Friday, April 12, 2024

Deer mouse: An all-American mouse

by Christian Ryan
| May 5, 2020 1:00 AM

There are hundreds of species of mice and mice-like rodents throughout the world. But to most of us, a mouse is a mouse is a mouse. After all, who cares about identifying what mouse species you are looking at when all you want to do is trap, poison, or sic the cat on them in your home? But the danger in overgeneralizing is that we miss out on learning what makes each species unique in its own right.

Take the humble deer mouse (Peromyscus maniculatus) for example. At first glance, it looks an awful lot like a regular house mouse. But despite their similar appearance and size, house mice and deer mice are not even the same family! The house mouse (Mus musculus) belongs to the muridae family and is more closely related to brown rats than deer mice. Their fur is all light brown or gray. Most importantly, their furry coats are the same color all over their bodies except for their hands, feet and tails (though exceptions exist, so this should be considered a rule of thumb). Deer mice, otherwise known as field mice, belong to the family cricetidae and are more closely related to packrats and lemmings. They get their name from brown or tan coloration on the top half of their coats, a white underbelly, and white legs and tail, reminiscent of white-tailed deer.

Deer mice are similar in size and overall body shape to house mice. They (barely) tip the scale from 15 to 110 grams and measure 3.1 to 6.7 inches from twitchy nose to scrawny tail. Their bulging eyes and large ears give them great night vision and sensitive hearing, which is crucial for their nocturnal lifestyle. This means they typically sleep during the day and come out to forage for berries and other fruit, seeds, nuts, and insects under the cover of darkness. Being active at night helps them to remain out of sight from would-be attackers, such as cats, owls and other birds of prey, snakes, coyotes, weasels, skunks and musophobic humans with brooms. By the way, you just learned a new word: musophobia is the fear of mice and rats.

Another difference between deer mice and house mice is where they prefer to live. House mice, as you may have guessed, like to live within close proximity to people. Deer mice tend to construct their nests in outdoor rural areas, places like hollow logs, debris piles, old fence posts. However, deer mice will occasionally invade our homes, and house mice often live outdoors as well, so living conditions in and of themselves cannot be used to differentiate the two.

Perhaps the biggest thing that separates deer mice from house mice is where they came from. House mice are Old World rodents. They are believed to have originated in India, but their ability to coexist alongside humans encouraged them to spread throughout both Asia and Europe. When humans set sail for continents abroad, the mice hitched a ride on our ships and planes. They now live on every continent except Antarctica. Deer mice, on the other hand, originated right here. It truly is one of our all-American mice!


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