Fox squirrels, unlike the native red squirrel and rock squirrel, are not native to Utah.
“They've lived and evolved in the Eastern United States, and they live in deciduous forests — that means oak trees, maple trees, ash trees — eating the acorns and the seeds from those trees. However, as humans have developed the West and planted those types of trees for shade trees, the fox squirrels have been able to establish themselves in new territory,” said Nicki Frey, an extension professor at Utah State University who monitors the fox squirrel expansion.
“We’re starting to see them in Utah, where we’ve never seen them before, predominantly up and down the Wasatch Front, because that’s where our cities have produced the parks with these big, beautiful shade trees that the fox squirrels like,” she said.
Once a few squirrels discover a suitable patch — be it a park, a backyard, or a line of mature maple or oak trees — they settle in.
“And so over generations of squirrels and decades of us developing the Western United States, they get a stronghold,” Frey said.
But what about outside of urban areas and parks, like Utah’s native foothills, canyons, or forests? Fry said fox squirrels are far less likely to thrive in wilder areas.
“They need water. They need oak, maple, and ash trees to find food," she explained. "So, as soon as we get into the higher elevations where it’s mostly coniferous trees, the fox squirrel really can’t get a stronghold. That’s not how they evolved. They need to stay down low where there's those deciduous trees."
Still, their growing presence raises ecological questions. New species can disrupt resource use, introduce parasites, or unsettle long-standing balances. But Frey stressed that the species really isn’t an issue yet and might never be.
“We don’t need to get out the pitchforks. It’s not cause for alarm, but it’s cause for concern," she said.
For homeowners already living alongside fox squirrels, Fry said management options exist, but removing them entirely might not be possible. Instead, for now at least, she advocates for increased monitoring and additional research.
For more information about Utah's incoming fox squirrels and how to properly identify native red squirrels and rock squirrels, check out the Natural History Museum of Utah.
