LUBBOCK The Texas wildlife agency said Tuesday it is suspending a policy that allows the killing of burros in a state park along the Mexican border after the Humane Society of the United States offered to devise a nonlethal plan to remove the destructive animals.

The Texas Parks and Wildlife Department will contribute up to $10,000 toward a humane society aerial survey of the wild donkeys at Big Bend Ranch State Park this spring to establish baseline data, agency executive director Carter Smith told The Associated Press ahead of an official announcement expected later in the day.

"We believe this could be valuable information to assess the problem with burros around the park," Smith said. "We still have a long way to go to see if a viable, long-term plan can be developed."

Officials estimate that only about 300 burros live in the 316,000-acre park on the Texas side of the Rio Grande, he said. Park rangers have killed 130 there since 2007, although not during the peak October-through-April tourist season.

"We are happy to work with the department and are pleased that they have halted lethal control of the burros while discussions are under way," Texas humane society director Nicole Paquette said.

The state considers burros to be destructive intruders, hogging forage and lapping up precious water in the drought-starved mountains. Officials say they threaten the survival of hundreds of other native species, including bighorn sheep which the state wants to re-establish in the park.

In Big Bend National Park, adjacent to the state-owned land, killing wild burros is prohibited by a 40-year-old federal ban that Congress said protects the "living symbols and pioneer spirit of the West."

Protesters rode three donkeys to the Texas Capitol in January to deliver 103,000 signatures asking Gov. Rick Perry to change the state policy and halt the shooting of the wild animals.

Wildlife officials say protecting the park's land and water is their highest priority and controlling feral burros is part of that. If nonlethal methods prove unfeasible, they made need to resume killing the animals.

Louis Harveson, professor of wildlife management at Sul Ross State University in Alpine, compared the burros to feral hogs that cause millions of dollars in damage annually in Texas. He said he hoped the humane society would devise a plan to at least reduce the burro numbers, which would take some pressure off native plants and animals in the park.

"We know that every exotic species has a negative impact," Harveson said "They didn't evolve within that system. They have an advantage in a system."