February 18, 2010
by Shannon Thompkins
The heavy aroma — an exotic combination of acrid, skunk-like odor and an almost cloying sweetness — caused Arturo Caso and Michael Tewes to exchange knowing smiles as they slowly, quietly and carefully pushed through a narrow opening in an otherwise impenetrable wall of clothes-shredding thornscrub.
To the two scientists, it was the unmistakable smell of success.
Proof squatted just a few yards deep in a thick tangle of brush on a hill above the Rio Soto la Marina in northeast Mexico.
In the shadows, a 23-pound spotted cat crouched inside a wire cage-trap, its amber eyes blazing as short, round ears atop its round head twitched.
The cat's coat, a stunning mix of gold, black, white and gray in splotches, streaks and stripes, was almost indistinguishable from the sun-dappled forest around it.
After slowly backing out of the tangle, an obviously pleased Tewes whispered, “Smell that? That's ocelot scent — urine. They use it to mark their territory. Pretty distinctive, isn't it?”
Tewes would know. The 52-year-old Corpus Christi-area native has spent more than half of his life deeply involved with research and management of ocelots, medium-size wild felines that once ranged through much of south, central and east Texas but today are the most endangered mammal in the state.
Tewes has been working with ocelots since the early 1980s, when Texas may have held 100 or so of the sleek, secretive, knock-you-to-your-knees beautiful wild cats and understanding of their natural history was woefully thin.
“I saw my first (wild) ocelot on Texas Independence Day, March 2, 1982,” he said of his initial encounter with the almost wholly nocturnal felines.
Today, Dr. Tewes — regent professor, holder of the Frank Daniel Yturria Endowed Chair in Wild Cat Studies, and research scientist with the Caesar Kleberg Wildlife Research Institute at Texas A&M University-Kingsville — is arguably the world's most experienced expert on ocelots.
And Texas' ocelot population — the only ocelots remaining in the United States — has eroded to perhaps 50 animals.
A dire outlook in Texas
“Ocelots' situation in Texas is extremely dire,” Tewes said.
Lack of places to live is the overarching problem facing ocelots, considered by many to be the most beautiful wild cat in the Western Hemisphere.
The cats thrive only in habitat providing thick — really thick — cover. Large areas where woody vegetation — brush or trees — is so dense the leafy canopy shades 75-95 percent of the ground are the ocelot's niche.
But in Texas, that habitat has become almost as rare as the cats themselves. The miles of jungle-like tangles along rivers in the eastern half of the state and the nearly unbroken expanses of thick-set brushland in the lower Rio Grande Valley have vanished.
More than 95 percent of Texas' ocelot habitat has been converted to agricultural fields, rangeland or commercial forest. Most of what remains are tiny islands too small to support ocelots.
Texas' surviving handful of ocelots are confined to a couple of the larger remaining tracts of livable habitat in the Rio Grande Valley — one on the Laguna Atascosa National Wildlife Refuge in Cameron County and the other on a private tract in adjacent Willacy County. Those two populations are struggling.
Surrounded by uninhabitable land, Texas' two ocelot populations can't grow. Those cats attempting to pioneer new areas wander into what, for an ocelot, is a wasteland and die from starvation, under the wheels of an automobile or from misadventure.
Long-term survival of Texas' ocelots depends on increasing the amount of habitat available to the cats and giving those animals travel corridors — strips of suitable habitat — connecting them to those scattered islands' suitable brushland.
But the cats face a looming threat in the short term.
Texas' ocelot population has fallen so low that inbreeding among the few remaining cats is rapidly eroding their genetic diversity. That genetic erosion invariably causes severe problems with reproduction and overall health.
“When you have an isolated population that small, it can't survive,” Tewes said. “They are in a death spiral.”
At the current rate of genetic erosion, Texas' isolated ocelots will suffer an inevitable population crash “probably in the next 20-40 years, and within 50 years, for sure,” Tewes said.
Perfect place for research
Texas' ocelot population desperately needs new blood. And that is what brought Tewes and fellow wild-cat scientists Arturo Caso and Sasha Carvajal-Villareal to the thorn-scrub-covered hills of central Tamaulipas earlier this month.
They are part of a cooperative effort between U.S. and Mexican scientists and officials, with crucial assistance of private landowners on both sides of the border, aimed at learning more about northeast Mexico's ocelot population and perhaps laying the groundwork for translocation of some of those Mexican cats to the Texas population.
Most of the effort is centered on the nearly 10,000 acres of dense Tamaulipan thornscrub on Rancho Caracol, a luxury wing-shooting resort in the rolling hills along the Rio Soto la Marina about 150 miles south of Brownsville.
Little more than a year ago, Rancho Caracol owner Barry Putegnat, a Rio Grande Valley native, contacted fellow Valley resident Frank Yturria about ocelots.
Yturria, whose family has extensive land holdings in Texas' ocelot range and has played a huge role in protecting what's left of the state's ocelot population, put Putegnat in touch with Tewes.
“I told Dr. Tewes we had ocelots on Rancho Caracol and if he was interested in studying them, we'd help any way we could,” Putegnat said.
“I really didn't think there would be many cats down there — some, but not a lot,” Tewes said. “I was pleasantly proven wrong.”
Tewes, Caso and Carvajal-Villareal, in cooperation with Mexican officials, set about surveying the cat population on the tract last spring. They set 40 remote-sensing “game” cameras along game trails and overlooking water holes.
The results were “amazing,” Tewes said. Rancho Caracol held a very healthy population of ocelots. And more. The tract, surrounded by thousands of acres of thornscrub, was the home of five species of wild cats — ocelot, bobcat, jaguarundi, cougar and jaguar.
An ambitious research project to document the ocelot population in the region was launched. The major thrust would be aimed at capturing as many ocelots as possible, fitting them with radio collars and tracking them over a year or more to determine their home ranges, yielding insight into their population density.
The ultimate goal is to show that the population of ocelots in the region is large enough and healthy enough that it would not be harmed by taking a few of those cats — three or four a year for a few years — and releasing them into the two genetically moribund Texas ocelot populations.
The project's early phase has been successful. Cameras have recorded 34 individual ocelots on the Rancho Caracol tract — almost as many ocelots as in all of Texas — and 11 have been captured and fitted with radio collars.
Caso and Carvajal-Villareal hope within a year or so to have the data they need to make a case for a translocation program.
“We learn a lot from every one of these cats,” Caso said, as he and other scientists fit one of the captured ocelots with a radio collar, took body measurements, and collected hair and blood samples for DNA profiles. “They are amazing, beautiful animals.”
Like anyone who sees an ocelot, Caso can't help but turn poetic when talking about these lithe, lethal creatures whose multicolored, splotched and spotted and streaked coats are perfectly designed for blending into their impossibly tangled, sun-dappled world.
“They are like smoke,” Caso said, watching a released ocelot stride into a wall of thornscrub and vanishing as though walking through a one-way mirror.
Those Mexican cats and the work scientists such as Caso and Tewes are doing in Mexico may well help Texas' fading ocelot population avoid disappearing like a very real wisp of smoke.