Nick Boulanger’s trouble began about two years ago, when he looked out his home office window during a work meeting and saw a flash of orange-brown fur skitter past.
The quick critter was carrying a clump of insulation — a clump from inside his Liberty Wells attic.
“This guy’s yoked, like he’s jacked,” Boulanger said of the tiny thief. “He puffs out his chest and everything like that.”
The burglar in question was a fox squirrel. These rodents are now ubiquitous in parts of the Salt Lake Valley, more numerous than any other species of squirrel — but they’re not from here, and they’re causing problems for more than just Boulanger.
They steal birdseed and munch on crops. They harass dogs, cats and people alike. They chew through wood, wiring and other materials, in some cases causing power outages, as their population has boomed into the tens of thousands.
Researchers at the Natural History Museum of Utah are curious about how these squirrels, which are native to the eastern U.S., are adapting to life in the Wasatch Front and interacting with — or wreaking havoc on — its residents. The museum is promoting a survey to collect more data on the species so researchers can draw better-informed conclusions, according to Ellen Eiriksson, the museum’s citizen science manager.
“We get fabulous, quality, well-thought-out responses from people who take the time to look for squirrels in their own backyards, on walks with the dog, wherever they happen to be,” Eiriksson said. “I think a lot of that is because these passions sort of swirl a lot when it comes to fox squirrels in town. They love them, they hate them.”
“It doesn’t matter (which),” interjected Eric Rickart, the museum’s vertebrate zoology curator. “They’re interested in them one way or another.”
Boulanger’s pest in particular has thwarted traps, and often leered or barked at him and his wife through their windows. Each time Boulanger fixes a hole in his attic, the squirrel seems to make another. Its reign of terror has recently seemed to subside, but Boulanger isn’t convinced.
“I got a pellet gun,” he said, “and I’ve been practicing.”
Meet the fox squirrel
Evidence suggests fox squirrels were introduced to the region more than 10 years ago, near the Jordan River, although it’s not clear exactly how, Rickart said. It’s likely someone brought them here. Or they hitched a ride on a railcar from California, Idaho or Montana.
The population then spread up the river’s riparian corridor into the Avenues neighborhood. They’ve since expanded as far west as Magna and as south as Midvale. Researchers have even gotten one-off reports of fox squirrels farther south in Utah County, west in Tooele or north in Ogden.
Before the invasion, the Salt Lake Valley was already home to at least two native squirrel species: the red squirrel, and the rock squirrel.
A fox squirrel is fairly large, with an orangey underbelly and bushy tail. The native red squirrel is smaller, with darker, brownish fur and a creamy, white underbelly. Both are tree squirrels, meaning they spend much of their time scurrying through tree canopies or, in an urban environment, power lines.
Fox squirrels are similar in size to rock squirrels, but rock squirrels are more gray, live mostly on the ground, retreat to holes or burrows when threatened, and have a wispier tail.
When researchers first noticed fox squirrel populations proliferating, they worried that these three species of squirrel might not get along, and that fox squirrels might push out their native cousins. So far, though, Rickart said it hasn’t been a problem.
Through the ongoing surveys, researchers have been able to determine that fox squirrels prefer deciduous trees, whereas red squirrels seem to like conifers.
But there are still many other questions about how they are adapting to their relatively new home.
Grabbing a fox squirrel skull from a desk and placing it between his fingers, Rickart moved the jaw up and down, showing how the squirrels bite or grind their food. The rodents’ incisors, or two front teeth, never stop growing, he said. That’s why the need to gnaw.
He’s seen specimens though where some kind of misalignment occurs, and the animals can no longer chew to grind away their teeth. As a result, the incisors grow so large the squirrels can’t eat or drink, and they die.
This can also happen when the animal isn’t eating food hard enough to grind down its teeth — food these fox squirrels are commonly eating in Salt Lake City’s urban environment, like birdseed or peanuts. The lack of hardier food options, like walnuts, to grind down teeth might be why people find so many of these squirrels chewing up wooden fences or parts of their home, Eiriksson said.
Salt Lake City’s fox squirrels in particular also seem to be strangely bold, Rickart said, which is “very unnatural.”
“Maybe it’s due to the fact that they’ve been through genetic bottlenecks and they’re kind of loopy as a result of that,” he said. “Or other things.”
Living with squirrels
Earlier this month, Rachel Taylor woke up to her recently rescued golden retriever Ellie bringing her a toy in bed. Normally, Taylor said she’ll pat the dog on the head and go back to sleep, but this night Ellie wouldn’t settle down.
“She was shaking the entire bed. Just excited,” Taylor said. “And then I felt the thing again, and it had a tail, and the tail was still warm. I flipped on the bedside light and then I squealed.”
Ellie had not brought Taylor a toy. This was a fox squirrel, and Ellie brought another to bed days later.
Living near Hogle Zoo, Taylor said her yard is full of squirrels. She watches them do acrobatics to get into her bird feeder, run along power lines or pester her dog. She said years ago, she clicker-trained and fed the squirrels at Fairmont Park, near her work — until one day a dog startled a squirrel and it bit her.
That’s how she found out squirrels don’t carry rabies. Now, she said, she knows better than to feed them.
Once, her workplace lost power for three days, likely because of squirrels.
“The landlord was blaming the power company, the power company was pointing back at the landlord,” Taylor said, “and it turns out it was a fox squirrel that chewed something in the transformer.”
Despite all that, Taylor said she has a soft spot for the critters. Mostly she finds them funny.
That is good because, according to Rickart and Eiriksson, it seems like the squirrels are here to stay — and so are their associated problems and peculiarities.
“We get this question all the time,” Eiriksson said, “like, ‘How do we get rid of them?’”
On the whole, the short answer is that you can’t, Eiriksson said, though the Utah Division of Wildlife Resources did note that fox squirrels are technically legal to kill and harvest without a license or permit, should homeowners like Boulanger get any ideas.
“They’re just here. They’re ... part of our lives now,” Eiriksson said.
Salt Lake Valley residents will just need to learn to live with their new neighbors.
To participate in the natural history museum’s fox squirrel research, visit nhmu.utah.edu/citizen-science/utah-fox-squirrels. There, you can find a link to their survey and other facts about fox squirrels.
Natural History Museum of Utah
Editor’s note • This story is available to Salt Lake Tribune subscribers only. Thank you for supporting local journalism.