Distributional limits to widespread and range-restricted species and their effects on species' abilities to respond to changes in climate and land use

The combination of climate change and anthropogenic land use changes are having a substantial effect on species' distributions worldwide. While climate change has led to range expansion in many areas, habitat loss and degradation are leading causes of extinction. It is therefore important to consider how these two forces are acting together to alter species distributions. Here, I have tested whether responses of butterfly species to climate change can be predicted based on range size and whether the level of human impact differs in areas where ranges have expanded and where they have collapsed. I found that the number of widespread species that have shifted their ranges north is not statistically different from the number of range-restricted species that have also shifted north. I also found that human impacts are greater in areas where ranges had collapsed than where they had expanded, and that this pattern was stronger for range-restricted species than for widespread ones. Butterfly species are not tracking changing climate in any predictable way with respect to range size, and are likely limited in their ability to do so by habitat losses