Falcon chicks resettled

and then flew off. They continue to live Downtown.

The birds’ usual Gulf Tower nesting site is surveilled by a live-streaming camera owned by the National Aviary. The media presence has made the birds local celebrities, and peregrine watchers were outraged that the chicks were moved to accommodate a developer’s schedule.

The contractor complied with the directives of wildlife managers, and the Game Commission and U.S. Fish and Wildlife Service granted permits for the removal of the chicks. They were taken by Game Commission staff and delivered to the Humane Animal Rescue Wildlife Center, a wildlife rehabilitation center near Verona.

“After the care received in rehabilitation, the young were capable of tearing food provided to them, and in the wild they’ll learn to hunt with their foster siblings,” Mr. Brauning said.

The cause of the other two chicks’ deaths was unknown, but the Game Commission said one had parasitic lesions on its lungs and it is possible both died from infections. The Game Commission said chick mortality is not uncommon, and about half of all birds die before fledging.

Rachel Handel of the Audubon Society of Western Pennsylvania said nestling mortality is particularly high among peregrines.

“In a 2008 study of peregrine falcons, it was found that only about one-third of hatched chicks lived to be more than 1 year old,” she said. “For the study, the birds were followed after fledging the nest, and only 37 percent of birds survived one year beyond hatching.” She said, nearly 60 percent of peregrine chicks do not make it through the first year. Once they pass that milestone, most peregrines live 12 to 15 years.

Peregrines were taken off the federal Endangered Species List in 1999 but remain protected under the federal Migratory Bird Treaty Act. In Pennsylvania, the birds are considered endangered and protected by statute under the Game and Wildlife Code.