By Holly Einess
Squirrels are some of Minnesota’s most familiar wildlife species, and there are plenty to be seen at the Arboretum, especially the red and the Eastern gray. Squirrel homes are easy to spot in the winter months when leaves are off the trees.
Their leaf nests (called dreys) can be seen high in treetops. These are constructed of twigs and leaves, are spherical inside, and are typically lined with soft materials such as moss, shredded bark or pine needles. The entrance hole is usually located at the bottom of the drey facing the trunk to keep out rain.
Most dreys are used for a year or two and then are abandoned. (Note: While birds use nests only for incubating eggs and raising their young to the fledgling stage, squirrels use their nests for shelter year-round as well as for bearing and raising young.)
Squirrels may also make their homes in tree cavities. These offer excellent protection from the weather, as well as from predators (provided the entrance hole isn’t too big!), and most of Minnesota’s red and gray squirrels seek winter shelter in tree cavities rather than in dreys.
While males and females nest separately in the summer, they often cohabitate, for warmth, in the winter. Next time you’re at the Arb, keep a lookout for squirrel-sized holes in trees; you’ll be surprised how many there are once you start looking!
Mating season for gray squirrels is January and February; for red squirrels, February and March. Males chase after females, and there is much jumping, bounding and biting. Baby squirrels (called kits or kittens) will be born from March to May, hairless and with eyes closed. Their eyes open at about five weeks, by week eight or nine they are weaned and by 12 weeks they are completely independent. Gray squirrels may have a second mating season, June to August, with the kits arriving 40 to 45 days later.
Red squirrels are about half as large as gray, but are twice as feisty, and can be seen chasing grays and other small mammals. They have a distinct white eye ring, a white belly and reddish fur and tail. While often associated with pine trees, they do well in non-coniferous habitats as well.
In addition to these two species, Minnesota is home to five other native squirrels: fox squirrels, flying squirrels, Franklin’s ground squirrel, Richardson’s ground squirrel and the thirteen-lined ground squirrel. (Note: The following photos are for illustrative purposes; unlike those above, they were not taken at the Arb.)
The Eastern fox squirrel can be found throughout the state (except the northeastern corner). It’s the largest of our tree squirrels and has a gray back with a rusty orange chin, chest, belly and tail.
Minnesota has two species of flying squirrels, northern and southern. Neither actually flies; rather, they glide through the air using the large flap of skin attached to their front and back legs and sides to keep them airborne for 20 to 50 feet after leaping out of a tree. These nocturnal creatures have large, bulging eyes to help them see at night.
Photo credit: Gary Eslinger/USFWS (left) and Purdue University College of Agriculture (right)
Richardson’s ground squirrels live in the far western part of our state, so we’re not likely to see them at the Arboretum. Franklin’s ground squirrels can be found throughout most of Minnesota except far north central and northeast. Both, as their names suggest, spend much of their time underground in burrows, and hibernate for up to eight months per year.
Photo credit: Pixabay (left) and Susan Elliott (right)
The thirteen-lined ground squirrel is about the size of a chipmunk and was the inspiration for the University of Minnesota’s mascot, Goldy Gopher (though this squirrel is not a gopher!).
Photo credit: Ohio DNR and University of Minnesota
For more information on five of our squirrels (and many of our other mammals), go to the DNR’s Mammals in Minnesota page.
Nature Notes 
I love it Holly. I just forwarded your article to a teacher who taught a squirrel unit last week
Thank you, Larry! And thanks for passing it along to a teacher!
Excellent job Holly and great pictures. I love all those hollow tree hole pics. We do have three more squirrel species the eastern and least chipmunks and the woodchuck the largest member of our squirrel family. Keep up the great work. Matt
Ahhh, of course! Thank you, Matt, for the reminder that not all of our squirrels are called squirrels!
Love your post, Holly! As always, I learned something new and laughed out loud- this time about red squirrels making up in spunk what they lack in size.
Thanks, Becca! I love those cheeky little reds!