The Peregrines started off the day under fair skies, wind from the Sw at 6MPh, and  temp at 47F.  The day ahead calls for increasing clouds, with a high near 68. West wind 5 to 11 mph. Tonight, a chance of showers, mainly after 10pm. Cloudy, with a low around 54. West wind 5 to 9 mph becoming calm in the evening. 

By day 31, the chicks often become actively interested in losing their down, preening themselves and sometimes ending up with feathers stuck to their beak as a result.  From the back they are looking increasingly dark, with the wing feathers approaching full length. In this photo, the chick in the back left corner was wing flapping, the others have been preening.  The darker feathers are coming in all over, and the down is decreasing rapidly!

Around this time, a nestling can rip up a prey item quite well, and at 39 days it soon demolishes even intact prey items. At this stage, prey is usually left intact for the young to deal with, though the parent may still break food up into smaller pieces.  There is, however, a considerable overlap between parental and self-feeding, and adults will present young with pieces of torn-up prey until they fledge, especially if nestlings solicit.

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