Red Squirrels Dying At Higher Rates

By Heather van Blokland
Published: Monday, March 12, 2018 - 5:05am

Arizona’s endangered Mount Graham red squirrels are dying at an unprecedented rate, and the increase in deaths is primarily due to predator bird attacks.

The Frye Fire last summer burned off brush lands, exposing areas squirrels use for cover. Researchers monitoring the Mount Graham squirrel population say predators including northern goshawks, Mexican spotted owls, Cooper's hawk, great horned owls, and red-tailed hawks have been hunting the squirrels at an alarming rate.

Melissa Merrick is a wildlife biologist at the University of Arizona. She said because of the roles red squirrels have in the ecosystem, we don’t know how the forest will fare in their absence.

The Mount Graham red squirrel is protected by the Endangered Species Act, by Arizona Game and Fish, and by the U.S. Forest Service and is a species of conservation concern by several different agencies in the state. 

"They may act as seed dispersers for a lot of these tree species ... and tree squirrels also eat fungi or mushrooms that occur within the forest, and when they eat them, they distribute the spores in their feces as they’re moving around the forest," she said.

Seventy-five percent of juvenile deaths and 65 percent of adult deaths are attributed to bird attacks, Merrick said.

Now the squirrels have to search farther in search of food, which makes them more vulnerable to birds of prey because they are more visible, Merrick said.

Merrick is part of a long-term ecological study monitoring the Mount Graham red squirrel.

The population has been monitored since the late 80s. Radio collaring began in 2002. The next count will be at the end of April.