The peregrines started the day under mostly cloudy skies, wind at NE 5MPH and the temp rising through 50F. Showers likely, mainly between 10am and 2pm. Patchy fog before 10am. Otherwise, cloudy, with a high near 57. Calm wind becoming west 5 to 9 mph in the afternoon. Chance of precipitation is 70%. New precipitation amounts between a quarter and half of an inch possible.

A slow moving upper level system currently over the eastern Great Lakes is tracking eastward and arrived in New England overnight and will be in residence with us both today and Monday bringing cooler conditions with lots of clouds as well as the risk for showers from time to time. A rumble of thunder not out of the question this afternoon as the air aloft will be much cooler than the surface. 

Again this morning, the female shows how she shuffles and turns very carefully around the eggs, and then fluffs out feathers, while leaning forward and settling in on the eggs in an effort to match the brood patches and the eggs.  The feathers become generally loosened and those of the lower back and the wing coverts are usually erected somewhat.

Day 17 & 18

* Scales appear on the lower legs.

* The embryo continues to grow and move.

* The ribs begin to ossify.

* Metanephros starts its function

* The Furcula is formed by the fusion of the 2 clavicles

Literature cited:

Veldhuis, Froona, Embryonic development day 15 – 18, Sept 20, 2008;   http://falcoperegrinus-froona.blogspot.com/search/label/embryonic%20development                                                                                                                                                                                     

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