This tendency for eggs to be light-colored in warmer climates and dark in colder climates is probably an adaptation to environmental conditions, allowing eggs to reflect heat in the former case and to absorb heat in the latter. The chicks of most crane species are predominantly brown. The exceptions are the Demoiselle, Blue, and Brolga Cranes, whose chicks are silver-grey. Chicks lose their egg tooth within a few days of hatching. The rate of chick growth is astonishing, especially among chicks of the northernmost species.
Legs grow rapidly during the first six weeks, followed by more rapid development of the wings.
Juveniles of all the other species are russet brown, providing cryptic coloration as a defense against predation. This is of particular importance to Siberian, Whooping, and Red-crowned Crane chicks, which are destined to be primarily white as adults. During the second year of growth, adult plumage gradually replaces the juvenile plumage. By the end of their second year, many juvenile cranes are difficult to distinguish from adults. Crowned Cranes have elaborate tawny crests, bare cheeks, and a gular wattle.