Just after peregrines awoke they found overcast skies with fog and mist, calm winds, and temp rising towards 50°F.  The forecast calls for areas of fog before 7am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 70. Calm wind becoming southwest 5 to 8 mph in the morning.  WOW…we had a great rebound in the afternoon with sunshine returning full force and temps topping out in the lower 70’s inland….WOW!

Incubating peregrines may turn at intervals during their time on incubation duty, rising up slightly from eggs to do so, based on space available.  The bird will periodically move the eggs with its beak, usually by a backwards pushing and hooking motion which rolls the eggs against the feet, each other, or the  small slope in the gravel.  The sitting peregrine sometimes preens itself, and may partly rise or even leave the eggs for a short while to engage in more vigorous preening and wing stretching.  This afternoon the female spent a bit of time preening and wing stretching, while also making sure that the eggs were protected from the sun and heat!

Hers’s the next update on the embryonic development sequence currently underway:

Day 16

* The toe claws begin to curve downward.

* The bottom of the feet become padded.

* Feather germs on the back and tail appear as long, tapering cones.

* The beak begins to harden.

* The comb appears serrated.

* The embryo begins to draw calcium from the eggshell for its growing bones.

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.