18 burrowing owls were tagged with GPS-data loggers (Catnip Technologies, USA) on Teflon harnesses as back mounts. The original case of GPS data-loggers was removed, and batteries were replaced by smaller rechargeable ones (100-150 mAh). Loggers were put in a heat-shrink tube for waterproofing. The final size was 25 × 43 × 10 mm and weights ranged between 12.8 and 16.4 g. GPS data-loggers were programmed with two settings: 1) loggers recording a position per minute until battery flat; and 2) loggers recording a position per minute during the night, while switched off during daylight hours (from 11:00 to 20:00 or from 8:00 to 17:00 UTC). Loggers started to log data the night following capture. All data loggers were operative at the moment of recapture or recovery, but two of them failed to provide useful data

Variables Description Ring Number of the ring of the GPS-tracked burrowing owl DateTimeUTC Date and time in dd/mm/yyyy hh:mm:ss (UTC) Latitude Latitude in decimal degrees Longitude Longitude in decimal degrees Altitude Altitude (in meters) taken from the GPS data logger Code Day or Night Airam Rodríguez (airamrguez@ebd.csic.es; airamrguez@gmail.com), José Hernán Sarasola (sarasola@exactas.unlpam.edu.ar)

Peer reviewed