Members of the squirrel family (Sciuridae)
include tree squirrels, flying squirrels, ground squirrels,
chipmunks, prairie dogs, and woodchucks (marmots).
In San Diego County, ground squirrels
are in the majority. All are primarily vegetarian, eating roots,
stems, bark, shoots, leaves, flowers, fruit, and nuts from
a wide range of plants.
Some include a few insects in their
diets. Most have long, cylindrical bodies with large bushy
tails that provide balance and slender toes with sharp claws
that aid in climbing.
The burrowing species (ground squirrels,
prairie dogs, and woodchucks) have strong front paws and short
tails.
Squirrels are known for their tendency
to hoard seeds and other food either in their nests or in caches
nearby. Squirrels often store more than they need and lose
or forget where it is stored; in doing so, they help scatter
seeds to take root and grow in new locations.
Ground squirrels (Spermophilus ssp.)
are 16 to 19 inches long, including the bushy tail, and weigh
1 to 3 pounds. Their coloration is grayish brown with buff
flecks. They have short ears and legs and strong front claws.
Litters range from two to eight.
Squirrels have powerful, gnawing
teeth for eating tough vegetable matter, and they can close
their mouths while leaving their front teeth exposed for digging.
Their other distinguishing feature
is that their teeth never stop growing. They must continue
gnawing to wear them down so that (1) they can close their
mouths (otherwise they would be unable to take in food and
would eventually starve) and (2) the teeth do not grow into
their skulls, eventually killing them.
The den of the ground squirrel is
an intricate burrow with several entrances.
Primarily herbivores, ground squirrels
eat plant material, including wild fruit plants, seeds, succulents
(such as ice plant), and grasses. They also prey on insects,
the eggs and young of ground-nesting birds, and, occasionally,
small mammals. They eat much food where it is found but also
carry seeds in cheek pouches to build up large stores underground.
Ground squirrels are active during
the day and sleep at night. Southern ground squirrels do not
truly hibernate but remain inactive in their burrows in winter.
Ground squirrels are not as social as prairie dogs but may
group together and live in large colonies where food is abundant.
They live from 5 to 12 years.
Squirrels are often prey for large
carnivores such as coyotes, owls, and bobcats, but their main
enemies are humans and automobiles. Destruction of woodland
habitats for development adversely impacts squirrel populations.
The ground squirrel's chief enemies
include foxes, weasels and hawks. Its primary defense is sighting
an approaching predator at a great distance and escaping to
the protection of its burrow.
Tips
1. Squirrels
rarely do significant damage to plantings, so try to determine
the real culprits. Because squirrels are active during the
day, it is relatively easy to observe whether they are feeding
on your garden or fruit trees. If the damage occurs at night,
squirrels are not at fault.
2. Because
squirrels are such excellent climbers, fencing is not a particularly
effective control. One way to protect trees is to wrap a 2-
foot band of sheet metal around the trunk about 6 feet off
the ground. Trim any branches below 6 feet. Also, make sure
no other trees are close enough to provide jumping access.
Some taste repellents applied to the food source may be effective;
be sure to follow instructions carefully.
3. Squirrels
will readily take up residence in a building if access is available.
It is important to block all holes with wood or wire mesh to
prevent entry. To remove a squirrel from an attic or other
similar space, do the following:
- Block the entry and set a live
trap baited with peanut butter, fruit, or nuts.
- Remove the captured animal in
the trap immediately and release it at a different location
with suitable habitat at least 5 miles away.
- Be careful not to block holes
if young are still inside. Adult squirrels can cause significant
damage gnawing to get back inside to their young. If a hole
is blocked, open it long enough for the adult to rescue the
young; then cover it again.
- Remember that live-trapping is
not a final solution. Be sure to close all possible access
areas to prevent repopulation.
4. Prune
overhanging tree limbs, shrubs, and vines that may provide
access to attics and other areas. Cover telephone and electric
wires near the house with long plastic tubing to discourage
use of the wires for entrance and exit.
5. Squirrels are excitable and can cause
severe damage if trapped inside a home. When badly frightened,
they tend to run recklessly in circles and will knock over anything
in their way. Quickly and quietly open a door or window to the
outside and leave the room. The squirrel wants out as much as you
want it out and will leave as soon as the threat of your presence
is gone.
6. A squirrel may fall in a chimney while
climbing on the roof. Do not remove the squirrel through the fireplace
as it may escape into the room. Secure a heavy rope from the top
of the chimney and drop it down to the fireplace. The rope provides
a perfect escape route during daylight hours. After the squirrel
has exited, remove the rope and properly cap the chimney. If a
squirrel is trapped behind a fireplace screen or doors and is unable
to exit up a rope, carefully set a live trap baited with peanut
butter inside the fireplace.
7. Easily accessible bird feeders provide
a source of food for squirrels. Install only free-standing (not
hanging) bird feeders in sites where squirrels cannot get access;
keep them away from shrubs and overhanging tree limbs. Put the
feeder on a metal pole at least 6 feet high. Attach a metal cone
to the pole to prevent squirrels from climbing up it. Hanging feeders
are not recommended, because squirrels can climb down the hanger
line or shake the line until food falls to the ground.
Do not attempt to handle
squirrels. Any handling of these excitable creatures causes
intense stress. When releasing a live-trapped squirrel, avoid
touching it, and wear gloves and long sleeves to prevent contact
with any squirrel parasite. Place the trap on the ground, open
the door, and allow the squirrel to exit on its own.
Information provided
by WildCare Terwilliger Nature Education & Wildlife Rehab,
San Rafael, CA
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