|
>
Department >
Home >
Forage
Forage Extension Program
Pronghorn Antelope
Habitat Management Suggestions
for Selected Wildlife Species
By R.J. Mackie, R.F. Batchelor, M.E. Majerus, J.P. Weigand,
and V.P. Sundberg
"The
degree of browse is of critical importance for
pronghorn survival during the fall and winter
months on their northern ranges...." |
Optimum pronghorn habitat is characterized by 1) the
presence of big sagebrush and/or silver sagebrush in
combination with rabbitbrush, and 2) the general environmental
factors associated with these plant communities.
Even though pronghorns generally occupy grassland ranges,
their diet consists of essentially browse and forbs.
Over 900 rumens sampled from seven states averaged 64
percent browse, of which 75 percent was sagebrush. The
degree of browse is of critical importance for pronghorn
survival during the fall and winter months on their
northern ranges, particularly when snow covers all other
feed. The major browse species utilized are Wyoming
big sagebrush, silver sagebrush, Douglas rabbitbrush,
rubber rabbitbrush, and western snowberry.
Forbs appear to be of critical importance for pronghorn
survival on more southerly ranges. Depending on their
season of availability, forbs make it possible for pronghorns
to be less dependent on what may be very limited free
water supplies. An extended greening-up period, coupled
with great species variety, make forbs a very important
summer and early fall food and water source. In some
drier areas, during some summers, forb use amounts to
as much as 93 percent of the pronghorns' diet. Biscuitroot,
knotweed, white and yellow sweetclover, alfalfa, lupine,
prairie clover, vetch, buckwheat and rockcress are only
a few of the preferred forbs.
Year-round, grasses are of minor importance in the
food habits of pronghorns, averaging less than 10 percent
of their diet. In early spring and fall, when it is
the only green succulent forage available, consumption
of grasses might be as much as 32 percent of the diet.
Some of the major grasses utilized include western wheatgrass,
needle-and-thread, Sandberg bluegrass, sand dropseed
and basin wildrye.
Habitat Management Suggestions
With respect to antelope habitat, more fruitful accomplishments
are most likely to be achieved through maintenance of
existing habitat then through efforts attempted to restore
antelope habitat where it has been degraded.
In range improvement programs that involve brush management,
sagebrush should not be treated until a conservation
plan has been formulated that includes the needs of
wildlife. Livestock allotments that occupy antelope
range need to be properly managed to insure sufficient
vegetative cover for antelope. Proper grazing of forbs
and grasses by grazing animals will not damage antelope
habitat.
Brush management programs should not be undertaken
when sagebrush crown canopy cover does not exceed 20
percent or on steep slopes with skeletal soils. Sagebrush
of this density or less is generally considered not
to be significantly competitive with desirable range
grasses. Improvement of such grass stands through chemical
control of brush would not likely be worthwhile considering
the financial cost, even with a complete kill of sagebrush.
Greatest improvement in range condition of such areas
is most likely to result through proper livestock management.
Where sagebrush management is judged necessary, control
should be applied in irregular patterns wherever possible,
using topographic features, soils, density of sagebrush
and habitat requirements of sage grouse, mule deer,
pronghorn and other native wildlife as pattern-determining
considerations.
|