Beat Naef-Daenzer and his team of researchers at the Swiss Ornithological Institute have created a miniature telemetry transmitter that will allow scientists to radio-track tiny species such as hummingbirds or insects for the first time.
Dr Naef-Daenzer's team initially designed the custom-made transmitters to follow the movements of barn swallows, but ecologists and population biologists will also use the miniature tags to track other small animals such as butterflies, tree frogs and bats.
The newly developed device weighs 0.2g but can transmit the animal's location for three weeks, the entire lifespan of the adult owl butterfly.
The development was published in the latest issue of the Journal of Experimental Biology .