May 4, Day 0 - BirthDay:

Five chicks have hatched -- some just in the past hour or so. The sixth eggshell is cracked but the chick has not yet emerged. The seventh egg - the last one laid - is still unbroken. The hatchlings are exhausted from the strenuous job of breaking out of their shells, and just flop down fast asleep wherever they are. While they rest, the parents carry away all the broken shell fragments to keep the nest soft, clean and safe.

The eyes look enormous in the tiny heads because songbirds' eyes start out at full adult size, and the hatchlings gradually grow into them. But they're still undeveloped, and won't open for a week. Their ears are also still sealed - the ear-holes will open in a few days.

You can see the yolk of the egg in the abdomen of the chick closest to the bottom of the photo. The yolk nourishes the embryo during development. Shortly before hatching, the yolk sac withdraws into the abdomen to continue providing nourishment for the first few days of life. Once it has fully retracted, the navel closes and heals, and the chick is ready to hatch.

May 4, Day 0 - BirthDay:

Five chicks have hatched -- some just in the past hour or so. The sixth eggshell is cracked but the chick has not yet emerged. The seventh egg - the last one laid - is still unbroken. The hatchlings are exhausted from the strenuous job of breaking out of their shells, and just flop down fast asleep wherever they are. While they rest, the parents carry away all the broken shell fragments to keep the nest soft, clean and safe.

The eyes look enormous in the tiny heads because songbirds' eyes start out at full adult size, and the hatchlings gradually grow into them. But they're still undeveloped, and won't open for a week. Their ears are also still sealed - the ear-holes will open in a few days.

You can see the yolk of the egg in the abdomen of the chick closest to the bottom of the photo. The yolk nourishes the embryo during development. Shortly before hatching, the yolk sac withdraws into the abdomen to continue providing nourishment for the first few days of life. Once it has fully retracted, the navel closes and heals, and the chick is ready to hatch.