What species of bird flies at the highest elevation?

Answer 1

Anser indicus

The Bar-headed Goose (Anser indicus) is a goose which breeds in Central Asia in colonies of thousands near mountain lakes. It lays 3-8 eggs in a ground nest.

The Bar-headed Goose is believed to be the highest flying bird having been seen at up to 10175 m (33,382 feet). It has a slightly larger wing area for its weight than other geese and it is believed this helps the goose to fly so high. The altitude record is held by a Rüppell's griffon Gyps rueppelli, a vulture with a 10-foot wingspan. On November 29, 1975 one was sucked into a jet engine 37,900 feet above the Ivory Coast in West Africa. The plane was damaged but landed safely. The bird that flies highestregularly is the bar-headed goose Anser indicus, which travels directly over the Himalayas en route between its nesting grounds in Tibet and winter quarters in India. They are sometimes seen flying well above the peak of Mt. Everest at 29,035 ft. This journey was one of the featured stories on the Discovery channels documentory Planet Earth. The journey over the mountains is a difficult one and wind conditions can force the birds backwards where they will rest and try again the next day. Birds have some natural advantages for getting oxygen at high altitudes, in particular an arrangement of air sacs that allows them to circulate inhaled air twice through the lungs with each breath--much more efficient than the in-and-out system used by mammals. Bar-headed geese have special adaptations that make them even better at high-flying than other birds. They have a special type of hemoglobin that absorbs oxygen very quickly at high altitudes, and their capillaries penetrate especially deep within their muscles to transfer oxygen to the muscle fibers.