Animal Tracks - Deer Mouse (Peromyscus maniculatus)


Natural History of Deer Mice
Deer mice are common nocturnal mammals. Adults are brownish gray. Juveniles are gray. Both have dark eyes and white feet and undersides. They have four toes on the forefeet and five toes on the hind feet. Their tracks are commonly found on the fine beach sand of river bars and in soft mud. Tracks are usually in groups of four with a trail width less than two inches. In firm sand, sometimes a whole print will show up clearly. Mice make nests lined with the softest materials they can find. Nests are located beneath rocks and logs, in burrows, or in trees. Three or four litters of four babies each may be born per year.

Mice will also gnaw on old bones and antlers to get the calcium. When you find a bone, look very closely at it and you may see tiny paired tooth marks where mice have scraped it. Mice eat seeds, mushrooms, fungi, berries, herbs, insects, larvae, and carrion. They are good climbers and will climb to escape danger. They are active year-round. Since mice are prey for so many animals, they are somewhat nervous in their actions. They are often seen running or moving very fast. In order to survive, they have to be able to outrun or escape predators. The two close-up photos above show the five toes of the hind foot. Front feet have four. Sometimes an imprint of the entire toe is visible, as in the photo on the left above. The photo at the top of the page shows five toes with just the toe pads leaving imprints. Track photo on right courtesy of Mark Seaver. Thanks Mark!



Personal Notes on Deer Mice
Deer mice are very common. I’ve found their tracks in fine mud and in dry river silt. Out on the river bar, they seem to stick to the same routes. There will be little trails between areas of cover with hundreds of little mouse prints on them. Sometimes, there will be a line of mouse tracks going off to a feeding place alone. The tail sometimes drags in the trail, leaving a mark like the one in the photo above. Mice seem to nest any dry place that is sheltered from predators. I’ve found nests in abandoned sheds, in food lockers in campgrounds, even inside old walls. Although mice are certainly cute and fuzzy creatures, they can bite! The photo here shows a sunflower seed for scale alongside the hind print of a mouse. The two lines running diagonally from left to right are the trail of an insect. These tracks were found in find river silt in Humboldt Redwoods State Park, California.

Mouse and Track Photo Gallery
	A mouse that I found nesting in the back of my truck. After posing for these photos, he was released into the tall grass to find himself a home in his natural environment.
After painting a shelf in the garage, I found these tracks of a tiny night-time visitor on the cement near the shelf.
	The suspected culprit in the case of the painted tracks looks like this... four toes on the front foot and five toes on the hind foot.
An entire set of all four tracks. The letters indicate front (F) and hind (H) tracks. This pattern, with the hind feet ahead of the front feet, is typical for rodents.

The left front track. The vestigial toe pad is visible in this photo if you look closely.		The right front foot with the vestigial toe pad indicated by arrow. If you look closely, you can find this on mouse tracks in very fine soil.
		Although this print looks a little larger than the other mouse tracks, it isn't. The paint spread out, making the track look bigger. The same happens in mud.
Just how big are mouse tracks? Well, that quarter is almost 1 inch wide. It's actually 15/16", but who's counting?		Quiz time: Which track is this? Hint: look for the location of that vestigial toe imprint.

Predator and prey: mouse track in the upper right next to a gray fox track.	Mouse track in upper left with a killdeer tack. A killdeer is a shorebird similar to a plover.
	Due to their tiny size, mice are prey for just about all predators out there. Consequently, they can have several litters a year to keep up their populations.
A curious nose and whiskers. Mice eat many things, as I found out when this one got into my truck and started nesting in various materials. First place it built a nest was in the ventilation system, chewing the foam to shreds.
	Look closely at the feet in the photo above. Can you see evidence of the vestigial toe? While not visible in the photo, it can easily be seen in the photo to the right. This toe is simiar to the dewclaw that dogs and cats have higher up on the wrist.
The hind track in paint. Note the tiny claw marks. On the toe in the upper left corner, you can see some of the ridges that are on the bottom of the foot.		The hind foot in mud. The heel pads are visible here. This grouping of the five toes (1-3-1) is typical.
	A group of all four tracks with quarter for scale. This is one complete set. Front tracks are in the lower part of the photo. The direction of travel is from bottom to top of photo.
Two complete sets of mouse tracks in a trail. The mouse was moving from right to left in this photo.
	More tracks found in the paint.
An older front track found along the Eel River in Humboldt County, California.

	These mouse tracks were found in fine river silt along the Eel River in northern California. The footprints of several mice crisscross each other here. These were near a clump of brush, which provided cover for the mice. It's a great habitat and plenty of food can be found here. You can also find the tracks of the predators that prey on mice in these areas.

This photo shows a lot of mouse activity. These numerous tracks were found near the entrance to a culvert. There was a lot of mouse activity going on within 20 feet of this location as well. I had my cat along on this walk and he jumped down into the culvert opening and left the two cat tracks seen above. Predator and prey in one photo. The cat tracks can be difficult to see at first, but look closely. Look for compressed areas where there is a lack of mouse sign.


Mouse of unknown species caught in the cracked corn! It was released unharmed outdoors.