The Secret Life of Squirrels

Squirrels are the quintessential woodland tree dwellers.

A squirrel hanging from a bird feeder

Squirrels are well known for dipping into bird feeders and occasionally destroying them.

Photo by iStockphoto/mrolands

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Ask a variety of people for their opinion on squirrels, you will likely receive a variety of responses. Some folks go out of their way to attract and feed squirrels, while others — those who have had bad experiences with them in the past — couldn't care less if they ever see another bushy-tailed rodent in their life. Love them or hate them, squirrels are so well-adapted to city life that they are often the only wild mammal that people in urban areas ever encounter.

Destructive guests

Although squirrels typically nest in trees, many homeowners have found that given the opportunity, squirrels love to make their homes in attics and outbuildings. Squirrels will establish nests in attics, garages and storage spaces. They've even been known to crawl down chimneys where they either get stuck and die, or enter the house and wreak havoc.

As messy as a nesting squirrel can be, the biggest threat from a home invasion is the possibility of a fire. Squirrels love to chew on the insulation around electrical wires, leaving them frayed, which is a major fire hazard. Their urine will leave odors and cause damage to ceilings and insulation, while they chew holes in roofs, siding and fascia.

Bird lovers everywhere know that squirrels can destroy feeders and make a mess of your birdwatching and feeding area. In most cases, mounting a squirrel baffle — a plastic or metal cone available from hardware and pet stores — on your feeder pole will keep squirrels out of your feeders. You can also hang your feeders away from tree limbs to further deter their efforts in raiding your feed.

Good grub

Squirrels are also valued as table fare by many folks who actively pursue the animal, treating them as wild game. In my home state of Minnesota, the Minnesota Department of Natural Resources (DNR) estimates that hunters harvest more than 300,000 gray and fox squirrels annually. In some parts of Louisiana, squirrel hunting is so popular that schools close for a day or two, marking the beginning of squirrel season.

In Bentonville, Arkansas, the World Championship Squirrel Cook-Off is an annual tradition. Competitors showcase their unique culinary skills in preparing squirrel dishes for the judges in hopes of winning the title of “Master Chef.” This competition is so popular that it has been covered by national media, including “Good Morning America” and The Wall Street Journal.

Biology

More than 200 species of squirrels live throughout the world; many reside in the United States. There are five species of tree squirrels well-known in the United States: the fox squirrel, the gray squirrel, the red squirrel, the southern flying squirrel, and the northern flying squirrel.

Tree squirrels nest in a variety of places: the cavity or hole of a tree; in a box that some kind steward made for them; or in a nest they construct by establishing a stick frame that is then filled with various materials like leaves, bark and even corn husks. Flying squirrels in particular often choose an attic for their nesting spot.

The home range of tree squirrels can vary dramatically, from as little as 1 acre to more than 100 depending on food availability. They favor mast bearing (nut bearing) trees and other fruits in fall, and the buds of elm and maple trees in spring. Squirrels have been known to cover up to 50 miles or more in search of a suitable habitat.

Gray squirrels

Two species of gray squirrels inhabit the United States: the western gray and the eastern gray.

The eastern gray squirrel is typically found in the Northeast, although it has progressively spread throughout the western states. The western gray squirrel is found in pockets that extend from the Mexico border up through Oregon and into the southern Cascade Mountains. Both of these large squirrels appear in a variety of colors: black, gray, brown, cream or red with white bellies. Although sometimes mistaken for a different type of squirrel, the black phase of the gray squirrel is only a genetic mutation that causes the color change.

Gray squirrels can weigh between 15 and 24 ounces and are 16 to 24 inches in length. They tend to breed mid-December through early January and again in June. They normally have two litters of anywhere from one to eight pups. The pups are weaned after two months, and for the first year of their life are referred to as juveniles.

Fox squirrels

Fox squirrels live throughout most of the United States except on the East Coast. The fox is the largest type of squirrel, ranging from 17 to 27 inches long, and weighing between 30 and 35 ounces.

Fox squirrels come in two distinct color groups. One group has dark fur in shades of black or gray, while the other group is reddish-tan or orange. The bellies of fox squirrels are tan or gold compared to the white bellies found on gray squirrels. Their mating habits are similar to those of the gray squirrel.

Red squirrels

Red squirrels are much smaller than fox and gray squirrels, weighing 4 to 8 ounces and measuring between 9 and 13 inches in length. Their coloration consists of a red-brown upper body and white underparts. They have small ear tufts in the winter and often have a black strip separating the dark upper color from the light belly. The amount of red in the fur will vary depending on the season, with a rust color in the winter to a gray-red mix in the summer.

Red squirrels prefer coniferous forests, but can be found in forests of mixed hardwoods and coniferous or even just hardwood forests. Their breeding season is February through September. Between two annual litters, red squirrels will have anywhere from one to seven pups that will disperse after eight or nine weeks to forage on their own.

Flying squirrels

The U.S. is home to two species of flying squirrels: the northern flying squirrel and the southern flying squirrel. Generally speaking, the northern flying squirrel is the larger of the two, measuring between 8 and 10 inches long and weighing 2 to 5 ounces. It is usually found in the higher elevations of Alaska, California, Arizona, Michigan, and the Appalachian and Adirondack mountains.

Depending on your location, the southern squirrel measures between 5 and 10 inches in length and weighs only 1 to 4 ounces. They are found in the eastern half of the U.S., as far south as Florida, and live in lower elevations of these areas.

Their coloration consists of various shades of gray and brown with lighter bellies. The most distinctive characteristic of the flying squirrel is the broad webs of skin connecting the fore and hind legs at the wrists, and the flattened tail. They use this skin as a type of parachute when gliding from tree to tree. While most “flights” are about 20 to 30 feet, they are able to soar for up to 150 feet.

Flying squirrels have two litters of two to four young each year. The young may stay with the mother through the winter, when the squirrels commonly group together. Flying squirrels are the only squirrels that are active at night.

With nests scattered throughout the treetops and attics of North America, squirrels are a common sight in rural settings and suburban neighborhoods alike. Shedding some light on the life of a squirrel might allow for a deeper appreciation of these creatures of the forest. So the next time you see one of these “tree chickens” munching on a nut, you just might be able to correctly identify which one you've encountered.


Removing Squirrels from Structures

If you find that squirrels have made a home in your attic, you will first need to remove them and then take steps to ensure they won’t return.

You will need to use a live trap to remove the squirrels because lethal methods are not only dangerous to family and pets, but if the squirrels die inside the house — sometimes even inside the walls — you may end up with a smelly, more costly repair job on your hands. Depending on the number of squirrels and the length of time they've been in residence, it makes sense to call a professional pest removal company. They have expertise in both removing the squirrels and helping you make sure they won’t return. Your local agricultural extension service or DNR should be able to provide you with a list of licensed and bonded pest removal companies.

Sealing any entrance holes created by the squirrels is essential to ensuring they won’t return. Make sure your chimney flue is covered with wire mesh and use hardware cloth to seal soffit corners and other areas that expose a gap or opening in which squirrels could gain entry.


Fun Squirrel Facts

• They mate twice a year.

• They can run up to 20 mph.

• Their teeth never stop growing, and gnawing keeps their teeth from growing into their necks.

• When squirrels are frightened, they dart back and forth to confuse predators. Because of high traffic in cities, most city squirrels don’t live longer than a year.

• Their nests are called dreys.

• Their sweat glands are on their feet.

• When gray squirrels forget where they have buried their acorns, the forgotten nuts sprout and grow into trees. This is how many oak and other hardwood forests grow and spread.

• Gray squirrels are also known as “living fossils.” Their species has changed very little in 37 million years.


Tim Nephew, a freelance writer living in northwestern Minnesota, manages his 80 acres for wildlife.