Mar 19 2009
Question: Sitting on Eggs – or Not
Question: After the mother peregrine has laid an egg, why doesn’t she sit on it all the time?
Answer: Peregrines usually lay 3-5 eggs per clutch but they don’t begin incubation (to raise the eggs’ temperature) until they’ve laid their next-to-last egg. The mother bird makes sure the eggs don’t get wet or freeze but otherwise delays development of the first eggs until the third appears. For more information, see my blog at: http://www.wqed.org/birdblog/2008/03/16/why-isnt-she-sitting-on-the-eggs/
(photo from National Aviary falconcam at Gulf Tower, Pittsburgh, 18 March 2009)
