Consultez les articles du Bulletin Aves !
Aves, 9/6 | 1972 | 226-240
Contribution to the study of prenuptial migration of the Reed Bunting (Emberiza schoeniclus).
Spring migration of Reed Buntings (Emberiza schoeniclus) has been studied for six years (from 1965 to 1970) at the biological station of Chertal (Meuse Valley, Liège, Belgium). About 1000 captures and more than 200 recaptures on the spot have provided many biometric data. All measurements were taken by the same bird ringer in order to allow a comparative study of the results. Analysis of the results leads to the following conclusions : 1. At Chertal, spring migration of Reed Buntings lasts about 45 days. First arrival records are likely to occur at very different dates from one year to another ( a three weeks interval has been recorded amongst earliest and latest first data : 18 II 1967 and 10 III 1965) (table I). 2. Data obtained by close observation of migrant birds catched (diagrams 1 and 2) together with analysis of the length of the folded wings (diagram 3) strongly suggest a migration sequence based both on sex and age. Males commonly migrate earlier than females; adults move before youngs. Therefore, the chronological sequence is as follows : adult males, adult females and young males, young females. 3. Birds are usually staying from 4 to 5 days at Chertal (table V). 4. Correlations between the highly stable values of mean wing lengths (table II) and the data recorded both in Finland during the breeding-season and in Camargue during winter (table III) support the view that only one Reed Bunting subspecies (Emberiza schoeniclus schoeniclus) migrates through Belgium. The North-Eastern limits of the breeding area of that race probably extend to the Southern Finland, while its winter-season area is to be found West of Camargue (which is out of bounds). 5. In 1965, the first spring migrants (catched from 10 to 20 March) were of a larger mean shape than in other years. At the same time, exceptionnally large numbers of Reed Buntings were recorded in Belgium. This suggests a west shifted migration route for birds usually migrating through Central Europe.