White-tailed Deer Food Habits and Preferences in the Cross Timbers

along the eastern boundary, forming irregular
ecotones of diverse tree and brush species
common to both zones.
Extensive open grasslands and brushy rangelands
also occur in the West Cross Timbers subregion.
In the western counties, where the average
size of land tracts increases, cattle ranching
is the predominant land use. Winter agricultural
forage crops such as wheat and oats are commonly
planted.
Post oak-blackjack oak woodlands characterize
much of the West Cross Timbers subregion.
Other associated woody species include shin
oak, Spanish oak, live oak, Texas ash, mesquite,
osage orange, Ashe juniper, eastern red cedar,
cedar elm, skunkbush sumac, elbowbush,
lotebush, tasajillo, rough-leafed dogwood,
flame-leaf sumac, hawthorn and hackberry.
Much of the subregion contains habitat that
supports populations of white-tailed deer and
many other wildlife species. Many of these
populations exist at or above the habitat potential
of the land. Leasing land for deer hunting is
an important economic enterprise of the subregion.
Fragmentation of wildlife habitat is also
rapidly increasing in the eastern counties of the
West Cross Timbers subregion where larger
land holdings are being subdivided and sold as
small home building sites, farms and ranchettes.
Climate and Rainfall
Rainfall in the Cross Timbers and Prairies
Region ranges from 36 inches per year in the
Eastern Cross Timbers subregion to 24 inches
per year in the western portion of the Western
Cross Timbers subregion, with most of the
Forth Worth Prairie and West Cross Timbers
subregions averaging between 28 and 32 inches.
During summer months, temperatures may
exceed 100º F for several days and extensive
drought periods are not uncommon. Winter low
temperature extremes occasionally approach
0º F, however, only a few days each winter
drop below 20º F. Mean annual temperature is
65º F. Seasonal flooding along major watercourses
may occur during spring and early
summer from storms and weather systems that
move through the region. Snowfall during
winter is uncommon and usually of limited
intensity and duration. Hail, high winds,
tornadoes and thunderstorms occur seasonally,
affecting only small portions of the region at
any given time. However, these events may
result in localized damage to wildlife habitat
and resident populations of wildlife.
The growing season ranges from 218 days in
Jack County in the north to 260 days in
Williamson County in the south, with most
counties in the Cross Timbers and Prairies
Region averaging between these two extremes.
Rainfall patterns and temperatures throughout
the year are a significant factor influencing
white-tailed deer habitat in the Cross Timbers
and Prairies Region. Peak rainfall occurs
normally in May and September. Below
average rainfall during late summer and winter
reduces the growth of forb, grass and brush
species important to white-tailed deer. Mast
production from a wide variety of plants used
by white-tailed deer depends on timely rainfall
patterns throughout the year. During periods of
drought, acorn production on oak species is
highly variable. Growth of cool season forbs
and grasses also depends on timely rainfall
during the early fall and winter months.
Agricultural crops planted for livestock grazing
or crop production provide forage for whitetailed
deer in the Cross Timbers and Prairies
Region and have become important seasonal
foods. In many areas, white-tailed deer distribution
is directly influenced by the presence
or absence of these planted agricultural crops.
During wet cycles, marginal habitat for whitetailed
deer may become occupied if adequate
agricultural crops are present within their home
range. When rainfall is inadequate or extreme
temperatures occur, crops become unproductive
and white-tailed deer populations and
habitat cannot be sustained. These artificially
THE CROSS TIMBERS AND PRAIRIES REGION 7