Wildlife radio-telemetry may be defined as the transmission of information from a transmitter on a free-ranging wild animal to a receiver. Wildlife-related telemetry is also known as radio tagging, radio-tracking or simply `tagging' or `tracking'. Advances in the field of wildlife telemetry have made it possible to acquire detailed data on many aspects of wildlife biology, including:
• habitat use
• home range size
• mortality and survivorship
• migration timing and routes
Since many wildlife species are secretive and difficult to observe, radio-telemetry has provided a valuable tool to learn more about their respective life-histories. As a result, radio-telemetry studies are very common throughout the current wildlife literature.
Considerations in advance
Despite its popularity, radio-telemetry is inappropriate under many circumstances. It is an expensive and time-consuming technique. Despite the frequency with which radio collars and other transmitters are attached to research animals, surprisingly little is known about their effects on the behaviour and survivorship of the species in question. The placement of a radio tag on an animal represents a commitment by the researcher, and there is the possibility that it is done at the expense of the animal it is placed on. Thus, transmitters should only be attached when project funding guarantees the ability to monitor a tagged animal for the life-span of the transmitter!

Before starting a telemetry research the researcher needs two permits:
• a permit to catch and handle bats
• a permit to attach a radio-transmitter
 
Samenvatting Nederlands:
Telemetrie levert een zeer gedetailleerd beeld op van ruimtegebruik van individuen. Bij telemetrisch onderzoek krijgen gevangen meervleermuizen een radiozender. Dit is een zender van iets meer dan een halve gram (0,3 tot 0,7 gram), die op de vacht van de rug wordt geplakt. Het signaal van deze zender is op afstand hoorbaar met een ontvanger en richtingsgevoelige antenne. Zo zijn met een zender uitgeruste dieren te lokaliseren en kan het landschapgebruik van deze dieren in kaart gebracht worden en zijn of haar verblijfplaats opgespoord worden.