PITTSBURGH (AP) - The annoying beeps from trucks backing up in a scrapyard and the throttling of a live rail line haven’t dissuaded a pair of bald eagles from nesting for a second season on a desolate bluff above the din in Pittsburgh.
They’re the first pair to do so in more than 150 years. But much has changed in Pittsburgh and other cities - Chicago, New York, Washington, Denver, Phoenix, Portland and Boston among them - that now host the once endangered raptor.
“Bald eagles aren’t exactly common in cities, but they are having an increased presence in cities,” said Brian Millsap, national raptor coordinator for the Fish and Wildlife Service.
While the federal agency doesn’t track the number of urban eagles, its numbers are not insignificant, he said.
They range widely throughout the country. For instance, about 15 percent of the eagle nests in Florida are built in urban and suburban areas.
Because Florida repopulated its eagle population quickly in response to a population crash in the 1970s, scientists including Millsap looked into the phenomenon of urban and suburban eagles there a decade ago.
While in a helicopter observing an eagle nest on a cellphone tower in Florida, Millsap said, “As far as the eye could see, there was not a smidgen of green.
“There were rooftops and nothing but urban surroundings. They had no trees, no grass.
“It struck me how totally bizarre it was to have this bird here that was so rare and tied to the natural environment.”
Cellphone towers, bridges, cranes, even a baseball stadium light pole have become suitable homes for bald eagles to rear young, according to Millsap.
“They can nest in the craziest places,” he said.
Apparently such environments are not too crazy, as Millsap’s Florida study documented that the urban and suburban eagles, for the most part, survived as well as their rural counterparts.
The ’Burgh’s birds
In recent years, there have been bald eagles nesting in and near cities in Pennsylvania such as Philadelphia, Erie, Allentown and other populated areas, according to Patricia Barber, endangered-bird biologist for the Pennsylvania Game Commission.
“These birds are living closer to people and development than they ever have,” she said.
The pair of bald eagles in the Hays section of Pittsburgh is the only pair so far in the state nesting this year in a large, intensely urban area, according to Barber.
Why are these birds nesting in greater number in cities these days?
“Bald eagles need a place to nest and a clean source of fish, and they are finding that in a lot of places,” said Tierra Curry, senior scientist at Center for Biological Diversity, which is based in Tucson.
“Nesting in an urban area depends on a species’ ability to adapt to the human infrastructure,” she said. “The eagles are smart. They figured it out.”
With the banning of DDT - which nearly decimated the country’s population of bald eagles by weakening the bird’s egg shell in the 1970s - and new laws regulating clean water, the birds began to thrive when boosted by re-introduction programs several decades ago.
The improvement in water quality alone in the last two decades in Pittsburgh has boosted the fish population, and that’s been the main factor allowing for the return of eagles, according to Charles Bier, senior director of conservation science at the Western Pennsylvania Conservancy.
“Also, the fish are not carrying the load of toxins they were carrying 50 years ago,” he said.
No room at the inn
The number of nesting eagles in the lower 48 states continues to soar since the species was taken off the federal endangered list in 2007. There are more than 9,800 pairs, according to a 2007 estimate by the Fish and Wildlife Service.
There’s no end in sight for how much the bird’s population will grow, Millsap said.
The most storied eagle habitat - remote wooded areas near bodies of water - are taken up by nesting eagles, according to biologists.
So the birds are settling along productive waterways with trees large enough to support their mammoth nests, which can weigh more than 2 tons.
Now that there are good-quality waterways and habitat in southwestern Pennsylvania, Barber expects more eagles to land permanently in the region.
“There’s going to be more eagles,” she said. “It’s like a locomotive gaining steam.”
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Information from: Valley News Dispatch, https://www.valleynewsdispatch.com
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