Leopold Center - ISU students find nests, more in southern Iowa

Ryan Marquardt knew about northern harriers from textbooks. But reading about this small, ground-nesting hawk was nothing like flushing one out in a southern Iowa pasture and discovering a nest with five young.

Marquardt is enrolled in the Iowa State University Graduate Program in Sustainable Agriculture. For 10 weeks this summer, he led a crew of three other students to collect data for a Leopold Center-funded project on wildlife habitat and grazing. The project was under the direction of James Pease, ISU extension wildlife specialist and professor in the Department of Natural Resource, Ecology and Management.

The students’ job was to keep detailed vegetation measurements, make general observations, and gather nesting data from 14 tracts of land covering about 75 acres. The tracts vary in size and include four CRP pastures and 10 paddocks used for grazing. They are located on the Adams County CRP farm and private property.

To collect nesting data, the team drags a heavy chain through grass. They found the northern harrier nest their second week at the site. The bird is listed as a “special concerns species” because of its low population in Iowa.

“There’s nothing like being hands on,” Marquardt said. “We’ll take an egg out of a nest and float it in water to determine how old it is. These are things you can’t do in a classroom.”

The information will determine where and what kinds of birds nest in an area, and how pasture could be managed for wildlife as well as grazing. An ideal rotational grazing system would include one-third to one-half warm-season grasses (preferred by wildlife) that are not grazed until early July, when most of the bird nesting activity is finished.

The study areas include pastures that are mostly cool-season grasses, some that have recently been transitioned to warm- season species, pastures with established warm-season grasses, and pastures with a mixture of both types.

“We call older CRP properties the ‘brome desert’ because it has nothing for birds to build their nests in,” Marquardt explained. “The most important thing for nesting is structure, not grass composition, such as standing tall vegetation, or clumps or openings where birds build nests.”

The crew has found eastern meadowlark, dickcissel, grasshopper sparrows, common yellow throat, northern harrier and pheasant (though not in nests).

“One thing I’ve learned is the importance of a complex rotation over time,” he added. “Even a small woody bush such as honeysuckle can provide enough structure for a red-winged blackbird.”

Also working with Marquardt are Karie Wiltshire, a recent ISU sustainable agriculture graduate; Dan Wehmeyer, a senior majoring in ecology; and Ben Varley, a sophomore majoring in animal science.

A native of Ames, Marquardt hopes to join his grandfather and his uncle on their Century Farm in Madison County and pursue direct markets for cattle, poultry and goats. He said he definitely would implement rotation grazing, and that grazing and wildlife uses can work together in a profitable enterprise.