Prolonged Texas Drought Impacts Wildlife

Austin, Texas — Despite welcome rains in late March, much of
Texas remains parched by prolonged drought of historic proportions,
and wildlife die-offs of whooping cranes and deer have been
reported. However, experts say native wildlife evolved to bounce
back from drought, and a bigger issue is how human water use is
changing the equation, and how drought underscores the need for
water planning and conservation.

“The current drought affecting all of Texas has reached historic
proportions, with the past six months among the driest since the
long-term drought of the 1950’s and 1917, the driest year on
record.” That sentence begins the March 11 situation report from
the governor’s Drought Preparedness Council.

The council report said last December through February was the
driest period on record for the east, south central, and upper
coast regions. It also noted the entire state was classified as at
least “Abnormally Dry” according to the United States Drought
Monitor.

Continued dry range conditions could have a negative impact on
wild turkey production and hunting prospects for spring turkey
season, according to Texas Parks and Wildlife Department
biologists. If parts of Texas remain parched, particularly the
south, experts say Rio Grande turkey breeding activity and nesting
effort will be greatly reduced or nonexistent. Rio Grande spring
turkey hunting season runs April 4-May 17 in the North Zone, with
special youth-only weekends March 28-29 and May 23-24. The South
Zone season runs March 21-May 3, with youth weekends March 14-15
and May 9-10.

At TPWD’s J.D. Murphree Wildlife Management Area near Port
Arthur, drought has delivered the second half of a one-two punch
that started with Hurricane Ike last September.

The lack of rainfall means freshwater marshes at Murphree WMA
that were inundated by Hurricane Ike are not being flushed of salt
water. That lack of flushing is killing plants and damaging soil
chemistry. The area’s brackish marshes are saltier than usual for
this time of year, suffering the same stresses as freshwater
marshes.

“Brackish marshes on the WMA and neighboring private ranch land
which would normally be at or below 10 parts per thousand salinity
are still up in the teens,” said Michael Rezsutek, Ph.D, a TPWD
wildlife biologist at Murphree WMA.

Rezsutek said little fresh water is available for use by mottled
duck broods, and that will likely lead to a very low production of
mottled ducks this season. Mottled ducks are the only Texas
year-round resident duck, and are prized by hunters and wildlife
biologists. They’ve been declining for the past 30 years due to
habitat loss and other factors, so drought effects are adding
stress to an already stressed population.

He also said alligators and amphibians are unable to recolonize
areas inhabited before Hurricane Ike because of the salt water, and
populations of these animals will likely remain depressed for the
next several years.

Down the coast at the Aransas National Wildlife Refuge, drought
may have contributed to the worst winter on record for the world’s
only wild flock of endangered whooping cranes. After an encouraging
multi-year comeback in which flock numbers grew each year, this is
the first decline since 2001. Only 249 birds will return north to
Canada this spring, down from 270 who arrived in Texas last
fall.

Refuge expert Tom Stehn attributes whooping crane losses to poor
habitat conditions on the middle Texas coast. He said low rainfall
in 2008 resulted in saltier bays and fewer blue crabs, the primary
food source for wintering whoopers. In addition, whoopers are
further stressed when cranes must leave the bays to fly inland
seeking fresh water.

In the Edwards Plateau of Central Texas, at spots like Garner
State Park, there were reports of non-native axis deer dying from
starvation coupled with cold weather earlier this year. TPWD
wildlife biologists report range conditions are in poor shape,
prickly pear is thin because of the lack of water and feral hogs
are looking very thin and drawn down. Native whitetail deer still
appear in decent condition but may not last long if the situation
continues.

In the Trans-Pecos region of West Texas, last summer TPWD
wildlife biologists observed a considerable drop in the pronghorn
antelope population in portions of Jeff Davis and Presidio
Counties, although overall Trans-Pecos pronghorn populations remain
only slightly below the 30-year average. The specific causes are
not known, but biologists believe there were several compounding
factors, including how much of the affected area received no
measurable rainfall from November 2007 to June 2008.

Meanwhile, this year a team of scientists is continuing work
that will eventually guide decisions about how water pumping from
the Edwards Aquifer in Central Texas should be restricted during
critical drought periods. The science team is part of the Edwards
Aquifer Recovery Implementation Program or RIP, a coalition of
organizations working with the U.S. Fish and Wildlife Service to
recover endangered species threatened by low spring and river
flows. The RIP approach has been successfully used in other parts
of the country to work out complex water use and endangered species
issues. The EA RIP was created by the same 2007 legislation that
raised the aquifer pumping cap during normal times, and as part of
that agreement to increase the cap lawmakers required the RIP to be
completed by the end of 2012. TPWD has four scientists on the team,
examining flow needs of aquatic creatures and plants from Comal
Springs all the way down the Guadalupe River to San Antonio
Bay.

Finally, wildlife experts say individual citizens can do a lot
to help manage problems caused by drought, including using
drought-tolerant native plants for spring gardening. TPWD’s Texas
Wildscapes habitat program for homeowners, businesses and
small-acreage landowners has a wealth of information online about
landscaping approaches that can save money, require less
maintenance and use less water.

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