Outside My Window

The photo in my last blog of the peregrine eggs with no mother sitting on them prompted several of you to ask this question.

Peregrines in temperate climates don’t begin incubating the eggs until the last or next-to-last egg is laid, though they do protect the eggs from cold and rain.  I’m not sure why peregrines wait to incubate but the result is that all the eggs hatch within a day or two.  This makes the chicks approximately the same age and size as they grow up together.  From what I have observed, peregrine nestlings are never aggressive against their siblings.

Bald eagles, on the other hand, begin incubation immediately and the chicks hatch days apart.  The first chick is older and larger than the second, and so on.  The parents focus on feeding the largest chick who then becomes better able to compete for food.  The smallest chick often starves.  Sometimes the largest chick kills his siblings.

Frankly, I’d rather be a peregrine.

March 17, 2008:  Over the weekend Tasha laid her 3rd egg so she will be incubating pretty much full time now.  See her progress on the National Aviary’s webcam

March 19, 2008:  We have confirmation today that Tasha has laid 4 eggs.  It’s likely her clutch is complete now.

I’m a little late announcing that there are now two eggs at the Gulf Tower peregrine nest in downtown Pittsburgh.  The second egg was laid late afternoon on March 13.

The interval between peregrine eggs is about 48 hours but can be as much as 72 hours for the last one. 

Tasha, the female peregrine at Gulf, usually lays 4 eggs so you can expect to see more in the next few days. 

Watch the National Aviary’s webcam for updates.

Thanks to Ed Shott who noticed that the Gulf Tower peregrine, Tasha2, had laid her first egg this afternoon around 3:30pm.  Ann Hohn of Make-A-Wish, whose offices are near the nest and can see the webcam on TV, confirmed that we should be proud indeed.  

Here are two snapshots from the Aviary’s webcam.  (You can take snapshots too by right-clicking on the webcam’s image and choosing Save.)

The first snapshot shows Tasha inspecting the egg - a rusty red color near her feet.  When she first lays an egg she waits for it to dry before she begins incubation.

The second snapshot shows Tasha incubating and Louie (father bird) coming to visit.  He appears to be bowing in congratulation.

As Ann Hohn said, “Cigars for everyone.”