Family: Heteromyidae, Pocket Mice and Kangaroo Rats view all from this family
Description The largest kangaroo rat. Dusky above; white below. Dusky-tipped tail; dark brown stripe above and below; white side stripes. Hindfoot has 5 toes. L 12 1/4-13 3/4” (311-348 mm); T 6 1/4-7 3/4” (157-198 mm); HF 1 3/4-2 1/8” (45-55 mm); E 5/8-3/4” (15-19 mm); Wt 4 5/8-6 3/8 oz (131-180 g).
Endangered Status The Giant Kangaroo Rat is on the U.S. Endangered Species List. It is classified as endangered in California. This species saw a rapid decline in the 1970s after the state of California completed several major water diversion and irrigation projects that resulted in a large swath of its habitat being converted to croplands. Urbanization and the use of insecticides have also contributed to this rodent's demise. It is not alone: 99 percent of California's grasslands have been modified by agricultural, industrial, and residential development over the last few centuries, and many grassland species have become endangered as a result. The Giant Kangaroo Rat was listed as endangered by the state of California in 1980 and by the federal government in 1987.
Similar Species Other large kangaroo rats (Desert, Banner-tailed) have 4 toes on hindfoot. Heermann’s and San Joaquin kangaroo rats have shorter hindfeet.
Breeding Reproductive season January-May; 3-6 young per litter.
Habitat Open desert grasslands in valleys. This is often a dominant species in areas lacking brush.
Range Southern California, in w San Joaquin Valley.
Discussion The burrow system of the Giant Kangaroo Rat has one to four entrances, a nest chamber, and special chambers in which large quantities of food are stored. This species does not store seeds in small pits in the walls of the tunnels, as most other kangaroo rates do. Near the entrances it makes tiny holes, which it fills with partially ripened seeds; when these are dry, the animal covers them with loose soil. At one site, 875 holes were dug by one individual. Some populations of this species make large stacks of seeds aboveground; there they are dried and later stored underground in large caches. A total of 24 caches was found in one burrow system, 12 old and 12 new. The new caches consisted mainly of storksbill (Erodium) and peppergrass (Lepidium) seeds. A typical burrow has two slanting shafts and one vertical shaft. Slanting shafts are about 3 1/8 inches (78-81 mm) high and 3 1/2 inches (88-89 mm) wide. Vertical shafts have openings about 2 1/4 inches (57-58 mm) in diameter. The total length of three systems ranged from 24 to 30 feet (7.3-9.1 m).
This species is primarily a granivore, but feeds on green plant parts as well. It practices scent-marking and sand-bathing, which includes side and belly rubs. Both bipedal and quadrupedal locomotion are commonly used. This species has been heard drumming from within its burrow, and has been induced to drum by a person drumming on top of the burrow. The Giant Kangaroo Rat appears to exclude other species of kangaroo rats, and is often the only mammal in its habitat. Areas in which this species lives generally receive less than 15 inches (380 mm) of rain per year, mostly between April and November, and daytime temperatures exceed 100 degrees F (37 degrees C). Perennial grasses were probably the dominant plants in the original range of this species. The Giant Kangaroo Rat is now often found in areas heavily grazed by sheep and cattle. Predators include Barn Owls, Great-horned Owls, Kit Foxes, Coyotes, and American Badgers.
