<abstract xmlns="http://www.w3.org/1999/xhtml"><p>At the end of the 1980s, a relatively large data set was collected from orientation cage tests of nocturnal migrants caught in one locality in south-western Spain. It was published in <italic>The Auk</italic> in 1989. At the time of publication, the use of orientation cages was a major advance in detailed studies on passerine migration patterns. The basic evaluation procedure was to calculate the average vector of all numbers representing bird activity in a number of sectors of the full wind-rose and to use the Rayleigh test to determine the statistical significance of the distribution. However, due to hidden assumptions in the procedure used at that time, the resulting heading patterns could be called into question in light of further methodological development. The paper revisits the original set of orientation data collected in the last century in the reported study. The new results from the multimodal distribution accepting procedure are compared with the older pictures and are found to be much better at explaining the migration pattern there. In particular, the Garden Warbler and Reed Warbler, which were claimed to be ‘disoriented’, now show acceptable directionality patterns which do not differ in shape from those of other species.</p></abstract>

At the end of the 1980s, a relatively large data set was collected from orientation cage tests of nocturnal migrants caught in one locality in south-western Spain. It was published in The Auk in 1989. At the time of publication, the use of orientation cages was a major advance in detailed studies on passerine migration patterns. The basic evaluation procedure was to calculate the average vector of all numbers representing bird activity in a number of sectors of the full wind-rose and to use the Rayleigh test to determine the statistical significance of the distribution. However, due to hidden assumptions in the procedure used at that time, the resulting heading patterns could be called into question in light of further methodological development. The paper revisits the original set of orientation data collected in the last century in the reported study. The new results from the multimodal distribution accepting procedure are compared with the older pictures and are found to be much better at explaining the migration pattern there. In particular, the Garden Warbler and Reed Warbler, which were claimed to be ‘disoriented’, now show acceptable directionality patterns which do not differ in shape from those of other species.

Orientation of Trans-Saharan Passerine Migrants in Southwestern Spain – Revisited

The Ring

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

At the end of the 1980s, a relatively large data set was collected from orientation cage tests of nocturnal migrants caught in one locality in south-western...

Orientation of Trans-Saharan Passerine Migrants in Southwestern Spain – Revisited

Published Online: Jan 16, 2020

Page range: 3 - 15

DOI: https://doi.org/10.1515/ring-2019-0001

Keywords
orientation cage data, methods, heading pattern, passerines, southern Spain

© 2019 Przemysław Busse, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Orientation of Trans-Saharan Passerine Migrants in Southwestern Spain – Revisited

Published Online: Jan 16, 2020

Page range: 3 - 15

DOI: https://doi.org/10.1515/ring-2019-0001

Keywordsorientation cage data, methods, heading pattern, passerines, southern Spain

© 2019 Przemysław Busse, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
orientation cage data, methods, heading pattern, passerines, southern Spain