Geese sightings over Everest lead to scientific discovery

Geese may have the ability to fly over Mount Everest, a study suggests, following reported sightings from climbers at the summit.

Researchers have found that bar-headed geese in particular can alter their metabolism to adapt to the low-oxygen atmosphere at high altitudes.

The discovery was made by kitting out test geese with censor-laden backpacks and breathing masks that mimic oxygen levels of up to 9,000m (29,5278ft), before analysing their flight in a wind tunnel.

To put this altitude into perspective, the summit of Mount Everest is 8,848m (29,029m), while commercial jet aircraft usually fly from an altitude of 8,534m (28,000ft) and above.

The results of the study published in eLife on Tuesday showed there were no changes in heart rate when geese flew in thinner air, suggesting the organ was not working at full capacity.

This could be explained by an additional discovery of the bird's ability to cool its veins by more than 2C, which researchers say could increase the amount of oxygen that passes from the lung into the bloodstream.

Claims of geese sightings from mountaineers scaling the world's highest peak have long been disputed.

The most famous came from George Lowe, the New Zealander who aided the climb of Edmund Hillary and Tenzing Norgay to become the first people to scale the world's highest peak.

Thanks to the new research, it could mean Mr Lowe's sighting was not a figment of his imagination as speculated.