within a semi-arid sagebrush desert. Harsh conditions, such as
high and low temperatures, scarcity of water, and lack of soil
nutrients, require unique adaptations for plants and animals to
flourish in this ecosystem. However, life flourishes even in the
harshest environments. Somehow the species that live in such hot,
dry areas adapt or evolve to exploit what is available.
The Ordís Kangaroo Rat is one such INL desert resident. Kangaroo
rats are about the size of a gerbil, but have large, slightly
bulging eyes and small hairless ears. Their tails are generally
longer than the rest of their bodies and their hind feet are
considerably longer than their front feet. They resemble tiny
kangaroos. Like kangaroos, these rats will walk on all fours, but
they also hop on their back feet. If disturbed, these creatures
can move quite rapidly in hops that can be as long as six feet.
Kangaroo Rats are unique in the animal world because nature has
provided them with the ability to survive with very little water
and, in the deserts, with no free water at all. They do not store
water in their bodies for future use like other animals, yet
experiments have shown that their bodies have about the same water
content as other animals.
In fact, their bodies have the ability to produce tiny amounts of
water when the food inside them, mostly dry seeds, combines with
the oxygen that they breathe. They neither sweat nor pant like
other animals to keep cool. They also have specialized kidneys,
which allow them to dispose of waste materials with very little
output of water.
To withstand the extreme climatic conditions in their range, these
rats dig deep burrows into the sand that, when plugged from the
inside, permit the occupants to spend the daylight hours in
comfort, and to avoid the hot, summer sun or the cold, wintery wind. They become active again at night, leaving their
dens after sundown, and go abroad even in the dead of winter when
snow is on the ground in their quest for food.
Kangaroo rats are well-adapted to nocturnal life. Their big head--equal to one-third of their body
length--allows space for an inflated
middle-ear echo chamber that magnifies sounds, enabling them to
easily hear predators like owls and rattlesnakes. Extra-large eyes
placed high on their head give them acute night vision.
Pouches on either side of the kangaroo ratís mouth are used to
transport seeds to its burrow. Unlike a hamster, the pouches are
not inside its mouth. Instead, the pouches are on the outside of
its cheeks, allowing the kangaroo rat to put seeds in them without
opening its mouth and losing water from its breath.
Although at first glance the desert seems to have little in the
way of wildlife, it actually contains large diverse populations.
The kangaroo rat is just one desert creature who has made
adaptations to the desertís harsh condition and fills an important
niche in the desert ecosystem.