The jumping mouse, genus Zapus, is distributed pretty much throughout North America north of Mexico. There are three species, Zapus hudsonius (meadow jumping mouse), Zapus princeps (western jumping mouse) and Zapus trinotatus (Pacific jumping mouse). The meadow jumping mouse is found in eastern US and Canada, extending northerly into Alaska. The western jumping mouse is found in western states and into Canada. The Pacific species inhabits the Pacific coast in California and extends northward along the shoreline and more into the interiors of Oregon, Washington, and British Columbia.*
The jumping mouse is slightly larger than the common house mouse. It has a long tail and hind legs much longer than fore legs. Fur is different shades of brown with white or whitish underparts. The western jumping mouse has bicolored pelage, with pale to grayish brown above, white to yellowish-white below.** It is well adapted to live in a variety of habitats, from grassy fields, vegetation along bodies of water, and in dense vegetation in wooded areas. The jumping mouse moves with a series of zig-zag hops and horizontal leaps. When fighting, the mouse squeaks. It rattles its tail, kicks with hind limbs, pushes with their forelimbs, and rattles its tail. Runways are obvious, cluttered with grass clippings. Jumping mice are mostly nocturnal in activity and are goos swimmers.
One of the remarkable characteristics of the jumping mouse is its ability to hibernate; it is one of the longest mammalian hibernators. From one-half to two-thirds or more of its life is spent in hibernation. Length of hibernation varies generally from September to April. Pre-hibernation deposition of fat depends on abundance of seeds and green vegetation. There is significant weight loss during hibernation and mortality occurs among individuals with insufficient fat deposits, especially among juveniles. If spring soil temperature do not change to above 8.0 to 9.5 degrees C, and if body weight drops below 18 to 19.5 g, animal mortality is high. Arousal from hibernation usually occurs when soil temperatures rise above 9 degree C in the spring.
Hibernation nests vary among species and individuals. Some are often found 0.5 m. or so below ground surface and often constructed of grass.
*Hall, E. R. 1981. Mammals of North America. Vol 2. John Wiley & Sons, New York.
**Hart, E. B., M. C. Belk, E. Jordan and M. W. Gonzalez. 2004. Zapus princeps. Mammalian Species, No. 749.
About Zapus, the Jumping Mouse
The three species of the Zapus jumping mouse (hudsonius, princeps, trinotatus) have much in common. Fossil forms are found in Oklahoma, Kansas, Tennessee and other areas. They normally hibernate from fall to the spring. During hibernation, breathing slows, body weight diminishes, and body temperature and oxygen consumption is lowered. Three to seven young are usually born in June after a gestation period of around 20 days. There may be more than one litter born per season. Zapus are found in a wide variety of habitat along streams and ponds and in forest vegetation. They are omnivorous feeding mainly upon the fruits and seeds of vegetation and insect larvae and fungi. Predators include owls, hawks, bobcats, weasels, skunks, raccoons, and garter snakes. They are hosts to parasites including trematodes, nematodes, bacteria, protozoans, ticks, chigger mites, fleas, botflies, etc. Home ranges are less than one acre.