What animal can be found in almost every state, and in northern Canada to southern Mexico?

A Deer Mouse

The deer mouse occurs as part of essentially all communities in North America below the treeline (high mountainous areas where trees do not grow). It has the broadest distribution of any species within the genus.   

Photo by David Cappaert, Michigan State University, Bugwood.org


You may not see it in the wild very often. Why? Because it is active at night and a rather small mouse-like rodent.

You may however, see it in a research lab. Deer mice are used because they are easy to care for and keep themselves clean.

This mouse is only three to four inches full grown with a multicolored tail that may be four to five inches long. The colorings, tail length, and markings vary widely with the soft fur color ranging from brown to black. The white underside and feet are consistent. The mouse got the name “deer” because its color pattern was similar to that of a white-tailed deer.


During the day the species spends a lot of time in trees a common nest location. They are excellent climbers and swimmers. They will also build soil burrows, use rock crevices, and a variety of other locations for their nests.

Nests are created using grasses, roots, mosses, wool, thistledown, etc.  They are often communal. Deer mouse litters are kept in separate, away from the communal nest.

These mice often stay in their original home range to reproduce. They are social, and will recognize and interact with mice that have overlapping ranges. Communications are chemical, visual, and vocal (such as shrieks, squeaks, trills, and drumming out a warning.

OCD-like Behavior

Movement is usually on foot walking or running. They will also leap when threatened. Limited movement leads to intrafamilial mating and limited gene flow within a range.

This may contribute to OCD-like behaviors that become evident by two months old. One behavior is creating overly large nests in the lab when not necessary.


This rodent reproduces profusely compared to other species and even to local mammals. Food availability, rather than season, will determined breeding opportunities.

It is not uncommon for female deer mice to have three or more litters per year. Captive deer mice have had as many as 14 litters in one year.

Mice reach adulthood at six weeks.


Deer mice are omnivores and will change their eating habits based on the season. This rodent heavily consumes arthropods such as spiders and caterpillars in the winter with seeds, insects in the spring, seeds, fruits, and leaves in the summer. They will also consume fungi.

Deer mice hoard their food and will store up to one pint of food in ground holes, tree cavities, and nests.


They are prey for almost everything like larger mammals, snakes, domestic pets, and birds. Deer mice are can carry viruses.

Disease Carrier

One particular virus to note is the Hanta. These rodents can carry the airborne hantavirus. Hanta can be passed to humans during clean up operations and through contaminated food.

Minimize the Risk

To minimize these rodents minimize potential nesting locations such as rock piles, firewood, and vegetation (especially vines connecting trees to attics) before cold weather hits. Close up any openings to your home. Get some help eradicating an infection.      

–Oregon Dept. of Fish and Wildlife, Deer Mouse (https://myodfw.com/wildlife-viewing/species/deer-mouse)
–USDA Forest Service, Fire Effects Information System (FEIS) (https://www.fs.fed.us/database/feis/animals/mammal/pema/all.html)
–(Wikipedia, Peromyscus maniculatus (https://en.wikipedia.org/wiki/Peromyscus_maniculatus)
–Orkin, Deer Mice (https://www.orkin.com/rodents/mouse-control/deer-mice)
–Animalia, Deer Mouse (http://animalia.bio/deer-mouse)

Pacific harbor seals

Harbor seals are the most widely distributed pinniped. On the Oregon Coast, you will most likely encounter the Eastern Pacific harbor seal, a subspecies found between Alaska and Baja California, Mexico. These seals have spotted coats in a variety of shades from white or silver-gray to black or dark brown. They favor near-shore coastal waters and use rocks, reefs, beaches, and drifting glacial ice as haul out and pupping sites. Pacific harbor seals spend about half their time on land and half in the water. They can even sleep with their bodies nearly submerged in water, exposing only the tip of their nose to the air – a posture called “bottling.”

Despite being skilled swimmers, harbor seals face a number of threats in the ocean. There is currently no commercial hunting of harbor seals, but some native subsistence hunting of seals still occurs. Because they compete for many of the same species of fish, harbor seals are sometimes killed by commercial fishermen. Seals can also become entangled and drown in fishing nets and gear. In addition, the species is preyed upon by killer whales, sharks and Steller’s sea lions. El Niño events can decrease the animal’s food availability, which includes a variety of fish, shellfish, and crustaceans.  

If you see a small shorebird scurrying over the sand, it is probably a Western Snowy Plover. There are many different types of shorebirds that are easily identified by their small to medium sized bodies, with relatively long legs and thin bills.

Western Snowy Plover
(Photo courtesy of ODFW)

Western Snowy Plovers have sand-colored back feathers and black markings on their faces and sides of their necks.  They are about seven inches long and have a wingspan of about 19 inches. They are found on the Pacific coastal areas, across both North and South America, Eurasia, and Africa.

Oregon Coast breeder

This is the only shorebird that regularly breeds on Oregon’s beaches and resides year-round between Heceta Head, near Florence, Oregon south to Cape Blanco, near Port Orford. The Snowy Plover will frequently raise two broods (or more) each year.

Young birds are very independent and leave the nest within three hours of hatching. They have an acute sense of sight and are intelligent and will forage unassisted by parents. Like their parents they are fully mobile walking, running, wading, and swimming well.

Upon parental signals indicating the approach of people or potential predators, they will flatten themselves on the ground.  


Snowy Plovers will consume many types of small crustaceans, worms, and insects. When they spy a potential morsel, they will pick it up or attempt to startle the creature into moving. Thus, if it moves, they are assured that what they caught is edible.

Human Interaction

Human activities on the beach often disturbs the Western Snowy Plover’s natural habitat and nesting attempts. Activities that frequently disturb the birds include dog walking, kite flying, off-road vehicles, and any nest disturbances.

These disturbances pushed the bird into a Threatened category under the Endangered Species Act several years ago. The bird has gradually been making a comeback, but often faces a number of human challenges.

The Audubon Society developed four recommendations to make beaches safer for birds that, in summary, include:

  • Give nests and nesting birds plenty of space
  • Keep pets on a leash (or use a different beach)
  • Clean up trash or food scraps that might attract predators, and
  • Avoid driving vehicles in nesting areas.

–Oregon Dept. of Fish and Wildlife, Western Snowy Plover (https://myodfw.com/wildlife-viewing/species/western-snowy-plover)
–All About Birds, Snowy Plover (https://www.allaboutbirds.org/guide/Snowy_Plover/)
–Wikipedia, Snowy Plover (https://en.wikipedia.org/wiki/Snowy_plover)
–Audubon Society, Snowy Plover (https://www.audubon.org/field-guide/bird/snowy-plover and