Wildlife Discovery : The gentle Crested Crane

Cranes are a family of large, long-legged and long-necked birds. There are fifteen species of crane in four genera. Unlike the similar-looking but unrelated herons, cranes fly with necks outstretched, not pulled back. Cranes live on all continents except Antarctica and South America. Most species of cranes are at least threatened, if not critically endangered, within their range. The plight of the Whooping Cranes of North America inspired some of the first US legislation to protect endangered species. They are opportunistic feeders that change their diet according to the season and their own nutrient requirements. They eat a range of items from suitably sized small rodents, fish, amphibians, and insects, to grain, berries, and plants. Most have elaborate and noisy courting displays or “dances”. While legends often state that cranes mate for life, recent scientific research indicates that these birds do change mates over the course of their lifetimes (Hayes 2005), which may last several decades. Cranes construct platform nests in shallow water, and typically lay two eggs at a time. Both parents help to rear the young, which remain with them until the next breeding season. Some species and populations of cranes migrate over long distances; others do not migrate at all. Cranes are solitary during the breeding season, occurring in pairs, but during the non-breeding season they are gregarious, forming large flocks where their numbers are sufficient. The cranes are diurnal birds that vary in their sociality by season. During the breeding season they are territorial and usually remain on their territory all the time. In contrast in the non-breeding season they tend to be gregarious, forming large flocks to roost, socialise and in some species feed. Species that feed on predominately on vegetable matter in the non-breeding season feed in flocks to do so, whereas those that feed on animals will usually feed in family groups, joining flocks only during resting periods, or in preparation for travel during migration. Large aggregations of cranes are important for safety when resting and also as places for young unmated birds to meet others. Cranes are highly vocal and have a large vocabulary of specialised calls. The vocabulary begins soon after hatching with low, purring contact calls for maintaining contact with their parents, as well as food begging calls. Other calls used as chicks include alarm calls and “flight intention” calls, both of which are maintained into adulthood. Ends