The effect of wind, season and latitude on the migration speed of white storks Ciconia ciconia, along the eastern migration route

The relation between wind, latitude and daily migration speed along the entire migration route of white storks was analysed. Mean daily migration speed was calculated using satellite telemetry data for autumn and spring migration of white storks from their breeding grounds in Germany and Poland to wintering grounds in Africa and back. The National Center for Environmental Prediction (NCEP) reanalysis data were used to systematically fit 850 mb wind vectors to daily migration speed along the migration route. White storks migrated significantly faster and had a shorter migration season in autumn (10 km/h) compared to spring (6.4 km/h). In autumn mean daily migration speed was significantly slower in Europe (8.0 km/h) than in the Middle East (11.1 km/h) and Africa (11.0 km/h). In spring mean daily migration speed was significantly faster in Africa (10.5 km/h) as birds left their wintering grounds than in the Middle East (4.3 km/h). Migration speed then increased in Europe (6.5 km/h) as birds approached their breeding grounds. In both spring and autumn tailwind (at 850mb) and latitude were found to be significant variables related to daily migration speed.

[1]  T. Alerstam,et al.  Satellite tracking of Swedish Ospreys Pandion haliaetus: autumn migration routes and orientation , 2001 .

[2]  W. Richardson.  Timing of Bird Migration in Relation to Weather: Updated Review , 1990 .

[3]  Anders Hedenström,et al.  THE DEVELOPMENT OF BIRD MIGRATION THEORY , 1998 .

[4]  W. Fiedler,et al.  Detection of a new important staging and wintering area of the White Stork Ciconia ciconia by satellite tracking , 2001 .

[5]  William S. Seegar,et al.  Routes and travel rates of migrating Peregrine Falcons Falco peregrinus and Swainson's Hawks Buteo swainsoni in the Western Hemisphere , 1998 .

[6]  R. Tibshirani,et al.  Generalized Additive Models , 1991 .

[7]  K. Bildstein,et al.  WITHIN- AND AMONG-YEAR EFFECTS OF COLD FRONTS ON MIGRATING RAPTORS AT HAWK MOUNTAIN, PENNSYLVANIA, 1934-1991 , 1996 .

[8]  Using a Convection Model to Predict Altitudes of White Stork Migration Over Central Israel , 2003 .

[9]  K. Bildstein,et al.  SEASONAL SHIFTS IN THE EFFECTS OF WEATHER ON THE VISIBLE MIGRATION OF RED-TAILED HAWKS AT HAWK MOUNTAIN, PENNSYLVANIA, 1992-1994 , 1997 .

[10]  R. Reynolds,et al.  The NCEP/NCAR 40-Year Reanalysis Project , 1996, Renewable Energy.

[11]  Reto Spaar,et al.  TO CROSS THE SEA OR TO FOLLOW THE COAST? FLIGHT DIRECTIONS AND BEHAVIOUR OF MIGRATING RAPTORS APPROACHING THE MEDITERRANEAN SEA IN AUTUMN , 2000 .

[12]  George S. Young,et al.  AMERICAN WHITE PELICAN SOARING FLIGHT TIMES AND ALTITUDES RELATIVE TO CHANGES IN THERMAL DEPTH AND INTENSITY , 2002 .

[13]  Bruno Bruderer,et al.  Soaring Migration of Steppe Eagles Aquila nipalensis in Southern Israel: Flight behaviour under Various Wind and Thermal Conditions , 1996 .

[14]  Yossi Leshem,et al.  The use of thermals by soaring migrants , 1996 .

[15]  W. Cleveland.  Robust Locally Weighted Regression and Smoothing Scatterplots , 1979 .