by LIZ TOTH
The falcons have been spending a lot of time wiggling on the eggs to press the bare skin on the chest, called the brood patch, down on the eggs to keep them warm. In species where only the female incubates the eggs the male doesn’t develop a brood patch. Male and female peregrines both have brood patches because they share incubation of the eggs. If you watch the Falcon Cam you’ll see the adult peregrines rock side-to-side as they settle on the nest. This rocking opens the feathers that have curled over the brood patch and puts their skin in contact with the eggs.
The chicks should hatch very soon. As the date for possible hatching draws closer we can expect to see the female arranging the stones around the scrape as she prepares for hatching. Just prior to hatching she may hear the chicks inside the eggs and seem more alert. The female has been very alert today indicating hatching should be soon.
Liz Toth is Associate Curator of Live Animals at the Boonshoft Museum of Discovery.