Breeding Florida panthers with cougars saved the state animal from extinction, new study says

Five Texas cats rid the panther population of genetic defects 24 years ago. To keep them from recurring, scientists recommend bringing in about five more cougars every 20 years.
Published July 19

In 1995, Florida's state animal was on the brink.

No more than 30 Florida panthers were left, and several suffered from genetic defects caused by inbreeding. Desperate, state officials tried something no one ever had before: Bringing in eight female Texas cougars, a close cousin of the panther, to breed with the remaining males.

A new scientific study, being published Monday, says that genetic rescue of the Florida panther has been a ringing success, and has not produced the monstrous hybrid that some feared. Not only did the rescue save the state animal but it continues providing benefits to the population five generations of cats later, according to University of Florida professor Madan K. Oli, one of the study’s authors.

“The population really was doomed to extinction” without the genetic rescue, Oli said Friday.

Now about 200 panthers roam what's left of Florida's wild places, and they are largely free of defects.

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The study, being published in a journal called Wildlife Monographs, says that the authors' review of panther genetic and population data provides “persuasive evidence” that bringing in the cougars "prevented the demise of the Florida panther and restored demographic vigor to the population."

If the state wants to avoid panthers slipping back into the same genetic trouble they were in 24 years ago, the study says, then Florida should bring in about five more cats from another region every 20 or so years. That’s assuming, of course, there is enough habitat left to accommodate the arrival of such a large group of apex predators.

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The study's authors strongly recommend the state follow up with continuous monitoring of the panthers' genetic stability to watch for signs of backsliding, Oli said. That way wildlife officials will know the right time to bring in more Texas cougars

"We should probably not wait until it's too late," he said.

Panthers were included on the first federal endangered species list in 1967. When the Endangered Species Act passed in 1973, some Florida wildlife officials contended it was time to take panthers off the list because they were extinct. An environmental group, the World Wildlife Fund, hired a laconic, Stetson-wearing tracker from Texas named Roy McBride to search for signs they still existed. He found one, a scrawny female, and signs that there were others — but not many.

With McBride's help, state biologists began capturing the remaining panthers and putting radio collars on them to track their movements from the air. A mishap during a capture in 1983 killed one of the few remaining panthers, leading to a decision to begin sending a veterinarian along with the capture team.

The veterinarian, Melody Roelke, discovered the panthers were suffering from serious genetic defects caused by inbreeding. Some cats had holes in their hearts, so their heartbeat sounded like an off-kilter dishwasher. Sometimes one or both of the males' testicles failed to descend, leaving them unable to reproduce.

Normally the way to save such a rapidly disappearing species is to launch a captive breeding program. But because of the genetic defects, that would not work for the Florida panther.

That's why biologists turned to bringing in a close relative, female Texas cougars. Their rationale was that back before the South became settled, the Florida panther had ranged far outside the boundaries of the state and crossbred with its Texas counterpart back then.

To save the panther, state wildlife officials dispatched McBride to the Texas mountain country where he grew up. Working alone, McBride pursued the female cougars while riding a mule that he blindfolded so it wouldn't bolt when it encountered one of the big cats. He said in a recent interview that he caught about 20 cougars, but only eight met all the necessary requirements for the experiment. Those are the ones he flew back to Florida to be released into the wild.

Five of the eight Texas cougars successfully bred with male panthers and produced healthy offspring, sparking a panther population rebound that continues today. Because of the success in Florida, scientists in other parts of the world are considering similar genetic rescues with other nearly vanished species, such as wolves in Michigan and possums in Australia.

As the results of the new study show, "it is a viable option," Oli said.

One irony about the study: It's dedicated to the memory of a biologist named David Maehr, who led the state's panther capture team from 1985 to 1994 and produced reams of scientific papers. Maehr, who in 2008 died in a plane crash while conducting bear research, was a vocal and persistent opponent of the plan to bring in cougars from Texas, arguing that the panthers had no genetic problems.

"If he knew then what we know now," Oli said, "he might have thought differently."

Contact Craig Pittman at craig@tampabay.com . Follow @craigtimes.

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