Radio telemetry

 

Radio telemetry is a technique that is used to track a tiny radio tranmitter by using an antenna and radio receiver. The transmitter (tag) sends out pulses (signals) that can be 'heard' thanks to the receiver. Depending on the strength and direction of the signal it is possible to locate each tag with it's unique frequency tags.

During our research we use miniature tags (less than 3% of the average body weight) to track Nightjars. To attach these tags, we need to catch Nightjars first with mist nets. You can only use these nets in Belgium if you have a special permittion of the Royal Belgian Institute of Natural Science and the Agency for Nature and Forest. After catching the Nightjars all biometrics are measures and they receive a unique scientific ring. Next, the miniature tags are glued on their tails.

When the tags are activates, we always test if they actually work. After this, the Nightjar is released. During night time we follow an area covering route with 22 observatory points. On these points we check the presence of all radio tagged individuals for 4 minutes. This technique makes it possible to gather standardized observations of the radio tagged Nightjars. During daytime we look for sleeping- and breeding locations.