caa a22 4500 469098643 CHVBK 20180323133038.0 cr unu---uuuuu 170328e19920701xx s 000 0 eng 10.1007/BF01875441 doi (NATIONALLICENCE)springer-10.1007/BF01875441 Helbig Andreas Institut für Pharmazeutische Biologie, Universität Heidelberg, Im Neuenheimer Feld 364, W-6900, Heidelberg, Federal Republic of Germany aut Population differentiation of migratory directions in birds: comparison between ringing results and orientation behaviour of hand-raised migrants [Elektronische Daten] [Andreas Helbig] Summary: Blackcaps (Sylvia atricapilla) from five areas in Central Europe were hand-raised. Their autumn migratory orientation was tested in funnel-shaped cages. Their directional choices were compared to recoveries of conspecifics ringed during the breeding season in the same areas, which are situated on a transect across a migratory divide between southeastward and southwestward migrating populations. Results from ringing and orientation tests were in good agreement with respect to mean direction and dispersion of flight directions. An exception is the area around Linz (NW Austria), right on the migratory divide, where ringing yielded a strong scatter, but hand-raised birds chose westerly directions. The recent establishment of a novel migration route toward the British Isles was reflected in both data sets: in southern Germany the percentage of northwestward migrants is 6.8% according to orientation tests and 11.8% according to ringing recoveries. Testing the orientation of young passerines in captivity can yield valuable information about population differentiation of migratory behaviour. It is more efficient than ringing in this respect, because it circumvents the low recovery rates and is free of biases affecting ringing data. In the blackcap, geographic differentiation of migratory directions occurs on a finer scale than previously recognized and can change significantly within 2-3 decades. Springer-Verlag, 1992 Population differentiation nationallicence Bird migration nationallicence Orientation nationallicence Sylvia atricapilla nationallicence Oecologia Springer-Verlag 90/4(1992-07-01), 483-488 0029-8549 90:4<483 1992 90 442 https://doi.org/10.1007/BF01875441 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01875441 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Helbig Andreas Institut für Pharmazeutische Biologie, Universität Heidelberg, Im Neuenheimer Feld 364, W-6900, Heidelberg, Federal Republic of Germany aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 90/4(1992-07-01), 483-488 0029-8549 90:4<483 1992 90 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer