Facts About Dulzura Kangaroo Rats

Taxonomy

Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Family:	Heteromyidae
Genus:	Dipodomys
Species:	D. simulans

The Dulzura kangaroo rat, or San Diego kangaroo rat,

Dipodomys simulans, is also found in Baja California

Dipodomys agilis  The agile Kangaroo rat

Dipodomys merriami  Merriam’s Kangaroo Rat  also found in Baja

Dipodomys insularis San Jose Island Kangaroo Rat – critically endangered species

Dipodomys gravipes San Quintin Kangaroo Rat – endangered

Identifying Features

Kangaroo rats have long tails and big hind feet with four toes. They have large heads with big eyes and small ears. They are a sandy brown color with a white underbelly.

Adaptations

The kangaroo rat is almost perfectly adapted to life in the desert. They can survive without ever drinking any water, getting needed moisture from their seed diet. They have excellent hearing and can even detect the silent sound of an owl approaching. Their large back legs enable them to jump up to 9 feet (2.75m) in one jump in order to escape predators.

Habitat

Kangaroo rats inhabit a variety of desert niches. These can include open desert scrub, open grasslands, washes, sandy soils or creosote flats.

Kangaroo rats live in complex burrow systems. The burrows have separate chambers for specific proposes like sleeping, living and food storage.[2] The spacing of the burrows depends on the number of kangaroo rats and the abundance of food. Kangaroo rats also live in colonies that range from six to several hundred dens.[4] The burrow of a kangaroo rat is important in providing protection from the harsh desert environment. To maintain a constant temperature and relative humidity in their burrows, kangaroo rats plug the entrances with soil during the day.[2] When the outside temperature is too hot, a kangaroo rat stays in its cool, humid burrow and leaves it only at night.[5] To reduce loss of moisture through respiration when sleeping, a kangaroo rat buries its nose in its fur to accumulate a small pocket of moist air.[5] The burrows of Merriam's kangaroo rats are simpler and shallower than those of banner-tailed kangaroo rats. Banner-tailed kangaroo rats also mate in their burrows, unlike Merriam's kangaroo rats.

Range

Kangaroo rats are found in the drier regions of the western and southwestern U.S.

Wild Status

The kangaroo rat is not endangered. Its status in the wild is good right now.

Diet

Kangaroo rats eat seeds from a variety of desert grasses as well as mesquite beans. On occasion, some kangaroo rats will eat green vegetation and some insects.

Food and foraging

Kangaroo rats are primarily seed eaters.[6] They will, however, sometimes eat vegetation at some times of the year and some insects, too.[2] They have been seen storing the seeds of mesquite, creosote, bush, purslane, ocotillo and grama grass in their cheek pouches. Kangaroo rats will store extra seeds in seed caches.[4] This caching behavior has an impact on the range-land and croplands where the animals live.[2] Kangaroo rats must harvest as much seeds as possible in as little time as possible.[6] They need to decrease the time away from their burrows as they are cool and dry. In addition, being away from their burrows also makes them vulnerable to predators.[6]

When on foraging trips, kangaroo rats hoard the seeds that they find. It is important for a kangaroo rat to encounter more food items than are consumed, at least at one point in the year, as well as defend or rediscover food caches and remain within the same areas long enough to utilize food resources.[3] Different species of kangaroo rat may have different seed caching strategies to coexist with each other, as is the case for the banner-tailed kangaroo rat and Merriam's kangaroo rat which have overlapping ranges.[1] Merriam's kangaroo rats scatterhoard small clumps of seeds in many small holes.[7] This is done close to the burrow and travel costs are minimized and harvest rates are maximized.[7] Banner-tailed kangaroo rats larderhoard on large mounds.[7] This could give them extra time and energy and decrease the risk of predation. They also spend less time on the surface digging small caches.

Predators

Unfortunately for the kangaroo rat, it has many predators. There are many creatures out there who would like to make a tasty meal out of this small creature. Owls, snakes, bobcats, foxes, badgers, coyotes, ringtail, and your cat or dog are just a few.

Home

Kangaroo rats generally live in underground burrows which they have excavated themselves. Often times the burrow is at the base of a shrub or bush. It spends most of its day underground sleeping, and comes out to feed at night when it is cooler.

Life Span

The life span of a wild kangaroo rat is not very long, only 2-5 years.

Mating and reproduction

Kangaroo rats have a promiscuous mating system. Their reproductive output is highest in summer following high rainfalls. During droughts and food shortages, only a few females will breed.  It appears that kangaroo rats can assess their local conditions and adjust their reproductive efforts accordingly. Merriam's kangaroo rats breed between February and May and produce two or three litters each.  Before mating, the male and female will perform nasal-anal circling until the female stops and allows the male to mount her. A Merriam's kangaroo rat female will allow multiple males to mount her in a short period of time, perhaps to ensure greater chances of producing offspring. Mating in banner-tailed kangaroo rats involve more chasing and foot drumming in the male before the females allows him to mate.  Banner-tailed kangaroo rats mate on mounds and the more successful males chase away rival males. The gestation period of kangaroo rats last 22-27 days.

The young are born in a fur-lined nest in the burrows. They are born blind and hairless.   For the first week, young Merriam kangaroo rats crawl, and develop their hind legs in their second or third week.[4] At this time, the young become independent. Banner-tailed kangaroo rat are weaned between 22-25 days. Offspring remain in the mound for 1-6 more months in the maternal caches.

Size

Depending on the subspecies, kangaroo rats can weigh up to 4.5 ounces (128 g). Their body length can be 3.5 to 5.5 inches (8 -14 cm) and their tail can be 5.5 to 6.5 inches long (14-16 cm).

Extra Fun-facts

        Kangaroo rats have pouches, but not for carrying their babies. Their pouches are on the outside of their cheeks and are used for carrying seeds back to their burrows.

Kangaroo Rats don't sweat or pant like other animals to keep cool because that would cause them to loose water from their bodies.

The San Quintin kangaroo rat is found in flat land with low vegetation. Kangaroo rats generally prefer well-drained, easily worked soil to dig their burrows in. They can also recolonize abandoned agricultural lands. Seeds usually comprise the major portion of the diet of kangaroo rats. Fruits, leaves, stems, buds and insects can also be included. Kangaroo rats are nocturnal and live in burrows which they excavate. Kangaroo rats are usually strongly territorial, with 1 adult per burrow.

The San Quintin kangaroo rat occurs only in a 100 km (62 mi) strip of coastal lowlands in northern Baja California, Mexico, from San Telmo to El Rosario. It was reported to be abundant in this area in 1972, but by 1980 its former habitat was plowed up except for an area 9 km (6 mi) north of El Rosario. The San Quintin kangaroo rat's recent decline has been caused by habitat loss due to agriculture.

Tidbits

*** The San Quintin kangaroo rat is regarded as an effective "keystone predator". It affects the composition of the plant community, thereby indirectly affecting ant and bird densities. This rodent species preys on large-seeded plants that would otherwise competitively reduce the abundance of small-seeded plants.

*** Kangaroo rats seldom drink water, since they are able to use water resulting from the chemical breakdown of their food. They conserve moisture by coming out of their burrows at night when the humidity is highest. They have kidneys at least 4 times as efficient as those of humans, and thus need much less water to remove wastes.

*** Kangaroo rats travel by hopping on their hind legs. When threatened, they can hop 2 m (6.6') or more with one hop.

*** Bathing in dust is apparently necessary for the well-being of kangaroo rats. When they are not able to do so, captive kangaroo rats develop sores on their body and their fur becomes matted from oily secretions on their back. 

Image Source:

alpenglowimagesSan Jacinto Centennial ResurveySan Jacinto Centennial Resurvey

About the Author:
Keith Jones is the founder of Baja Jones Adventures, Jones Adventures, Tigress Tours in Thailand and Butanding Tours in the Philippine Islands and has led thousands of people to Mexico and other interesting locations around the world. He specializes in gray whale tour, blue whale tour, gray and blue whale combo tour, giant panda bear tour, walk a tiger tour, shark tour, African safari tour, African gorilla trek, arctic narwhal tour and Magdalena Bay whale watching tour. He also writes about Baja travel and gray whales. Keith Jones is the author of Gray Whales My Twenty Years of Discovery.