a grey squirrel on our deck
February 19, 2019
You may think it is still the dead of winter, but some members of our
wildlife community are already busy starting their families. Female
squirrels are advertising for mates from the treetops, using duck-like
“come hither” calls, and interested males have responded by racing
through the branches after them. After a female relents and
accepts a suitor, she prepares a warm sheltered nest in a hollow tree
if one is available, or builds a leaf nest if no cavity is handy. She
generally gives birth to two or three kittens in this first litter, but
the second pregnancy that takes place in late spring can often produce
up to six young.
Wisconsin is home to ten species of squirrels. Besides the gray and red
squirrels, we have the fox squirrel, two species of flying squirrels
(Northern and Southern), two species of chipmunk (Eastern and Least),
the 13 lined ground squirrel, the Franklin's ground squirrel and the
woodchuck. Black squirrels are considered a color variation of the gray
squirrel, and all squirrels are members of the rodent family.
Of the tree squirrels, the red is the smallest, only 11 to 14 inches
long including a 4- to 6-inch tail. It is reddish to reddish-gray on
top with a white or cream underside. Red squirrels live in
coniferous and mixed forests throughout northern Wisconsin where they
feed primarily on pine seeds. The fox squirrel is the largest
species and has rusty brown fur with a pale yellow to orange belly. Its
diet is made up of nuts, seeds and buds and although it is a tree
squirrel, it spends a lot of its time on the ground.
Most commonly seen is the gray squirrel. This has muscular hind
legs that allow it to leap more than 20 feet, and long hind feet that
are double-jointed and equipped with sharp claws to help it scramble
head first down a tree trunk. If it should fall, it can land safely
from heights of 30 feet and more, and we have seen one just drop to the
ground rather than bother to climb down. When danger threatens a
squirrel will sidle inconspicuously around the trunk of the tree,
keeping just out of sight. When it remains motionless against tree
bark, it can be very difficult to see.
The most notable physical feature of this squirrel is its large bushy
tail. This acts as a rudder when the animal jumps from high places, as
a warm covering during the winter, as a counterbalance when walking a
telephone wire, as a signal to other squirrels, and as a distraction to
a pursuing predator. If necessary, a squirrel can lose much of the skin
and even some of the bones of its tail to escape a marauder’s grasp,
and it is not uncommon to see one with only a partial tail.
The eastern grey squirrel’s diet varies with the seasons. In early
spring, it eats the buds of hardwood trees, especially maple. During
the summer, maple and elm seeds are major food items, as well as a wide
variety of berries and wild fruits. Squirrels also eat insects,
caterpillars, and will happily clean out a nest of birds’ eggs or young
birds. In the autumn, their most important foods are nuts,
including acorns, hickory nuts, walnuts, and pine seeds.
The squirrel's front teeth continue to grow throughout life, so they
can never be worn away by the animal's gnawing on such hard materials.
Squirrels bury hundreds of nuts and seeds for the winter. They will
wait out very cold weather in their nests, often with others of their
kind for warmth, and then emerge to search for a larder. Contrary to
popular myth, squirrels do not find buried nuts by memory but by their
highly developed sense of smell. Not all hidden nuts will be found
though, and some will germinate and grow into new trees.
Tree cavities, usually those formed by woodpeckers, often serve as
nurseries. If existing trees lack cavities, leaf nests known as
dreys are built by cutting twigs and weaving them into warm, waterproof
shelters. The newborn kits are naked and blind but mature quickly
and by 12 weeks they will be almost fully grown. An adult grey squirrel
grows to about 18 inches in length, half of which is tail. It is
usually grizzled salt and pepper with a white belly but can also occur
in a black color phase. The average squirrel’s lifespan is normally
less than six years, although some have been found to be as old as 13
years in the wild.
I think it somewhat ironic that although these little rodents cause
limited damage in America, they were considered a major pest in England
and Europe, much as the English sparrow is here. They were introduced
there in the late 1800's from North America and their numbers reached
the point where strong fears were being expressed for their effects on
both the bird population and the general health of the forests. Bird
enthusiasts were noting the rapid decline in songbird numbers and
blaming it upon squirrel predation of eggs and the young chicks.
In addition, Great Britain’s inoffensive native red squirrel was being
squeezed into isolated areas, not because the grey physically attacked
the red, but because it competed for the food supply and carried a
virus lethal to the reds. This situation seems to be improving with the
protection and reintroduction of the pine marten in that country,
because in areas where these predators now exist, the grey squirrel
numbers are declining to everyone’s relief.
When I was a youngster, a wild squirrel would come to our Chicago
suburban backyard and accept nuts from my brother’s and my fingers, an
experience that led to a lifelong passion for the outdoors and its
inhabitants. Fortunately, in our country, eastern grey squirrels
are only nuisances when they invade an attic, dig up bulbs in gardens
or drive birds away from feeders. Balancing this is the pleasure
they give to numerous city dwellers, campers, and everyone who enjoys
the outdoors. The woods would be a much lonelier place without
their hustle and bustle and cheerful chatter.