The peregrines started the day off under overcast skies, with with winds from the SW at 6MPH, and temp at 57F.  The day ahead calls for partly sunny skies, with a high near 75. Southwest wind 7 to 11 mph. Very nice!

In their fourth week of life, the chicks undergo significant changes almost daily.  Around day 25, the brown tips to the secondaries become clearly visible, and the number of colored feathers visible on the breast increases noticeably.  Behaviorally, they are rarely resting on their tarsi anymore at this age. IN this image, the chicks are loafing in the nest box, and the female is perched looking in…..notice the changes in feather coloration.

In terms of feeding times, the pattern is irregular overall.  The young are twice as likely to be fed during the early morning and evening periods than middle of the day.  There tends to be a higher frequency of feeding visits during morning or late afternoon/early evening.  Interval times between feeding visits usually averages about 2 hours, and average duration of a meal runs about 8-11 minutes, with duration of meal time increasing a bit as the chicks get older. Here we see a late day feeding just before 7:30 PM, with sunset at 8:18 tonight.

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; http://www.peregrine-foundation.ca/info/ageguide.html