Bar-headed Goose

Description:

The bird is pale grey and is easily distinguished from any of the other grey geese by the black bars on its head. It is also much paler than the other geese in this genus. In flight, its call is a typical goose honking.

Habitat:

Seen at Nalsarovar Bird Sanctuary.

Notes:

In a 2012 study that tagged 91 geese and tracked their migration routes, it was determined that the geese spent 95% of their time below 5,784 m (18,976 ft), choosing to take a longer route through the Himalayas in order to utilize lower-altitude valleys and passes. Only 10 of the tagged geese were ever recorded above this altitude, and only one exceeded 6,500 m (21,300 ft), reaching 6,540 m (21,460 ft) on an overnight flight, when the air was particularly cool (and therefore dense). The main physiological challenge of bar-headed geese is extracting oxygen and transporting it to aerobic muscle fibres in order to sustain flight at high altitudes. Flight is very metabolically costly at high-altitudes because birds need to flap harder in thin air to generate lift. Studies have found that bar-headed geese breathe more deeply and efficiently under low oxygen conditions, which serves to increase oxygen uptake from the environment.