Peromyscus maniculatus

Deer Mouse


The Peromyscus Maniculatus (also known as the deer mouse) is a small, white-footed mouse with a sharp bicolour tail (white beneath, dark above). It's ears are shorter than the hind foot and looks prominent and leaf like. The upper parts of the mouse is bright fulvous or brownish, intermixed with dusky, and the underneath parts are white like the feet. They usually measure at an average total length of 170mm, the tail being 81mm, hind foot 20mm, ears 12-20mm and the weight is around 15-32g.

How its natural selection has helped them evolve over the years

The Deer Mouse is commonly found in Nebraska in the sandy soils, the pale coat which has evolved over thousands of years has helped the mouse to hide and evade from predators. The Deer Mouse found in North America, has darker coats to blend into their dark soils and be hidden from owls. A gene called Agouti was discovered in the mice and shows higher amounts in light coloured mice, lasting longer than the gene for the darker mice. The gene had emerged a few years after the mice had colonised to the sandy homes, spreading in a rapid pace. The Deer Mouse is unique as its new traits had evolved from new genes where as mostly all other animals evolve from an existing gene. The Agouti gene had formed after the colonisation of the light sandy environment, selection had acted on it, creating an advantage and making the mouses population spread widely.

Fact- Deer Mice have 4-6 offsping year round

Fact- Deer Mice are Omnivores that store or cache their food

Economic Importance

The Deer mouse is quite important to the human race in both positive and negative ways. A positive impact they have for humans is how they provide food for carnivores, which are valuable to the fur-bearing mammals and they eat insects that are considered to be pests, controlling the pest population.

However the negative impacts they have to humans is by eating seeds that prevents the regrowth of the ecosystem, destructive to food supplies and is known to be a host for hantavirus called Sin Nombre virus. it can be contracted by humans from deer mice, and causes fatal diseases and pulmonary syndrome.


Peromyscus Maniculatus are commonly eaten by snakes, owls, weasels, foxes, coyotes and bobcats during the species night-hunt. These predators are the deer mouses biggest threat and help the food chain remain consistent and level to the environment and other predation needs.

By Emily Walda

Yr 12 Biology

Mr Stephens