Mute swans: the silent killers of Lake Lily

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swans  CAPE MAY – Looking out on Cape May Point’s Lake Lily, one might spot a mother mute swan and her four cygnets (baby swans). The bevy of swan offspring often huddle around their mother, or sometimes form a line behind the pen as she glides elegantly on the water, looking majestic and proud.

What is not readily apparent to anyone, perhaps even to her young, is that the mother mute swan is a killer.

According to Mike Crewe from the Cape May Point Bird Observatory (CMBO), the female and her mate were one of two breeding pairs of mute swans on Lake Lily. He said the one couple attacked the male of the other pair and killed. The female, he said, apparently left the area.

Crewe said concerned residents contacted the CMBO regarding the attack, which took place over several days around the weekend of May 17-18. He said people first called to see if they would intervene, and then to give assistance to the injured swan.

“I guess the feeling was, you do research and conservation, you should do something,” Crewe said.

Crewe said no one at the CMBO is permitted to do anything by New Jersey statue. He said there are strict laws regarding animal control and rehabilitation efforts.

“The only thing we could do is give the telephone number for a rehabilitator or animal control,” he said.

He said, compassionately, they could have tried to stop the attack as much as anyone else. However, when the incident was first reported, the only person who was at the CMBO was a store clerk who wasn’t able to go out. As a result, Crewe said, there has been anger expressed toward the CMBO for not taking direct action.

“This just came down on our heads,” he said. “But this is like a call we had from Wildwood Crest the other day about an injured bird on the beach. We had to tell them we are not licensed to handle that.”

Crewe said it’s not easy, even for a licensed bird rehabilitator, to tell if a bird is injured. He said a rehabilitator came out and observed the bird, and thought it looked stressed, tired, beaten, but generally okay. It was eventually drowned by the other swans.

Crewe said the attack by one pair of mute swans on the female of the other pair is natural behavior for swans. He said swans will stake out an area they feel will provide them and their offspring with enough food. They will, therefore, attack other birds they see as a threat to their food supply.

“They are selective about who they attack. They would not attack a heron because herons eat fish. They would chase off any bird (including other swans) they consider a threat to their supply of food” he said. “They will attack a bird not because they are took close or are bothering them, but because they are seen as competitors.”

Crewe said the other breeding pair of mute swans probably seemed vulnerable. He said they had their nesting interrupted by a pair of Canada geese, which used their regular nesting area on the island in Lake Lily. The other female mute swan laid her eggs late, and the other pair apparently attacked and killed her mate.

Crewe said because mute swans are beautiful, people became very concerned about the attack, and probably more concerned that the CMBO couldn’t do anything. He said explanations given for their inability to respond to the situation were not well received.

Explanations about the relationship between mute swans and the local environment were rejected outright.

 

An invasive species

Crewe said mute swans are a non-native species, which are affecting the local environment.

Introduced from Europe in the 1800s, mute swans were released into the wild and have proliferated in some areas, expanding their range as far west as the Great Lakes. In December 2013, the New York State Department of Environmental Conservation completed a draft management plan for mute swans in New York. The plan, which included culling the number of swans through various means, met with a lot of opposition from individuals and groups. Crewe said he believes people are very emotive about swans.

“They are very beautiful, but they don’t belong here,” he said.

Mute swans are associated with a number of problems, which according to the NYDEC website, include, “…aggressive behavior towards people, destruction of submerged aquatic vegetation, displacement of native wildlife species, degradation of water quality, and potential hazards to aviation.”

As a result, the NYDEC had proposed “listing mute swans as a ‘prohibited species’ under new invasive species regulations, which would prohibit sale, importation, transport, or introduction of this species in New York.”

Crewe said the damage to the ecology of Lake Lily is as obvious as the “bubblers” installed in the lake to raise the level of oxygen in the water.


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