Microdipodops megacephalus
(Dark Kangaroo Mouse)

Description:
Kangaroo mice seem to fit between pocket mice and kangaroo rats. They are slightly smaller than kangaroo rats, but their hind feet are modified for hopping, kangaroo-like. Their tails are shorter than kangaroo rats but are thicker in the middle, which may provide support while hopping on their hind feet. The Dark kangaroo mouse has blackish to grayish hair above, with the hair being gray or lead-colored at the base. Their total length is about 5 ¾ to 7 inches (148-177 mm) long with the tail being from 2 7/8 to nearly 4 inches long (74-100 mm). The tail is thicker in the middle than at either end.

Range:
Southeastern Oregon, northeastern and central-eastern California, Nevada, and west-central Utah.

Habitat:
Found in loose sands and gravel in shadscale scrub, sagebrush scrub, and alkali sink plant communities. May occur in sand dunes near margins of range.

Diet:
Seeds are primary food source, but will also eat some insects.

Ecology:
They are known to store food in seed caches within their burrow systems which consist of an unbranched burrow from 2 to 4 feet long, often about one foot deep. Like most members of this family they do not appear to utilize free water, but acquire water from metabolic processes. They use bipedal locomotion hopping about on their hind limbs, but also walk on all fours. It is not known for certain that they hibernate, but when inactive, they are underground. Activity has been observed only from March to October. They are nocturnal with peak activity occurring in the first 2 hours after sunset. Moonlight and ambient temperature influence activity Predators include owls, foxes, and badgers. In west-central Nevada, a mean yearly circular home range for males was 6613 m2; for females, 3932 m2. Insufficient fall and winter precipitation may limit growth of animals, which may, in turn, affect reproduction.

Reproduction:
Possibly polyestrus. litter size ranges from 2-7 young (average 3.9). Most young are born in May or June.

Conservation:

Status:	Protected nongame species
Global Rank:	G5
State Rank:	S1

Important State References:
Hafner, J.C. 1985. New kangaroo mice, genus Microdipodops (Rodentia: Heteromyidae), from Idaho and Nevada. Proc. Biol. Soc. Wash. 98:1-9.