It has become a bit of a fad in the last few days at my current workplace to open a browser tab to either http://www.lbwl.com/falcon.htm or http://www.lbwl.com/falcon2.htm , take a quick look now and then, say "Awwww," then get back to work. After all, to us these are home-town heroes.
But over the last couple days, I've observed something that I'm not sure how to explain. For those who come along later, things may change on the web-cam, so here is a still I captured this morning (Wednesday 5 Jun, 2019):
The Michigan DNR has been by to give these chicks a health check and place the bands, and the local Energy company, upon whose building the falcon chose to nest, place the cams. But notice how the one on the far left of the picture is still in down, while the two siblings are much further along in the molt and almost have full adolescent plumage. At the same time, this downy chick appears to be quite a bit larger than the siblings. This might be just a trick of the eye caused by the down, but as I continue to watch the web-cam I am convinced this one really is 5 to 10% bigger. I assume in another month or two the chicks will again be indistinguishable, but for now the one clearly stands out.
I read this little resource, but the language was rather technical and a bit over my head, plus it really didn't explain sibling variation. Any ideas?