Related Experiment Video
Updated: Jul 27, 2026

A Simple Flight Mill for the Study of Tethered Flight in Insects
Published on: December 10, 2015
The use of low-level jets by migrating birds
1Swiss Ornithological Institute, CH-6204 Sempach, Switzerland. liechtif@orninst.ch
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.
Related Concept Videos
Migration
Optimal Foraging
Adaptations that Reduce Water Loss
Conservation of Declining Populations
Habitat Fragmentation
Free Jet

