TRANSCRIPT

INTRODUCTION

If you walk through a forest anywhere in North America, you're likely to hear the scolding chatter of a tree Squirrel. These lively creatures are among our most popular and visible wild animals.

We watch Squirrels, in city parks or in our backyards, collecting nuts and acorns to store for the Winter. But how much do we really know about their life in the wild?

From the tiny Red Squirrel to the handsome husky Fox Squirrel, these tree-top acrobats come in a wide range of sizes and colors. Let's take a look at the unusual and often unseen behavior of these "BUSHYTAILS."

Squirrels are highly specialized. They have adapted to the tree tops as have few other mammals.

SQUIRREL RUNNING ON POWER LINE

With sharp, hook-like claws for clinging to bark, and a large, fluffy tail for balance, they are well-equipped for life above ground. One of the most notable characteristics of Squirrels is their compatibility with humans. They arouse our sense of wonder and they amuse us with their gravity-defying acrobatics.

Squirrels were not always as popular as they are today. During colonial times, Gray Squirrels were so abundant that they threatened the crops of pioneer farmers, especially their corn. It's been estimated that before the dense eastern hardwoods were cleared for farmland, a billion Gray Squirrels roamed the forests.

In the 1700's, bounties were imposed to control these voracious pests. A few colonies even accepted Squirrel scalps as payment for taxes. Colonists became such marksmen from shooting Squirrels, they devastated the ranks of British soldiers during the American Revolution later.

Only a small fraction of the once enormous Gray Squirrel population exists today. But they are still the most familiar of all the North American Squirrels.

DRAWING OF DIFFERENT SQUIRREL SPECIES

Even more common than the Gray Squirrel, yet rarely seen, is the nocturnal Flying Squirrel. This species is our smallest native Squirrel, weighing only 2 to 3 ounces.

The Douglas Squirrel, below, also called Chicory, inhabits the coniferous forests of our Pacific coastal states.

The Red Squirrel, above, makes up for its small size by being the noisiest.

The versatile Gray Squirrel, so named for its salt and pepper fur, is equally at home in woodland, suburb, or city park.

The Ponderosa Pine forests of the western US. are home to the beautiful Tassel-eared Squirrels, the Abert's Squirrel, on the right, and the darker Kaibab Squirrel, on the left.

The Fox Squirrel is the largest of all, weighing up to three pounds. This species exhibits a wide variety of color phases.

The best season to observe Squirrels is autumn, when most of their time is spent foraging on the ground, collecting nuts and seeds. Like the Fox Squirrel, chipmunks also store food for the winter.

Some of their favorites are Acorns, Hickory nuts, Beechnuts, Walnuts and Maple seeds.

It was once believed that Squirrels could remember where they buried each nut. But experiments indicate that, within a half hour, they forget these locations. Now we know they find food, buried under leaves and even snow by using their keen sense of smell. Ironically, the nuts that Squirrels eventually dig up aren't necessarily the same ones they buried.

With abundant food, the Squirrels fatten quickly. Their extra weight will sustain them through the lean months ahead.

BURYING NUTS AND SEEDS

Gray Squirrels are equally industrious. One ambitious bushytail can bury thousands of nuts and seeds by the time winter arrives.

Each Squirrel works fast and furious to hoard its winter food supply, for the competition is intense. Deer, bears, hogs and turkeys also feast on the nutritious mast.

GRAY SQUIRREL

Both Fox and Gray Squirrels are found throughout the entire eastern half of the United States. They've also been released into parts of the west. The adaptable Gray Squirrel has even been introduced into England where it now drives out the native Red Squirrels.

Autumn is a time of restlessness for most animals, and the tree Squirrels are no exception. Juveniles, born during February or March, must leave their birthplaces and find a home of their own.

During this "fall shuffle," the inexperienced young often fall prey to Hawks, Bobcats, Foxes and Martens.

HUMAN HUNTER

Human hunters also stalk the colorful woods.

Squirrels outwit their predators, human and otherwise, by hiding behind a tree trunk until the danger passes.

HUNTER GATHERING SHOT SQUIRRELS

Approximately 40 million Squirrels are shot annually by hunters. While over-hunting can reduce populations in isolated woodlands, Squirrel numbers are more influenced by severe weather and disease than by hunting.

With the threat gone, the juveniles resume their playful games.

All too soon, the fall colors slip away.

RED SQUIRREL/WHITE FOOTED MOUSE

Only the high-pitched bark of a Red Squirrel pierces the hush of the winter woods.

In cold weather, Squirrels are rarely seen in the open. Even so, they don't hibernate like their ground Squirrel cousins. The Red Squirrel of our northern Evergreen forests avoids the icy winds by digging a network of tunnels under the snow.

White-footed mice also seek shelter in the Squirrel's tunnels.

The Red Squirrel is the most territorial of all the tree Squirrels, with good reason. It caches nuts and pine cones in one pile which must then be protected from other hungry rodents.

COURTING/MATING

In late December, the mating season is ushered in by a chorus of chattering Squirrels.

Squirrel courtship involves more fighting than courting. Male Squirrels will chase a female for hours in a frenzied attempt to mate with her. Though unwilling to mate at first, the female leaves scent marks along the branches, enticing her suitors to follow. Several males join in the chase and fight one another for mating privileges.

It's believed that the female's protests serve to intensify the competition between males.

The stronger the competition, the better her chances are that the strongest, most dominant male will persevere.

ALBINO GRAY SQUIRREL

An albino Gray Squirrel watches the commotion from a nearby tree.

Besides eliminating the weaker or inexperienced males as potential mates, the ritualized mating chases also stimulate ovulation in the female.

The males are polygamous, meaning they will mate with as many females as they can catch.

The interbreeding between normal Grays and Albino's may produce offspring that are gray, white, or even pure black. These color variations are simply genetic mutations in their pigment and apparently have no bearing in matters of courtship.

FOX SQUIRREL

While the Gray Squirrels range from white to black, Fox Squirrels exhibit an even greater diversity of fur color, the greatest, in fact, of any North American mammal.

For now, this male gives up the chase and settles for a sweet taste of tree sap.

Squirrels are members of the largest order of mammals, the Rodents. Fossil evidence suggests that rodents originated in North America and evolved into many different species from a common, Squirrel-like ancestor.

Rodents proved so adaptable that they invaded almost every major ecological niche in an amazingly brief span of about two million years.

The appearance of springtime flowers, mushrooms and tree buds provides a banquet for woodland creatures.

This female Fox Squirrel returns to her den to nurse her four week old young, snuggled beneath a blanket of leaves.

A male Fox Squirrel, with no parental responsibilities, continues to dine on the succulent buds.

While male and juvenile Squirrels are very social and often den together, neither are tolerated in the same nest as a female with young.

FLYING SQUIRRELS/FULL MOON

Tree Squirrels are most active at dusk and dawn, with one exception. As the moon rises, Flying Squirrels begin their nighttime forays, gliding from tree to tree like furry kites. The Flying Squirrel's name is a misnomer since it can't fly. But it can glide up to fifty feet by spreading the loose flaps of skin along its sides.

Like most Squirrels, they nest in natural tree cavities or abandoned woodpecker holes. When fleas and other parasites become intolerable, the female moves her litter to a new den. A baby finds comfort in its fresh bed of shredded bark.

Tree Squirrels normally produce one litter a year, but, if food is plentiful, they will nest twice. Once in early spring and again in mid- summer, after the young from the first litter leave the nest.

MOTHER FLYING SQUIRREL MOVING BABIES/NURSING

A typical litter for Flying Squirrels is three, but there may be anywhere from two to six young. The baby Squirrels are weaned at eight to nine weeks, but they may remain with their mother for up to three months. Young tree Squirrels take longer to develop than most other mammals their size. This ensures that their coordination and eyesight are highly developed by the time they face life on their own.

About 10,000 years ago, a species of Tassel-eared Squirrel inhabited the forests of the American southwest. As the Kaibab Plateau rose on the north rim of the Grand Canyon, the Squirrels there became geographically isolated from those on the south rim.

Two sub-species eventually evolved.

ABERT'S SQUIRREL

The more common and widespread of the Tassel-eared Squirrels is the Abert's Squirrel. Its range overlaps that of the Ponderosa Pine, on which it depends for food and cover.

Besides eating the pine cone seeds, the Squirrels survive the critical months of winter eating the cambium, or inner bark, the Ponderosa.

They also eat Truffles, a subterranean fungi. Truffles enhance the health of the forest by providing moisture and nutrients to the pine tree's roots. The Squirrels help spread the fungi by leaving spores in their droppings.

It's a three-way relationship that helps to propagate the fungi and the pine trees, while providing food for the Squirrels.

Living at an elevation of six to nine thousand feet their mating season begins as late as April or May. The young are born about forty days later.

KAIBAB SQUIRREL

A subspecies of the Abert's, the Kaibab Squirrel, was cut off from its ancestral population by the Grand Canyon to the south and treeless deserts to the east, north and west.

Separated, they evolved distinctive characteristics such as a dark gray belly and pure white tail. But the Kaibab, too, depends on the Ponderosa pine.

As with other members of its family, mating is preceded by a high-speed chase through the forest.

The Kaibab Squirrel provides scientists with a rare look at how geographic isolation affects an animal's development. The few miles that separate the Kaibab and Abert's Squirrels can be measured in thousands of years of evolution.

We tend to give more attention to rare or seldom-seen animals. Yet, however common, Squirrels are no less important.

We should value tree Squirrels not only for their unique role in nature, but also for the touch of wildness they bring to our civilized world.

CONCLUSION

Squirrels provide us with a close-up look at nature. We enjoy watching their antics and we benefit from them in another, less obvious way. Since every buried seed or nut is a potential tree, the health of our woodlands is enhanced by these rodents.

As long as their habitat is preserved, forests will always resound with a persistent chatter of "BUSHYTAILS".