To space and back
The satellite telemetry enables us to get very detailed data. In one of our long-term studies on Osprey and Marsh harrier migration we have obtained positions every hour in three dimensions with 10-20 m accuracy during the birds’ repeated journeys between Sweden and Africa. With this data, course changes during days could be analysed in relation to different possible compass mechanisms as well as to wind, landscape and possible goal areas and landmarks from preceding journeys.
Different types of data
Depending on what observations we are interested in, the transmitters can be equipped with different kinds of sensors, enabling the collection of data not only on position information, but also on for example animal heart rates, atmospheric pressure and sea temperatures. As the transmitters so far are fairly big, they can only be fitted on animals of a certain size, like the Ascension green turtle (Chelonia myda) in one of our displacement experiments in Southern Atlantic Ocean.