Birds of Mount Everest: Life at the Edge of the Atmosphere

Mount Everest's extreme altitude (8,848 m), cold (−40°C to −60°C at summit), and hypoxia (⅓ sea-level O₂) exclude almost all birds. Only a handful of specialists inhabit the lower slopes and valleys (below ~6,500 m).

Resident / Regular Species

High-Altitude Migrants (Trans-Himalayan)

• Bar-headed Goose (Anser indicus): Migrates over Himalaya (recorded 7,000+ m); enhanced hemoglobin O₂ affinity, larger lungs, hyperventilation. Not resident on Everest.
• Demoiselle Crane, Ruddy Shelduck, Whooper Swan: Cross high passes.

Why So Few?

• O₂ limitation: Flight muscle demand > supply above 6,000 m for most birds.
• Food scarcity: No insects, plants, prey above snow line.
• Cold stress: Thermoregulation cost prohibitive for small endotherms.
• Nesting sites: Cliffs exist, but incubation at altitude unviable for most.

Choughs at the Summit?

Alpine choughs have been observed at South Col (7,906 m) and even near summit—scavenging food waste from expeditions. They don't live there; they commute from lower valleys. Remarkable physiological plasticity.

Everest's avian life is a lesson in evolutionary limits—and a few remarkable exceptions.