When might they hatch?

Mom and chicks, 2003
Courtesy of PaleMale.com

Reader Nan I. Holmes sent in a question:

Dear Marie,

It would seem we must be close to having hatchlings. Can it be time?

My answer:

My guess is that hatch time at the Fifth Avenue nest might be between April 8 and April 15. I think incubation began somewhere around March 10, give or take a few days, and the incubation window is 28-32 days. Even if incubation began a bit later, if there are no signs of a hatch by April 18, let's say, I'd be pretty sure it isn't going to happen this year.