Nature’s drama is unfolding just a block from the Capitol on the eve of the annual June budget showdown.
The plotline is of Shakespearean proportions: the resident male challenged by a younger suitor, the disappearance of the female while her two chicks were still nestbound, several feather-raising falls off a 15-story ledge, complete with daring rescues amid traffic by falcon watchers.
It is a real life-and-death struggle atop the building that houses the DEP, where families of peregrine falcons have nested for 12 years.
Falcon pairs began breeding there shortly after DEP staff put out the welcome mat: a three-sided wood nesting box and a few handfuls of gravel.
At the time, falcon populations around the country were slowly rebounding after being nearly wiped out by the pesticide DDT in the mid-20th century.
After the chemical was banned in 1972 the falcons began to recover, building nests on structures like bridges and skyscrapers that mimicked their natural cliffside habitats.
In a development that DEP falcon guru Jack Farster dubbed a "happy irony," the first falcon pair — both hatched from nests on Philadelphia bridges — moved onto the ledge at the DEP building, which is named for Pennsylvania native daughter Rachel Carson, the biologist who exposed the threat of DDT to the environment in her landmark 1962 book, Silent Spring.
Peregrine falcons were removed from the federal endangered list in 1999 but remain endangered in a number of states, including Pennsylvania, where 25 years ago, there was only one active nest.
Today, the number of breeding pairs in the state grows each year, doubling from 15 in 2005 to 31 in 2011, according to the Pennsylvania Game Commission.
The state’s biggest metropolis is no exception: For the third straight year, a falcon pair is raising a family 15 stories above Philadelphia streets, in a nest on City Hall tower. Over the weekend, the four chicks took their first flights under the watchful eyes of volunteers and falcon fans in neighboring office buildings.
All told, 40 fledglings have hatched at the Carson building in the last decade and established nests of their own as far away as Delaware and Ohio.
This year’s breeding season at the Carson building started in February with a series of aerial battles as the resident male successfully fended off a younger challenger.
As the world watched on the Internet via the DEP’s 24/7 "Falconcam," two male chicks tapped their way out of their eggs on April 17.
Then tragedy struck. The female that had ruled the roost since 2010 suddenly disappeared, leaving the not-insignificant feeding and care duties to the smaller male.
Farster believes she succumbed to disease or injury, perhaps a confrontation with another raptor or by flying into a building.
Fortunately, the chicks were a month old and healthy, but the male has had to work double time hunting pigeons and other prey until the young are able to fend for themselves sometime in late June.
More drama ensued days later. High winds swept the smaller chick — known as "red band" — off the ledge before he had taken his first flight and he was unable to fly back up.
Fortunately, volunteers who help DEP staff monitor the nest from dawn to dark during the two-week fledge season were on hand to scoop him up.
The rescue was achieved with the help of some "high-tech devices," Devine joked, holding up a cardboard box containing heavy gloves, a towel, traffic flags, and a fishnet.
A little after 9 a.m. Thursday, Devine and interns Hope Comden of Downingtown and Colin Gardner of Carlisle were scrambling up parking garage stairs in search of the red-banded male after he disappeared again.
He turned up two hours later, happily perched atop the nearby Department of Education building.
Twelve hours after the two young birds were spotted testing out wobbly wings, they were soaring over the Susquehanna River, flying high, then plunging with great speed and chasing each other above the rooftops.
It was, as volunteer coordinator Deb Hannon put it, "payoff day" for falcon watchers.
"They got their wings last night," said Hannon, who tracked one of the birds as he glided confidently toward the river.
"The sky is home to them now, not a ledge."
Contact Amy Worden at 717-783-2584, firstname.lastname@example.org, or follow @inkyamy on Twitter.