It's a New Day
rss

February 2020

Vol. 48, No. 1

Gleanings: Flying High

David M. Larson

Every year in Mass Audubon's Birder's Certificate Program, when I am presenting information about avian physiology, I mention the amazing phenomenon of the migration of Bar-headed Geese. These birds migrate between their wintering and nesting grounds over the Himalayan Mountains and Tibetan Plateau, at 5000–6000 meters (approximately 16,000–20,000 feet), and have been seen in flight at almost 7300 meters (24,000 feet). In comparison, human mountain climbers commonly use bottled oxygen above 7000 meters. Combining the metabolic demands of flapping flight (already metabolically expensive), the greater exertion required to fly in the lower air pressure at altitude (thinner air requires faster flight to maintain lift), and the decreased oxygen concentration at altitude, makes flying to this level pretty impressive.

To view the rest of the article you'll need to subscribe. Bird Observer publishes original articles on birding locations, on avian populations and natural history, on regional rarities, field notes, field records, photographs, and art work.

Our mission: to support and promote the observation, understanding, and conservation of the wild birds of New England.