Methodology:

Global Positioning system (GPS) devices were fitted to 51 Adelie penguins on Signy Island between December and February, over three seasons between the years 2011 to 2019. Breeding penguins were caught during incubation, brood and creche periods and fitted with GPS loggers (Sirtrack Fastloc) using Tessa tape and a two-part quick-setting glue. Handling time did not exceed 10 minutes for deployment and 5 minutes for retrieval. Loggers were always less than 1 percent of the bird's body mass.

Devices were retrieved on average after 4.7 days.

GPS loggers recorded locations every 4 minutes, with longer intervals if the GPS could not connect to satellites (when the bird was underwater).

The number of retrieved tags with data per year are as follows:

2011-2012: 11

2013-2014: 23

2015-2016: 11

Data collection:

Sirtrack Fastloc 33 F2G133A (38.4 g in air, 65 x 28 x 22 mm) with 40 mm whip antenna

Sirtrack Fastloc 33 F3G133A (31.0 g in air, 63 x 24 x 22 mm) with 40 mm whip antenna

Data quality:

Files were included the timestamp, latitude and longitude in decimal degrees. Any NaN or '0.00' values (in latitude and longitude) were removed.

When the sex of the bird was not known, 'U' was used in the metadata file.