ARE HERE FOR THE FALL
by Whit Gibbons
October 29, 2006
it is said, a young man's fancy turns to love. In autumn many people's
thoughts turn to . . . squirrels. You may enjoy watching these acrobatic
characters in trees or on the ground in woods, parks, and suburban areas.
People with bird feeders begin to wonder if they are feeding more gray
squirrels than avian visitors. In many states, squirrel hunting season
begins in the fall. Whatever your interaction with squirrels, a new book,
"Squirrels: The Animal Answer Guide" (2006, Johns Hopkins University
Press) by Richard W. Thorington Jr. and Katie Ferrell, will make them
more interesting to observe.
is not just about the common tree squirrels and flying squirrels everyone
is familiar with. It is about the entire family, 278 species, which includes
prairie dogs, chipmunks, and groundhogs (aka woodchucks). Like other rodents,
members of the squirrel family have two upper and two lower incisors in
the front of the mouth. These powerful teeth can gnaw through any type
of plant material, including bark, roots, and hard-shelled nuts. In fact,
the teeth of squirrels grow throughout their lives, and without the constant
gnawing to keep them trimmed back, the front teeth will become longer
family is found on all major land masses worldwide, except Australia,
where a variety of marsupials fill their ecological niche, and Madagascar.
The authors partition squirrels into three major groups: tree, flying,
and ground squirrels. The United States has eight different species of
tree squirrels, two of flying squirrels, and a surprisingly high number
(56 species) of ground squirrels. South Asia has about the same number
of tree and ground squirrels as the United States, but a remarkable three
dozen species of flying squirrels.
squirrels in the family are some of the ground-dwelling marmots, which
can weigh almost 20 pounds. None of these will be seen jumping from limb
to limb of a tree like the agile tree squirrels. A typical gray squirrel
weighs about a pound and is about 18 inches long from nose to tail tip.
A fox squirrel, a less common species in the Southeast, weighs more than
two pounds and is a little bit longer. The impressive giant tree squirrels
of southern Asia hold the record with an average weight of about four
pounds and a total length of 30 inches. Imagine one of those at your backyard
bird feeder. The smallest in the world are the South American pygmy squirrels
that weigh less than two ounces.
addresses a variety of questions, such as, can they see color? Yes, but
only in the manner of someone who is red-green colorblind. That is, squirrels
see colors but cannot distinguish between red and green. In enjoying fall
colors, a squirrel is most impressed by the yellow leaves. Can squirrels
swim? Yes, tree squirrels have been observed swimming across rivers, and
a red squirrel in Wisconsin swam more than a mile in Lake Superior from
the mainland to an island. Why it chose to swim a mile through the coldest
lake in the country remains a mystery. What is the greatest distance a
flying squirrel can glide? The maximum recorded distance for North American
flying squirrels is 148 feet. The longest documented glides are for a
Japanese flying squirrel that traveled 377 feet and a woolly flying squirrel
of Pakistan that landed after gliding 492 feet. These are only what have
been recorded by ecologists studying the squirrels. The actual record
glides are much longer but just haven't yet been measured.
also has a section on coat color, which explains that populations of black
squirrels, especially in northern regions, are actually gray squirrels.
And sections on squirrel reproduction and mating behavior, food and feeding,
and general ecology answer numerous questions about this intriguing group
no book about squirrels would be complete without the obligatory section
on how do I keep squirrels away from my . . . house, bird feeder, or garden.
In the time-honored tradition of people giving book reports, I advise
you to read the book to find the answer to those questions. But in the
meantime, learn to enjoy the squirrels.
you have an environmental question or comment, email