HARRISBURG, Pa. (WHTM) – It’s a different and most welcome sort of Easter egg. On April 6 the female peregrine falcon at the Rachel Carson State Office Building laid her fourth egg of the year.

The first egg this year arrived nearly 2 weeks ago. It takes a month for falcon eggs to hatch.

The State Department of Environmental Protection has provided a nest for the falcons on the 15th floor of the building since the first breeding pair showed up in 2000. Over 80 falcons have hatched since 2000, making it the most prolific nest site in the commonwealth.

As the falcons have come back year after year, they have become international celebrities. The network of webcams eavesdropping on them has expanded; four cameras now watch them, including an infrared camera for nighttime viewing.

They stream full-time year-round, catching the falcons’ comings, goings, and most importantly, their hatching.

Not bad for a bird that was effectively extinct in Pennsylvania for almost three decades.

Between 1959 and 1987, no peregrine falcon nesting was observed in Pennsylvania. In fact, the species was declining all over the world. In 1973 it was listed as an Endangered Species by the U.S. Fish and Wildlife Service.

Research pointed to a chemical, DDT, as the primary cause of the decline of the falcon, and many other bird species. DDT, widely uses as an insecticide, accumulated in birds at the top of the food chain, and interfered with their ability to metabolize calcium. This caused them to produce eggs with thin shells, which shattered easily.

With the use of DDT regulated, the affected bird species started making a comeback, helped at times by humans reintroducing them to areas where they’d disappeared. The peregrine falcon was removed from the federal endangered list in 1999, and Pennsylvania’s threatened list in 2021. They are still under the protection of the Migratory Bird Treaty Act, as well as the state Game and Wildlife Code.

It is indeed a happy coincidence (and we are not the first to make note of it) that these falcons are thriving on a building named after Rachel Carson. It was her book Silent Spring, published in 1962, that first brought public attention to the problems caused by the indiscriminate spraying of pesticides, including the thining eggs.

If all goes as normal, the falcon might lay another egg or two. The chicks grow rapidly; sometime in May, when they start losing their fluffy down and start growing adult feathers, DEP biologists will put bands on their legs, so their future travels can be tracked.