New York State is proposing to kill or capture all wild mute swans by 2025 because, officials say, the aggressive Eurasian species is outcompeting native birds.

Under the Department of Environmental Conservation's newly proposed rules, adult swans that live on public land or in waters could be shot or euthanized by state employees or caught for people licensed to keep them in captivity. Private landowners could ask the state to remove their flocks.

The agency said mute swans, which it says is an invasive species, can exhibit "aggressive behavior towards people," destroy water plants, displace local birds, harm water quality and put planes at risk. Feeding wild mute swans would be banned under the proposed rules.

The public can comment on the proposal through Jan. 31.

New York is following other states, from Michigan to Maryland, that several years ago decided the large ornamental birds with distinctive orange bills posed too big a threat to local fowl.

Prized for their majestic appearance, mute swans were brought to New York in the late 1800s. They are known for fiercely defending their young, according to experts.

Long Island had the largest population -- 1,843 -- according to the DEC's 2008 census. The state now has a total of about 2,200, the DEC said Thursday.

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The agency also proposed cutting their numbers by destroying nests, puncturing or coating eggs with oil, or sterilizing the swans with surgery or chemicals.

Several conservation and humane officials bashed the DEC's plans, noting there are far more Canada geese, which have brought down planes and taken over golf courses.

"I don't know why they would pick on mute swans," said Sally Newbert, on the board of the Eastern Long Island Audubon Society. Calling their population fairly stable, she added, "They're beautiful birds."

Gary Rogers, a Nassau SPCA spokesman, said the mute swans should not be eliminated. "We have brought these animals here, and we have a responsibility to find a way to manage these animals better, but to completely say, 'We're basically going to eradicate them' -- what's next?"

After years of delays, New York last autumn proposed outlawing 115 nonnative species -- including mute swans -- it said were driving out local plants, insects and animals.