This morning the peregrines started the day with clear skies and lots of sunshine, with winds on the lighter side from the SW at 7MPH and the temp at 55F.

The female had been holding down the overnight incubation duties.  At 5:32 AM, she rose up and off the eggs, headed to the left edge of the nest box, and departed.  Minutes later, the male entered and did his usual and extended shake, rattle, and roll before finally settling on the eggs.  The incubation total coverage by both male and female has been terrific. Contact incubation of eggs is one of the most conspicuous features of avian biology.  Its purpose is the maintenance of a warm and steady egg temperature, and the parents adjust their lives around this entire objective.

The transfer of heat onto the eggs is regulated  through adjustments to blood flow through the previously mentioned brood patch, and heat production by the parent, mediated through temperature sensors in the skin of the brood patch.  It s all about the maintenance of a steady egg temperature!