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High altitude flights by ruddy shelduck Tadorna ferruginea during trans‐Himalayan migrations |
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| Authors: | N. Parr S. Bearhop D. C. Douglas J. Y. Takekawa D. J. Prosser S. H. Newman W. M. Perry S. Balachandran M. J. Witt Y. Hou Z. Luo L. A. Hawkes |
| Affiliation: | 1. http://orcid.org/0000‐0001‐6115‐6816;2. College of Life and Environmental Sciences, Univ. of Exeter, Penryn, Cornwall, UK;3. US Geological Survey Alaska Science Centre, Juneau, AK, USA;4. Audubon California, Tiburon, CA, USA;5. US Geological Survey Patuxent Wildlife Research Centre, Beltsville, MD, USA;6. Foods and Agriculture Organization of the United Nations (FAO), Italy, and CMC Road next to ILRI, Gurd Shola, Bole Sub City, Kebele, Addis Ababa, Ethiopia;7. Dixon Field Station, Dixon, CA, USA;8. Bombay Natural History Society, Mumbai, India;9. Environment and Sustainability Inst., Univ. of Exeter, Penryn, Cornwall, UK;10. Qinghai Lake National Nature Reserve, Xining, China;11. Computer Network Information Center (CNIC), Chinese Academy of Sciences, Beijing, China |
| Abstract: | Birds that migrate across high altitude mountain ranges are faced with the challenge of maintaining vigorous exercise in environments with limited oxygen. Ruddy shelducks are known to use wintering grounds south of the Tibetan Plateau at sea level and breeding grounds north of Himalayan mountain range. Therefore, it is likely these shelducks are preforming high altitude migrations. In this study we analyse satellite telemetry data collected from 15 ruddy shelduck from two populations wintering south of the Tibetan Plateau from 2007 to 2011. During north and south migrations ruddy shelduck travelled 1481 km (range 548–2671 km) and 1238 km (range 548–2689 km) respectively. We find mean maximum altitudes of birds in flight reached 5590 m (range of means 4755–6800 m) and mean maximum climb rates of 0.45 m s–1 (range 0.23–0.74 m s–1). The ruddy shelduck is therefore an extreme high altitude migrant that has likely evolved a range of physiological adaptations in order to complete their migrations. |
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