Merriam's Kangaroo Rat | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Heteromyidae |
Genus: | Dipodomys |
Species: | D. merriami |
Binomial name | |
Dipodomys merriami Mearns, 1890 | |
Subspecies | |
Dipodomys merriami ambiguus | |
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Merriam's kangaroo rat (Dipodomys merriami) is a species of rodent in the family Heteromyidae. [2] The species name commemorates Clinton Hart Merriam. It is found in the Upper and Lower Sonoran life zones of the southwestern United States, Baja California, and northern Mexico.
Merriam's kangaroo rats, like other kangaroo rats and pocket mice, are members of the family Heteromyidae. Each species within this family has fur-lined food storage pouches. The cheek pouch is utilized as a portable cache for food while foraging. 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. Because of this, most heteromyid rodents also have a relatively long tail that acts to counterbalance the hopping/jumping form of locomotion.
Fur color varies between populations within the species' range, but the back color is generally light brown or tan. The merriami species is smaller than most of the other kangaroo rats in the southwest. Adults average about 14 inches in length. The tail is relatively long with a large tuft of hair at the tip. The tuft is thought to act like fletching on an arrow, providing drag to keep the animal stable during locomotion. merriami have four toes on each hind foot in contrast to the pacific kangaroo rat, Dipodomys simulans and the Stephens' kangaroo rat, Dipodomys stephensi (both kangaroo rat species also found in San Diego County), which have five toes.
Merriam's kangaroo rat can be found in desert scrub, alkali scrub, sagebrush steppe, pinyon-juniper woodland, and Joshua tree habitat throughout the southwestern United States and Mexico. [3]
Merriam's kangaroo rats live individually within a maze of burrows. Males and females each establish individual territories. They defend their territories against other male and female merriami, primarily to protect often scarce food resources. It is typical that they locate multiple entrances to their burrow complex at the base of shrubs near the middle of their territory. This allows more opportunities for them to escape from predators.
Most kangaroo rats are exclusively nocturnal. Even so, they tend 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. When the amount of moonlight is great they retreat underground in order to avoid predation. In some areas, above ground activity is limited to two hours or less. [3] During the day, they remain in their cool burrows. They often seal entrances to their burrows with soil to prevent exposure to heat. When they are active above ground they move about within their territory and attempt to fill their cheek pouches with seeds and plant material. When their cheek pouches are full they retreat to their burrows where they disgorge the seeds they have collected. Some of the food is eaten immediately while the remainder is stored (often building a seed cache of considerable size) in several chambers within the burrow system.
Kangaroo rats lose water mainly by evaporation during gas exchange, and so have developed a behavioural adaptation to prevent this loss. As they spend a lot of time within their burrows to escape the heat of the day, the burrows become much more humid than the air outside (due to evaporative loss). When collecting seeds, they store them in the burrows rather than eating them straight away. This causes the moisture in the air to be absorbed by the seeds, and the kangaroo rat regains the water it has previously lost when it then consumes them.
Merriam's kangaroo rats produce up to three litters per year, with an average of four pups in each litter. Weaning of young occurs 24–33 days after birth. [4]
The diet of Merriam's kangaroo rat is almost exclusively plant seeds (they are granivorous). The bulk of their diet consists of the seeds of desert and grassland plants. They rarely drink water. Rather, they obtain water through metabolic processes augmented by the moisture content of their food.
Kangaroo rats are a common prey items for many other desert animals. Typical predators of the Merriam's kangaroo rat include barn owls, great horned owls, coyotes, foxes, badgers, bobcats, and several snake species including sidewinders and glossy snakes. Cougars and American black bears are known to prey on kangaroo rats when they encounter them, although both predators typically prefer larger prey to sustain themselves.
In general humans have not caused adverse impact to the Merriam's kangaroo rat through most of its range. However, in southern California one subspecies, the San Bernardino kangaroo rat, Dipodomys merriami parvus , is at risk due primarily to urban development including construction of dams and alteration of hydrologic regimes throughout its range. Once common on alluvial plains in the washes of San Bernardino and Riverside counties, the United States Fish and Wildlife Service listed the San Bernardino kangaroo rat as endangered in 1998.
Kangaroo rats, small mostly nocturnal rodents of genus Dipodomys, are native to arid areas of western North America. The common name derives from their bipedal form. They hop in a manner similar to the much larger kangaroo, but developed this mode of locomotion independently, like several other clades of rodents.
The giant kangaroo rat is an endangered species of heteromyid rodent endemic to California.
Heteromyidae is a family of rodents consisting of kangaroo rats, kangaroo mice, pocket mice and spiny pocket mice. Most heteromyids live in complex burrows within the deserts and grasslands of western North America, though species within the genus Heteromys are also found in forests and their range extends as far south as northern South America. They feed mostly on seeds and other plant parts, which they carry in their fur-lined cheek pouches to their burrows.
Dipodomyinae is a subfamily of heteromyid rodents, the kangaroo rats and mice. Dipodomyines, as implied by both their common and scientific names, are bipedal; they also jump exceptionally well. Kangaroo rats and mice are native to desert and semidesert ecosystems of western North America from southern Canada to central Mexico. They are generally herbivorous foragers, and dig and live in burrows.
The Texas kangaroo rat is a rodent of the family Heteromyidae. It is found in Texas and Oklahoma in the United States, where it often lives in association with brush species, like mesquite and lotebush, growing in areas with firm clay-loam soils. The species is listed as threatened by the Texas Parks and Wildlife Department and the IUCN lists the species as vulnerable.
Perognathinae is a subfamily of rodents consisting of two genera of pocket mice. Most species live in complex burrows within the deserts and grasslands of western North America, They feed mostly on seeds and other plant parts, which they carry in their fur-lined cheek pouches to their burrows.
Ord's kangaroo rat is a kangaroo rat native to western North America, specifically the Great Plains and the Great Basin, with its range extending from extreme southern Canada to central Mexico.
The San Diego pocket mouse is a rodent species in the family Heteromyidae. It occupies the northern region of Baja California near San Diego extending into Mexico.
The Gulf Coast kangaroo rat is a species of rodent in the family Heteromyidae found in Mexico and the state of Texas in the United States. Its appearance and ecology are very similar to those of its putative sister species, Ord's kangaroo rat.
The desert kangaroo rat is a rodent species in the family Heteromyidae that is found in desert areas of southwestern North America. It is one of the large kangaroo rats, with a total length greater than 12 inches (300 mm) and a mass greater than 3.2 ounces (91 g).
The San Quintin kangaroo rat is a species of rodent in the family Heteromyidae. It is endemic to Mexico, where it is known only from western Baja California. Its natural habitat includes arid lowlands with sparse vegetation.
Heermann's kangaroo rat is a species of rodent in the family Heteromyidae. Their long smooth pelage resembles typical kangaroo rats, with their dorsal side showing a mixed range of olive, black and orange colors. There are 9 distinguished sub-species of Dipodomys heermanni: D.h. arenae, D.h. berkeleyensis, D.h. dixoni, D.h. goldmani, D.h. heermanni, D.h. jolonensis, D.h.morroensis, D.h. swarthi, and D.h. tularensis. The dental formula of Dipodomys heermanni is 1.0.1.31.0.1.3 × 2 = 20.
The San José Island kangaroo rat is a subspecies of rodent in the family Heteromyidae. It is endemic to Mexico, where it is found only on San José Island off the east coast of Baja California Sur. is restricted to an area of only 30 km2 in the southwestern coast of San José Island, Lower California, with the population having been drastically reduced in size and being close to extinction No other species of Dipodomys occur in sympatry with D. insularis.
The Fresno kangaroo rat or San Joaquin kangaroo rat is a species of rodent in the family Heteromyidae. It is endemic to areas within and near the San Joaquin Valley of California in the United States. Habitat destruction due to agricultural development and urbanization has put this species at risk, and the International Union for Conservation of Nature has assessed its conservation status as "vulnerable".
The Panamint kangaroo rat is a species of rodent in the family Heteromyidae. It is endemic to the Mojave Desert in eastern California and western Nevada, in the United States.
Phillips's kangaroo rat is a species of rodent in the family Heteromyidae. It is endemic to Mexico. Its natural habitat is hot deserts.
The banner-tailed kangaroo rat is a species of rodent in the family Heteromyidae. It is found in arid environments in the southwestern United States and Mexico where it lives in a burrow by day and forages for seeds and plant matter by night.
Stephens's kangaroo rat is a species of rodent in the family Heteromyidae. It is endemic to the Southern California region of the United States, primarily in western Riverside County. The species is named after American zoologist Frank Stephens (1849–1937).
The Dulzura kangaroo rat, or San Diego kangaroo rat is a species of rodent in the family Heteromyidae. It is found in Baja California, Mexico, and in the Colorado Desert and elsewhere in California in the United States. It is a common species and the IUCN has assessed its status as being of "least concern".
The San Bernardino kangaroo rat is a species of rodent in the family Heteromyidae. It is one of 19 recognized subspecies of Merriam's kangaroo rat that are spread throughout the arid regions of the southwestern United States and Mexico.