Eaglets active today, March 18, 2017

[tczig]

I arrived at the nest around noon.  There was no sign of either adult, however, the eaglets were very active and flapping around in the nest.  I stayed a while and took a couple photos.  The parents never showed up, but I wasn't there that long.

Does anyone know why one eaglet is a light gray and the other appears very dark?  Could that be that they are different sexes, or is that just normal coloring?

[NewMexiKen]

The gray color is due to the presence of white natal down. When hatched the eaglet is completely covered with down. As its dark body and flight feathers emerge they replace the down. The down persists for over a month and is especially noticeable on the head.

As you probably know, the eagle incubates each egg as soon as it is laid, causing the eaglets to hatch sequentially rather than all at once as is the case with most other birds. The size differential may also be related to the sex of the eaglets. Females are larger at all stages of life, and 2 out of 3 first eggs produce a female. The second-hatched is more likely a male. If so, this can be a good sign, as they are less likely to be in conflict than if a male hatches first and must then compete with an aggressive and fast-growing younger female sibling. These two seem to be getting along with each other-- let's hope!

The smaller eaglet is probably about three days younger than the first-hatched, although it is within the realm of possibility that there could have been a second egg which failed to hatch, meaning that the young one could be up to a week younger than its sibling.

The older eaglet hatched on or about February 5, so it is six weeks old this weekend.

[tczig]

Thanks Ken for the great reply; I learned something new today.  I was happy to see both eaglets very active when I was there yesterday.  There was a guy there with a fancy camera; I wish he would have posted photos.

Thanks.