The trans-Himalayan flights of bar-headed geese (Anser indicus)

Proceedings of the National Academy of Sciences of the United States of America
By: , and 

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Abstract

Birds that fly over mountain barriers must be capable of meeting the increased energetic cost of climbing in low-density air, even though less oxygen may be available to support their metabolism. This challenge is magnified by the reduction in maximum sustained climbing rates in large birds. Bar-headed geese (Anser indicus) make one of the highest and most iconic transmountain migrations in the world. We show that those populations of geese that winter at sea level in India are capable of passing over the Himalayas in 1 d, typically climbing between 4,000 and 6,000min 7-8 h. Surprisingly, these birds do not rely on the assistance of upslope tailwinds that usually occur during the day and can support minimum climb rates of 0.8-2.2 km??h-1, even in the relative stillness of the night. They appear to strategically avoid higher speed winds during the afternoon, thus maximizing safety and control during flight. It would seem, therefore, that bar-headed geese are capable of sustained climbing flight over the passes of the Himalaya under their own aerobic power.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The trans-Himalayan flights of bar-headed geese (Anser indicus)
Series title Proceedings of the National Academy of Sciences of the United States of America
DOI 10.1073/pnas.1017295108
Volume 108
Issue 23
Year Published 2011
Language English
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Proceedings of the National Academy of Sciences of the United States of America
First page 9516
Last page 9519