TAMPA BAY - For all the talk about Burmese pythons invading the Everglades and doing untold environmental damage, a new study suggests that a common household pet is doing far more damage than any other animal, except humans.
"They're natural born killers," said Angeline Scotten of the Florida Fish and Wildlife Conservation Commission. She's referring to felines, the common domestic cat.
"Most people really don't understand that when these cats go outside, even if they're well fed, they're still driven by instinct," Scotten said. "If they see a lizard come by, they're going to pounce on it. That's just what cats do," she said.
The journal Nature Communications published a report Tuesday that said a single cat can kill as many as 18 birds a year, and more than 20 rodents annually. When multiplied by the estimated millions of pet and feral cats outdoors, that equals billions of animal deaths every year.
In Florida, birds are the most vulnerable, as many species travel to the peninsula during migration periods.
"Our birds don't know how to respond to the feral cats," Scotten said. "It's really very disrupting and it's really harmful to our ecosystem."
For years, state officials have encouraged people to be responsible with their cats and keep them indoors. Unfortunately, the problem appears to be getting worse, as more feral cat colonies are appearing either because cats are abandoned in the wild, or people feed the animals that are already living outdoors.
Because domestic cats are an invasive species with virtually no predators, they have an impact all the way down the food chain.
The so-called "catch and release" program is also considered a threat to the environment. FWC says while that program does spay or neuter captured cats to prevent breeding, they are released back into the wild where they can continue to kill other animals, especially birds.
"I think it's very possible we're going to start seeing a lower population of birds, especially neotropical migrants and the songbirds," Scotten said.
For now, state officials are hoping that educating cat owners to prevent their pets from going outside will lead to a reversal in the trend.
"They really do belong indoors," Scotten said. "It's really important for people to be responsible pet owners."
Copyright 2013 Scripps Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
There is only a 20% chance for an afternoon shower or storm. The possibility for rain will go down even more by Friday.