Family: Heteromyidae, Pocket Mice and Kangaroo Rats view all from this family
Description A medium-size kangaroo rat. Brownish above; white below. Fur long and silky. Tail uniformly dusky above and below, with typical white side stripes; crest varies from slight and dusky to black with well-developed white tip. Hindfoot has 5 toes. Ears dusky or nearly black. Juvenile gray. L 9 7/8–13 3/8" (250–340 mm); T 6 3/8"–8 1/2" (160–217 mm); HF 1 1/2–1 3/4" (38–46 mm); E 3/8"– 5/8" (10–17 mm); Wt 1 3/4–3 1/4 oz (50–94 g).
Endangered Status The Morro Bay Kangaroo Rat, a subspecies of Heerman's Kangaroo Rat, is on the U.S. Endangered Species List. It is classified as endangered in California, where it survives in in very small numbers in one small area of only 200 acres. The species owes its decline to the loss of its habitat to residential and commercial development. Because the population is so small and localized, it could be wiped out by a single catastrophic event.
Similar Species Giant Kangaroo Rat is usually larger, with longer hindfoot. San Joaquin and California Kangaroo Rats have 4 toes on hindfoot. Agile Kangaroo Rat is generally darker. Big-eared Kangaroo Rat has larger ears.
Breeding Reproduction season February - October; peaking in April. 2-5 young born after gestation of 30-32 days. Newborn average weight 1/8 oz (3.7 g). Weaning starts at about 17 days.
Habitat Broad range of habitat types: open, sloping terrain; grassland and woodland in foothills; live oak and pines in low valleys.
Range Central and s California, south from line between Suisun Bay and Lake Tahoe, to slightly north of Point Conception, and west from foothills of Sierra Nevada and Tehachapi Mountains to Pacific Ocean.
Discussion Nocturnal, as is typical of kangaroo rats, Heermann’s is a fast-moving species; it has been clocked running at 12 mph (20 km/h). Its burrow systems may be 6 to 10 feet (2–3 m) long, with two or three passages (there is usually a nest in one) and with several blind "escape" tunnels ending an inch (25 mm) below the surface. This species often uses burrows of ground squirrels. The dirt excavated from burrows is sometimes used for dust-bathing, the sites for which are usually near burrow entrances. This kangaroo rat eats the seeds of many plants, as well as the green parts of prairie trefoil (Lotus), Dudleya, Lupine, and bromegrass (Bromus). It consumes green vegetation heavily in spring, eating soft or succulent foods while foraging and placing seeds in the cheek pouches for storage. Most of the food is gleaned from the ground, except when grasses are ripening; then the animals reach up on their hindlegs and cut off the heads.
