Miniature light-level geolocator tags - record light levels against time which can be processed to give latitude and longitude. Although not as accurate as GPS or ARGOS, this method allows a much smaller and cheaper device that can record for a long time.

For seabirds, logging of wet/dry information and sea surface temperature can also be included. The wet/dry recording has been developed to measure the activity of the birds, and the temperature information can be correlated with satellite recorded sea-surface temperatures to improve location accuracy.