April 10, 2014

One of the trumpeter swans that lived at Swan Lake State Park was likely killed by a coyote in recent weeks, just before it was set to return to the park this week after a two-year hiatus, said Matt Wetrich, a Carroll County Conservation naturalist.

Swan Lake's most recent pair of swans - which lived at the park as part of a state Department of Natural Resources reproduction program - had successfully produced offspring for two years before they were forced to move from their large pen on the northeast side of the lake in 2012 when conservation workers started a two-year draw-down of the lake to accelerate the growth of aquatic plants.

The swans spent most of those two years away in a Pocahontas County park but moved in the past few weeks to an outdoor pen in Buena Vista County, where the male swan was found dead this week when conservation workers went to retrieve the swans for their return to Carroll.

The female trumpeter now struts and swims alone in Carroll. Her wings are clipped so that she can't fly away.

"There is a chance that a wild male trumpeter swan would come in and pair up with her," Wetrich said. But in lieu of that Wetrich seeks $450 of donations to pay for her new partner.

"They tend to pair up pretty well. ... If we're lucky, they'll have enough chemistry that they'll reproduce," Wetrich said. "They have their own personalities, and sometimes they're not compatible."

The swans might reproduce yet this year if Wetrich finds a male companion within the next two weeks, he said. The new swan might come from eastern Iowa or Virginia.

It's fortunate that both swans weren't killed because "if we need a new pair, there might be only one available in the country," Wetrich said. "They're very valuable."

The park has also searched in recent months for a buffalo to replace one that died last year. Wetrich said it will likely come in the fall from a wildlife refuge east of Des Moines.

Residents who wish to donate money for the new swan and its food - or who are willing to lend a large livestock trailer to transport the buffalo later this year - can call Carroll County Conservation at (712) 792-4614 to help.

Trumpeter swans nested throughout Iowa before farming and other development eliminated much of their habitat by 1883, according to the Iowa Department of Natural Resources. The department launched a program in 1993 to restore the swan's presence in the state.

Carroll's trumpeter swans spend most of their lives - unable to fly - at Swan Lake State Park, but their offspring are allowed to fly away with the hope they nest in Iowa.