Is the ocelot, South Texas' endangered wildcat, making a comeback?

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McALLEN — It has been more than 50 years since the South Texas ocelot — a medium-sized spotted wildcat known for parallel stripes on its neck — was placed on the federal endangered species list.

According to officials, there are only about 100 of these animals left in their native South Texas, mostly in Cameron and Willacy counties on the state's east coast.

When two conservation groups learned that the DNA of a male ocelot killed by a driver dozens of miles away in Hidalgo County in 2021 pointed to a previously unknown population of the animals, they celebrated.

“The results suggest that this cat may inhabit a region of South Texas that is not yet known to ocelot researchers,” Sharon Wilcox, senior Texas representative for Defenders of Wildlife, said in a statement. “There may be more ocelots in the more remote parts of Hidalgo County where suitable habitat and access to prey are available.”

Ocelots once lived across much of South Texas. According to Texas Parks and Wildlife, records indicate the ocelot lived in the southern Edwards Plateau region and along the coastal plain. However, the population declined due to erosion of their natural habitat, hunting and traffic deaths.

The decline has led to a decline in their contribution to the local ecosystem – typically dense thorn scrub land in the Rio Grande Valley – where they hunt rabbits, small rodents and birds, keeping these populations in check.

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But some scientists warn that it is too early to celebrate.

Dr. Mike Tewes, a biologist at Texas A&M University-Kingsville who has studied ocelots for 42 years, said DNA analysis did not provide enough evidence to conclude that ocelots' range is expanding in South Texas . He questioned last week's announcement by the Friends of Laguna Atascosa National Wildlife Refuge and Defenders of Wildlife.

Tewes said the only conclusive information that emerged from the analysis was that the ocelot was likely not a captive cat.

“I would be extremely cautious about attempting to generalize or summarize beyond that,” Tewes said.

Over the course of his time studying ocelots, Tewes said there have been numerous cases of “frustrated dispersal,” in which an ocelot leaves its population and travels a certain distance – usually 10 miles or less, although it can travel up to 25 Miles can travel 30 miles – and eventually get killed on the road.

“I would be very careful to say or even suggest that this population is increasing because of this one traffic fatality in the last 40 years,” Tewes said.

But Dr. Tom deMaar, a wildlife veterinarian in the Rio Grande Valley who was part of the team that obtained the ocelot's genetic information, believes there are several ways to explain the cat's DNA.

The ocelot was discovered north of Edinburg on Highway 281, about 50 miles from where wild ocelots occur in the state. Scientists determined that the ocelot had suffered blunt force trauma, likely caused by a collision with a vehicle. DNA samples were finally tested in January.

With DNA testing, scientists look for genetic markers. According to deMaar, ocelots within the Texas population have seven unique characteristics and this animal had all seven. However, the ocelot also had two markers that were found in the Mexican population.

He said these results suggest three possibilities.

Echoing Tewes, deMaar said the ocelot could have dispersed from Mexico, but believes that scenario is unlikely because the animal would have had to pass through Reynosa, Pharr, Edinburg, McAllen and possibly other areas along the Texas-Mexico border region.

The second possibility is that the cat is a population that researchers have not yet recognized and has preserved Mexican DNA.

Finally, deMaar said it is possible that these Mexican markings already exist in the Texas ocelot population and these markings simply went undetected.

Laura De la Garza, a biologist with the U.S. Fish and Wildlife Service, said more information is needed before any conclusion can be reached.

She agreed with Tewes' reluctance to say that the ocelot's range could expand and said scientists and authorities must continue to work together to learn more.

“As we share information, we will get answers to these questions, and this is where we have to be very careful about what we share with people out there,” De la Garza said. “We have to be very careful and give informed answers because we want to make sure that we are doing our duty of care towards the species and that we are not detracting from this recovery and conservation but are contributing to it.”

Earlier this year, the U.S. Fish and Wildlife Service signed a safe harbor agreement with the East Foundation, an organization that owns and manages ranch land in South Texas.

Through the agreement, participating landowners will allow the ocelots to use the habitat on their land and work with the foundation to enable ocelot monitoring.

Wilcox, of the Defenders of Wildlife, said in an interview with The Texas Tribune that the findings challenged her to think broadly about these conservation efforts.

“Ocelots are making their final stand against human development, which is occurring at an unprecedented rate in South Texas,” Wilcox said. “These cats need wild spaces and places to roam, and this documented sighting of this cat gives us hope that they are holding fast in the wildest corners of our region.”

The challenge now before them, she said, is to protect remaining habitat while restoring it in places that could connect ocelot groups in Texas and give the cats space to roam.

“Ocelots are a symbol of this region, and their fight for survival in the wildest fringe areas represents a larger fight to preserve South Texas’ native landscapes,” Wilcox said. “With open spaces rapidly disappearing, the ocelot’s plight raises far larger concerns about development and loss of wild places across Texas.”

Reporting in the Rio Grande Valley is supported in part by Methodist Healthcare Ministries of South Texas.

Disclosure: Texas A&M University has been a financial supporter of The Texas Tribune, a nonprofit, nonpartisan news organization funded in part by donations from members, foundations and corporate sponsors. Financial supporters play no role in the Tribune's journalism. A full list of them can be found here.

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