Top ocelot researcher calls conservation strategy 'ecological fairy tale'

ocelot
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In the early 1980s, many scientists believed the endangered ocelot, a spotted wildcat that once roamed as far north as Arkansas and Louisiana, had died out in Texas. Then, on a late winter day in 1982 on a remote Willacy County ranch, a young biologist named Michael Tewes trapped the first Texas ocelot of the modern era.

Since then, Tewes has gone on to become the dean of ocelot research, training a generation of ocelot scientists, and the cat has become perhaps the most iconic endangered species in South Texas.

The ocelot has been the rallying cry for decades of efforts to preserve in the rapidly urbanizing Rio Grande Valley and the centerpiece of a series of environmental campaigns against controversial projects like the border wall.

So it was noteworthy when earlier this month, Tewes delivered a blistering condemnation of ocelot preservation work, declaring the push to create additional habitat an abject failure.

In a report released April 8, Tewes wrote that the strategy of building corridors to connect the last remaining groups of 80 or so ocelots with Mexico, the very underpinning of what the U.S. Fish and Wildlife Service and had spent millions of dollars to pursue, was based on "ecological fairy tales" that might have done more harm than good.

"My intention was to give the facts as well as I've seen and understood them," he said before delivering his findings as part of a faculty lecture at Texas A&M University-Kingsville, where he is the Frank Daniel Yturria Endowed Chair for Wild Cat Studies. "Over 35 years, I've developed insights no one else has. ... I expect to be attacked quite a bit."

Tewes' conclusions could have far-reaching consequences in the Rio Grande Valley and comes just as the region is wrestling with twin environmental fights over the border wall and proposed natural gas facilities on environmentally sensitive land at the Brownsville Ship Channel. The need to protect ocelot habitat has been a central theme of efforts to block both projects.

But Tewes argues that while building and protecting expensive wildlife corridors and refuges in the Valley might have helped other species, such as migratory waterfowl, they have failed to bring any benefit to the ocelot. The wildcat's future, he argues, has been hijacked, in some instances for political causes.

"I believe we have less habitat and fewer ocelots than when I began working on ocelots," he wrote. "Perhaps even more concerning, we squandered 25 precious years in the ongoing countdown to ocelot (extinction) within the United States."

Environmental activists say Tewes' message, however well intentioned, represents a dangerous threat to the larger conservation movement in Texas and to species that don't enjoy federally mandated protection under the Endangered Species Act.

Jim Chapman, vice president of the Rio Grande Valley group Friends of the Wildlife Corridor, said Tewes' report could undercut environmental campaigns to protect sensitive habitats and hurt the push to acquire new conservation lands.

"He is one of the preeminent cat biologists, but his focus is on nothing but the cats," Chapman said. "There is a real damaging downside to that narrow focus. ... He's doing more damage to wildlife overall than any other biologist."

Mitch Sternberg, a U.S. Fish and Wildlife biologist with the South Texas Refuge Complex, said agency officials were shocked by Tewes' report but said it contained some valid points. The agency plans to reach out to him to be part of a more transparent dialogue.

"We are equally frustrated with the challenges to make progress for ocelots," Sternberg told the American-Statesman. "But we would all be better off to be communicating and collaborating more."

The last remaining Texas ocelots live in two small groups in the Rio Grande Valley about 30 miles apart. About a dozen cats are believed to live on the U.S. Fish and Wildlife Service's Laguna Atascosa National Wildlife Refuge along the Gulf Coast, while a larger group of perhaps 50 or so ocelots lives on private ranches in the northern reaches of the Rio Grande Valley in Willacy County.

Ocelots depend on a particular type of habitat that is rapidly disappearing in the Rio Grande Valley: Tamaulipan thornscrub, which is made up of gnarly catclaw bushes, spiny hackberry and mesquite. It's territory that has largely been plowed over for farmland and cities over the past century. Prime ocelot habitat, in often isolated patches, now makes up less than 1% of the Rio Grande Valley.

The Fish and Wildlife Service's central ocelot strategy has involved protecting and connecting those patches of habitat through land acquisitions to allow ocelots to expand their ranges. The ultimate goal of the wildlife corridors is to build a connection to Mexican ocelots and introduce some badly needed genetic diversity into the Texas populations, which have been inbreeding for generations, making them more susceptible to extinction.

In all, the agency has sought to build five wildlife corridors in the Rio Grande Valley, including a connection between the two ocelot groups.

According to agency reports to Congress, federal officials spent $17.7 million on ocelot protection efforts in 2016 and 2017. Overall, more than $75 million has been spent on land acquisition over the past three decades. In addition to preserving habitat suitable for ocelots, the refuges protect habitat for rare migratory birds and provide one of the last remaining bulwarks against increasing development.

But Tewes says he has found no evidence that ocelots are using landscape corridors to connect with other groups. Instead, he writes, "I am concerned that dispersing ocelots are likely using landscape corridors to enter an 'ecological black hole' destined for oblivion."

Tewes worries that the unfinished corridors, which contain gaps and run close to roads, will lure ocelots out of the relative safety of the Atascosa refuge and into an inhospitable area of highways and open ground. Vehicle strikes represent one of the greatest threats, with half a dozen ocelots killed on roadways in 2015 and 2016.

And if Texas ocelots make it to the Rio Grande, it's unclear what they would find. Tewes says the closest verified ocelot populations in Mexico are at least 100 miles from the border and genetic studies show that it has been many decades since Mexican and Texas cats intermingled.

"Quit talking about the fairy tale of linkage with Mexico," he said.

Environmental groups say Tewes paints an overly grim assessment, pointing to isolated cases of ocelots traveling great distances. In 1995, a Mexican ocelot crossed the Rio Grande into the Santa Ana National Wildlife Refuge, though it did not mate, and a few years later, a ranch ocelot nearly made it to the Atascosa group.

"It really is possible, so why not make it easier and less dangerous for them?" said Rob Peters, senior representative for the southwest office of Defenders of Wildlife. "Conservation doesn't happen overnight. It takes a huge amount of work and investment."

Sternberg, the government biologist, said that while it has been a challenge to "see more direct benefits for ocelots ... we are hopeful and look to the long-game."

"Wildlife corridor establishment in South Texas has been driven in part by ocelot recovery but also for the benefit of hundreds of other wildlife species," he said.

Tewes argues the ocelot's best hope lies in expanding habitats on private ranches in Willacy County, where development pressure is low and where he says ranchers have a natural goal to preserve ocelot habitat, which is also ideal for lucrative quail and deer hunting leases.

Two ranches—one owned by the family of Frank Yturria and another owned by the East Foundation—have been active in promoting conservation of ocelots on their property. Yturria granted a conservation easement to the Nature Conservancy for thousands of acres before he died last year; the foundation has a research team studying its ocelots in partnership with Texas A&M-Kingsville.

Tewes said nearby ranchers, who likely have ocelot populations of their own, could be persuaded to undertake a conservation program if they receive assurances from U.S. Fish and Wildlife regarding liability and land use regulation.

Sternberg said the agency is ready and willing to discuss arrangements with private landowners.

Peters said that while the private ranches are an important piece of the puzzle, publicly managed lands can offer permanent protection and dedicated staff, such as the ocelot biologist at Laguna Atascosa.

Tewes' condemnations come at a particularly sensitive time for the Fish and Wildlife Service's Lower Rio Grande Valley National Wildlife Refuge, a string of protected parcels stretching along the river from Brownsville to Starr County. Since 1979, the wildlife agency, aided by nonprofits and citing potential benefits for the ocelot, has created nearly 100,000 acres of protected habitat along the Rio Grande.

Fish and Wildlife documents obtained last month by the Statesman show that about 15% of refuge lands are slated for planned border fencing in Hidalgo and Starr counties, which environmental groups say will have a devastating impact on the refuge's mission. U.S. Customs and Border Protection did not dispute the agency's estimate and told the Statesman the border wall is planned across 17 miles of refuge lands.

Customs and Border Protection spokesman Rick Pauza said the agency has taken some steps to mitigate environmental damage on refuge land, including moving border fencing on the Arroyo Ramirez tract to its northern edge. He said the agency also is acting on Fish and Wildlife recommendations to broaden ramps over flood levees to aid animals during floods.

"CBP continues to consult with USFWS to identify animal migration corridors within the Rio Grande Valley where design elements can be incorporated into the barrier that will allow for continued migration of animals," Pauza said.

But the Texas Observer had previously reported that border officials brushed off Fish and Wildlife concerns about wall placement, ignoring a request that border fencing "skirt the edges of the refuges, rather than bisecting them and destroying habitat."

Chapman said that between the plans and Tewes' report, "wildlife is getting hammered, that's for sure."

Tewes' report also comes as environmental groups are trying to stop three liquefied natural gas projects just south of the Atascosa refuge. Among the chief arguments against the facilities is that they would prevent the establishment of a corridor that would allow ocelots to reach the Rio Grande. In March, federal regulators ruled the facilities would have adverse environmental effects, but that they could be mitigated with proper planning, according to the Houston Chronicle.

Chapman said Tewes' report hurts the effort to stop the plants and some environmental groups have questioned Tewes' relationship with one of the energy companies seeking to build a liquefied natural gas facility.

In December 2015, Annova LNG donated $40,000 to Texas A&M-Kingsville's Caesar Kleberg Wildlife Research Institute for ocelot research. Tewes hailed the donation, saying it would allow the purchase of high-end GPS collars for ocelots.

Tewes said that he had concluded linkage with Mexico wasn't feasible before the donation, which he said did not affect his thinking. He said he declined to serve as a consultant to Annova on the project to avoid any perceived conflict of interest. His report, he said, came from years of growing "frustration and anguish" over the lack of benefits for ocelots from the conservation strategies.

While there are deep differences on the best strategy to help ocelots, both sides agree on one crucial step: the need to physically move an ocelot from Mexico into Texas in hopes that it passes on its genes. The effort has been in limbo for several years, in part due to cartel violence that temporarily halted research on the Mexican side.

But that effort appears to be gaining steam. In 2018, Mexican scientists found 88 individual ocelots in a mountainous region of Tamaulipas, about 120 miles from the border. Researcher

Rogelio Carrera, a professor at the Autonomous University of Nuevo Leon, is hopeful the number is high enough to persuade the Mexican government to release a few.

Carrera said that researchers are planning to conduct a health and disease study this year. "This will be the last piece of information needed to plan for moving cats to Texas," he said. "We feel optimistic in making all this a reality and hoping to do so next winter."


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Citation: Top ocelot researcher calls conservation strategy 'ecological fairy tale' (2019, May 1) retrieved 14 October 2019 from https://phys.org/news/2019-05-ocelot-strategy-ecological-fairy-tale.html
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