NatureMapping Animal Facts

Western Harvest Mouse

Western Harvest Mouse (Reithrodontomys megalotis)
Species Code: REME

distribution map

Description: The Western Harvest Mouse is a slim, long-tailed mouse that has prominent, naked ears, a slender sparsely haired tail, grey above and whitish below. The coat is a reddish yellow color with some white on the underside of its belly.

They can actually come in a range of colors and depending on the weather and season their coloring will alter. Their eyes are of an average size for a mouse and their ears are typical in their perked up roundness. Their hind feet have 5 toes, while their front feet only have 4.

 photo by US Forest Service

It is often confused with the Deer Mouse and House Mouse, two species that coexist with the harvest mouse. It can be distinguished from these two species by: more buffy dorsal color and a smaller size.

Size: The Western Harvest Mouse is around 2-3 inches long' its tail is around 2-3 inches long. If we do the math, the Harvest Mouse can be as large as 6 inches long and as small as four inches long from head to tail. It weighs between 8 and 17 grams.

Range / Habitat: The Western Harvest Mouse lives in all European countries except for Ireland, Spain and Scandinavia. It also lives in Siberia, China, and Taiwan. They can live in fields of grain for a short while but have to live in a place with tall grass to be comfortable. They build round nests for their homes that look like small bird's nests. They use leaves and stalks that they tear off with their sharp teeth to build their nests. During the winter they have two choices, to either build a larger nest high in the grass or build one underground.

Diet: The Western Harvest Mouse eats seeds, grain, and sometimes insects.

Habits: The Western Harvest Mouse is active by day and night. It has so much energy that it climbs quickly and easily up and down the tall grasses where it lives. Its tail helps it climb down the tall grasses and lets it swing from the grass like a monkey in a tree. The Western Harvest Mouse does not hibernate through the winter, but stores the food it collects through the rest of the year to survive at that time. Its cry is sharp and piercing and sounding like a small scream.

Lifespan/Longevity: The Western Harvest Mouse has a very short lifespan - less than one year. The longest reported lifespan for this species is 18 months

Predation: There are many predators of the Western Harvest Mouse, including snakes, owls, squirrels, skunks, hawks, weasels, coyotes, cats and scorpions.

Did you know?:

  • The Western Harvest Mouse is a nocturnal species (active at night).
  • They use the ground runways of other rodents and stores food in underground vaults. 
  • This mouse dines primarily on seeds.

Western Harvest Mouse Silhouette

Animal silhouettes available to purchase »

More Information:

Western Harvest Mouse - Royal BC Museum

Photo: US Forest Service

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