Crittering 
Becoming a Flying Squirrel Landlord
The flying squirrel may own the title of Colorado’s rarest mammal because just one single specimen has ever been recorded in the state. Although they are only found in a small sliver of the state, this probably has more to do with how difficult it is to find them, and not as much to do with the size of the population. The northern flying squirrel (Glaucomys sabrinus) is common in northern latitudes of the US and Canada, but its range barely extends down into northwest Colorado. Just reaching a suitable site to search for them is a long drive on rough jeep roads into some of Colorado’s most remote country. And then there is the fact that they are nocturnal. And they fly (well, glide, actually). Basically, a photographer’s worst case scenario.
Nest box shop class
Back in the summer of 2014, Lana and I took a road trip back to Michigan to visit family. My mom’s house has a nice stand of hardwood forest out the back door, and ever though she’d never seen them there before, it just seemed like a nice place for flying squirrels. Both the northern flying squirrel and the similar, but smaller southern flying squirrel (G. volans) inhabit Michigan. At Mom’s house in the southern Lower Peninsula, only the southern flying squirrel might be found.
Before we left Colorado, I whipped up a couple of flying squirrel nest boxes using some plans that you can download here and put them in the truck. When we arrived in Michigan, I mounted the boxes as high as I could reach using the tallest ladder in the garage and we all crossed our fingers.
Nest box installed at my mom’s in Michigan
It was more than a year before we made another trip back to Michigan – this time for Thanksgiving. It was a cold, drizzly weekend, but we had to make it out to check the nest boxes. I noticed some gnawing around the opening – not enough to allow a fox squirrel or gray squirrel to fit through. Lana gave the tree trunk a rap and two little squirrel noses poked out.
We knew immediately by their giant round eyes that they were flying squirrels. We’d seen a captive southern flying squirrel once before when Rob Mies brought one to a presentation at the Denver Museum of Nature and Science. But to see them living in the wild was a lifer for both of us! It’s not uncommon to see flying squirrels in pairs at this time of year. During the colder months, they “buddy up” to stay warm. One of the squirrels crawled completely out of the nest box onto the tree trunk, giving us a good look at its broad tail and patagium (the “wing” membrane connecting the legs and body that allows it to glide). After snapping a few photos, we left them alone so they wouldn’t feel the need to “evict”. Hopefully they’ll stick around and I’ll have a chance to photograph them in flight on a future visit.
This southern flying squirrel briefly climbed out of the nest box at my mom’s house in Michigan, giving us a great view.
Back in Colorado last summer, I was able to capture some infrared video footage of northern flying squirrels in the wild. It was a taxing job, with many trips to the western slope, and at least one seriously epic 4WD adventure. I’m nowhere near satisfied with any photos that I have capture so far, but just to locate a site to photograph these squirrels and confirm their presence is half the battle. The videos will help me to understand their habits and better position my cameras when the snow melts next spring.
Crittering 
Lovely photo and post, thank you for sharing! 🙂
Thank you!
Another great post! Really straightforward and comprehensive nestbox instructions, with wonderful graphic of a flying squirrel a la native artists of the Pacific Northwest.
Thanks, Chris! I hope the pikas are staying warm up on Niwot Ridge this winter!
Very cool post! Keep them coming. 😀
Thanks, Corey! Hope you are doing great!
Sweet! You have the best adventures.
What a range of adventures! I’m the retired schoolteacher from a school district near the Santa Rita Mountains in southern Arizona- you may remember seeing my name once before. As students’ parents and I continue to collect photos of animals in the Santa Rita Mountains – your photo of the antelope jackrabbit near Madera Canyon caught my eye. Wondering if we could have permission to use that photo in our project. Thank you.
Hi. Where in NW Colorado did you make the sighting?? I’m above Buford at the base of the flattops WA and just pulled up the plan and am going to build/set a few boxes. I’d love to know where you had the sighting. Thnx! Valerie
You are on the western edge of where they are expected. Their range comes into Colorado out of Utah to the west. Please let me know if you discover any! You can send me an email through my website at http://www.jamesbeissel.com
Will do !
I’ve come across 3 marten just in the last 6 wks at elev between 7300′ and 8500′. Are you seeing more than usual or have you heard from others on sightings? Doug fir/spruce habitat.
My buddy saw one this past September in the Book Cliffs north of Grand Junction. He was positive as it almost smacked him in the face. When he told me, I thought he was crazy. that is until I read this story that is. I will have to share this with him.
Reblogged this on Serendipity Seeking Intelligent Life on Earth and commented:
In case you’d like to have your very OWN flying squirrels … especially if you happen to live in Colorado!
Much to my amazement, I discovered that at least a dozen flying squirrels were happily hooked to my three bird-feeders. I had no idea that these little furries lived in Massachusetts. No pictures because it was dark and I don’t have a night camera — AND I didn’t expect anything to be out on the deck in the middle of the night!
We got a not very good motion-generated camera. All the night pictures are in black & white but boy oh boy, do we have flying squirrels. We had to take our feeders in at night because there were so many, they would empty out 10 lbs of seed from a big feeder in a couple of hours — and then, there are the raccoons, They took the whole feeder. Some of them, we never saw again and those were huge feeders,
Also, our are very friendly. They almost ask you to put them in your pocket and take them home.