Methodology:

Argos Platform Terminal Transmitters (PTT) devices were attached to 53 Adelie penguins during the breeding season from 1999 to 2014. Each PTT was fitted to the lower medial portion of the back of each penguin using Tesa tape, plastic cable ties and quick-set epoxy resin ensuring the position of the device did not hinder the bird's movement, or access to their preen gland. Each bird was restrained according to BAS procedure.

Device specifications for each deployment year are specified below. Additional information when known is also provided.

1999-2001:

Deployment: 18 birds fitted with devices from mid-December to mid-February.

Device: SirTrack ST-10 (97g) or SirTrack ST-18 (97g), 115 x 44 x 15 mm, 90-degree antenna

2004-2005:

Deployment: 9 birds fitted with devices in December. Handling did not exceed 10 min. Each bird was restrained using a net, according to existing BAS procedure.

Device: KiwiSat 101 transmitters (125x43x20 mm, 107 g) or KiwiSat ST10 transmitters (135x32x18 mm, 107g) Each PTT was set to transmit every 45 s and was equipped with a saltwater switch, which stopped the instrument from transmitting after a 3-h period out of water (a means of conserving battery power), only reactivating after re-submergence. Recovery: Following the attachment procedure, the penguins were released close to their nest sites. All devices were lost during the moult.

2012-2014:

Deployment: 25 birds fitted with devices in January. Handling did not exceed 10 min. Each bird was restrained using a net, according to existing BAS procedure.

Device: Devices (KiwiSat 101 transmitters (125x43x20 mm, 107 g) or KiwiSat ST10 transmitters (135x32x18 mm, 107g). Each PTT was set to transmit every 45 s and was equipped with a saltwater switch, that reduced the transmission rate when the bird hauled out of the water, either on land or on ice. The reduced transmission rate was intended to conserve battery power.

Data quality:

Satellite uplinks are given error values as the loc_class and loc_ind, which have an associated readme file further describing their values. The loc_class field indicates an error value for the location which is determined by the number of satellites the tag connected to. The loc_ind field indicates the IQ (quality indicator), which gives information on the transmitter in terms of X and Y.

PTT location data were obtained from the ARGOS system (www.argossystem.org).

Deployment data is filtered to include uplinks within trip duration provided in the metadata. When trip start and end timestamps were not provided, the first and last uplink for that deployment were used.