About the Authors
- Graeme M. Buchanan
- The Royal Society for the Protection of Birds, Edinburgh, United Kingdom
- Paul F. Donald
- The Royal Society for the Protection of Birds, Sandy, Bedfordshire, United Kingdom
- Stuart H. M. Butchart
- BirdLife International, Cambridge, United Kingdom
The authors have declared that no competing interests exist.
Conceived and designed the experiments: GMB PFD SHMB. Analyzed the data: GMB PFD. Contributed reagents/materials/analysis tools: GMB SHMB. Wrote the paper: GMB PFD SHMB.