Tracking devices: miniaturized geolocators

    Satellite based positioning systems for unraveling migration are still too heavy for passerines. Only recently, a more lightweight alternative has been developed: the geolocator. Geolocators measure the intensity of sunlight and save this data together with date and time in an internal memory. Once retrieved, these data allows determining sunrise and sunset times and hence geographic latitude and longitude.

    Aims

    The Swiss Ornithological Institute together with the Bern University of Applied Sciences is developing and producing two types of geolocators: 1) a very lightweight device (0.5 g) for the exclusive recording of positioning data; 2) a slightly heavier device (1.3 g) equipped with additional sensors for measuring temperature, air pressure (flight altitude), acceleration (activity) and the geomagnetic field.

    Approach

    Under the responsibility of the Swiss Ornithological Institute, the Bern University of Applied Sciences is developing hard- and software of the geolocators. The devices are tested and produced by the Swiss Ornithological Institute.

    Significance

    Before the introduction of the geolocator, the knowledge about the whereabouts of our songbirds outside the breeding season was very fragmentary. Thanks to the geolocator, it is now possible to record the course of migration of individual songbirds in space and time and year round.

    Results

    The 0.5g geolocator and our new GDL3_PAM mulitsensor logger are available for field projects. Possible tools for data analysis and resulting insides into individual migration performances are listed in the publication section below. 

    Geolocation Manual

    Project management

    Swiss Ornithological Institute: Felix Liechti, Erich Bächler

    Bern University of Applied Sciences: Roger Weber

    Partners

    Bern University of Applied Sciences

    Financial support

    Environmental technology Promotion, Federal Office for the Environment (FOEN)

    Publications

    Brlík, V., J. Kole?ek, M. Burgess, S. Hahn, D. Humple, M. Krist, J. Ouwehand, E. L. Weiser, P. Adamík, J. A. Alves, D. S. Arlt, Bari?i?, D. Becker, E. J. Belda, V. Beran, C. Both, S. P. Bravo, M. Briedis, B. Chutný, D. ?ikovi?, N. W. Cooper, J. S. Costa, V. R. Cueto, T. Emmenegger, K. Fraser, O. Gilg, M. Guerrero, M. T. Hallworth, C. Hewson, F. Jiguet, J. A. Johnson, T. Kelly, D. Kishkinev, M. Leconte, T. Lislevand, S. Lisovski, C. López, K. P. McFarland, P. P. Marra, S. M. Matsuoka, P. Matyjasiak, C. M. Meier, B. Metzger, J. S. Monrós, R. Neumann, A. Newman, R. Norris, T. Pärt, V. Pavel, N. Perlut, M. Piha, J. Reneerkens, C. C. Rimmer, A. Roberto-Charron, C. Scandolara, N. Sokolova, M. Takenaka, D. Tolkmitt, H. van Oosten, A. H. J. Wellbrock, H. Wheeler, J. van der Winden, K. Witte, B. K.Woodworth, & P.Procházka (2020):
    Weak effects of geolocators on small birds: A meta-analysis controlled for phylogeny and publication bias.
    Lisovski, S., S. Bauer, M. Briedis, S. C. Davidson, K. L. Dhanjal-Adams, M. T. Hallworth, J. Karagicheva, C. M. Meier, B. Merkel, J. Ouwehand, L. Pedersen, E. Rakhimberdiev, A. Roberto-Charron, N. E. Seavy, M. D. Sumner, C. M. Taylor, S. J. Wotherspoon, E. S. Bridge (2020):
    Light-level geolocator analyses: A user's guide.
    Dhanjal-Adams, K. L., S. Bauer, T. Emmenegger, S. Hahn, S. Lisovski & F. Liechti (2018):
    Spatiotemporal Group Dynamics in a Long-Distance Migratory Bird.
    Liechti, F., S. Bauer, K. L. Dhanjal-Adams, T. Emmenegger, P. Zehtindjiev & S. Hahn (2018):
    Miniaturized multi-sensor loggers provide new insight into year-round flight behaviour of small trans-Sahara avian migrants.
    Meier, C. M., H. Karaadiç, R. Aymí, S. G. Peev, E. Bächler, R. Weber, W. Witvliet & F. Liechti (2018):
    What makes Alpine swift ascend at twilight? Novel geolocators reveal year-round flight behaviour.
    Scandolara, C., D. Rubolini, R. Ambrosini, M. Caprioli, S. Hahn, F. Liechti, A. Romano, M. Romano, B. Sicurella & N. Saino (2014):
    Impact of miniaturized geolocators on barn swallow Hirundo rustica fitness traits
    Liechti, F., W. Witvliet, R. Weber & E. Bächler (2013):
    First evidence of a 200-day non-stop flight in a bird.