Bar-headed geese: See the highest flyer in action

A tracking study has revealed the secrets of the world's highest bird migration - the Himalayan flight of the bar-headed goose. The geese have been recorded at heights of more than 7,000m (23,000ft).

Their ability to fly in such extreme conditions has fascinated scientists for decades. This clip shows previous research by University of British Columbia scientists - one of the research institutes involved in the new study.

This footage is shot with high speed cameras and allows scientists to view their flight in super slow-motion. The birds are trained to wear masks that measure how much oxygen they use in flight.

Footage courtesy of James Whalen/Jessica Meir/University of British Columbia (UBC)