Archive for Saturday, December 3, 1994

LAKE WILDLIFE A BALANCING ACT

December 3, 1994

Advertisement

Is Clinton Lake for the birds? That depends on the bird.

Perched at the bottom of a slope blanketed with autumn leaves, binoculars pressed to our eyes, we searched above blue waters for the tell-tale arc of a bald eagle in flight. We had seen one earlier and had hiked maybe a mile of horse trails to be closer to the nest.

Teresa Rasmussen, a U.S. Army Corps of Engineers park ranger, pointed across the southwest shore of Clinton Lake, west of Lawrence, into a stand of dead, drowned trees that stretched several hundred yards into the water.

"There it is," she said. Eventually I spotted the massive jumble of sticks 30 feet above the water in the upper branches of one of the trees.

But the eagles were nowhere to be seen.

"They must be off eating somewhere," Rasmussen said.

Still, the sight of their nest was stirring enough. Bald eagles build the biggest bird nests in the world. They average a ton in weight and a pair of eagles may return to the same nest for more than 20 years, adding to it each year.

This one, about six feet wide and six feet tall, was built amid a graveyard of barkless trees that poked like stilts out of the water. Two decades ago those trees lined the Wakarusa River, before it was dammed and flooded in the 1970s to create the reservoir, which provides drinking water for Lawrence and helps control flooding in the region.

We heard the water lap at the shore, the wind, the crunch of leaves beneath our feet, the occasional gunshot, and little else.

It turned out that dead calm said as much about the challenges of managing 22,000 acres of public lands as did the success of the lake's resident bald eagles.

'What they do best'

It was the last day of November, the first day of deer hunting season, and Clinton Lake's prolific breeding pair of American bald eagles had been back for about a month after their annual disappearance from August through October. Researchers aren't sure where they go.

Since 1989 they have spent most of each year nesting at Clinton Lake. They were the first documented breeding pair of bald eagles in Kansas when they hatched two males on May 7, 1989. More significantly, they have since produced three offspring a year, an unusually fertile confirmation of the great strides that bald eagles have taken since the 1960s, when their reproduction rates plummeted due to the pesticide DDT.

DDT was banned in 1972, when it was estimated there were fewer than 2,000 bald eagles in the lower 48 states.

A year later Congress passed the Endangered Species Act, which offered various protections to wildlife threatened with extinction, among them the bald eagle.

By this July the white-capped birds had made such a comeback nationwide, to a population of more than 10,000, that the U.S. Fish and Wildlife Service proposed downgrading the raptor's status from endangered to threatened in most parts of the country, including Kansas.

"Sometimes it doesn't take a lot more other than giving them a chance to do what they do best," said Dan Mulhern, a Fish and Wildlife Service biologist in Manhattan.

Duck numbers down

In the fall, the Clinton Lake eagles usually return to their nest joined by waves of migrating ducks that arrive from the north.

But this fall there have been few ducks at the lake, despite what wildlife officials say was a tremendously successful breeding season in the Dakotas and Canada, helping to reverse a 20-year continentwide decline in duck populations that had long troubled conservationists.

Marvin Kraft, waterfowl program coordinator for the Kansas Department of Wildlife and Parks, thinks the ducks benefited this year from good rainfall to the north and the availability of habitat in agricultural land taken out of service under the federal government's conservation reserve program.

Clinton bypass?

But at Clinton Lake, ducks have yet to show up in the large numbers that would suggest a great rebound.

"We haven't had the waterfowl this year that we've had in the past," said Gary Reed, the Wildlife and Parks department's area wildlife manager. "I don't know if they're still up north. It seems like when we get ducks here they don't stay."

It may be that the migration is yet to come.

"The big push hasn't started yet," said Paul Pendry, Lawrence chapter president of Ducks Unlimited, a wildlife conservation organization that purchases wetland areas to improve breeding grounds for waterfowl. "A lot of people were worried that they might overfly us. That could happen, but I don't think the migration has started."

But Kraft thinks that's just what has happened: the ducks have bypassed Clinton Lake. He said other nearby areas, such as along the Marais des Cygnes River about 60 miles south of Kansas City, have already had large numbers of migrating ducks pass through.

Kraft speculated that conditions weren't optimal at Clinton and the birds simply weren't stopping there.

"We could have some more wintering type mallards show up, but if they had the habitat they would already have ducks," Kraft said.

What's to blame

He suspected Clinton Lake was low. But Reed said the culprit is actually high water over the summer, which killed vegetation that ducks depend on. Had the U.S. Army Corps of Engineers lowered the reservoir's level this summer, there might have been more vegetation available for ducks.

Which gets us back to the eagles, and the gunshots of hunters, and the roar of powerboats in the summer, and the gush of tapwater in thousands of Lawrence homes.

"There's no way you can manage for everything," Reed said. "We try to take it in the middle where everyone can get something. Usually we have a little vegetation.

"They've got to watch that they don't get too much water, but then they have to keep it up because it's our drinking water."

"They can't force the ducks to stop," said Pendry of Ducks Unlimited. "Anytime you have a facility that's there to serve the public, you're going to have the people that want to ride their bikes and don't want motorcycles. You've got your hardcore environmentalists that would want to outlaw outboard motors. They've got something for everyone."

Except ducks.

Commenting has been disabled for this item.