What is the most abundant mammal in North America? I saw that question used in trivia recently. The answer was deer mouse. I am not so sure about that, in part because deer mouse is used to refer to a genus of mice as well one of the species of the genus. Either way, deer mice are certainly one of the contenders.
There are over a dozen species of small mammals that the casual observer may refer to as mice in North Dakota. That would include the house mouse, deer mice, voles, pocket mice, jumping mice, and shrews. The term deer mouse is used to refer to mice in the genus Peromyscus. Most are gray or reddish brown with a white underbelly, white feet, and comparatively large ears. And they are often characterized as having large “bulging” eyes. Robert Seabloom in his Mammals of North Dakota lists two species of Peromyscus in North Dakota.
What is commonly known as a deer mouse (P. maniculatus), a species of the grasslands, is common and abundant throughout the state. They are around 6 inches long, including a tail about 2.5 inches long. Although juveniles may be gray, adults are usually a brown to grayish-brown. Seabloom also notes that they have “distinctly” bicolored tails which helps in identification.
The deer mouse feeds largely on seeds and insects. Home range for these mice is around 2-3 acres. They are prey to several animals including snakes, hawks, owls, and fox. They are also a major carrier of the hantavirus.
The white-footed deer mouse (P. leucopus) is a species of wooded areas, and as such is less common. It is similar in appearance to the deer mouse but is perhaps a bit larger. Seabloom also notes that their “indistinctly bicolored tail” is a key characteristic in identification.
Like the deer mouse, the white-footed deer mouse feeds largely on seeds and insects. Acorns can also be an important food item. Their home range is less than that of a deer mouse, averaging around one acre
If you are interested in more information on the biology, ecology, and identification of these and other North Dakota mammals, I suggest you check out Mammals of North Dakota by UND professor emeritus Robert Seabloom. First published in 2011, it is now in its second edition.
