Taxonomy
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D. simulans
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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.
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.