Winging It in Restored Wetlands

Pennsylvania has lost more than half of its wetlands since colonial times, including about 28,000 acres between 1956 and 1979 alone. Landowners often considered soggy sites to be essentially worthless and drained them for development or agricultural use. But wetlands provide habitat for waterfowl and other species of wildlife.

Nearly 70 percent of Pennsylvania's threatened or endangered species use wetland habitat at some point in their lives. Many of the remaining wetlands in the United States are privately owned. As scientists today educate the public about the role wetlands have in controlling erosion and flooding, as well as filtering pollutants and harmful sediments from drinking water, homeowners and farmers are becoming more interested in preserving and retaining wetlands.

Much of the acreage drained for agricultural uses proved to be marginal farmland at best, often plagued with drainage problems, and state agencies, conservation groups, and private citizens have made inroads into recovering wetlands by reclaiming filled-in agricultural sites for wildlife habitat. The U.S. Fish and Wildlife Service, in cooperation with the Pennsylvania Game Commission, the Natural Resource Conservation Service, county Conservation Districts, and private conservation groups, has a highly successful program called Partners for Wildlife that is restoring wetlands across the state. Since 1992, more than 200 restoration projects in Pennsylvania have been completed and more than 2,000 acres restored.

Wetland restoration is still a fairly new endeavor, and experts have relatively little scientific data on how to design wetlands to provide habitat for specific wildlife. One big question in wetlands restoration is, if we build it, what will come? Scott Cashen, a master's degree candidate in wildlife and fisheries science from Livermore, California, is examining variables that attract bird species to wetlands."Although wetlands have been studied as bird habitat, there has been little in-depth research on how different wetland variables affect bird communities in restored sites," he explains."For instance, what species will be attracted to a particular wetland habitat? Are some species limited by wetland size? How does the amount of vegetation influence what species will settle there? What is the difference between wetlands in hilly terrain and those in flat prairie areas?"

Cashen became fascinated with birds while taking an ornithology course as an undergraduate majoring in resource management at the University of California- Berkeley. At Penn State, he is working with wildlife scientist Margaret Brittingham, as a way to turn his hobby into a career."The opportunity to study at Penn State was perfect because I wanted to learn more about birds in the eastern United States," says Cashen, who has already encountered173 of Pennsylvania's 368 bird species."This project is really exciting because there is such a diversity of birds in Pennsyl-vania's wetlands, including ducks, geese, songbirds, herons, and birds of prey."

Wildlife and fisheries science student Scott Cashen patiently observes and records the type of birds using this central Pennsylvania wetland as a habitat. His tools include a spotting scope, a field book, a tape-recorded bird call device, and a global positioning system.

"Some of the wetlands Scott is working with were drained more than 75 years ago," Brittingham explains."Their restoration involves removing drainage tiles or ditches so the natural water levels can return and dormant seeds can start growing. Restored wetlands are often confused with mitigated or created wetlands, which are entirely man-made. A created wetland is often constructed to mitigate damage to wetland areas that are being destroyed, such as sites in the path of a highway project."

Cashen divided his study of restored wetlands into two stages. The first year, he studied 18 sites in central Pennsylvania. These sites, situated over a wide geographic area stretching from State College to Bedford to York, were categorized according to size and type of vegetation. Now in his second year, Cashen is studying 24 wetlands in and around Erie County."The northwestern part of the state has geography that was formed by glaciers, so there are a lot of low-lying wetlands," he explains."The land around Erie is part of the Midwest's prairie pothole wetland region, which is a breeding ground for various species of waterfowl, particularly ducks and geese."

–John Wall