Peregrine falcon nesting follows the same pattern every year. Here are the seasonal milestones in Pittsburgh from Art McMorris, Peregrine Coordinator for the Pennsylvania Game Commission:
- Territorial defense and courtship begins: January. The birds are seen flying together and circling their territory.
- Courtship intensifies: February and early March. The birds are seen flying together more often. Male presents food to female. They bow at the nest. Frequency increases as egg laying approaches.
- Egg laying: Begins in mid March or early April (as of 2016, earliest is March 10). An egg is laid every other day until the clutch is complete.
- Incubation: Begins when the next-to-last egg is laid.
- Hatching: 33-35 days after incubation begins. Typically in late April, early May.
- Brooding: Lasts for 8+ days after hatching. Typically in late April, early May.
- Banding in Pittsburgh: Conducted by the PA Game Commission. If the chicks are in an accessible location they are banded at 23-30 days old.
- Chicks fledge: 38-45 days after hatch. Typically in early June. Timing depends on age, sex and physical condition of the chick.
- Young birds disperse: Young in Pittsburgh are dependent on their parents for 6-10 weeks after fledging. They leave home from July through September.
When (in the fall) are peregrine’s likely to migrate away from the Pittsburgh area? I have never seen one and will be in the area (closest to the Tarentum Bridge site) in mid-Sept.
The adults will still be at the bridge but the young will leave soon. Most likely they have left already.