Wild burros in Big Bend Ranch State Park are getting a reprieve — for now.

The Texas Parks and Wildlife Department announced Tuesday that it will suspend the killing of burros in the park and work with the Humane Society of the United States to find nonlethal methods of removing the animals. The Humane Society will conduct an aerial survey this spring to determine the size and location of the park’s burro population. TPWD will contribute up to $10,000 toward the assessment.

“We understand concerns that have been expressed by many people, and are open to considering feasible, nonlethal alternatives,” Carter Smith, TPWD’s executive director, said in a prepared statement.

“However ... our responsibility to protect Big Bend Ranch State Park’s sensitive lands and waters is our highest priority," he said. "If nonlethal methods are determined to be unfeasible, we retain the option to conduct lethal control as conditions require.”

According to TPWD, burros are exotic animals that threaten the desert park’s water sources, as well as its native plants. Photographs on the department’s website show springs, creeks and an archaeological site contaminated by burro droppings and urine. The burros also compete with native animals for food, disrupting some species’ food chains.

Parks and Wildlife officials began lethally controlling the park’s burro population in 2007. Park rangers have killed about 130 burros. An estimated 300 burros now live in the park. Next door, at Big Bend National Park, a ban on killing burros has been in place for 40 years.

In 2008, TPWD temporarily ceased using lethal control and allowed the Peaceful Valley Donkey Rescue, a national organization, to try trapping burros in the park. After two years, the organization was unable to trap a single burro within the park, although it caught 100 burros in the Big Bend region, said Mark Meyers, the organization’s co-founder. Meyers added that rescuers were limited to setting traps along the park’s roads, which made it difficult to trap animals that roamed freely throughout the park and over the border into Mexico. The mountainous terrain in the 316,000-acre park presents problems with burro capture.

“I’m glad to hear it,” Meyers said of TPWD’s recent decision, though he wondered where the animals would go. “To my knowledge, we are the only organization that can take 100-plus burros at a go. To be honest, I’m not sure I can take another 100 burros [in] Texas.”

In Texas, Meyers currently keeps 800 burros on his ranch and another 300 at a sanctuary.

The Peaceful Valley Donkey Rescue accepted 800 burros in Texas in the past year, and 120 wild donkeys from the Humane Society in Hawaii, which were airlifted to California. According to Meyers, it costs $100 initially to take in each new donkey and $40 per month thereafter to care for the animals.

If the Humane Society’s survey results indicate that nonlethal alternatives for population control are possible, the organization will provide TPWD with a proposal detailing the methods, costs and strategies for carrying out such methods. At present, there is no formal, binding agreement between the two entities.

“We’re very happy that the Parks and Wildlife Department has temporarily suspended lethal control,” said Nicole Paquette, Texas senior state director for the Humane Society.

While the Humane Society and TPWD will not be able to determine what to do with the burros until after the survey is completed, Paquette said the Humane Society has used relocation and birth control methods to manage wild burro populations in other parts of the country.

And although the park does not currently have a strategy for burro capture, Smith believes the park’s mountainous terrain may require innovative solutions.

“This is a rough, rugged, inhospitable environment,” Smith said. “The techniques that have been used to trap them have simply not worked. I suspect [a viable strategy] might involve the use of aerial herding. Helicopters are often used to herd cattle. A skilled helicopter pilot can maneuver animals into a certain place.”

However, Smith said, burro relocation can be a costly proposition; the animals must be quarantined to check for disease, and then redistributed to people or organizations who will care for them. TPWD has said organizations that come forward with a nonlethal control plan must also come forward with a sustainable financial solution to carry out the plan.

“We’re managing Big Bend Ranch State Park to benefit native plants and wildlife, not feral burros that happen to wander into the park,” Smith said. “As hard as it is for some people to understand, this is a state park. It is not a feral burro sanctuary.”