GPS and Time-Depth Recorder tracking of Adelie and Chinstrap penguins from Signy Island 2008

The birds were fitted with Fastloc2 GPS loggers (Sirtrack, Havelock, New Zealand) paired with CEFAS G5 TDRs (CEFAS Technology Ltd, Lowestoft, UK) whose clocks were synchronised in other years. Dive statistics from the TDR tracks were extracted using the R package diveMove (Luque, 2016 - diveMove: Dive Analysis and Calibration. R package version 1.4.1. https://cran.r-project.org/package=diveMove). The filter method of zero offset correction within diveMove (Luque & Fried, 2011 PLOS ONE, 6(1), e15850) was used to define the sea-surface and a depth threshold of 5m was used to exclude any non-foraging dive events (Kokubun, Takahashi, Mori, Watanabe, & Shin, 2010 doi:10.1007/s00227-009-1364-1).