Fox squirrel, Sciurus niger

Tree squirrels may be divided into three groups: large tree squirrels (gray, fox, and tassel-eared), pine squirrels (red and Douglas), and flying squirrels (northern and southern) (Jackson 1994). Squirrels eat plants and fruit, dig up newly planted bulbs and seeds, strip bark and leaves from trees and shrubs, invade homes, and consume bird eggs (Jackson 1994, Hadidian et al. 1987). They cause problems by shorting out transformers and gnawing on power and telephone lines (Marsh and Howard 1990, Hamilton et al. 1987).

Squirrels can often be observed at the damage site. Damage to conifer seed is indicated by green, unopened cones scattered on the ground under mature trees and by the accumulated cone scales and “cores” at feeding stations. Bark stripping can be observed in trees and bark fragments are often found on the ground, as are the tips of twigs and small branches.

Summary of Damage Prevention and Control Methods

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), Ropel, 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.