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

Manual Multisensor Analysis (PAMLr)

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