How quickly do chicks leave the nest?
Eggs and chicks are particularly vulnerable to predation, so the sooner a chick can leave the nest, the better its chances of survival. A key aspect that determines how quickly a youngster can leave the nest is how developed it is at the point of hatching. Some emerge well developed – already covered in down and with their eyes open. These are known as precocial young, and may leave the nest immediately, or within a day or two. Ducks, gamebirds and waders have precocial young, while owls (whose chicks are born with their eyes closed) and falcons (eyes open) have semi-precocial young, covered in down but not ready to leave the nest. Chicks that emerge naked and with their eyes closed are known as altricial young and are characteristic of songbirds. In some species, such as blackcap and whitethroat, the babies develop rapidly, typically leaving the nest within a fortnight of hatching. Blackcap chicks may leave the nest earlier, at just seven days of age, if they are disturbed by a predator.