Correction: A previous version of this story included a photo of a different type of squirrel. The photo has been updated to one that depicts a fox squirrel.
Orange-bellied fox squirrels have been residents of Utah since 2011. Members of this invasive species have been noticed more in the Salt Lake area since then.
The presence of fox squirrels puts pressure on their native Utah counterparts, red squirrels. Both species together make food resources more scarce.
Red squirrels are usually about 11 to 14 inches long. Comparatively, fox squirrels are about twice as long, averaging about 17 to 28 inches. Fox squirrels are also known to be more aggressive than red squirrels, because these two species don't naturally exist in the same area.
Competition between these squirrel species can create unforeseen consequences, but we're starting to see some of them now.
Wynter Varner
What are some of the issues we're seeing for native red squirrels?
Nicki Frey
Well, right now, a lot of issues that we are thinking about are really just hypothetical. The fox squirrels are so new to the area, we're not really sure exactly what the overlap will look like.
We know that red squirrels live in the higher elevation areas, and they like fir trees and spruce trees. In contrast, the fox squirrels like lower elevation areas. They like tall, shady trees. We think of them as moors, like backyard wildlife with oak trees and maple trees and the big shade trees in people's backyards.
There are a few areas where these two habitats kind of mingle, and that's where we might start seeing fox squirrels and red squirrels interact.
We know from interaction between red squirrels and gray squirrels that this overlap can lead to some competition. And, I should say, some reduction in the health of the red squirrel population if or where that might happen.
Wynter Varner
So, we're predicting this issue with red squirrels. What are some consequences that we see for the surrounding environment, other animals in the ecosystem, and nearby homeowners?
Nicki Frey
Well, because fox squirrels are relatively new to the area, scientists were a little concerned about how that's going to look for competition with other species that tend to live in urban areas along the Wasatch Front. That could mean a reduction in available resources or a reduction in food for other species.
I know it doesn't sound very new — 2011 is when we first started seeing them, but ecologically, that's new. We're still just trying to figure out what these species are, and what these little individuals are going to do.
Where I get involved is conflict between the fox squirrels and homeowners. Because they like the shade trees and the big trees in people's backyards, that's where the conflicts occur.
I get phone calls about fox squirrels eating people's backyard fruits or getting into the vegetable garden, which is annoying, of course. But if this happens in an orchard or a commercial area, they could cause some economical damage as well.
We also see in areas where they're native, we struggle with fox squirrels getting into people's attics, raising their young in people's crawl spaces, and other things like that. They're very much a nuisance issue. There's an entire economy essentially based on trying to keep fox squirrels out of bird feeders.
We are very used to having our bird feeders unmolested, and we can watch our beautiful birds in our backyards. But fox squirrels will love those bird feeders as well, so that tends to be a source of some serious contention among urban residents.
It's all just very new. So people are like, "what is this new animal, why is it causing problems, and what am I supposed to do with it?"
Wynter Varner
Oh, that's so funny. I had no clue.
Nicki Frey
Well, to be honest, most of our squirrels are in the ground, right? When we think of squirrels, we think of Paiute ground squirrels or prairie dogs. We're not used to having a squirrel that lives in a tree in our environment.
So it's just it's new, and we need to figure out how to adjust and adapt.
Wynter Varner
How are scientists responding to this issue, and how can homeowners deal with the fox squirrels near their homes?
Nicki Frey
Well, scientists are monitoring the dispersal of fox squirrels. The Museum of Natural History has a really good record base, there's a link that you can go to if you see fox squirrels. That's our way of being able to track where they are and where they're spreading to.
Right now, they're congregated along the Wasatch Front. We're just going to try to keep a handle on it and see what we see, and start studying what's going on.
There's more information online from USU Extension and also Living with Wildlife. There are good sources of information on what you can do to make your crawl spaces squirrel-proof, putting caps on your chimneys so that animals can't get into them, and generally making your backyard less attractive for fox squirrels to want to create nests or find a place to live in your backyard.
