Peregrine potential nest

Art McMorris who leads the PA Game Commission's Peregrine Falcon Nesting program asked me to keep an eye on the potential nesting activities of a peregrine pair that has nested on the Schuykill Expressway bridge near University of PA. This is the pair that used to nest on City Hall before the scaffolding went up. I believe it might be a new female however, as in new since the male moved to the bridge site. The female is banded and was hatched I believe four maybe five years ago on New york Presbyterian Hospital. They know it's the same male because he visits the spots on his old route through center city, including the a frame eon top of Liberty Two.

Yesterday, Art and Ed who had been monitoring the pair, took me to the site and down to the CSX offices, as we have to be near their tracks to view the nest. We saw the pair, the female is definatly hanging out on a plate where several girders meet on a flange that forms a buttress where concrete pylon meets the bridge. She was not incubating, but may be fidgeting with some eggs. Most birds do not incubate until all the eggs are laid so they hatch at once.

Today I was at the site from 4:00 to 5:10pm, although the first half of that was waiting for the two trains blocking the view to leave. I tried calling CSX's yardmaster to alert them to my presence but no one answered. At first the potential nest ledge was empty, I could hear a peregrine calling, but could not locate the bird. The female soon appeared flying in from under the bridge near west bank, She landed on the nest(?) site and tucked down for about ten minutes, she appeared to fidget with something towards the back of the ledge,she would call periodically. She left the ledge and landed on top of a cement pylon nearer to the west bank, I could see that she was banded. She preened and would lift her talons and clean? them and call. After about fifteen minutes the male flew in from below and down stream and landed on her back and copulated,flying off immediately. The female remained on the pylon for further ten minute sand I left, with her still on perch.