F is for Florida panther
Introducing new blood into the Florida panther population has created fitter animals more likely to survive and expand into new ranges, new research suggests. The findings indicate that a controversial programme to interbreed Texas cougars with Florida panthers has solved some of the genetic problems caused by inbreeding.
The Florida panther – Puma concolor coryi – is one of more than 20 subspecies of cougar. By 1995 its population in Florida had fallen to just 30, and individuals showed signs of inbreeding such as kinked tails, undescended testicles, and low sperm counts.
So the US Fish and Wildlife Department began a controversial programme to mix Texas cougars – Puma concolor stanleyana – with the Florida panthers. In 1995 they released eight female Texas cougars in Florida and left them free to mate with the native cats. Critics at the time were concerned that the hybrid animals might actually be less fit than purebreds, since Texas cougars were adapted to a different environment. But since then, the population has bounced back to about 100 animals.
Now Stuart Pimm, a conservation ecologist at Duke University in North Carolina, US, and colleagues have released a study showing that hybrids between the two subspecies are three times more likely to survive until adulthood than purebreds, and adult female hybrids survive longer than adult female purebreds. And hybrids do not breed more often, or have more kittens per litter, than purebreds.
The study does not explain why the hybrids are more fit, although it is known that the purebred cats are especially prone to disease.
Flood danger
Robert Lacy, a population geneticist at the Chicago Zoological Society, US, says the results show that the breeding programme has resulted in fitter animals and has countered the danger of inbreeding, at least for now.
But David Maehr, a conservation ecologist at the University of Kentucky in Lexington, US, says more analysis of the data is needed. He thinks hybrids might simply have settled in under-populated parts of the panther habitat which are subject to periodic floods. Although that habitat has been rich with deer over the last 10 years, and allowed hybrids to thrive, another cycle of wet weather could kill a disproportionate number of them.
Read more: https://www.newscientist.com/article/dn7868-new-blood-pulls-florida-panthers-back-from-brink/#ixzz6raKPWe4p
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