The third brood of Black-capped Chickadees to be raised in our yard will be out of the nest most likely on Friday, the 16th day after their hatch. You can see chicks just out of the egg in the first photo below. At least two eggs were yet to hatch when the photo was taken May 26. The bulging dark spots are unopened eyes. The new birds are naked but for a few tufts of down. They began to develop contour feathers, those that cover the body, in a day or two. The down will be pushed out by the growth of true feathers, remaining attached to those feathers until it wears off after the bird leaves the nest. This is why young birds you see after fledging (leaving the nest) often have a downy appearance. By day nine, the chicks are showing "pin feathers," the shaft of the feathers they will wear when fully grown. By day 12 the birds have most of their feathers in place. By day 16, they resemble adults except for shorter tails and distinct mouth corners. Those corners allow the mouth to form the gape that baby birds present to their parents when food is offered. I have read that the bright color of the inside of the mouth stimulates the adults to feed. It certainly presents a can't-miss target. The young birds will be fed by the parents for as long as four weeks after fledging. The birds at hatch weighed one gram. They will be 12 times that size when they hop out of the nest box.

These chickadees were photographed on the day they hatched. At least two eggs were yet to hatch. The bulging dark spots are unopened eyes. The "lips" on either side of the bill allow the mouth to gape open for feeding.

Here are the chicks at day seven. They have some feathers. You can see feather shafts on the wings. Those will develop into complete feathers. The individuals can be distinguished by their mouths.

Yesterday, Tuesday, June 7, the birds looked like chickadees. Five birds are visible. Others might be out of sight. I did not keep the nest box in hand long enough to find out. Wings on the bird center bottom show feather shafts. These birds will be out of the nest by Friday or Saturday.