CROW Case of the Week: Baby Flying Squirrel (#19-0048)

A flying squirrel (Glaucomys volans) should be renamed a gliding squirrel since its “flight” is more of a descending float than an ascending soar. Rather than wings, the small mammal employs a stretchy membrane that is attached from its back feet to its front feet and parachutes downward to escape from predators. 

Baby flying squirrels develop fur and open their eyes when they are about a month old. These youngsters begin to glide when they are roughly t wo months old. 

On January 8, a young Southern flying squirrel was admitted to CROW. There was no information provided about the squirrel’s home area. The juvenile’s right eye was crusted with debris. It also suffered from mild dehydration when it arrived. 

“The eye was likely crusted with debris from a fall, although this did not seem to affect the patient’s vision or cause any further trauma to the eye,” said Dr. Kyle Abbott, CROW veterinary intern. “Ophthalmic flush is a solution used to clean the eyes. We prepared the flush, but it was not needed. The mild debris was wiped away using a cotton-tipped applicator.” 

CROW rehabilitation staff will care for the squirrel until it is old enough for release since no information was provided about where its parents may be located. Breanna Frankel, CROW rehabilitation manager, believes the patient is between 6 to 7 weeks old based on its developmental characteristics. 

“While it was a little on the small size – slightly thin and small stature – its front teeth had grown in, and its fur was consistent with that age,” she said. “Release will likely be assessed around 12 weeks of age, but depends on if the baby is showing appropriate release qualifications – is it eating well on its own, is it eating the appropriate diet that it would find in the wild, does it forage well enough to consistently gain weight, does it know to return to nest box to sleep?”

The young flying squirrel will be monitored daily until it is evaluated for release. “While at CROW, the squirrel has received several days of subcutaneous fluids to keep it well hydrated following admission to the hospital. We weaned him on to our Fox Valley formula so it had a milk supplement while beginning to eat on its own. It has been weighed every day, sometimes twice a day, to monitor weight and progress appropriately. It started getting environmental enrichment to introduce him to branches, trees, leaves and natural food sources,” said Frankel. “Most recently, it was weaned off the milk formula because it has started eating well enough that it no longer needs supplemental feeds. When the weather warms up a little, it will be placed in an outside enclosure to allow it to adjust to environmental factors in preparation for release. Even after release, it will be observed for a period of time." 

“Since it is a baby and does not have an established territory, we can place it in an area we deem fit for a flying squirrel with plenty of food, water and hide sources. Since it came in alone, it will be soft released when ready. A soft release means it will be monitored following release and offered food for an extended period of time until it becomes capable of feeding itself entirely based off foraging skills. It will be released with a hide box it is familiar with to offer an initial source of protection and warmth.”


CROW Case of the Week stories are written by Bob Petcher and appear weekly in the Island Sun and River Weekly Newspapers.

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