A mixture of the fuzzy feathers of a nestling are giving way to contour feathers. Here you can see the newly completed primary and secondary flight feathers on his wings and the brownish contour feathers coming in around his head, back and breast.

The energy it must take to produce two sets of feathers at such a young age. No doubt a testimony to the value of high quality insect food full of proteins and fats.

Location: Glacier National Park, MT