Our two eaglets are around six weeks old at this point, and you can see that they’re quickly developing dark areas all over their bodies. These dark areas are where their blood feathers — or pin feathers — are growing. They’re called “blood” feathers because each feather (which looks like a “pin”) is enclosed in a blood-filled shaft that feeds the feather. The color of the blood in the shaft looks blue from our angle, as you can see in this photo of an eaglet from a nest in Shiawassee National Wildlife Refuge in east central Michigan. Notice the dark brown feather protruding from the shaft. Once the feather is fully grown, the shaft will fall off or the eaglet will pull it off, and the feather will unfurl.
Eventually the eaglet will develop feathers all over its body, and when the feathers are completely developed, the eaglet will be dark brown in color. The eaglet will not develop its distinctive white head and tail until it reaches maturity, at about 4-5 years of age.
In the video below, you can watch biologists working with an eaglet at Stony Creek Metropark (courtesy of Macomb Audubon Society). The eaglet in the video is six weeks old — about the same age as our chicks. This eaglet is probably close in appearance to our older chick. Watching the video, you can see the blood feathers on this eaglet’s wing, and you can also get a new appreciation for how big our chicks’ beaks and talons are about now.
As you might have seen me mention on the cam page a little while ago, we’ll be launching the 2014 Eaglet-Naming Contest on April 9 now that our two chicks look like they’re healthy and going to make it to fledgling age. On the afternoon of April 9, we’ll post a note on the cam page with details on how to enter our contest.