Igor files of depth, temperature and 3-axis acceleration of data-loggers deployed on European shags at Isle of May Scotland in late May-early June 2006. File name is bird ID. Information of all birds is in the Excel file "Shag2006Birds."

The study was conducted on the Isle of May National Nature Reserve, south-east Scotland (56° 11’N, 02° 33’W) in the 2006 breeding season. Twenty-eight known aged males, brooding 1–3 medium-sized chicks were captured between 26 June and 2 July. Our sampling period was 2–4 days for each bird and ranged between 26 June and 5 July. A depth and acceleration data logger (D2GT, Little Leonardo Co Ltd, Tokyo; 15 mm in diameter, 53 mm in length, 18 g in mass) was attached to the back feathers with Tesa-tape. All birds returned to the nest within 5 min of logger deployment and immediately resumed normal breeding behaviour. All individuals were recaptured at the nest 2–4 days later and the loggers were retrieved. Data loggers were set to record surge (tail-head) and heave (dorso-ventral) accelerations at 16Hz and depth (at 1m accuracy) at 1Hz. Calibration of acceleration, estimation of logger attachment angle, the filter used to separate stroke-based acceleration from that caused by gravity and the protocol to estimate body angle and heave are described in Watanuki et al. (2005). To quantify flight duration and wing stroke cycle, we applied continuous wavelet transformation to take into account the non-stationary oscillation of the heave acceleration using Ethographer (Sakamoto et al. 2009). We calculated the power spectral density and defined its dominant cycles as the wing stroke cycle. We calculated the power spectral density and defined its dominant cycles as the wing stroke cycle.

Igor and Ethographer