Bird migration

    How reliable are full light patterns recorded by geolocators to define flights of nocturnal migrants into the day?

    The smallest data loggers used for tracking the migratory journey of small passerines weigh between 0.3 g to 0.5 g. They record light intensities every 10 min. From these data time of sunset and sunrise is calculated, which then are used to estimate geographic positions. In most passerines shading due to vegetation has a strong impact on the level of light intensity recorded. However, if a bird is flying during sunset or sunrise, light data is expected to be much clearer, as shading only can occur due to clouds. Therefore, these so-called full-light patterns have been interpreted in recent publication as an indication of active flight and were used to support the hypothesis of non-stop flights across the Sahara. The data recorded by the multi-sensor logger allow verifying this assumption and quantifying potential errors. Finally, the results have to be visualized properly and prepared to be published, most likely together with the results from the task described here (temperature patterns).There are about 40 year-round tracks of individual birds available for this study.


    The time resolution is 5min. and 30min., respectively. The student must have a good mathematical/statistical background and some R-programming experience.

    Contact and further information

    Swiss Ornithological Institute
    Dr. Felix Liechti
    Seerose 1
    CH-6204 Sempach
    Tel: +41 41 462 97 82