Re: Question: If they bond, can Pride and the new female nest later?

Posted by NewMexiKen on
URL: http://bald-eagles-of-broward-county-florida.17.s1.nabble.com/Question-If-they-bond-can-Pride-and-the-new-female-nest-later-tp7573854p7573857.html

Our southern eagles are also smaller, and this pair had adapted to a diet that included many birds. Not sure whether they were a more important protein source than fish, but the Bald Eagles up north, especially Alaska subsist almost entirely on fish.

I think this proves they are adaptable creatures, just as they have adjusted to the urban environment and the presence of humans. My guess is that the northern range was the norm earlier in time but that breeding to the south conferred certain advantages to those who wandered there to breed a long time ago, particularly a longer breeding season and food availability during the winter. Their smaller size provides relatively more surface area to cool them, while the northern eagles can better conserve heat because of a lower surface/mass ratio. This latter trait is common in many species. Those in the northern part of their ranges tend to be heavier and also often have darker plumage.

Of course my theory may be upside-down, but I am not familiar with the fossil record of eagles. My guess is that they moved north as the glaciers retreated until about 14,000 years ago, but where did they move FROM? Maybe they started as smaller eagles in the south and their range slowly moved northward. They may have adapted in the opposite direction, becoming bigger and heavier up north. Need Help from a Paleontologist!!