Forest management efforts designed to limit the severity and size of wildfires are increasing across the Southwest. A recent multi-agency study examined how fire versus thinning affects black bears across 1,400 square miles in New Mexico’s Jemez Mountains.
Bears were fitted with radio collars to track their habitat use in areas which had been recovering for varying lengths of time since a wildfire, prescribed burn or thinning treatment. The researchers also looked at other important factors, like topography.
It turns out that "pyro diverse" forests with a mosaic of differently-aged burns are good for bears.
In spring and summer, the animal avoids forest that has been newly thinned or experienced high severity fire. They prefer areas that burned recently at low to moderate intensity, where the newly open canopy and release of nutrients stimulates the rapid growth of grasses, forbs and shrubs. These provide both cover and fruits like wild raspberries and thimbleberries, which bears love to eat.
In fall, bears enter what’s known as "hyperphagia." They max out their calorie intake to prepare for hibernation. At this time, they move into forest affected by older fires where trees help them to pile on the pounds, especially oaks with acorns and shrubs with berries.
Bears avoid recent thinning treatments with little cover all year round, showing a preference for areas that have experienced the renewing power of fire on the landscape.
Being able to eat and sleep in private is apparently what bears love best!
The research was carried out by a team headed by James Cain from the U.S.G.S. New Mexico Cooperative Fish and Wildlife Research Unit and Matthew Keeling, graduate student in the Department of Fish, Wildlife, and Conservation Ecology at New Mexico State University, who provided the information for this story.
This Earth Note was written by Diane Hope and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.
