In 2011 and 2012 we marked 85 of Bird Island’s breeding Sooty Terns with geolocators, tiny devices that record geographical location during their migration. Geolocators have to be recovered the next breeding season to download the data and in 2012 and 2013 we manged to find 40 of the marked birds. The data showed that … More More trouble for Bird Island’s Sooty Terns?