Merriam's kangaroo rats are little rodents. They have fur-lined food storage pouches which are used as a cache for food while animals forage. Kangaroo rats are named for their extremely long, kangaroo-like hind feet and they are almost completely bipedal. They hop or jump rather than scurry or run. Fur color varies between populations within the species' range, but the back color is generally light brown or tan. The tail is relatively long with a large tuft of hair at the tip. This tuft acts like fletching on an arrow and provides drag to keep the animal stable during locomotion.
Merriam's kangaroo rats are found in the southwestern United States, Baja California, and northern Mexico. They live in desert scrub, alkali scrub, sagebrush steppe, pinyon-juniper woodland, and Joshua tree habitats.
Merriam's kangaroo rats live alone in their underground burrows. Males and females establish their own territories and defend them from other Merriam's kangaroo rats. They make multiple entrances to their burrow complex at the base of shrubs near the middle of their territory. This helps them to escape from predators. Merriam's kangaroo rats are strictly noctural creatures. They try to avoid being outside their burrows when the moon is full. The greater the amounts of moonlight the less time they spend collecting food, defending their territory, or searching for mates. During the day, they remain in their cool burrows. When they are active above ground they move within their territory and try to fill their cheek pouches with seeds and plant material. When these little kanagroo rats are threatened they kick sand in the face of the predator or jump up and down on their hind legs.
Little is known about the mating system and reproductive habits of Merriam's kangaroo rats. The breeding season occurs in February-May. The gestation period lasts around 28-32 days. Females produce up to three litters per year, with an average of four kittens in each litter. Young are weaned 24-33 days after birth and reach reproductive maturity between 60-84 days.
There are no major threats to this species. However, in southern California one subspecies, the San Bernardino kangaroo rat suffers from urban development including construction of dams and alteration of hydrologic regimes throughout its range.
The IUCN Red List and other sources do not provide the Merriam's kangaroo rat total population size, but this animal is common and widespread throughout its known range. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today remain stable.
Due to caching seeds, Merriam's kangaroo rats serve as important seed dispersers of their range.