The Cathedral of Learning is many things — a symbol of… The Cathedral of Learning is many things — a symbol of higher education, a quiet study area surrounded by Gothic Revival architecture and, quite literally, a lovers’ nest.

Dorothy, an 11-year-old peregrine falcon, and her partner, E2, have nested at the very top the Cathedral of Learning since 2002. Dorothy recently laid three eggs — the third just two nights ago — in the sandy nest, which is being monitored by the National Aviary in Pittsburgh.

Kate St. John, a volunteer who monitors the pair of peregrine falcons, calls the building “the Taj Mahal for falcons.”

“The Cathedral of Learning is fantastic. It’s a gorgeous building, [with a] good view, and the nearest nest is far away, so there’s no competition,” said St. John, who has been monitoring falcons since 2001.

Because peregrine falcons nest on cliffs with sand and gravel, the Cathedral provides the right environment for the falcons, albeit with an urban twist, said St. John. Sand and gravel are necessary for the falcons to dig a shallow “bowl” to prevent eggs from rolling away, so some was provided by the National Aviary when it was discovered Dorothy and her previous partner, Erie, had nested there, St. John said.

Dan Brauning, the Wildlife Diversity Chief of the Pennsylvania Game Commission, said the Pittsburgh environment is “suitable” for the falcons.

“To some degree they are successful in the urban setting because they avoid predation. The buildings and bridges have cliff-like resemblances. There are plenty of songbirds for food,” Brauning said.

The nest at Pitt has produced 29 fledglings since 2002, but Dorothy flew to Pittsburgh from Wisconsin in 2001, according to the National Aviary website.

Dorothy — who was named after a parking lot attendant who monitored falcons — hatched in Wisconsin in 1999. When she was about a year old, Dorothy flew to Pittsburgh. Because Dorothy had been banded after she hatched, the National Aviary was able to find out from where she had flown. Dorothy’s long journey is consistent with the nomadic tendencies of peregrine falcons.

“Peregrines wander. They don’t migrate. They go every which way,” St. John said.

In 2002, Dorothy first nested in Pittsburgh with her mate, Erie, who was identified from his band as coming from Columbus, Ohio. Erie, who made national news for fighting and killing a competing male falcon from Cleveland, mysteriously disappeared in October 2007.

Erin Estell, assistant director of Animal Programs at the National Aviary, said there are a number of different scenarios explaining the disappearance of Erie. E2 (short for Erie 2) could have fought off Erie, or Erie could have died, Estell said.

While peregrine falcons don’t necessarily mate for life, they will often mate with the same partner if both consenting individuals show up at the mating site during mating season. After the babies fly away, the adult falcons will migrate to different winter grounds.

Erie’s unexplained absence left Dorothy single, but she didn’t remain on the market for long.

“Dorothy doesn’t die of heart sickness. She finds another mate,” Estell said.

E2, who was hatched at the Gulf Tower in Pittsburgh, arrived on the scene in fall 2007, and in spring 2008, Dorothy began nesting with him. Three eggs nestled on top of the Cathedral mark the third time Dorothy and E2 have made a generous contribution to the peregrine population.

The Pennsylvania Game Commission and the National Aviary band eyases, or baby falcons, when they are around three to four weeks old. When eyases are banded depends on the size of the bird, Estell said. The people in charge of banding the eyases wait for the feet to be completely grown so that the band does not get too tight or fall off.

While it is possible to track falcons through the Pennsylvania Game Commission’s telemetry research study (available through the Pennsylvania Game Commission website), the bands serve as an identification and research tool, Brauning said.

Because of the bands, two falcons who hatched at the Cathedral have been located and identified by falcon watchers in the area. A female hatched in 2007 was last recorded at her own nesting site in Rochester, N.Y., last year. The second falcon, a male hatched in 2008, was spotted last December in Tarentum, Pa., according to Brauning and the National Aviary.

The peregrine falcon was removed from the national list of endangered species in 1999, according to the Environmental Protection Agency’s website, but peregrine falcons remain a Pennsylvania Endangered Species. The banding of the falcons has helped monitor the birds, and while it does not directly contribute to the repopulation of peregrine falcons, it does serve as a tool, Brauning said. He also said the banning of DDT in 1972, a pesticide used on crops and forest lands, was a prerequisite to helping the falcons repopulate.

Now, Brauning says that the Pennsylvania Game Commission helps protect peregrines from human activity. Their numbers are still small, with only 1700 breeding pairs in the U.S. and Canada, according to the Pennsylvania Game Commission. Peregrine falcons can be found on all places of the earth except Antarctica; in addition to the Cathedral of Learning, Pittsburgh has other nesting locations at the Gulf Tower in Downtown, East Rochester-Monaca Bridge and 62nd Street Bridge, according to the National Aviary website.

Although Dorothy and E2 have been exposed to humans since birth, St. John stresses that these birds are not pets.

“They do not like people. They will attack anyone who messes with their nest,” St. John said. “But, they will put up with people being around.”

While the urban environment does provide certain amenities — like an unlimited supply of pigeons to eat — there are certain dangers in Pittsburgh that don’t exist in a falcon’s natural habitat.

One of the most common ways for falcons to die is to collide with window panes, Brauning said. In June 2008, a Pittsburgh falcon crashed into the Rand Building and broke his neck, according to a previous article in The Pitt News.

People can watch live video of the famous lovers in their nest on The National Aviary’s website. St. John writes about the peregrines in her blog, Outside My Window, which is on the WQED website.

The typical mating season of peregrines lasts from late March through May, according to Defenders of Wildlife. The average nest usually has three to four eggs, which will hatch after about 30 days of gestation.