Tuesday, February 17, 2015

Southern Flying Squirrels

A Southern Flying Squirrel in its typical head-down escape position.

     The Southern Flying Squirrel is the only locally occurring type of the 2 species of flying squirrels found in North America. It is also the smallest tree squirrel in the USA and the most predatory. These nocturnal acrobats are very elusive and seldom seen, even though they are very common (more numerous than Gray Squirrels in the right habitat). Their scientific name, Glaucomys volans, breaks down to the "flying gray mouse."

Southern Flying Squirrel cuttings. Note the singular smooth-edged opening per nut.

     Sometimes the easiest way to determine their presence is by the way they leave nuts behind with a single, circular opening cut in them. Other animals leave "cuttings" with multiple jagged holes (many voles and mice for instance) or with the husk completely destroyed (other squirrels). These are often good signs that they live in the area.
     Flying squirrels do not actually "fly" but rather glide using their skin flaps (called a patagium) and flattened tails as airfoils (they do not actually steer with their tails, despite this being widely quoted). They are among the most accomplished gliders in the world, capable of glides up to 100 yards (though preferring much shorter distances). I've seen them maneuver deftly around trees and even completely change directions to land at the base of the same tree they took off from. Catchcing them in flight, no matter how brief, is indeed a memorable experience. Flying squirrels typically quickly flip to the opposite side of the trunk immediately upon landing, using the tree as a shield in case they are pursued by an owl (a tactic I've been lucky enough to see work on several occasions). They also usually hang head-down on the darkest side of trees so they can easily simply release and be in the best position to glide to safety. As a general rule, for every two feet high they get, they can get close to one foot in gliding distance.

Flying Squirrel raiding a bird feeder.

     Although Southern Flying Squirrels prefer to eat insects during the warmer months, they will also feed on other small animals, eggs, carrion, fruits, fungi, seeds, and nuts. They are the most predatory of all our squirrels. These charismatic rodents are more solitary during warmer seasons and may make leaf nests (dreys) if no better hiding places are available, though they prefer tree cavities. They change their behavior in winter however, becoming social and relying principally on seeds and nuts in the absence of their regular fare. Flying Squirrels are readily attracted to feeders and bait stations during winter as well. Placing nuts, suet, and/or peanut butter out a 1/2 hour after dusk on an elevated spot and checking them nightly often results in making them regular and easily observed visitors. They are most active for about an hour after it gets dark and are quite habitual in their use of these bait stations
     I have had great results in conducting evening programs observing these charismatic creatures feeding and gliding. I actually started the programs at the nature center I used to work at and have conducted regional and national trainings on conducting these types of programs at other centers as well. Long Branch Nature Center became well known for its flying squirrels, being featured in numerous newspaper articles and even on Animal Planet. "Fairy Diddles" (a nickname for them) get quite accustomed to people, lights, and even groups very easily, being almost fearless of humans.

A Flying Squirrel reaches out for some peanut butter, not even waiting for it to be applied to the feeder.

     In fact, the first time I discovered the flying squirrels at the nature center, I was moving the bird feeders inside during the evening when one popped around the tree to look at me. A bit surprised, I decided to put some peanut butter out and see if I could get a better look at it. Imagine my surprise when it scurried around the trunk and started eating the peanut butter right off the knife I was using! It didn't even wait for me to finish spreading the peanut butter on the tree. This wild squirrel simply did not see me as a danger and was fearless in getting the food, trusting in its speed and reflexes.

A Flying Squirrel peeks out from a roosting box. Note the metal barrier along the entrance edge to help prevent gray squirrels from chewing their way in, though you can see the chew marks on the metal flashing and box itself.

     Roosting boxes for them are easy to construct, the most important feature being having an opening 1 1/4" or 1 1/2" in diameter and preferably bordered with metal to keep gray squirrels (who do not like flying squirrels) from chewing their way in. Flying squirrels often pack together in den trees or roosting boxes for warmth (up to several dozen if space permits). Being so small, warmth is a critical factor and by roosting in groups, they can conserve 30% more energy. Since the males are more feisty (and since food is more available and they do not need each other for warmth) in spring and summer, attracting flying squirrels to feeders is really something best done in the coldest months of winter.

Flying squirrels are very social during winter, vocalizing and feeding or sleeping in groups.

     Breeding females get very solitary and secretive outside of winter as well, having 1-2 litters a year of 2-7 young with a 40 day gestation period. Winter roosting boxes or shelters are rarely used for nesting, the females seeking secret locations instead, since flying squirrels are not beyond eating each other's young. A third of all squirrels do not make it past their first year, with owls, outdoor cats, large snakes, foxes, and raccoons being primary predators. They otherwise can live 3-6 years in the wild, up to 15 in captivity.
     Although not legal to keep as pets locally, Flying Squirrels were quite popular in the past. Captain John Smith during his explorations was acquainted to "Assapanicks" as the Native American Indians referred to them in the Virginia Algonquian dialect. King James I requested one as early as 1609, "The King is eager to have one of the Virginia Squirrels that are said to fly." Even Teddy Roosevelt had flying squirrels during his presidency. Having taken care of un-releasable rehabilitation squirrels at the nature center, I can say they are interesting indeed. However, their nocturnal nature means that they are awake and very active when you want to be asleep.
      For a short video on them, check out this video from my YouTube Channel:  
                                  https://www.youtube.com/watch?v=d0VlytjtueU

     After seeing them perform their acrobatic glides and how readily they come to entertain at feeding stations, it easy to see the attraction. Flying squirrels have a special place in my soul. If you try to observe them at night, perhaps provide some roosting boxes, and feed them in winter, I bet you will feel the same way about them also. Luckily I get a chance to conduct a flying squirrel program each year at Long Branch Nature Center. Call them if you'd like to see if there are still any places left (703-228-6535). It's fun for the whole family (and for me). As long as it's not too windy (it's hard to glide safely in heavy winds) or extremely cold (<14 degrees F), they're fairly reliable at arriving for their dinner time. Let's hope for good "flying" weather that weekend!

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