Animals Take Refuge in Forests and Avoid Human-Dominated Areas in Hotter Regions, Study Finds

In hotter climates, North American mammals — like wolves, bears, pumas and rabbits — depend on forests to cool down while avoiding human-dominated areas like cities and farms.

Preserving forest habitats is important as the climate warms for many reasons, but a new study has found that it will be essential for wildlife conservation, a press release from the University of California, Davis (UC Davis), said.

“Different populations of the same species respond differently to habitat based on where they are,” said Mahdieh Tourani, lead author of the study and an assistant quantitative ecology professor at the University of Montana, Missoula, in the press release. “Climate is mediating that difference.”

The researchers found that, on average, mammals are 50 percent more likely to inhabit forests on hot days than open habitats. They also discovered that, in the planet’s coldest regions, the opposite is true.

The study, “Maximum temperatures determine the habitat affiliations of North American mammals,” was published in the journal Proceedings of the National Academy of Sciences.

Tourani said the research team discovered that, in hotter climates, the eastern cottontail rabbit preferred the forest, while in colder regions, the common rabbit preferred agricultural areas and other human-dominated habitat, according to the press release.

The tendency of animals of the same species to have different preferences is called “intraspecific variation,” which the researchers found was common across all mammals in North America. Historically, the practice in conservation biology was to categorize species by those that coexist well with humans and those that do not. However, the authors of the study explained that ecological flexibility is being more readily recognized, along with the realization that species are more complex than the categories using humans as a reference imply.

“We can’t take a one-size-fits all approach to habitat conservation,” said Daniel Karp, senior author of the study and an associate professor in the Department of Wildlife, Fish and Conservation Biology at UC Davis, in the press release. “It turns out climate has a large role in how species respond to habitat loss.”

If conservation biologists assumed, for example, that elk could only survive in protected areas, opportunities for them to be conserved in landscapes dominated by humans could be missed.

“On the other hand, if we assume a species will always be able to live alongside us, then we might be wasting our effort trying to improve the conservation value of human-dominated landscapes in areas where it is simply too hot for the species,” Karp said.

The researchers worked with Snapshot USA, a monitoring program that has thousands of camera traps across the United States.

“We analyzed 150,000 records of 29 mammal species using community occupancy models,” Tourani said. “These models allowed us to study how mammals respond to habitat types across their ranges while accounting for the fact that species may be in an area, but we did not record their presence because the species is rare or elusive.”

The results of the study give conservation managers direction in shaping their plans for protected areas and conservation, including enhancing working landscapes like pastures, farms and developed areas.

“If we’re trying to conserve species in working landscapes, it might behoove us to provide more shade for species,” Karp said in the press release. “We can maintain patches of native vegetation, scattered trees, and hedgerows that provide local refugia for wildlife, especially in places that are going to get warmer with climate change.”