The cool of the forest is a welcome escape on a hot day. This is especially true for mammals in North America's hottest regions, according to a study from the University of California, Davis. The study indicates that, as the climate warms, preserving forest cover will be increasingly important for wildlife conservation.

The study, published today in the journal PNAS, found that North American mammals — from pumas, wolves and bears to rabbits, deer and opossums — consistently depend on forests and avoid cities, farms and other human-dominated areas in hotter climes. In fact, mammals are, on average, 50% more likely to occupy forests than open habitats in hot...