Cedar Rapids osprey nesting effort may turn bald eagles into bandits

Program includes pair of nesting platforms along Cedar River

Rick Smith
Published: February 26 2013 | 12:15 pm - Updated: 28 March 2014 | 11:58 am in
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Cedar Rapids just might be in store for one big fish fight.

That is hardly the intent of a joint effort by the city’s Parks and Recreation Department, Indian Creek Nature Center and the Iowa Department of Natural Resources to erect two nesting platforms for ospreys at spots along the Cedar River, one at the city’s Prairie Park Fishery and another at the mouth of Indian Creek next to Nature Center.

The platforms, which city parks workers have attached to 25-tall salvaged utility poles, are slated to be lifted into place by Alliant Energy crews on Wednesday in an area frequented by bald eagles.

And bald eagles and ospreys apparently get along only so well.

In short, bald eagles rob fish from ospreys, according to Bruce Ehresman, a wildlife bird biologist with the DNR. But bald eagles rob from each other, too, he adds.

The phenomenon is called "kleptoparasitism," noted Neil Bernstein, professor of biology and chairman of Mount Mercy University’s biology program.

Even so, Ehresman said ospreys and bald eagles can occupy the same area, and he reported that they got along fine at Don Williams Lake in Boone County in central Iowa last year.

"Apparently there were plenty of fish for both species," he said.

The two osprey nesting platforms going up along the Cedar River are part of a larger statewide osprey restoration project, which began in 2003 and which has seen 90 osprey chicks produced from 53 nests. There are currently 18 nesting pairs of ospreys that the DNR knows about in the state, the agency said.

Two of the nesting platforms were placed in Linn County’s Wickiup Hill Park in recent years, but Dennis Goemaat, deputy director of Linn County Conservation, said ospreys twice tried to nest on the platforms without success. However, one osprey pair relocated nearby at the Duane Arnold Energy Center outside Palo, and successfully has nested there four times.

"I like to say our birds are high class and prefer the security of a gated community," Goemaat said, referring to the high security at the Duane Arnold nuclear plant.

In Linn County’s program, young ospreys were brought in to the county at 40 days old, held until they were ready to fly and released. The idea is that eventually they will choose to nest in the place where they learned to fly, explained Goemaat.

Ospreys migrate from Iowa in the winter, and return in March to start nesting.

Daniel Gibbins, the city of Cedar Rapids’ parks superintendent, said the hope is that the new platforms will attract a nesting pair of ospreys in time for the females to lay eggs in May. The eggs hatch 38 days later.

The idea is to attract adult ospreys already in the wild, said Rich Patterson, director of the Nature Center.

A growing urban area like Cedar Rapids needs to find new ways to enhance its natural areas, Gibbins said. Now, people who frequent the city’s Prairie Park Fishery and the Indian Creek Nature Center to watch birds and eagles will get a chance to view the osprey as new birds are hatched, grow and leave the nest, he said.

According to the DNR, American Indian accounts talked of ospreys nesting along waterways in Iowa. However, no ospreys had been in the state from the time of European settlement until the DNR began its restoration program in 2003, the DNR said.

Ospreys, said Pat Schlarbaum, a DNR wildlife technican in Boone, Iowa, are superb at fishing and they catch their prey with their feet after feet-first dives that usually submerge the bird in the water.

The osprey talons are pale blue and are tipped with claws sharp as needles. Schlarbaum called the claws "nature’s finest fishhooks."

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