A few unexpected visitors, like the warbling vireo, turned up in the nets Thursday, but they were eagerly welcomed in the name of science.
Despite the humidity and relentless mosquitoes, the work of nature experts and volunteers continued unchecked for the second annual breeding bird survey and banding project at the Rollins Savanna Forest Preserve.
"We were busy today and we got some species we don't always get," explained Cynthia Trombino, a professor of biology at the College of Lake County. "We're targeting passerines, which are songbirds, and woodpeckers as well."
That Rollins Savanna, Lake County's second largest forest preserve, boasts a cornucopia of birds, including the endangered yellow-headed blackbird, is undeniable.
Named an Important Birding Area in 2005 by the National Audubon Society, the 1,225-acre holdings near Grayslake and Round Lake Beach is considered a mecca for birders.
The work on Thursday was not meant to yield immediate results but is part of a longer term study. Scientists will gain a better understanding of the types of birds using the savanna habitat and an idea of how they are faring in terms of breeding.
"We can gauge population trends," Trombino said. "This is our second year but you want to look at five- or 10-year trends."
Over time, the results will allow the forest district to determine how best to restore and maintain Rollins Savanna and other locations.
"We have lots of smaller preserves and one of our goals is to create more savannas," said Gary Glowacki, a wildlife biologist for the district. "This information provides excellent data."
A savanna is a mix of prairie and forest, in which trees account for 20 percent to 70 percent of the landscape, Glowacki said.
Because it is the site of the largest restoration effort ever undertaken, what happens at Rollins is of note for other district holdings. More than 450 acres of former farm land have been restored to attract grassland birds, water fowl and other wildlife. Rollins is the template for an extensive restoration under way at the Lakewood Forest Preserve, the district's largest, near Wauconda.
According to district literature, the large interior wetlands at Rollins provide food and rest stops for ruddy ducks, blue-winged teals, great blue herons, egrets and a variety of water fowl.
While some birds are permanent occupants, most stay awhile and move on.
"There's a concern over the migratory bird population," Trombino said. "This is their breeding habitat so this is what we want to manage."
Last year, 279 birds representing 30 species were banded. Preliminary counts were in the 215 range Thursday, with a guest list that included grackles, blue jays, eastern bluebirds, red winged blackbirds and young orioles.
"We've had a pretty diverse day because we're getting in to the migratory patterns," Trombino said.
The diversity of the wildlife and restoration of the area is not lost on visitors. Marti Leider, a longtime Grayslake resident, remembers the cows from when the area was a farm.
She walks the trails regularly and sees swans, egrets and other birds.
"Every day it's something different," she said as she started her walk Thursday morning. "It's beautiful to have this."