Correction Department officials consider them the worst kind of wild animals - and they've begun a program to round them up, isolate them and sterilize them before they reproduce.

Relax - I'm talking about cats.

Strange as it might sound, New York's Alcatraz is home to roughly 500 feral felines, who are every bit as nasty, antisocial, misanthropic and territorial as the 15,000 humans housed behind its barbed wire.

The cat problem began more than a decade ago, when a couple of randy animals apparently either crossed the Hazen Street bridge or were left there by prison visitors. Since then, Rikers - at least for the cats - has been a sexual Shangri-La.

"Oh, man, these cats don't care if it's a brother or a sister, they just keep [reproducing]," said Chris Fagan, who helps spay and neuter the animals in a new Correction Department program run by the ASPCA, the Center for Animal Care and Control and the group Neighborhood Cats.

More than 200 cats have been sterilized - and it looks like the party is over.

"After the operation, the males don't even pay attention to the females, and vice-versa," Fagan said. "I guess we're ruining their fun."

Just as Alcatraz had its Bird Man, Rikers has its Cat Lady.

That would be prison guard Gloria Murli, a self- professed "dog person" who started feeding Rikers cats after being transferred to the island in 1990. Her mercy missions quickly took on a life of their own.

"I brought a couple of [the cats] to a vet and spent $600," Murli recalled. "The vet just said to me, 'Gloria, this thing is going to mushroom on you.' Was he right!"

For more than a decade, Murli spent $30 a week on food. And she paid $50 for medical treatment for each of the 200 cats she placed in a loving home.

That adds up to more than $25,000, I gasped.

"Yeah, it's a lot of money, but it was my vice," she said. "Don't tell my husband it was so much. But whether it's a cute kitten or an ugly tomcat, you want to save them all."

Murli pushed her bosses to begin the sterilization program - and now she no longer pays to feed, care for and shelter a bunch of wild cats.

But that doesn't mean her husband is entirely pleased.

"Now, I'm taking care of the Canada geese out here," she said. "What can I say, I love animals."

gersh.kuntzman@verizon.net