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DETECTION BY RADAR OF AUTUMN MIGRATION IN EASTERN SCOTLAND
Author(s) -
Wilcock John
Publication year - 1965
Publication title -
ibis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 80
eISSN - 1474-919X
pISSN - 0019-1019
DOI - 10.1111/j.1474-919x.1965.tb07311.x
Subject(s) - bird migration , anticyclone , radar , geology , weather radar , heading (navigation) , geography , prevailing winds , observatory , climatology , meteorology , geodesy , paleontology , telecommunications , physics , computer science , astrophysics
SUMMARY Radar observations through one autumn in Aberdeenshire are described showing that more migration takes place in anticyclonic weather than transitional weather, and even less migration takes place in disturbed weather. More migration is detected by radar with following winds than with opposed winds. Comparison of data collected in Norfolk and Aberdeenshire during one season at each shows that more migration is detected by radar in Norfolk, and westward movements, which are a feature of migration into Norfolk, appear in Aberdeenshire only when birds are first drifted northwards. Dawn ascent and reorientation movements of birds in the northern North Sea are described, showing that changes in heading were consistently between S.W./S.S.W. and S.S.E. during the autumn studied. Weather data, radar data and ground observer data from Aberdeenshire and the Isle of May Bird Observatory were analyzed and show again that the normal migration pattern is to fly high with following winds and low only with opposing winds as in Norfolk. However, the weather in Aberdeenshire was more disturbed than it had been in Norfolk, with the consequence that weather factors, other than wind, which affect the normal migration pattérn were found to be much more common.