Lawrence Peregrines: Day 25!

May 29, 2019 in In the Nest Box, lawrence peregrines, Peregrine Falcons Eastern Massachusetts, Peregrine Falcons Massachusetts

The Peregrines started off today under overcast skies with fog and mist, wind from the N at 8MPH, and tempt at 46F. The forecast calls for patchy fog before 8am. Otherwise, mostly cloudy, with a high near 64. North wind 5 to 7 mph becoming light and variable. Tonight, a chance of showers, mainly after 8pm. Patchy fog between 11pm and 1am. Otherwise, cloudy, with a low around 50. Southeast wind around 6 mph becoming calm in the evening. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

2019.0529.1Had early looks at peregrine chicks just before 5:30AM this morning, and now that the webcam has been cleaned….WOW, the view is much sharper!  The chicks are now growing much larger and exercising their wing muscles. 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 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;