PronghornAntilocapra
americana; Although its scientific name
means "American goat-antelope," the
pronghorn is not directly related to either goats
or antelopes.
Description
Looking somewhat like a deer, the pronghorn is
about 4-1/2 feet long, stands about 3-1/2 feet at
the shoulder, and weighs 90-150; males are
heavier than females. Overall color is tan to
reddish brown, with white markings on the face,
neck, stomach and rump. The neck markings are
white stripes. The rump has extra long white
hairs that the pronghorn can stick up when
scared. Males have a broad black mask that runs
from their eyes down their snout to their nose
and black neck patches; females lack the black
markings.
The most noticeable features of pronghorns are
also the source of their common name. Both
males and females have a pair of horns on the top
of the head. The females horns are
small, usually only a bump, but those of the male
are around 10-12 inches long. They also
have a unique shape, because unlike other
ungulates, a pronghorns horns point
backwards. The horns extend straight up and
then curve towards the rump. At the front of the
horn is a small notch or prong that points
forward. The pronghorn's horns are also unique in
that they are neither true horns nor true
antlers. True antlers are made of bone and shed
each year, while true horns are made of
compressed keratin that grows from a bony core
and are never shed. The sheath of the pronghorn's
horn is made of keratin, but the horns shed
yearly. True horns also have only one point, not
the prongs or forks that antlers have. The
pronghorn is, therefore, the only animal in the
world with branched horns, as well as the only
one that sheds its horns each year.
The pronghorn is also the fastest animal in
the Western Hemisphere, and the second fastest
land mammal in the world, after the cheetah. Not
only can it attain speeds of over 53 miles per
hour (compared to the cheetah's top speed of 70
mph), it can run at speeds of 30-40 mph over long
distances (while the cheetah can only run at top
speed for a few hundred feet). Although it can
easily clear up to 20 feet in one bound while
running, the pronghorn is not good at jumping
over obstacles (such as fences).
Excellent eyesight allows the pronghotn to
spot a threat up to four miles away.
Distribution and
Habitat
Pronghorns once roamed in huge herds from
southern Canada to northern Mexico. Today,
however, they are mainly found in Wyoming,
Montana, northeastern California, southeastern
Oregon, Nevada, Utah, Colorado, Arizona, and New
Mexico. They inhabit open plains, fields,
grasslands, brush, deserts, and basins.
The migration of pronghorns depends entirely
on geography. Some do not need to migrate because
the nearby land has plenty of food all year long,
but one Wyoming herd undertakes an annual
roundtrip migration of about 300 miles. The only
North American land animal to cover more ground
in a migration is the caribou. Other herds in the
northern plains also migrate, but usually cover
much shorter distances.
Reproduction
Males have breeding territories with a group
of females that they defend against other
males. Fighting between males can become
very heated, with aggressive movements and even
physical combat, and serious injury is a very
real possibility.
Breeding takes place in September and October.
Pronghorn have a longer gestation period than
typical North American ungulates, averaging eight
months, and twins are common. The does seek time
and space alone to give birth and care for their
offspring. The newborns can take their first
wobbly steps just 30 minutes after birth, and can
outrun humans by their fourth day. The mother
keeps her fawn(s) hidden in tall prairie grasses,
coming back to nurse every few hours. The fawns
will join the herd when they are about a week
old, begin grazing at about three weeks, are
weaned at about twelve weeks, and are completely
independent at about a year. Females reach sexual
maturity at about two years, males at about age
three.
Diet
Pronghorns dine on grasses,
forbs, and cactus in the summer, while sagebrush
and other available plants make up their winter
diet. They receive most of their water
from the plants they eat, but will take advantage
of fresh water when available.
Other Information
Pronghorns live in herds that change in size
depending on the season. In the summer, females
and their young will gather in bands of less than
a dozen individuals, young males less than two
years old form bachelor herds, and breeding males
establish individual territories. In the winter,
the herd will include males and females and can
include hundreds of pronghorns.
Most active at dawn and dusk, pronghorns
rarely close their eyes to sleep because they
must remain alert to any possible danger.
If a pronghorn spots a predator, it raises its
white rump hairs so that the white patch can be
seen by other pronghorns. Although running
away is the typical response to danger, a
pronghorn may attack with its sharp hooves if
cornered.
Scientific
Classification
phylum Chordata
subphylum Vertebrata
class
Mammalia
order
Artiodactyla
family Antilocapridae
genus & species Antilocapra americana

National Wildlife Federation http://www.nwf.org/wildlife/wildlife-library/mammals/pronghorn.aspx
NatureWorks http://www.nhptv.org/natureworks/pronghorn.htm

Cheetah
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