Scientists Prowl to Destroy Mute Swan Eggs Nobody objects when government biologists move to kill off ecologically destructive invasive species, such as zebra mussels or snakehead fish. But when the target is the elegant mute swan — which destroys native wetlands — nasty fights break out. In Maryland, biologists are using Wesson oil and wiles to destroy swan eggs.
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Scientists Prowl to Destroy Mute Swan Eggs

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Scientists Prowl to Destroy Mute Swan Eggs

Scientists Prowl to Destroy Mute Swan Eggs

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block.


And I'm Robert Siegel. This is the time of year when wildlife biologists around the country perform a controversial task. They destroy the eggs of a bird so beautiful, it is celebrated in fairy tales. The bird is the European mute swan. Biologists say the swans threaten native birds, but that isn't deterring some animal rights activists.

As NPR's John Nielsen reports, they are fighting to save the swans.

JOHN NIELSEN: Mute swans are big and elegant looking and white as snow, but they're not really mute. In fact, when they're angry, they can be downright loud.

(Soundbite of machinery)

Mr. JONATHAN McKNIGHT (Associate Wildlife Director, Maryland Department of Natural Resources): Do you see the way the wings are held up?


Mr. McKNIGHT: That's the beginning of his aggressive display. He's letting us know that he's not happy with us here. He's making himself big.

NIELSEN: Jonathan McKnight is a swan expert with the State of Maryland. He's just led me to a mute swan nest in a reedy wetland near the Chesapeake Bay, where an angry male swan looks like he's about to try and chase us away.

(Soundbite of water splashing)

Mr. McKNIGHT: Oh, charge(ph).

(Soundbite of water splashing)

NIELSEN: Fifty years ago, there were no wild mute swans in this part of the Chesapeake Bay, according to McKnight, but there were people in the area who imported swans from Europe because they like the way they looked.

Mr. McKNIGHT: All of Maryland's swans started out as lawn ornaments in an estate over on the eastern shore.

NIELSEN: Then, in 1962, five swans got loose from that estate and started breeding in the wild. By the year 2000, there were 4,000 mute swans, and the population was doubling every four years. McKnight says these foreign swans started chasing native water birds off crucial breeding grounds. He learned how aggressive those swans can be by watching them respond to robotic decoys of native birds.

Mr. McKNIGHT: They would fly down and attack them and eventually tore the head off one of the decoys.

NIELSEN: Those tests helped convince state officials that the mute swans would have to go. And so they started shooting adult mute swans. They also started sending biologists like Jonathan McKnight out to addle or kill the big green eggs mute swans lay in nests like this one.

Mr. McKNIGHT: So we've got seven eggs, and I'm going to squirm them down with a liberal coat of corn oil.

(Soundbite of squirming)

NIELSEN: The oil keeps the eggs from breathing, killing them but leaving them intact. McKnight says the adult swans will sit on these dead eggs for months until it's too late to lay more.

Mr. McKNIGHT: If you stomp on the eggs, the swans will very quickly lay again.

NIELSEN: These eradication programs have reduced the number of mute swans in Maryland from 4,000 to about 1,500. Mainstream environmental groups say they approve, but animal rights activists are furious.

Ms. TERESA CUMMINGS (Head, Poplar Spring Wildlife Center): It's a horrible thing. I can't see how anybody could call that humane.

NIELSEN: Terry Cummings runs the nonprofit Poplar Spring Wildlife Sanctuary in Poolesville, Maryland. She shelters injured and abused animals, including some lucky turkeys.

(Soundbite of turkeys crowing)

Ms. CUMMINGS: This big one is Victor(ph). He was found on Thanksgiving Day walking down a sidewalk.

NIELSEN: Then, there's Amanda(ph), a female mute swan brought here to recover from a bad case of lead poisoning. Cummings thinks the State of Maryland has made a scapegoat out of Amanda and other mute swans, blaming them for environmental problems that are really caused by humans.

Ms. CUMMINGS: You know, there's things that we can change about what we're doing that should absolutely happen first rather than killing animals to solve the problem.

NIELSEN: In Maryland and other states, Cummings and her colleagues have sued to stop the mute swan killing programs, but so far, they've only slowed them down.

(Soundbite of water splashing)

NIELSEN: Jonathan McKnight, the biologist, says it's not an easy thing to kill a bird as beautiful as the mute swan.

Mr. McKNIGHT: This is a battle between the hearts and minds of Marylanders, and, you know, it's one of those things where you need to get your mind, your knowledge and our science about the Chesapeake Bay to override the part of your heart that says this bird is so beautiful it can't possibly be bad.

(Soundbite of water splashing)

NIELSEN: McKnight will be out on the field oiling eggs for a few more weeks. He expects to keep hunting down nests until the wild swans have all but disappeared.

John Nielsen, NPR News, Washington.

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