Habitat - Squirrels inhabit both hardwood and coniferous forests.
Diet - Fox and gray squirrels - Acorns, hickory nuts, walnuts, and osage orange fruits in fall and early winter; tree buds in late winter and early spring; fruits, berries, and succulent plant materials in summer. Fungi, corn, and cultivated fruits are taken when available. When food is scarce, they may chew bark from trees or eat insects and other animal matter. Flying squirrels - same as above except more animal matter, such as bird eggs and nestlings, and insects.
Behavior - Home range size varies from 1 to 100 acres depending on the season and availability of food. During fall, squirrels may travel 50 miles or more in search of better habitat. Typically about half the squirrels in a population die each year. Squirrels are a food source for hawks, owls, snakes, and several mammalian predators.
Flying squirrels are active at night, while all other species are active during the day.
Reproduction - Squirrels breed when they are 1 year old. They breed from mid-December to early January and again in June. Young squirrels may breed only once in their first year. The gestation period is 42 to 45 days.
About 3 young comprise a litter. At birth they are hairless, blind, and their ears are closed. Young are weaned at 10 to 12 weeks.
During the breeding season, noisy mating chases take place. They nest in tree cavities, human-made squirrel boxes, or in leaf and stick nests. Cavities are the preferred nest sites.
Forest trees - they chew bark, eat cones and nip twigs. They frequently chew holes through pipelines used in maple syrup production.
Nut orchards - they eat nuts prematurely, carry off mature nuts, or chew bark.
Residential areas - they travel power lines, shorting out transformers; gnaw on wires; enter buildings, and build nests in attics.
Lawns - they bury or search for and dig up nuts; chew bark and clip twigs on ornamental trees or shrubbery; eat food at bird feeders; eat seeds, mature fruits and grains in gardens, and sometimes chew to enlarge openings of bird houses and enter to eat nestling songbirds.
Squirrel damage in yards, gardens, forests,
and orchards is often very difficult to
control. During population highs, new squirrels arrive quickly to replace
those shot or trapped.
Exclusion - Prevent squirrels from climbing isolated trees and power
poles by encircling them with a 2-foot-wide collar of metal 6 feet off the
ground. Attach metal using encircling wires held together with springs to
allow for tree growth. Prevent squirrels from traveling on wires by installing
2-foot sections of lightweight 2 to 3 inch diameter plastic pipe. Slit the
pipe lengthwise, spread it open, and place it over the wire. The pipe will
rotate on the wire and cause traveling squirrels to tumble.
Close openings to attics and other parts of buildings with heavy 1/2-inch
wire mesh, but make sure not to lock squirrels inside. They may cause a
great deal of damage in their efforts to chew out. A squirrel excluder can
be improvised by mounting an 18-inch section of 4-inch plastic pipe over
an opening. The pipe should point down at a 45o angle. A one-way door can
also be used over an opening to let squirrels out and prevent them from
returning.
Wire mesh fences topped with electrified wires may effectively keep out
squirrels out of gardens or small orchards.
Habitat Modification - Trim limbs and trees to 6 to 8 feet away from
buildings to prevent squirrels from jumping onto roofs.
To keep squirrels from bird feeders, consider providing an alternate food
source. Wire or nail an ear of corn to a tree or wooden fence post away
from the bird feeder. In high-value crop situations, it may be necessary
to remove woods or other trees near orchards.
Repellents - Naphthalene (moth balls) may temporarily discourage
squirrels from entering attics and other enclosed spaces. Use of moth
balls in attics of occupied buildings may cause severe distress to people.
Lights or cats in the attic may discourage squirrels.
Ropel or Hinder are taste repellents that can be applied to seeds, bulbs,
and flowers; trees and shrubs; poles and fences; siding and outdoor furniture.
Polybutenes are sticky materials that can be applied to buildings, railings,
downspouts, and other areas to keep squirrels from climbing. To prevent
a mess, apply masking tape on the area beforehand.
Poisons - None are registered.
Trapping - A variety of traps will catch squirrels, including No.
0 or No. 1 leghold traps, box traps, cage traps, rat-sized snap traps and
glue traps. Check with the DNR before trapping.
Wire cage traps and box traps can be used to capture squirrels alive. Tie
trap doors open for 2 to 3 days to get squirrels accustomed to feeding in
the traps. Then set the traps and check them twice daily. Inform your neighbors
of the trap.
Good baits are slices of orange and apple, walnuts or pecans (without the
shell), and peanut butter. Other foods familiar to the squirrel may also
work well, such as corn or sunflower seeds.
Shooting - Where firearms are permitted, shooting is effective. Check
with the DNR for regulations pertaining to the species in your area.
Other Methods - To remove a squirrel from an attic, watch squirrels
to determine where they enter. Then use repellents and lights to drive them
out. After squirrels have left, use appropriate exclusion methods to keep
them out. Baited traps will catch squirrels that are accidentally closed
in. This last step is very important because locked-in squirrels may cause
damage.
Prepared by: Michigan State University Extension, Genesee County.
G-4215 West Pasadena Avenue, Flint, MI 48504. (810) 732-1470.
Michigan State University Extension
programs and materials are open to all without regard to race, color, national
origin, sex, disability, age or religion. Michigan State University, U.S.
Department of Agriculture and counties cooperating. MSU is an affirmative-action
equal opportunity institution.
