High-Altitude Avian Migration across the Himalayas: Challenges, Fly Strategy and Physiological Adaptation

Abstract

Migrants that fly across the Himalayas, one of the highest geographical blocks in the world, must overcome severe challenges of the extreme high-altitude environment. Supported by evolved specifically adapted physiological performance, migrants such as geese, ducks, shorebirds, cranes, raptors, passerines, take diverse strategies, which is a balance of complex factors, as a result of evolution. This review draws an overall picture of high-altitude avian migration specifying findings in: fly strategies including routes, heights, stopovers, wind use patterns; physiological adaptions including special hypoxia tolerance of birds and unique adaptions of high-altitude migrators; evolution explanations; threats including impact caused by climate change on wetland and phenological mismatch; conservation. Enhanced unclarified questions on: avoid-barrier strategies; wind use patterns; predation pressure; phenomenon of lowland species flying at high altitudes; and most importantly, climate change and conservation. This study on avian high-altitude migration provides a relatively comprehensive summary of relevant findings, helps to understand the complex behaviors of migrants, and arranged various prospects for future studies