These furry rodents are invading the Wasatch Entrance, wreaking havoc on some owners

Nick Boulanger’s troubles began about two years ago when he looked out his home office window during a work meeting and saw an orange and brown fur coat scurrying past.

The nimble animal was carrying a chunk of insulation – a chunk from his attic in Liberty Wells.

“This guy’s tense like he’s jacked,” Boulanger said of the diminutive thief. “He puffs up his chest and stuff.”

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 squirrel species — but they’re not native and aren’t just a problem for Boulanger.

They steal bird seed and nibble on crops. They bother dogs, cats and humans alike. They eat through wood, cables, and other materials, and in some cases cause power outages as their population has swelled to tens of thousands.

(Francisco Kjolseth | The Salt Lake Tribune) A fox squirrel navigates an urban environment while foraging for food on Sunday, January 22, 2023 in Salt Lake City. The Natural History Museum of Utah has been studying the species native to the eastern United States, with the help of Citizen Scientists. The species was first reported along the Jordan River in 2011 and has since spread across the region.

Researchers at the Natural History Museum of Utah are curious how these eastern US native squirrels are adapting to life on the Wasatch Front, interacting with or ravaging their residents. The museum is sponsoring a survey to gather more data about the species so researchers can make more informed conclusions, according to Ellen Eiriksson, the museum’s citizen science manager.

“We get fabulous, high-quality, well-thought-out responses from people who take the time to look for squirrels in their own backyards, on dog walks, wherever they happen to be,” said Eiriksson. “I think a large part of that is because these fox-squirrel passions are very swirling around town. They love them, they hate them.”

“It doesn’t matter (which one),” interjected Eric Rickart, the museum’s curator of vertebrate zoology. “They care about her in one way or another.”

Boulanger’s pest in particular has foiled traps, often snapping or barking at him and his wife through their windows. Every time Boulanger fixes a hole in his attic, the squirrel seems to make a new one. His reign of terror appears to have eased recently, but Boulanger isn’t convinced.

“I have a shotgun,” he said, “and I’ve been practicing.”

Meet the fox squirrel

(Francisco Kjolseth | The Salt Lake Tribune) Lightly falling snow ricochets off a fox squirrel Sunday, January 22, 2023 as it navigates the urban environment in Salt Lake City. The Natural History Museum of Utah has been studying the species native to the eastern US, with the help of citizen scientists. The species was first reported along the Jordan River in 2011 and has since spread across the region.

There is evidence that fox squirrels were introduced to the region near the Jordan River more than 10 years ago, although it’s not clear exactly how, Rickart said. Someone probably brought her here. Or they would hitchhike a railcar from California, Idaho, or Montana.

The population then spread up the river bank corridor into the Avenues neighborhood. Since then they have spread as far west as Magna and as far south as Midvale. Researchers have even received unique 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 quite large, with an orange belly and a bushy tail. The native red squirrel is smaller, with darker, tan fur and a creamy white belly. Both are tree squirrels, meaning they spend much of their time scurrying through tree canopies or down power lines in an urban setting.

Fox squirrels are similar in size to rock squirrels, but rock squirrels are grayer, live primarily on the ground, retreat into holes or burrows when threatened, and have a thinner tail.

When researchers first noticed that fox squirrel populations were proliferating, they became concerned that these three squirrel species might not get along and that fox squirrels could crowd out their native cousins. However, Rickart said it hasn’t been a problem so far.

Through the ongoing research, the researchers were able to determine that fox squirrels prefer deciduous trees, while red squirrels seem to like conifers.

But there are plenty of other questions about how they’re adjusting to their relatively new home.

Rickart picked up a fox squirrel skull from a desk and placed it between his fingers, moving his jaw up and down, showing the squirrels biting or grinding their food. Rodents’ incisors, or two front teeth, never stop growing, he said. Hence the need to gnaw.

(Francisco Kjolseth | The Salt Lake Tribune) Eric Rickart, Curator of Vertebrate Zoology at the Natural History Museum of Utah, speaks on Friday, January 20, 2023 about a fox squirrel’s ever-growing teeth. Specializing in handling hard nut shells, squirrels need to wear down their teeth, which is not achieved with soft peanuts left behind by those who feed them.

However, he has seen specimens where some sort of misalignment occurs and the animals can no longer chew to grind down their teeth. As a result, the incisors grow so large that the squirrels cannot eat or drink and die.

This can also happen if the animal doesn’t eat hard enough to bite off its teeth — foods these fox squirrels typically eat in the urban Salt Lake City environment, like bird seed or peanuts. The lack of more robust food options, like walnuts to grind down your teeth, could be why people find so many of these squirrels chewing up wooden fences or parts of their home, Eiriksson said.

The fox squirrels in Salt Lake City in particular also seem strangely bold, Rickart said, which is “very unnatural.”

“Maybe it’s because they went through genetic bottlenecks and it kind of freaked them out,” he said. “Or other things.”

Living with squirrels

(Francisco Kjolseth | The Salt Lake Tribune) Fox squirrels navigate an urban environment while searching for food in Salt Lake City on Saturday, January 21, 2023. The Natural History Museum of Utah has studied the species native to the eastern United States, with the help of citizen scientists. The species was first reported along the Jordan River in 2011 and has since spread across the region.

Earlier this month, Rachel Taylor woke up when her recently rescued golden retriever, Ellie, brought her a toy in bed. Normally, Taylor said, she would pat the dog on the head and go back to sleep, but tonight Ellie wouldn’t calm down.

“She shook the whole bed. Just excited,” Taylor said. “And then I felt the thing again, and it had a tail, and the tail was still warm. I turned on the bedside lamp and then squeaked.”

Ellie hadn’t brought any toys for Taylor. This was a fox squirrel, and days later Ellie brought another to bed.

Taylor lives near Hogle Zoo and said her garden is full of squirrels. She watches them perform acrobatic moves to get into their bird feeder, run over power lines, or molest their dog. She said years ago she trained clickers and fed the squirrels at Fairmont Park near her work – until one day a dog startled a squirrel and it bit her.

This is how she found out that squirrels do not transmit rabies. Now, she said, she knows better than to feed them.

Once the power went out at her place of work for three days, probably because of squirrels.

“The landlord blamed the utility company, the utility company pointed at the landlord,” Taylor said, “and it turned out to be a fox squirrel that had been chewing something in the transformer.”

(Francisco Kjolseth | The Salt Lake Tribune) High-voltage power lines serve as a freeway for a fox squirrel as it moves through an urban environment in Salt Lake City. The fox squirrel is very well adapted to life in trees and traveling along power lines and fences, and when startled escapes by climbing. With the help of citizen scientists, the Natural History Museum of Utah is searching for new observations and insights into the distribution of the rodent, first reported along the Jordan River in 2011.

Despite all of that, Taylor said she had a soft spot for the critters. Most of the time she finds them funny.

That’s a good thing, because according to Rickart and Eiriksson, the squirrels seem to be staying here – and with them the problems and peculiarities that come with them.

“We get this question all the time,” Eiriksson said, “like, ‘How do we get rid of them?'”

Broadly speaking, the short answer is that you can’t, Eiriksson said, although the Utah Division of Wildlife Resources found that fox squirrels are technically legal to kill and harvest without a license or permit, should homeowners like Boulanger have any have ideas

“They are just here. They’re… part of our lives now,” Eiriksson said.

Salt Lake Valley residents just have to learn to live with their new neighbors.

Squirrel Poll:

To participate in the Natural History Museum’s fox squirrel research, visit nhmu.utah.edu/citizen-science/utah-fox-squirrels. There you will find a link to their survey and other facts about fox squirrels.

Natural History Museum of Utah

Editor’s Note • This story is available only to Salt Lake Tribune subscribers. Thank you for supporting local journalism.