Migratory birds are those that move from one part of the world to another, according to the season. Some of the wetlands of India are popular with migratory birds. During winter, birds, such as Siberian Crane come in large numbers. One such place favourable with birds is the Rann of Kachchh. At a place where the desert merges with the sea, flamingo with their brilliant, pink plumage, come in thousands to build nest mounds from the salty mud and raise their young ones.