Recovering an endangered species requires legal protection, habitat, motivated staff, funding and time. Sometimes it can take decades for a species to recover. When a species has an extended reproductive period and breeds only once each year, time will be the limiting factor in the species' recovery.
Consider, for example, bald eagles in Pennsylvania. In 1983, only three pairs nested in the northwest part of the state. That's when the Game Commission began a seven-year bald eagle restoration program.
With funding from the Richard King Mellon Foundation and the federal Endangered Species Fund, biologists traveled to Saskatchewan where they collected and transported seven-week old nestlings to Pennsylvania. Over seven years, a total of 88 eaglets were relocated to hacking sites on the Susquehanna River near Harrisburg and in the northeastern part of the state.
By 1988, the state's population of nesting bald eagles had grown to 25 pairs. In three years, the population doubled, and by 2006, biologists confirmed 100 nests statewide. In early July this year, 30 years later, the Game Commission confirmed 252 eagle nests in 56 of the state's 67 counties.
Patti Barber, a Game Commission biologist with the Endangered and Nongame Bird Section, could barely contain her enthusiasm when we talked recently. "Young are still fledging, and we're still finding nests," she said. "The nest count for 2013 is up to 264."
Three of those nests are in the Pittsburgh area, one on each of the Three Rivers. The one on the Monongahela River in the community of Hays just five miles from downtown Pittsburgh has received the most media attention. It has been repeatedly featured on television, on radio, and in print.
"The Hays location is ideal," Barber said. "It's on a steep inaccessible hillside, yet close to people."
Bob Mulvihill, an ornithologist at Pittsburgh's National Aviary, has coordinated well-attended eagle watches from Hays for several months. One young eagle fledged just two weeks ago and is now learning to fend for itself.
Barber expects more bald eagles to nest in southwestern Pennsylvania in the future. "Right now we have 16 active nests in southeastern counties in the Philadelphia area," she said, "so eagles seem to be adapting to urban life."