CAPE MAY, N.J. — Suspected by the feds of a few killings, Cape May’s feral felines were all set to start new lives far from where endangered shorebirds nest.

Then howls from the cats’ backers persuaded the Cape May City Council to back down on the relocation plan and risk losing millions of dollars in federal sand replenishment.

In this historic beach community, where both cats and birds are wildly popular, the debate is more than the love of fur versus feather. Deputy mayor, Neils Favre, who said he received 600 e-mails against the plan on a single day last week, suggested the council instead try to convince state and federal environmental authorities that its own measures were working. The city’s plan includes a trap, neuter, and release program that has gradually reduced Cape May’s wild cat population to about 100 from 450 during the past decade, he said.

Wild cats are as much a part of genteel Cape May culture as rainbow-colored Victorian bed and breakfasts, trolley tours, and cocktails on the porch at sunset.

But Cape May is also one of the prime bird-watching spots in all of North America. The World Series of Birding is held here each year.

The cats have become the top suspect in many deaths of the endangered piping plover, a fist-sized, white-and-brown fuzzball of a bird that has closed beaches and stopped development projects in the interest of protecting their habitat.

“People are really upset about the lack of action on this,” vice president of conservation with the New Jersey Audubon Society, Eric Stiles, said. “There is a thriving nature-based tourism industry in Cape May, and I’ve heard talk about boycotting the city.”

Cat-lovers said people are the real threat to endangered shorebirds.

“The cats should be kept away from there, but so should people,” resident Bill Pollock, who feeds a wild cat colony near his house, said.

Brenda Malinics, who loves cats and birds, said she patrols the beach each summer to see what — and who — is near Cape May’s two known nesting grounds for endangered birds.

“I have not seen any cats along those stretches of nests,” she said. “To pick on just cats is a witch hunt. I am a birder, and I see both sides of this. Humans are the real problem. Teenagers play Frisbee behind the ropes where the birds are. People ride their bikes there.” The U.S. Fish and Wildlife Service considers every plover death to be a big deal. As of last summer, only 115 pairs were left in New Jersey. The population actually rebounded somewhat; by the end of the year, there were 129 pairs, a spokeswoman for the state Department of Environmental Protection, Elaine Makatura, said.

The federal Endangered Species Act prohibits killing, harming, or even bothering endangered birds like piping plovers and least terns, both of which nest in the shallow sandy ruts of Cape May’s popular beach during the summer. Because they nest on the ground, they are vulnerable to predators, including wild cats, foxes, and other animals.

The government originally wanted feral cat colonies moved back a mile from the beach — something that cat lovers say would have mandated eliminating all wild cats from Cape May. They dug in their heels and resisted, leading to a compromise proposal to move the cat colonies at least 1,000 feet from the beach, and a half-mile from areas already identified as nesting grounds.

A spokesman for the Fish and Wildlife Service, Jim Cramer, said the agency was skeptical of the compromise.

“The situation is a bit fluid,” he said. “We’re trying to decide exactly what we’re going to do next.” Withholding beach replenishment money is something the feds view as a last resort, but it is a possibility, Mr. Cramer said.

Cape May officials plan to reconsider the situation in early March, which would leave little time to move the cats. The state expects the plovers to start returning to Cape May around March 15, Ms. Makatura said.

“I know in my heart if we don’t do something with this soon, it’s going to jeopardize our beach fill for this fall,” Mayor Inderwies said. “It’s serious, it’s real, and we have to come up with something.”