Mighty atlas
BIRD migration has fascinated people ever since its discovery. The arrival of Swallows in spring and their disappearance in autumn was long known about but the mechanism of their coming and going, and the precise nature of it, remained unknown for centuries. Bird ringing started to provide answers, and we began to discover where birds went, as well as some of their stopping places. It is only recently, however, with the advent of satellite tracking and geolocators that we have begun to fill in the many blanks.
Now the latest information about the movements of more than 300 bird species has been consolidated into the Eurasian African
Bird Migration Atlas, a fantastic online database.
Funded by the Italian Government, with support from the Convention on the Conservation of Migratory Species and the Institute of Avian Research in Germany, it provides amazing interactive maps along with informative texts, written by experts. The web application was developed by staff at the BTO using data on the movements of ringed birds (from EURING) and tracking data (from Movebank).
The colours used on the Whooper Swan map clearly show that the different breeding populations have distinct wintering areas. A fascinating map of Kittiwake movements mapped from ringing recoveries is composed of layers of coloured lines from different geographical regions which can be added and removed to build up a picture. A separate layer of tracking is also offered in a different menu. Well-studied species contain a wealth of information as shown by European Turtle Dove with its clear migration paths out of Europe, and then the tracking paths which show exactly where some birds head for south of the Sahara.
The most fascinating aspect of this new atlas is its emphasis on migratory connectivity – defined as ‘the linkage among individuals between the periods and areas where they spend different phases of their annual life cycle’. Breeding populations of a species from different regions may share the same wintering area while in another species they will be totally different. As well as the visual aspect of the maps to show this, there is also a written analysis which gives a more detailed interpretation.
The Atlas is freely available at migrationatlas.org, where all you have to do is select a species from a drop-down list. Unlike many book publications which are out-of-date as soon as they are published, this online project is continually updated with the very latest findings as tracking technology improves and more information becomes available. Not only is this an amazing research tool, it is an informative wealth of data that can be dipped into with a guarantee that few will fail to be amazed by it.
Chris Harbard