Fuelling in front of the barrier - are there age based behavioral differences in Garden Warblers Sylvia borin?
- Subject Areas
- Animal Behavior, Ecology, Zoology
- bird migration, Sahara crossing, Eastern Mediterranean, stopover, Crete, Radio tracking
- © 2014 Barboutis et al.
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
- Cite this article
- 2014. Fuelling in front of the barrier - are there age based behavioral differences in Garden Warblers Sylvia borin? PeerJ PrePrints 2:e244v1 https://doi.org/10.7287/peerj.preprints.244v1
Garden Warblers Sylvia borin were studied during autumn stopover in Crete before crossing the barrier of the Mediterranean Sea and the Sahara desert. Birds followed with transmitters show extensive stopover periods, which were longer in first-year birds, 16 days, compared with adult birds, 14 days. The distribution of body masses from birds trapped in fig trees were used to estimate the departure body mass and the results found indicate that both age categories on average depart with a fuel load close to 100% of lean body mass. The movement of transmitter birds shows differences between first-year and adult birds. Adult birds move further away from the release site and many also left the study area. Several were found settled outside the study area, up to 17 km away, indicating that they regularly make longer stopover movements. It is suggested that this might be a result of that they return to a place where they stayed during an earlier migration. It was shown that stopover site fidelity exists and nine garden warblers were recaptured in the area during a following autumn. The results found highlights the importance of stopover areas close to the Sahara desert.