A goose flies over the Himalayas under its own power

Bar-headed geese climb from near sea level to between 4,000 and 6,000 metres in a single day, flapping, often at night, without needing an updraft to do it.

Lucy Hawkes and colleagues tagged geese that winter on the Indian plain and breed in Central Asia. The tracks show the mountain crossing done in one day, a climb of several thousand metres in seven or eight hours. The birds did not wait for the afternoon winds that would have helped. They often flew in the quieter night, when the climb was harder and the control was better. The rate they sustained, about a kilometre an hour of altitude or more, is within what their aerobic engine can pay for. That engine is the one-way lung already in this library, plus haemoglobin that holds oxygen more tightly than a lowland goose's, plus a flight muscle full of capillaries.

Older stories had them at the height of Everest's summit as a matter of routine. The logged flights are over the passes, typically four to six kilometres up, which is already an altitude where an unacclimatised person is in trouble and a helicopter is near the edge of its hover. A few birds, in other records, have gone higher. The 2011 result does not need the exaggeration. A goose the size of a Christmas bird, flapping, in air that thin, all night, is the measurement.