In July 2017 we put 10 geolocators on the colony of Ortac as part of the T.A.G. project
The geolocators weigh just 1g and are about half the size of a penny, attaching to a colour ring on the Gannets leg. For such small pieces of technology they are quite sophisticated, containing a battery (lasting up to two years), small computer, clock and memory. They use light levels to work out the geographical location of the bird by looking at light levels throughout the day, which can determine latitude and longitude. The data is then stored and will, once downloaded, create a map of where the birds have been. Temperature is recorded, which can help find the altitude birds are flying and pinpointing the birds location more accurately. Finally the geolocators record wet/dry and conductivity, showing whether the water is salty so how much time the birds spend on the coast salty (not so useful for Gannets which do not fly over land) and how long the birds are spending on the water.
The geolocators last up to two years gathering data. In summer 2019 recaptured one of the birds fitted with a with geolocator on Ortac. Finding the birds with geolocators may sound like hunting for a needle in a haystack but is not as difficult as it may sound! The geolocato-fitted Gannets have bright colour rings which are fairly easily spotted on the colony.
The 10 sponsors of our geolocators named their birds and the class of 2017 was Saoirse, John, Wilf, Hector, Prospero, Figaro, Mercury, Lysander, Quetzalcoatl and Minnie
The map for Saoirse the gannet is below, showing where she went in winter of 2017/18. You can see this gannet spent spent a lot of time around the bay of Biscay and strait of Gibraltar. We hope to return to the colony in 2020 so deploy 10 more geolocators and see if we can find any of the nine remaining geolocators.