Quirks & Quarks

The Roller Coaster Flight of the Bar-headed Goose

Geese migrating over the Himalayas follow terrain rather than keeping a consistent altitude.
Bar-headed geese deal with severe hypoxia and pain to scale the Himalayas.
The bar-headed goose breeds in central Asia and winters as far south as the southern tip of India. This means that their migration route takes them over the Himalayan Mountains.

Historically, it had been thought that the geese would fly to extremely high altitudes and remain there for the duration of the crossing.

But a new study by Dr. William Milsom, a Professor in the Department of Zoology at UBC in Vancouver - and his colleagues - has found something different. Data loggers attached to several geese indicate a 'roller-coaster' flight path. Even though it makes the migration longer, following the profile of the ground makes it easier for the geese to meet the incredible physiological and biomechanical demands of flying in the low oxygen and thin air of high altitudes. 

Related Links

- Paper in Science
Bangor University release
CBC News story
BBC News story
NPR story