in Italy by two sympatric amphibians (Bufo bufo spinosus and B. viridis) as a function of habitat type, prey density, and temperature. We applied a Bayesian resource selection model at three spatial scales: (1) home range placement within the floodplain, (2) space use within 95% home ranges, and (3) space use within 50% core areas. Using these data we explored whether processes acting at large scales lead to space use patterns at small scales and whether the two species use the same habitat types in a way that would facilitate coexistence.Habitat selection was determined by habitat type, prey density, and temperature at all spatial scales, resulting in slightly higher prey density and significantly lower temperature within than outside home ranges. We conclude that amphibians perceive the distribution of habitat types as well as gradients in prey density and temperature at all spatial scales. The effects of habitat type dominated home range placement while prey density and temperature most strongly affected space use within home ranges. Our results suggest that home range placement relies on broad habitat features that indicate resource availability at small spatial scales. At the smallest spatial scale, the selection of prey and refugia is most probably facilitated due to the accumulation of environmental information as animals may sample the entire area.Both species largely preferred the same habitat types, but used them differently in relation to resources across the three spatial scales. For example, while one species used the same habitat type for foraging, the other used it for resting or both resting and foraging. Niche differentiation through differential resource selection within shared habitat types at all spatial scales may therefore facilitate the coexistence of the two species in terrestrial summer habitats.