Christian Hof (1), Joel Methorst (2), Imran Khaliq (3)
2 Senckenberg Biodiversity & Climate Research Centre (BiK-‐F), Frankfurt, Germany, email@example.com
Species react to climate change via physiological tolerance or adaptation, dispersal (e.g. range shifts), or they have to face extinction. However, whether and how these response pathways interact has rarely been investigated. Here, we present our analyses on (1) the relationships among species’ thermal capacities, geographical distributions and the variation of ambient climatic conditions and (2) the relationships between dispersal ability and thermal tolerance. We assembled data on thermal tolerances of birds and mammals from physiological experiments of more than 500 species, as well as empirical dispersal distance data for about 90 species from all over the world and analyzed them, along with data on ambient climate and species’ geographical distributions, in a phylogenetically and spatially explicit context. We found that thermal tolerance breadth was a poor predictor of geographical range size, and that, overall, the ambient temperature conditions that species experience across their distributions do not match well with their thermal tolerances. In the tropics, phylogeny was much more important for explaining the variation in physiological traits than environment, whereas environment was more important than phylogeny in temperate species. Dispersal appeared to be unrelated to thermal tolerance measures. Based on these results, we assess the vulnerability of species to climate change and explore how the findings can be used to build better projections of species distributions. Overall, we emphasize the need for more cross-‐ disciplinary research among physiologists, ecologists, and biogeographers, to improve future projections of biodiversity in a changing world.