CROW Case of the Week: Southern Flying Squirrel (#18-3788)

The southern flying squirrel (Glaucomys volans) is also known as an assapan or an eastern flying squirrel. The main difference between a southern flying squirrel and a common tree squirrel is body structure, as the flying squirrel has a gliding membrane, called a patagium, and a flattened tail.

Another distinguishing feature is its size, as it averages only nine inches in length and 2.5 ounces in weight compared to the 12-inch length average and one pound weight average of the eastern gray squirrel in this region. Flying squirrels are also nocturnal, while most tree squirrels are more active during the day. 

Interestingly, while not seen very often due to their nocturnal activity, flying squirrels can be identified by their high-pitched, bird-like “cheeps” after sunset... if you can hear them. These sounds, which are meant to warn or keep track of other flying squirrels, sometimes are above the upper limits of frequencies heard by human ears. 

At CROW, an infant southern flying squirrel was admitted to the clinic from Estero on September 25. The young squirrel was found on a pool deck and was covered in ants. Upon admittance to the hospital, the squirrel weighed just 12 grams, and its eyes were still closed. Veterinary staff noted the squirrel to be hypothermic and that it had a depressed mentation. There were no ant bites noticed on the squirrel. Dr. Robin Bast, CROW’s staff veterinarian, explained depressed mentation. 

“Normal babies are active, alert, and often vocalizing to alert the parent to their need for food,” she said. “This baby was cold, laying in one place and only moved when touched. In other words, this is “depressed” compared to normal activity level and neurologic status.”

The squirrel was given fluids and an oral sugar source. Once the squirrel received the sugar source, its mentation immediately improved, leading the veterinary staff to believe it was hypoglycemic (low blood glucose).

“In this case, we gave a small amount of Manuka honey orally since we stock it for other reasons – namely wound care. Other options for an oral sugar source include a dextrose solution or Karo syrup,” said Dr. Bast. “Within five minutes after being given a supplemental heat source and a small amount of honey orally, the baby perked up and was moving around more on its own. After it warmed up, we gave it subcutaneous fluids to help with rehydration, and started it on a feeding schedule.”

Rehabilitation staff noted that the squirrel immediately began suckling when they attempted to nipple feed it later in the day. Since admission, the squirrel has continued to eat well. It has gained 4.6 grams in weight, has opened its eyes and continues to grow toward release weight.

“We release the flying squirrels around 60 to 80 grams or approximately 20 weeks of age,” said Dr. Bast. “In order to be cleared for the release, they must be climbing well in an outside enclosure and eating dry diet entirely on their own.”

The baby patient is nearing an ounce in weight, and will need more care and size before the challenges of the wild. “The squirrel’s most recent weight was 20 grams, so it still has a lot of growing up to do, but continues to do well,” concluded Dr. Bast.


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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