The incubation period for incubating Blackbird (turdus merula) is published as 13 to 14 days which for a bird of this size is quite a short time. They hatch helpless and blind covered in wispy down. I discovered the nest in my garden about 9 days ago and i t contained 3 eggs, incubation had already begun. I was expecting chicks any time now and this morning, we had baby Blackbirds. In the photo they look a little bit damp still, when they emerge from the egg they are wet. The down is yet to fluff up and as the chicks grow they will become increasingly fluffy. The eyes will open and the down will be replaced with feathers. In the next 14 day s they will increase in size and weight by more than 10 fold. I am going to take a photo every day until they fledge and it will be interesting to see how they develop day by day. Of course, as one of Europe's commonest birds they will have been studied in great detail but it's still going to be a fascinating experience.
Today, a sample weight of one chick at random was 7.4 grams.