Squirrels of the Portland-Vancouver Metropolitan Region
In the Portland-Vancouver metro area there are five species of native squirrel: the western gray squirrel, Douglas squirrel, California ground squirrel, Townsend's chipmunk and the northern flying squirrel.
Western gray squirrels were once the most common squirrel species in the Portland area but have now almost completely disappeared due to development and competition from non-native species. Today our two most common urban squirrels, the fox and eastern gray, are non-native, invasive species from the East Coast.
Fox squirrels were brought to Oregon from the eastern United States and have established themselves in urban and suburban habitat through the state. They are the most common tree squirrels found in Portland and have contributed to the decline of native squirrel species.
Fox squirrels are reddish brown in color with large bushy tails and tan undersides. Oregon's fox squirrels are notorious for breeding "out of season," and infant and very young squirrels found later than Oct. 1 and earlier that April 1 are typically members of this species.
Eastern gray squirrels are small gray-and-brown squirrels with a white belly that were introduced to Oregon and Washington from the eastern United States. It is smaller than the native western gray squirrel.
Wildlife Care Center Non-Native Squirrel Policy
The Audubon Society of Portland's Wildlife Care Center does not accept non-native animals for treatment. This includes fox and eastern gray squirrels, both of which are non-native animals introduced to the Pacific Northwest from the eastern United States.
Introduced species compete with and reduce the numbers of native wildlife. Injured and orphaned non-native squirrels left at the Wildlife Care Center will be humanely euthanized.
Situations and Solutions
Squirrels in attics, chimneys, basements and crawlspaces
Squirrels will take advantage of accessible attics, chimneys, basements and crawlspaces both to raise young and escape the winter cold. Many problems can be avoided by sealing up entryways before squirrels take up residence. Half-inch mesh is effective for preventing squirrel entry.
If a squirrel does take up residence in your home, it is important to determine whether she is raising young before attempting removal. Please remember that the squirrel breeding season in Portland can begin as early as February and extend all the way to November. If you determine that the squirrel is raising young, it is best to wait until the young are able to fend for themselves before attempting removal.
Most squirrels are able to survive on their own at 10-12 weeks of age. If you must remove squirrels sooner, use one of the repellant methods listed below that will allow squirrels the opportunity to leave on their own and take their young with them.
There are several methods to remove squirrels from homes. Non-lethal repellants can be bought at local feed, home and garden stores.
Placing a radio set to a talk station in close proximity to the denning area is also an effective method for causing a squirrel to leave. Live traps can be used, but only in cases where the squirrel has been determined not to have young. Trapped squirrels should be released back into the same neighborhood after entry holes into your home have been sealed up.
A one-way door can be made very simply or purchased commercially, and acts as a door that allows the squirrels to exit the attic but not get back in. This lets you make sure all squirrels have left the interior and then permanently block the entrance. One-way doors can be built cheaply with items at your local hardware store.
Fasten a double layer of hardware cloth or wire mesh to the top of the entrance. Allow the cloth to drop shut flush.
No method will ultimately be successful unless you determine how squirrels are accessing your home. Once squirrels have been removed, all access points must be covered with hardware cloth or squirrels will quickly regain entrance.
Squirrels losing their fur
Hair loss in squirrels is generally a sign of mange, a naturally occurring microscopic mite that causes hair loss and scabbed skin. Mange is often a secondary problem that afflicts squirrels that are already debilitated or in poor health.
If you see a squirrel with possible mange, it is best to leave the squirrel alone and allow nature to take its course. Some squirrels will recover on their own while others will eventually succumb.
In order to reduce transmission between squirrels, it is also helpful to remove feeders where squirrels congregate. We recommend feeders be taken down for a period of at least two weeks. Free-roaming squirrels with mange do not pose a risk to either humans or domestic pets.
Squirrels in the bird feeders
Squirrels are incredibly agile and persistent when it comes to raiding bird feeders. Unfortunately, there is no one-size-fits-all method for preventing squirrels at you feeders.
Deliberate feeding of squirrels is not recommended as they can quickly become habituated to human handouts. Wild animals that lose their instinctive fear of humans are more likely to become pests and incur injuries.
The key to discouraging squirrels from your feeder is to be inventive. Find out how the squirrels are accessing your feeders and work from there. There are several commercial products available to try to limit squirrel access, such as specially designed caged bird feeders, weight triggered trap door feeders and baffles to place above or under feeders. Hang feeders away from easy access points such as tree limbs and fence posts.
Relocation of squirrels
The Audubon Society of Portland generally opposes the relocation of wildlife as a solution to human-wildlife conflict situations. In the case of squirrels, relocation is usually only a temporary solution as the relocated animal will quickly be replaced by another of the same species.
Relocation of squirrels has contributed to the proliferation of non-native species into new habitat. It is also important to note that different squirrel species have very different habitat needs. For example, the fox and eastern gray squirrels that do very well in our urban and suburban neighborhoods cannot survive in the dense forest of Forest Park.
Finally, squirrels are territorial. Squirrels relocated into new habitat will inevitably have to fight with squirrels that are already established in that location. It is far better to look for local solutions when conflicts between humans and squirrels arise. More information on relocation of wildlife.
Squirrels as pets
Squirrels do not make good pets. They have expensive and unique medical, care and housing needs that are difficult to accommodate in a captive situation.
They can carry diseases that are transmissible to both humans and pets especially when long-term, close contact occurs.
Finally, squirrels become territorial and aggressive when they reach sexual maturity (six months to one year of age). They can become a danger to their captors and especially to unfamiliar visitors.
These animals are also typically not suitable for release into the wild since they frequently behave aggressively toward humans after release.
Injured squirrels may be brought to the Wildlife Care Center from 9 a.m. until 5 p.m., seven days a week. When capturing and transporting injured squirrels, it is important to remember squirrels can bite, scratch and transmit disease to humans.
Care should be taken to avoid direct contact with the animal. Place the squirrel in a well-ventilated box and provide the animal with water but no food. To reduce stress on the animal, house in warm, quiet location and transport for treatment as soon as possible.
The Wildlife Care center does not provide treatment for non-native squirrel species. Injured and orphaned non-native squirrels brought to the care center will be humanely euthanized.
Squirrels frequently move their young around and sometimes drop them when spooked. Adolescent squirrels are also prone to wandering away from their nests for increasingly long periods as they develop.
Unless the young are clearly injured it is best not to interfere. The mother is usually nearby and will retrieve the young after humans leave the vicinity. While this may seem harsh, it is important to remember that many squirrels thrive in even the most urban of environments.
Baby squirrels have a far greater chance of survival being raised by their mother than they do in captivity. Leave the young out and avoid the immediate area for at least 4-6 hours. If you are concerned about predators, place the animal in an open box suspended from a nearby branch or other high area.
Often the mother will approach and leave several times before retrieving the young. This is her way of testing to make sure the coast is clear. If you observe the mother in the area, your job is complete.
If the youngster has not been retrieved after 4-6 uninterrupted hours, it can be brought to the Wildlife Care Center for treatment. The care center does not raise non-native squirrels. Non-native squirrels will be provided with humane euthanasia.
Squirrels from Washington
We are not allowed to accept any mammals from outside the state of Oregon. Any Washington mammals should be referred to Washington Department of Fish and Wildlife.