Radio-telemetry is an essential tool for field-based biological research. It has been applied for more than 40 years to track range use and behaviour of individual animals. A tiny radio transmitter is mounted to the animal. The mass of the radio-tag is so low that the animals are neither disturbed nor handicapped. The signals allow location of the subject individual anywhere and at any time.


We develop tailor-made tools of telemetry for our research. In conventional radio-telemetry (VHF), we focus on miniaturisation of transmitters while simultaneously improving the reception range and the lifespan of the tag.


We closely collaborate with the Bern University of Applied Sciences (BFH-TI, Simon von Ballmoos, Roger Weber) and with the University of Geneva (Brice-Olivier Demory). In parallel to the development of hardware, we also advance the associated software and appropriate statistical methods for data analysis.


Various aspects in the ecology of small birds are still poorly known, which is mainly due to the difficulty in following them individually for an extended period of time. The miniaturisation of radio-transmitters allows filling these important gaps in avian ecology.


So far, our work resulted in the development of the lightest and smallest radio-transmitter worldwide (0.2 g). Based on this device, a new transmitter including microprocessor control was developed. This technical innovation considerably improved radiated power and lifespan of the transmitter.

Project management

Beat Naef-Daenzer


Bern University of Applied Sciences - Engineering and Information Technology
University of Geneva


Naef-Daenzer, B., D. Früh, M. Stalder, P. Wetli & E. Weise (2005):
Miniaturization (0.2·g) and evaluation of attachment techniques of telemetry