Study
The trans-Himalayan flights of bar-headed geese
Hawkes, Lucy A.; Balachandran, Sivananinthaperumal; Batbayar, Nyambayar; Butler, Patrick J.; Frappell, Peter B.; Milsom, William K.; Bishop, Charles M.
Proceedings of the National Academy of Sciences, 2011
Fitted satellite transmitters to bar-headed geese and recorded altitude and timing continuously through their migrations across the Himalaya.
- Studied in
- Anser indicus
- Sample size
- satellite-tagged geese tracked across the Himalaya
The geese flew mostly at night and in the early morning, tracked the terrain closely rather than cruising at a constant high altitude, used passes and valleys, and spent very little time above 6,000 metres. Climb rates were nonetheless remarkable, achieved without riding tailwinds.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
The birds minimise time at extreme altitude, exploiting cooler denser night air and the lowest available routes, rather than habitually flying at the heights the species is famous for.
How NatureHQ reads it
A correction NatureHQ takes seriously: the famous claim that these birds fly over Everest is largely an artefact of what could be observed before tracking. They are extraordinary climbers who work hard to avoid the altitudes they are celebrated for — which fits the sprint’s pattern of avoidance rather than endurance.
- Tagged birds from particular populations and routes; other populations may behave differently.
- Very high but brief excursions are hard to exclude from sampled tracking data.
Finding out where the birds actually were
Bar-headed geese are said to fly over the highest peaks of the Himalaya. Where do they actually fly?
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Bar-headed goose
Tracked bar-headed geese fly mostly at night, close to the ground, through passes, and spend very little time above 6,000 metres. The physiology is exceptional; the flying-over-Everest story is not accurate.
Bar-headed goose
There is no single thing that lets a bar-headed goose fly in thin air. Every link in the chain that moves oxygen from air to muscle is improved a little, and the effect is cumulative.
Published by: Proceedings of the National Academy of SciencesPublished in PNAS.
doi.org/10.1073/pnas.1017295108
Checked against Crossref on 2026-09-28, and they agree on the title, the authors and the year.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-09-03.