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Title

Tree Squirrels

Document Type

Article

Date of this Version

July 1994

In this chapter tree squirrels are divided into three groups: large tree squirrels, pine squirrels, and flying squirrels. Large tree squirrels include fox (Sciurus niger), eastern gray (Sciurus carolinensis), western gray (Sciurus griseus), and tassel-eared (Sciurus aberti) squirrels. Fox squirrels (Fig. 1) measure 18 to 27 inches (46 to 69 cm) from nose to tip of tail. They weigh about 1 3/4 pounds (787 g) to 2 1/4 pounds (1,012 g). Color varies greatly, from all black in Florida to silver gray with a white belly in Maryland. Georgia fox squirrels usually have a black face. Ohio and Michigan fox squirrels are grizzled gray-brown above with an orange underside. Sometimes several color variations occur in a single population. Eastern gray squirrels are also variable in color. Some have a distinct reddish cast to their gray coat. Black ones are common in some northern parts of their range. Eastern gray squirrels measure 16 to 20 inches (41 to 51 cm). They weigh from 1 1/4 pounds (567 g) to 1 3/4 pounds (794 g). The western gray squirrel is gray above with sharply distinct white underparts. Size is similar to that of the eastern gray squirrel. Tassel-eared squirrels are similar in size to gray squirrels and have several color phases. The most common is gray above with a broad reddish band down the back. Black tufted ears are their most distinguishing characteristic (the tufts are larger in winter, about 1 inch [2.5 cm]).

There are two species of pine squirrels: the red squirrel (Tamiasciurus hudsonicus) and Douglas pine squirrel (Tamiasciurus douglasii). Pine squirrels are 10 to 15 inches (25 to 38 cm) in total length and weigh 1/3 to 2/3 pounds (151 to 303 g). Red squirrels are red-brown above with white underparts. Douglas squirrels are gray-brown above with yellowish underparts. Both species have small ear tufts and often have a black stripe separating the dark upper color from the light belly.

Two species of flying squirrels occur in North America. The southern flying squirrel (Glaucomys volans) is 8 to 10 inches (20 to 25 cm) long. The northern flying squirrel (Glaucomys sabrinus) averages 2 inches (5 cm) longer. It can be difficult to distinguish between the two; both may be various shades of gray or brown above and lighter below. A sharp line of demarcation separates the darker upper color from the lighter belly. The most distinctive characteristics of flying squirrels are the broad webs of skin connecting the fore and hind legs at the wrists, and the distinctly flattened tail.

Exclusion:Install sheet metal bands on isolated trees to prevent damage to developing nuts. Close external openings to buildings to stop damage to building interiors. Place an 18-inch (46-cm) section of 4-inch (10-cm) diameter plastic pipe or a one-way door over openings to allow squirrels to leave and prevent them from returning. Plastic tubes on wires may prevent access to buildings.
Cultural Methods: Remove selected trees or their branches to prevent access to structures.
Repellents: Naphthalene (moth balls), Ro-pel, capsaicin, and polybutenes are registered for controlling tree squirrels.
Toxicants: None are registered.
Fumigants: None are registered.
Trapping: Leghold traps. Box and cage traps. Rat snap traps. Box choker traps.
Shooting: Effective where firearms are permitted. Use a shotgun with No. 6 shot or a .22-caliber rifle.