Cottontails seek habitats with lots of food sources and thick brush for protection, so it's possible there are still some hiding out. No one introduced the rabbits, which have been living there since well before the park was established 161 years ago.

No other New York park has seen a decline in wild rabbits, said Sarah Aucoin, director of Urban Park Rangers for the New York City Department of Parks & Recreation.

"I've been here for 17 years, and there were not many when I got here," Regina Alvarez, director of horticulture for the Central Park Conservancy, a nonprofit that manages the huge Manhattan park for the city, said in an e-mail. "But I would see them once in a while."

Though abandoned pet rabbits perennially turn up after each Easter in what's affectionately called New York's backyard, a wild cottontail hasn't been spotted in the park for about four years.

NEW YORK — If anyone knows why the bunnies have disappeared from Central Park, wildlife officials are all ears.

Because bunnies "mate like rabbits," if there are still a few, "we'll see an increase, definitely," Aucoin said. "Only time will tell."

The bunnies are especially vulnerable to weather, predators and automobiles -- all features of the park, said Alan Hicks, a state wildlife biologist.

A recent storm took out large trees throughout the park, and several city streets cut through it. Hawks and falcons are a common sight there, and a random coyote is not out of the question. One was spotted in the park in 2006.

But Aucoin said she didn't think an increase in predators was to blame, because they generally don't decimate their own food source, she said.

"That's not smart, evolutionarily speaking," she said. "That predator population would die off if they didn't have anything to eat."

So since no one has the answer, officials are doing what they can to encourage repopulation. The city has been working to remove invasive plants and planting others to make the park more livable for small animals, including rabbits, Aucoin said.

"When people see a wild animal, even if it's just a bunny, it helps people connect to the environment in a more tangible way," she said. "That's a really important relationship we're trying to encourage here in the city."

But if you're dying to see a bunny in the park, visit on Monday.

Some people give them to their children as pets, discover they require feeding and cleaning, and set them free in the park, Aucoin said. When that happens, park rangers rescue the domesticated bunnies and take them to a shelter.

"It's a horrific problem," said Mary Cotter, who teaches veterinary technology at LaGuardia Community College in Queens and has founded a rabbit rescue group in the city.

Her group put up posters around the city reading, "Setting Your Pet Rabbit Loose Doesn't Make Her 'Free.' It Makes Her 'Food.' "

"Domestic rabbits do not survive in the park," she said. "The ones that are caught and are taken to a shelter are the lucky ones."

-- Associated Press

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Photo: A cottontail sits in brush in Malibu, Calif. Credit: Mel Melcon / Los Angeles Times