Flying south: foraging locations of the Hutton’s shearwater (Puffinus huttoni) revealed by time-depth recorders and GPS tracking

1. The Hutton’s shearwater Puffinus huttoni is an endangered seabird endemic to Kaikōura, New Zealand, but the spatial and temporal aspects of its at-sea foraging behaviour are not well known.
2. To identify foraging areas and estimate trip durations, we deployed Global Positioning Systems (GPS) devices and Time-Depth Recorders (TDR) on 26 adult Hutton’s shearwaters during the chick-rearing period in 2017 and 2018.
3. We found Hutton’s shearwaters travelled much further from their breeding grounds at Kaikōura than previously considered, with most individuals foraging in coastal and oceanic areas 125–365 km south and near Banks Peninsula. Trip durations varied from 1 to 15 days (mean = 5 days), and total track lengths varied from 264 to 2157 km (mean = 1092.9 km).
4. Although some diving occurred in near-shore waters near the breeding colony, most foraging was concentrated in four regions south of Kaikōura. Dive durations averaged 23.2 seconds (range 8.1 to 71.3 sec) and dive depths a...