Dark kangaroo mice inhabit dry desert areas where there is an abundance of loose sand and gravel. Because they inhabit the Great Basin, sand dunes and other ridges provide adequate shelter and temperature for dark kangaroo mice. They create an underground system throughout sand dunes that provide protection from predators and extreme temperatures. Typical elevation ranges from 1200 to 2050 m. (Hafner and Upham, 2011; Jenkins and Breck, 1998; Light, et al., 2013; O'Farrell and Blaustein, 1974; O'Farrell, 1974; Pierce, et al., 1992)
Dark kangaroo mice are named for their dark brown and black fur color and elongated hind legs. Their average adult weight is 13.5g (range 10 to 17g), and average total length is 158.5 mm (range 140 to 177 mm). Their average tail length is 84 mm (range 68 to 103) and average hind foot length is 25 mm. Sexes are alike in relative size and weight. Because the ears and head are large, similar in profile to the body is similar, their appearance is like one round shape.
The dark brown and black fur color distinguishes dark kangaroo mice from the closely-related species, Microdipodops pallidus (pale kangaroo mouse), which has a lighter, pale brown fur color. Because dark kangaroo mice hibernate in the harsh winter, no geographic or seasonal variation in pelage or mass has been reported. (Djawdan and Garland, 1988; Hafner, et al., 1979; O'Farrell and Blaustein, 1974; Schitoskey, 1968)
There is little information known about the specifics of the dark kangaroo mice mating systems. After the winter hibernation months, dark kangaroo mice begin the breeding season. This species is promiscuous, with multiple males mating with multiple females. (Andersen, et al., 2013; O'Farrell and Blaustein, 1974)
Pregnant female dark kangaroo mice have been observed throughout the month of March extending through the month of October. For this reason, these mice are thought to have multiple litters per season. Gestation periods have been measured at 24.5 days (range 22 to 27). Most juvenile captures have been in May and June, but presumably they could be found later into the summer and fall months. Litter sizes are known to average 3.9 (range 2 to 7). Additional information about the general behavior of reproduction is unknown. (Andersen, et al., 2013; O'Farrell and Blaustein, 1974)
The parental investment of the dark kangaroo mouse remains unknown other than the mother nurses and protects the young until they can survive on their own. (O'Farrell and Blaustein, 1974)
The only information known about the lifespan of dark kangaroo mice is the average years the species survives in the wild and in captivity. On average, the lifespan in both captivity and the wild is 5.4 years. (Harris, 1984; Harris, 1986; O'Farrell and Blaustein, 1974; O'Farrell, 1974)
Dark kangaroo mice are solitary, living mainly independently from others of their species. They live in underground burrows due to the species' sensitivity to sunlight as well as moonlight. They emerge from these burrows during two hours following the sunset. The main form of movement is bipedally - hopping with their large hind legs.
Foraging behavior of dark kangaroo mice consists of scratch-digging. Scratch-digging is used when there are seeds mixed into the soil that the mice need for food. The seeds from the soil are collected and stuffed into the external cheek pouches of the dark kangaroo mice to be used as a food source during the winter. Dark kangaroo mice exhibit a food-hoarding behavior, only sharing food with dependent young. They are nocturnal, with activity affected by rain, moonlight, and relative humidity.
These mice are through to hibernate but no concrete evidence has been presented. (Andersen, et al., 2013; Djawdan and Garland, 1988; Hafner, et al., 2006; Harris, 1986; Jenkins and Breck, 1998; Lance, et al., 2010; Morgan and Price, 1992; O'Farrell and Blaustein, 1974; Pierce, et al., 1992; Roach, 2016)
Individual home ranges of dark kangaroo mice may overlap, and individuals will actively defend their burrow. Although their home ranges can change seasonally, the annual average home range was 6613 square meters for males and 3932 square meters for females. (O'Farrell and Blaustein, 1974; O'Farrell, 1974; Roach, 2016)
Dark kangaroo mice communicate strictly using tactile and chemical means. They perceive the environment using the same means of touch and smell. No record has been made of information concerning the communication between potential mates nor on any notable form of specific communication within the species. (Hafner and Upham, 2011; Morgan and Price, 1992; O'Farrell, 1974; Schitoskey, 1968)
Dark kangaroo mice use external cheek pouches to carry food. Because they are granivores, the main food source are small seeds from the shrubs and vegetation in the Sagebrush Scrub zone of the Great Basin. In summer months, these mice are thought to consume insects, as well. They don’t drink water, but instead meet all of their water needs through metabolic breakdown of the seeds they consume. (Harris, 1986; Jenkins and Breck, 1998; Morgan and Price, 1992; Pierce, et al., 1992; Roach, 2016; Schitoskey, 1968)
Anti-predator adaptations found in dark kangaroo mice include the complex burrow underground as well as a high-pitched squeal they emit when threatened. They are also cryptically colored to minimize detection by predators. Known predators of this species include foxes (Vulpes species in this range), rattlesnakes in the genus Crotalus, owls, and badgers (Taxidea taxus) native to the Great Basin Desert. (O'Farrell and Blaustein, 1974; O'Farrell, 1974; Pierce, et al., 1992; Roach, 2016)
Dark kangaroo mice are prey to mammalian and avian predators foxes and owls This species does not act as predators in their ecosystem. Their burrows serve to function in soil aeration.
Dark kangaroo mice provide detailed information about water conservation when studied in laboratories. The information gathered from these studies can be used to benefit human water conservation tactics. (Harris, 1984; Harris, 1986; O'Farrell and Blaustein, 1974; O'Farrell, 1974)
Dark kangaroo mice are a species of "Least Concern" on the IUCN Red List, although their population is believed to be declining. They have no special status on US Federal List, State of Michigan list, or CITES. The introduction of non-native grasses has apparently negatively affected some populations. Habitat alterations, including the alteration of natural lands to agricultural fields, combined with habitat fragmentation may also be having a marked impact on these mice. There are no known conservation efforts in place for this species. (Andersen, et al., 2013; O'Farrell and Blaustein, 1974; O'Farrell, 1974; Roach, 2016)
Emily Amos (author), Radford University, Alex Atwood (editor), Radford University, Karen Powers (editor), Radford University, Joshua Turner (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
an animal that mainly eats seeds
An animal that eats mainly plants or parts of plants.
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
specialized for leaping or bounding locomotion; jumps or hops.
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
digs and breaks up soil so air and water can get in
places a food item in a special place to be eaten later. Also called "hoarding"
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
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