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Naturwissenschaften

, Volume 86, Issue 11, pp 549–551 | Cite as

The Use of Low-Level Jets by Migrating Birds

  • Felix Liechti
  • Esther Schaller
Short communication

Abstract

 Birds flying at high altitudes have occasionally been observed above mountain areas and the open sea. For the first time the regular occurrence of migrating birds flying within a low-level jet at heights of 5000 to almost 9000 m asl. have now been verified by radar above the Negev desert in southern Israel. Tracks of rather large birds with wing-beat frequencies of 5–6 Hz were measured to have horizontal flight speeds up to 50 m/s. Visual observations, seasonal occurrence, and wing-beat frequencies allowed to associate them with small species of the order Ciconiiformes (mainly Ardeidae) and possibly with members of the Laro-Limicolae group. These wading birds seem prone to continuing nocturnal migration into daytime under favorable conditions and to make use of high wind speeds at sometimes extreme altitudes.

Keywords

Wind Speed Radar High Altitude Mountain Area Visual Observation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Felix Liechti
    • 1
  • Esther Schaller
    • 1
  1. 1.Swiss Ornithological Institute, CH-6204 Sempach, Switzerland e-mail: liechtif@orninst.chCH

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