Biology Reference
In-Depth Information
same winter home, and one observer reported that
fifty
southern flying squirrels shared a single tree
cavity in Illinois!
Although flying squirrels generally make little noise, they can vocalize, though the sounds are a bit
different for each species. The northern flying squirrel emits low chirps and sometimes makes little
clucking sounds when upset. The southern species, on the other hand, twitters, chirps, and utters high-
pitched sounds sometimes described as “tseets.”
As might be expected of small, largely defenseless creatures, flying squirrels of both species are a
target for a wide variety of predators. Owls of various sorts are a major predator; according to one
Alaska biologist, a pair of nesting northern spotted owls can cause the demise of as many as 440 flying
squirrels in a single year.
Hawks are also listed as a predator of both species, but if flying squirrels are indeed totally nocturnal,
as some sources indicate, it seems inconsistent for those same sources to list the completely diurnal
hawks as their predator. However, this inconsistency aside, hawks probably do catch an occasional fly-
ing squirrel from those that now and then forage in daylight hours.
Far more serious predators than hawks abound, however. Weasels, martens, fishers, foxes, coyotes,
raccoons, snakes, and bobcats all take their toll. That leaves one more important predator, at least where
humans live— the house cat.
I can personally testify to the efficacy of these small felines when it comes to catching flying squir-
rels. Until it unfortunately burned, there was a very large barn on our farm. Built in 1866, it was forty-
five feet wide, seventy feet long, three stories high, and was full of hollow partitions and a multitude of
nooks and crannies. An amazing assortment of wildlife inhabited that barn, including flying squirrels.
Although we never saw a live flying squirrel in the barn, we often found evidence of their presence.
Our house cats regularly prowled the area, sometimes during daylight hours and sometimes at night.
Often when we entered the barn we would see the tails of squirrels that the cats had killed and eaten.
The majority of them were from red squirrels, but it was by no means uncommon to find the soft,
silky tails of flying squirrels—mute testimony both to the abundance of the squirrels and the predatory
prowess of the cats.
It's perhaps appropriate to mention that two subspecies of the northern flying squirrel are considered
endangered, according to the U.S. Fish and Wildlife Service. One is the Carolina northern flying squir-
rel
(Glaucomys sabrinus coloratus),
which is found in just five locations—three in western North Caro-
lina and two in eastern Tennessee. Its closest relative is the other endangered subspecies, the Virginia
northern flying squirrel
(Glaucomys sabrinus fuscus);
this latter is found in just a few areas of Virginia
and West Virginia.
While we hope that these two endangered subspecies survive, we can also take comfort from the fact
that both the northern and southern flying squirrels are generally doing quite well throughout the ma-
jor part of their respective ranges. Despite the attrition from disease and a horde of predators, the little
gliders are sufficiently elusive, and have a high enough reproductive rate, to ensure their survival.
