This 2014 video about bar-headed geese is called The Highest Flying Birds in the World.
Another video used to say about itself:
17 January 2015
The geese have been recorded at heights of more than 7,000m (23,000 ft) and mountaineers have claimed they have seen the birds fly over Mount Everest.
Their ability to fly in such extreme conditions has fascinated scientists for decades, as the BBC’s science reporter Victoria Gill reports.
Researchers have shed new light on how some geese can fly high for long periods of time, according to a study published today in eLife. The team collected the first ever cardiorespiratory measurements of bar-headed geese flying in a wind tunnel at a simulated altitude of 9,000m. They discovered that the animals are able to maintain flight in these low-oxygen conditions via a reduction in their metabolism: here.