Heteromyids

Heteromyidae is a family of small to medium-sized New World rodents that inhabit arid and semi-arid regions of North and Central America, with some species reaching into parts of northern South America. The group includes the kangaroo rats and kangaroo mice, which have adaptations for hopping and desert living, as well as the pocket mice, which carry seeds in fur-lined cheek pouches.

A distinctive feature of heteromyids is their external fur-lined cheek pouches used to transport seeds. Many species are adapted to xeric environments, with efficient water use and, in some cases, well-developed auditory systems. Some kangaroo rats and related species have large hind limbs and long tails, enabling bipedal locomotion and rapid escape from predators. Most heteromyids are nocturnal or crepuscular and rely on seed caching in burrows to survive dry periods. They generally obtain most of their water from food and produce highly concentrated urine.

Ecology and behavior vary among genera. Kangaroo rats (Dipodomys) and some kangaroo mice (Microdipodops) are highly specialized for sandy deserts, while pocket mice (Perognathus, Chaetodipus) occupy a range of arid habitats, often with extensive seed storage and territorial behavior. Diet is primarily granivorous, with seeds forming the core, though occasional insects may be eaten. Reproduction is seasonal in many species, with multiple litters per year in favorable conditions.

Taxonomy places heteromyids within the superfamily Geomyoidea, and the family is commonly divided into lineages including two traditional subfamilies: Dipodomyinae (kangaroo rats and kangaroo mice) and Heteromyinae (pocket mice and related genera such as Heteromys and Liomys). The group faces threats from habitat loss and climate change, though many species remain widespread and common.