Lawrence Peregrines: Day 35/36

June 8, 2019 in Near the Clock Tower

The Peregrines started off the day under fair skies, calm winds, and temp at 55F. The day ahead calls for sunny skies, with a high near 79. Northeast wind 3 to 7 mph. Tonight, clear, with a low around 52. Light southeast wind.

2019.0609.2Looking back, at 28 days, or 4 weeks old, the young falcons really began to show their juvenile plumage, and became much more active around the nest box. They started much more active wing flapping, which helps to shed the down.  At 35 days, or 5 weeks, they became well feathered and most of the down has been lost, though some adheres patchily to the young birds. The quill feathers are quite strongly developed, though the wings and tail are still short and rounded. At day 36, the chicks look almost like full-fledged juveniles.  They are spending much of their day flapping their wings, which both strengthens their flight muscles and shakes loose some of the few remaining down feathers.  In the midst of wing flapping frenzy, those remaining bits of down go airborne, along with all the feather remnants and other debris!

Literature cited:

Ratcliffe, D. 1993. The Peregrine Falcon. 2nd ed. Carlton, England: T. and A. D. Poyser.

The Canadian Peregrine Foundation, Peregrine Falcon Development – Age Guide;