The desert shrew ranges across the arid south-west of the United States. It is also found in the drier areas parts of Mexico. Although it can survive in desert conditions, this shrew can also be found in a range of other habitats, including marshland.
The desert shrew preys mainly on invertebrates such as worms, spiders and insects, but it also eats lizards, birds and small mammals such as mice. The shrew must consume three-quarters of its own body weight in food each day to survive. (This is actually a relatively small amount for a shrew.) In the driest parts of its range, the desert shrew can survive on the water it gets from its food. However, it is most often found close to a supply of drinking water.
The desert shrew's tail is at least half as long as its small body. Desert shrews are often found living in garbage dumps around human settlements.
Desert shrews hunt at night, restricting themselves to areas with thick brush to avoid owls and other predators. They rest in the burrow of another animal during daylight hours. In the hottest part of the day, the shrews enter a torpor - an inactive state similar to hibernation. In this state, they use only a fraction of the energy that they would do when normally active. The female makes a crude nest from hair, grass and other vegetation. The blind, hairless young develop rapidly and may accompany their mother for a short period before they disperse.
Distribution: South-western United States, from California to Texas and Colorado.
Habitat: Deserts, semi-arid grasslands, chaparral, woodland and marshland.
Food: Invetebrates such as insects, spiders and worms; also lizards, small mammals and young birds.
Size: 5 - 6 cm (2 - 2.5 in); 4.5 - 8 g (0.2 - 0.3 oz).
Maturity: 2 months
Breeding: 1 - 2 litters of 3 - 5 young born each year.
Life span: Unknown.