Ord's kangaroo rat

The currently accepted scientific name for Ord's kangaroo rat is Dipodomys ordii Woodhouse. It belongs to the family Heteromyidae, kangaroo rats and mice. Hall listed 35 subspecies, but Kennedy and Schnell reported many of these subspecies are probably not legitimate since they were based on the assumption of little sexual dimorphism in the species. It has now been established that sexual dimorphism within the taxon is considerable. ==Distribution==

Ord's kangaroo rat ranges from southern Alberta and southern Saskatchewan to southern Hidalgo, Mexico, and from central Oregon and eastern California east to central Kansas and Oklahoma. In Utah, Ord's kangaroo rats have an affinity for open shrublands and grasslands on sandy soils. In intermountain salt-desert shrublands, the population density averaged 28 individuals per 10 ha in shadscale communities and 135 individuals per 10 ha in black greasewood (Sarcobatus vermiculatus) communities. ==Plant communities==

Ord's kangaroo rats occur in communities on sandy soils, including semiarid grasslands, mixed-grass prairie, shrub- and scrublands, and pinyon (Pinus spp.)-juniper (Juniperus spp.) woodlands. In Oregon, Ord's kangaroo rats occur in big sagebrush (A. tridentata), western juniper (J. occidentalis), and greasewood (Sarcobatus spp.) communities. In Idaho, they are most abundant in juniper woodlands with rabbitbrush (Chrysothamnus spp.) and winterfat (Krascheninnikovia lanata) in the understory, In Colorado, Ord's kangaroo rats comprised 19% of small mammal captures in pinyon-juniper forest, scattered pinyon-juniper, and pinyon-juniper in canyon habitats. They are particularly abundant in mesquite sand dunes. ==Cover requirements==

Even in shrub-dominated communities, heteromyids including Ord's kangaroo rat tend to concentrate their activity in open areas between shrubs. They scoop out small, shallow depressions to be used as dusting spots. ==Lifecycle==

Ord's kangaroo rats are nocturnal, and spend their days in deep burrows. Ord's kangaroo rat breeding season varies with subspecies and area. Usually, one or two peak breeding seasons occur per year, and in many areas, some breeding activity occurs year-round. The size of ovaries is significantly positively correlated with temperature. The average length of the breeding period is 6.8 months. In Texas, males are fertile all year, with peak reproductive activity occurring between August and March. Higher reproductive rates are associated with increased precipitation and food supply and decreased population density. In a favorable growing season, most females breed at least twice a year, but when population density increased, females did not breed until November though growing conditions and food supplies were favorable. In Arizona, the lowest proportion of males in breeding condition (about 60% of the male population) occurred in January and September–October. The lowest number of females in breeding condition occurred in November, but at least a few females were breeding at that time. In Oklahoma, the two peaks in breeding activity are August–September and December through March. In many areas, the onset of breeding activity follows a period of rainfall the previous month. Gestation lasts 28 to 32 days; one to six embryos are usually found. In captivity, the maximum litter size was six young. The maximum number of litters produced per year by a captive female was five, the maximum number of litters per lifetime was 9, and the maximum number of young per female's lifetime was 38. The longest-lived Ord's kangaroo rat in captivity is a wild caught female who lived until 9 yr 1 months. Brown and Zeng calculated an annual death rate of 0.35 for all age classes. ==Food habits==

Ord's kangaroo rats are primarily granivorous and herbivorous. They consume a variety of foods, but most commonly eat the seeds of grasses and forbs, green vegetation, and dry vegetation. They occasionally consume animal material, mostly arthropods. In Colorado, seeds comprised 74% of their diets, forbs 13%, grasses and sedges 5%, arthropods 4%, and fungi and mosses 2%. Seeds of mesquite, Russian-thistle, sunflowers (Helianthus spp.), and sandbur (Cenchrus spp.) are also major dietary items. Kangaroo rats are physiologically adapted to arid environments. Most water is obtained from seeds and succulent plants. They drink water when it is available, but apparently do not require free water. ==Predators==

In the Great Basin sagebrush, intermountain sagebrush steppe, and intermountain salt desert shrublands, potential predators of Ord's kangaroo rats include coyotes (Canis latrans), kit fox (Vulpes velox), bobcats (Lynx rufus), badgers (Taxidea taxus), long-eared owls (Asio otus), short-eared owls (Asio flammeus), great horned owls (Bubo virginianus), burrowing owls (Athene cunicularia), hawks (Buteonidae and Falconidae), rattlesnakes (Crotalus spp.), and gopher snakes (Pituophis melanoleucus). In Idaho, the remains of Ord's kangaroo rats were found in up to 25% of prairie falcon (Falco mexicanus) nests. The three-year average frequency of Ord's kangaroo rat remains in prairie falcon nests was 4%. ==References==