World's Rarest Bustard

Bengal Florican (Houbaropsis bengalensis), Critically Endangered

The Bengal Florican, known by locals as "the whispering bird," has a long black head and neck, long, mostly white wings, and long yellow legs. It received it's nickname from the displays of male birds, which in mating season, struts into a clearing and ruffles it neck feathers. It jumps into the air, then drifts back to the ground, giving a deep humming call as it descends--hence "the whispering bird." It usually competes with other nearby males.

Sree more here