Tracking devices: miniaturized geolocators

      Satellite based positioning systems for unraveling migration routes, stopover areas and wintering grounds are still too heavy for passerines like barn swallows or wheatears. 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 development of the 0.5 g geolocator is terminated, and the device has already been successfully used in several projects. The geolocator with additional sensors has been successfully tested for the first time in 2013.

      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

      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.