Elephant bird determined that "Vorombe titan" reached weights of and stood tall, making it the world's largest bird, slightly larger than the much older "Dromornis stirtoni". Elephant birds have been extinct since at least the 17th century. Étienne de Flacourt, a French governor of Madagascar in the 1640s and 1650s, mentions an ostrich-like bird said to inhabit unpopulated regions, though it is unclear whether he was repeating folk tales passed on from generations earlier. In 1659, Flacourt wrote of the "vouropatra – a large bird which haunts the Ampatres and lays eggs like the ostriches; so that the people of these places
Preening (bird) sail-shaped secondaries of the drake Mandarin duck) or distinctive color (such as the ) on the bird. Preening may also be performed as a displacement activity. In some cases, it is done in place of another activity that birds are strongly motivated, but unable, to do. In one study, black-headed gulls which were prevented from incubating a full clutch of eggs (by the removal of eggs from their nest) responded by preening and nest building—both displacement activities. When all three eggs in their regular clutch were removed, the gulls showed a significant increase in the amount of time they spent