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.”
Fortunately, Pennsylvania is not the only place bald eagles are thriving. In fact, many states are seeing similar nesting success thanks to similar restoration efforts.
In New Jersey, for example, bald eagle nests jumped from one in 1982 to 135 in 2006. Today, Ohio has more than 200 nests, Maryland and Virginia more than 400 nests, Maine more than 500, and Michigan more than 700.
Florida, Minnesota, and Wisconsin report more than 1,000 nests.
A variety of factors helped bring bald eagles back. The Bald Eagle and Golden Eagle Protection Act provided federal protection. The Clean Water Act provided the authority to clean the nation’s rivers and lakes. It took many years, but today’s clean waterways provide the fish that eagles eat.
Educational efforts have taught the public to respect eagle nests and stay a reasonable distance from active nests to prevent disturbing them.
Thanks to Rachel Carson’s warnings from the early 1960s, we came to understand that the insecticide DDT crippled the reproductive success of bald eagles, ospreys, peregrine falcons and brown pelicans.
DDT caused birds that ingested it from lower on the food chain to lay eggs with shells so thin they cracked during incubation. Nest success for these species dropped to near zero.
Outlawing DDT in the early 1970s caused hatching rates to increase rapidly. (Though still illegal in the U.S., DDT is still manufactured and exported to Latin America.)
Thirty years have passed since many of these efforts to restore bald eagle populations were initiated. Clearly time heals even environmental wounds.
The story of the bald eagle’s restoration and recovery has become one of wildlife management’s greatest success stories. In 1982, bald eagles were critically endangered. In 1994, their status was upgraded from endangered to threatened. And in 2007, bald eagles were removed from the national list of threatened species.
Today seeing a bald eagle along a big river or lake is more an expectation than a surprise. And it’s an encounter no one ever forgets.