Zion National Park Wildlife: The Deer Mouse

​    The Deer Mouse lives all over North America, and is plentiful in both Zion as well as Bryce Canyon National Parks. Some have said that it would require quite a lively imagination to see much similarity between a deer mouse and an actual deer; with the only blatantly obvious similarity being the pattern of the fur which is dark brown above and light below (though they can be quite diverse in their coloring.) I do believe, however, that it may also be called the “Deer Mouse” because of its general thriving all across the continent, even as deer thrive. The Deer Mouse is about 3-4 inches long in the body with a 2-5 inch tail. 

   Rather than seasonal changes, the Deer Mouse’s breeding season is more directly determined by the availability of food (though this, of course, is very often affected by the changes of seasons.) They use many kinds of plants and grasses to build nests and often use the nest, not only to raise their young, but also to huddle together with other adult mice for warmth. The typical female Deer Mouse will bear 3-4 litters per year, with each litter having as many as 9 young (though usually 3-5 young.) This makes the Deer Mouse one of the most rapidly breeding mammals in North America.

   In the winter, the Deer Mouse, which is quite social and does not hibernate, huddles together to keep warm in bundles of over a dozen mice together. Since they do not hibernate, they survive on seeds which they have stored. Like many mice, the Deer Mouse is nocturnal and usually finds a place to rest during the day such as a building, log, burrow, or even a bird’s nest. Because of the great diversity of their climate, and the fact that there are over 50 subspecies, it is rather difficult to determine their life-span. However, it does seem that the usual life span for a Deer Mouse in the wild is less than one year (though they have lived up to 8 years in a lab.)