Satellite Tracking

We began our osprey GPS satellite tracking research in 2007. In 1999 and subsequent years, in partnership with Rutland Water Nature Reserve and Anglia Water plc we used early non GPS models on ospreys to study their migrations.  For many years we had ringed ospreys and studied their migrations, and colour rings are very useful in that they enable us to build up life histories of individual ospreys.  But there was a huge gap in our knowledge: we knew very little about their movements once they left Scotland and started their annual migration to Africa.  The use of GPS satellite telemetry has opened up a whole new field of study, and enables us to follow every movement our ospreys make, anywhere in the world.

Red 8T at Rothiemurchus Fishery. Photo by Gary Ridsdale

The project was started with funding assistance from Talisman Energy UK plc in Aberdeen, who had previously helped the Foundation to carry out osprey conservation, especially building and refurbishing nests, around the Moray Firth, through its small grants fund, and to date they have generously funded ? transmitters. 

We use tiny satellite radios, called PTTs, made by Microwave Telemetry in Columbia, USA (  Each PTT has a unique identification number supplied under our conservation agreement with Argos CLS, the French Satellite Tracking company based in Toulouse, France (  The radios have GPS technology so that the positions of the bird are extremely accurate (within 18 metres), and they also record speed, altitude and course. A solar panel keeps the battery charged.

The radio is attached to the bird’s back by a lightweight harness, like a tiny rucsac, and is programmed to take GPS readings at hourly intervals and then at intervals of between 1 and 10 days to transmit the data. CLS Argos have satellites which circle the earth, mainly collecting information from ocean weather buoys, and they pick up the signals. We can connect to their website and database, and extract our data using dedicated passwords. It’s possible to open my laptop and receive information transmitted an hour earlier from Africa. We then download the data into the fantastic GoogleEarth mapping system (, and build up extremely detailed pictures of the birds’ movements.

Roy sewing the harness that holds the transmitter in place

The transmitter sits on the bird's back and is charged by a solar panel









To date we have fitted satellite transmitters to 13 ospreys: 8 males and 5 females. 7 have been fitted to chicks in the nest, and 6 to adults.  Most of our adult ospreys have been caught using an eagle owl decoy and a dho ghaza net.  Please click on the individual links on the left to find out about their lives and migrations.

The radios are expensive, costing £3000 each, and for the data for each bird we pay a monthly charge to CLS Argos, approximately £750 per year.  We hope to satellite tag another four ospreys across the Highlands this year and donations would be very welcome for this and future projects.   To donate, please click here: