Techniques to improve the accuracy of location estimation using light-level geolocation to track shorebirds

We review the use of light-level geolocators to track long-distance migrant shorebirds and describe several techniques that an analyst can employ to obtain the best possible estimates of a bird’s location. These include: calibration using perfectly bright and clear days, longitude averaging, point clusters, habitat knowledge, the use of resightings of the birds, dealing with the different error patterns before and after the spring and fall equinoxes, weather pattern correction, the effects of artificial light, interpretation of geolocator fixes obtained during migratory flights, the use of data recorded by a geolocator’s conductivity sensor to determine flight duration and location estimation when a bird is in the Arctic using the nightshade technique. We also review the accuracy that can be expected in shorebird studies using geolocators.