The Peregrines started off today under fair skies, wind from the NE at 3MPH, and temp at 55F. The forecast calls for mostly sunny skies, with a high near 77. Calm wind becoming southeast 5 to 7 mph in the afternoon. For tonight, a slight chance of showers between 1am and 2am. Mostly cloudy, with a low around 54. Southeast wind 5 to 10 mph becoming light after midnight. 

The chicks were seen moving around the nest box this morning, at times restless and flapping their wings in an awkward way, and then going back into huddle mode for period of time. Just after 6:15PM, the female arrived with a freshly caught Blue Jay for dinner.  As they approach four weeks of age, the chicks are rapidly growing their juvenile feathers both below and above, and are looking visibly darker with each passing day. The chicks are nearing the midpoint of their transition from down-covered chick to juvenile-plumaged fledgling, and are nearly full-grown in terms of body size and weight.

Around this time in the growth cycle, the chicks may sometimes join their parents in alarm calling instead of falling silent. They are able to follow the flight patterns of their parents outside the nest box.  They will also become more vocal in calling for food.  As we see in this photo, they begin to grab or steal the incoming food offerings, and sometimes head away from the other chicks.  Sleeping and dozing still occupy a large part of the day, but close huddling begins to diminish.

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