Wildlife Identification & Info


Identification & Information

A coyote slinks through a forest at twilight.

Many kinds of wild animals are found in San Mateo County, and most will occasionally enter urban and suburban neighborhoods in search of food, water, or shelter. These are a few of the species that may cause problems for residents of San Mateo County.

Vector ecologist Warren Macdonald poses beside a 4 ft tall woodrat nest made of sticks

​Dusky-Footed Woodrat
Neotoma fuscipes

Wood rats (Neotoma fuscipes, sometimes called pack rats or trade rats) are native to San Mateo County and frequently live in wooded areas near creeks and streams, where they make large, elaborate nests of twigs and leaves. These nests often provide shelter for other species, including deer mice.

Woodrats are similar in appearance to roof rats and Norway rats, but with larger ears and furred tail (though not fluffy, like the tails of squirrels).

One raccoon pounces on another.

Northern Raccoon
Procyon lotor

Raccoons are nocturnal animals with brown fur, distinctive black mask-like markings on their faces, and ringed tails. They are usually about the size of a cat, but may be larger when well-fed on garbage.

Raccoons will eat almost anything, but urban and suburban raccoons often feed on garbage and pet food. You can help discourage them from visiting  your property by harvesting all fruits and vegetables promptly, keeping garbage and compost in closed containers, and bringing pet food in at night.

A squirrel scampers down a tree trunk.

Tree Squirrels

Squirrels are common throughout San Mateo County, including urban and suburban areas. In the wild they nest in trees and feed on nuts, fruits, and buds. However, they may sometimes damage property by nesting in attics.

Squirrels will not usually create their own opening to a structure, but may enlarge an existing opening by gnawing. You can prevent this by ensuring that there are no gaps or holes that will allow a squirrel to enter your attic. You should also use a chimney cap to keep squirrels and other animals out of your chimney.


Virginia Opossum
Didelphis virginiana

A person holds an opossum.

The opossum is about the size of a house cat, with gray fur and a bare, pink tail. Although some people think opossums look like large rats, they are actually marsupials – like kangaroos. A mother opossums carries her babies in a pouch on her belly when they’re small, and when they get too big to fit in her pouch she allows them to ride on her back.

A striped skunk takes a defensive posture with its fluffy tail raised.

Striped Skunk
Mephitis mephitis

Skunks are small black and white animals. They are not usually aggressive, but when threatened may spray a very unpleasant-smelling substance. Skunks often do a ‘hand stand’ on their front paws with their tail and body in the air before spraying. If you see a skunk in this position, you should retreat quietly and slowly to avoid being sprayed.


Crows and Ravens

Several members of the corvid family are common throughout San Mateo County, these include the American crow (Corvus Brachyrhynchos) and the common raven (Corvus corax). Crows and ravens are both large birds with shiny black feathers. However, with close observation they can be easily distinguished.

Ravens are larger and have a heavier beak, and their feathers look shaggy, especially around their throats. Ravens usually live alone or in pairs, and make a variety of croaking calls.



Deer are welcome visitors for many property owners, but may sometimes cause damage to gardens and other landscaping.

Feeding deer is illegal in California. It is unsafe and unhealthy for both people and deer!

Most deer will be discouraged by a 6′ fence, but if they are particularly determined you may need a taller fence to keep them out. Fences built on slopes may need to be taller to keep deer from jumping over them in a downhill direction and becoming trapped.



Coyotes are an increasingly common sight in suburban San Mateo County, especially in neighborhoods that border our may parks and open spaces.

A coyote looks similar to a small German shepherd dog or a large fox. The stand around 18″ tall at the shoulder and have fluffy or bushy gray to brown fur. More information on distinguishing coyotes from dogs is available on the CA Department of Fish and Wildlife website. No wolf species are found in San Mateo County.


Mountain Lions

Mountain lions are sometimes seen in rural and suburban areas of San Mateo County. More information on preventing problems with mountain lions is available from the California Department of Fish and Wildlife.