Microdipodops megacephalus

Dark Kangaroo Mouse

Family: Heteromyidae · Class: Mammalia · Order: Rodentia

The dark kangaroo mouse is a small, specialized rodent endemic to the Great Basin region of the western United States, with limited distribution extending into extreme eastern California. Adults measure 60 to 70 mm (2.4 to 2.8 inches) in body length, with a distinctly long, tufted tail measuring 85 to 105 mm (3.3 to 4.1 inches) that exceeds body length. The species weighs between 10 to 17 grams (0.35 to 0.6 ounces). The dorsal pelage is dark grayish-brown to blackish, contrasting with white or pale gray ventral fur. The tail exhibits a distinctive bicolored pattern with dark upper surfaces and white undersides, terminating in a prominent dark tuft. Large hind feet, measuring 23 to 26 mm, are adapted for saltatorial locomotion, while the relatively large head houses prominent dark eyes suited for nocturnal activity. The dark kangaroo mouse occurs primarily in Nevada, with the California portion of its range restricted to a narrow strip along the Nevada border in Mono and Inyo counties. The species inhabits scattered locations in the Owens Valley and areas near the Nevada state line. Historical records indicate the species may have occurred more broadly in suitable habitat, but current distribution appears fragmented across its range. This species occupies arid shrubland habitats characterized by sandy or gravelly soils at elevations ranging from 1,200 to 2,100 meters (3,900 to 6,900 feet). Preferred vegetation consists of Great Basin shrub communities dominated by sagebrush, shadscale, and four o'clock shrubs. The sandy substrate is critical for the species' burrowing behavior and provides the fine-grained material necessary for dust bathing, which maintains fur condition in the arid environment. Dark kangaroo mice are strictly nocturnal and solitary, emerging from burrows after sunset to forage. The species exhibits highly specialized feeding behavior, consuming primarily small seeds from shrubs and forbs, with a particular preference for seeds of four o'clock plants and other desert shrubs. Individuals do not drink free water, obtaining all moisture requirements from metabolic processes and seed consumption. Reproduction occurs from April through August, with females producing one to two litters annually. Litter size ranges from two to five young, with an average of three offspring per litter. The species constructs elaborate burrow systems with multiple entrances and chambers for nesting, food storage, and protection from predators and temperature extremes. The dark kangaroo mouse is not federally listed but faces conservation challenges due to habitat fragmentation and loss. Primary threats include urban development, agricultural conversion, off-road vehicle use, and invasive plant species that alter native shrubland communities. Climate change poses additional risks through altered precipitation patterns and increased temperatures that may affect seed production and habitat quality. The species' limited California distribution and specialized habitat requirements make local populations particularly vulnerable to environmental changes and human disturbance.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.