Biologically, everything about Gruidae (Cranes) seems to indicate that the birds are of very old origin having appeared on earth some 60 million years before man. Now, probably, they are on their way out. They are not found in abundance anywhere except in several Hindu and Buddhist countries like India, Tibet, Japan and Korea, where they receive socio-religious protection. Small groups of cranes do exist elsewhere in Asia, Europe, Africa, North America and Australia. Most species of cranes are migratory and some of them travel large distances each year.
Most cranes have gray, white, brown, or blue plumages with black primaries, and long inner secondaries that hang over the tail. All cranes have long legs, long straight bills and necks and an elevated hind toe,which normally bears none of the bird’s weight when it walks. They fly with their heads and necks straight out, their legs and feet stretched out behind and with a regular, steady and slow downward wing beat matched by a rapid upstroke. They may circle at tremendous heights (sometimes 5 km above the ground) to form long V-shaped patterns. Cranes seldom glide, except when preparing to land. A distinctive feature about this bird is its windpipe, which is shaped differently in each species but is always elaborately coiled somewhat like a trumpet. This permits the bird to produce a sound very much like that of a trumpet – a loud, resonant, far-reaching cry which can sometimes be heard miles away. To this clarion call they may occasionally add, when on the ground, a series of softer notes to produce a pleasant musical sound.
Spectacular dancing ceremonies, considered graceful by some and ungainly by others, are renowned amongst the crane family. The dance involves a stiff walk around one another in quick mincing steps, with wings half-spread and legs held gracefully below them, followed by leaps and bounds about two or three meters high into the air to the accompaniment of loud calls. This behavior, seen in both sexes, is most often displayed before the breeding season and sometimes whole flocks of cranes can be observed taking part. At other times a lone crane or even pairs perform, bowing deeply and stretching sideways. Bits of grass or sticks are picked up in their beaks, thrown up into the air, to be jabbed at as they come down. Joining in the show, as actively as the adults, are the baby cranes! No definite explanation for this behavior, which goes on throughout the year, is available although it is assumed that the crane may be using this ritual as a means of releasing extra energy or emotion. With its nest or young nearby, the crane may well use similar tactics to distract probable predators. Many species of cranes give ‘unison calls’ during the early morning, mid-day or occasionally when they are about to change incubation duties. With their necks and heads extended upwards and wings held tight against the sides, both birds utter a series of bugle calls so well synchronized that the ensuing sound seems to be single call from a single bird. The following species of cranes are found in India:
Sarus Crane Grus antigone - common resident