The study team also found that the hybrid cats moved into sections of the Everglades National Park and Big Cypress National Preserve, wild areas in south Forida once thought unsuitable for panthers.
Puma Concolor Coryi once roamed across the southeastern United States. But the tawny cats became isolated on the southern tip of Florida more than a century ago.
Hunting, habitat loss, and reduced prey drastically shrank the panther population, landing the animal on the federal government's endangered species list in 1967.
Today federal protection has been extended to the hybrid cats produced in the genetic enrichment program.
Darrell Land of the Florida Fish and Wildlife Conservation Commission in Naples has studied panthers for 20 years. He says he's encouraged by the population increase.
"At least now it looks like we have a technique that we can use to make sure the panthers aren't going to go extinct solely because of genetic pressures," he said. "Now we can focus a lot more attention on trying to preserve as much of a habitat base as we can and perhaps even expand it over time."
Not everyone, though, believes the novel panther program is a conservation success story.
"It's still too early to say whether this rescue, which is really just an increase in numbers, is a result of genetic changes or it's simply the result of a jump-start in reproduction," said David Maehr, an associate professor of conservation biology at the University of Kentucky in Lexington.
Maehr believes the introduction of Texas cats simply occurred at a time of favorable environmental conditions. He said future fluctuations in habitat quality could adversely affect the panther population.
"I think we need to wait a lot longer to allow Mother Nature to tell us how she is going to treat the Everglades in terms of water levels and deer numbers, before we can say this experiment has succeeded or not," he said. "This case study is still an open book, and it's still very much being written."
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