Highest migrant

The bar-headed goose (Anser indicus) of Central Asia migrates through the Himalayas, regularly reaching altitudes of 9,000 m (29,000 ft), although there are unconfirmed reports of the geese reaching 10,175 m (33,380 ft) – a height at which the air is so thin not even helicopters can fly. The goose’s large wing area and efficient oxygen uptake means that it can fly higher than other birds of the same size, and its unrivalled strength allows it to cope with headwinds that would knock other birds out of the sky. The birds migrate to avoid monsoon summer and freezing winters. They overwinter in India, Pakistan and Burma.