Flying south: Foraging locations of the Hutton's shearwater (Puffinus huttoni) revealed by Time‐Depth Recorders and GPS tracking

• Published in: Ecology and evolution Vol. 9; no. 14; pp. 7914 - 7927
• Main Authors: Bennet, Della G., Horton, Travis W., Goldstien, Sharyn J., Rowe, Lindsay, Briskie, James V.
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.07.2019; John Wiley and Sons Inc; Wiley
• Subjects: Adults; Aquatic birds; Birds; Breeding grounds; Chlorophyll; Depth recorders; Endangered & extinct species; Fisheries; Flight; Foraging behavior; Global Positioning Systems; GPS; Hutton's Shearwater; Mapping; Marine conservation; Marine environment; New Zealand; Original Research; Puffinus huttoni; Recorders; Satellite navigation systems; Temporal distribution; Time‐Depth Recorders; Tourism; Trip estimation; New Zealand; New Zealand; Puffinus huttoni; Hutton's Shearwater; Global Positioning Systems; Time‐Depth Recorders
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.5171

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 behavior are not well known. 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. We found Hutton's shearwaters traveled 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 2,157 km (mean = 1092.9 km). 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 s (range 8.1 to 71.3 s) and dive depths averaged 7.1 m (range 1.5 to 30 m). Foraging locations had higher chlorophyll a levels and shallower water depths than nonforaging locations. Birds did not feed at night, but tended to raft in areas with deeper water than foraging locations. Mapping the spatial and temporal distribution of Hutton's shearwaters at sea will be fundamental to their conservation, as it can reveal potential areas of overlap with fisheries and other industrial users of the marine environment. To identify the at‐sea behavior of Hutton's shearwater, a threatened New Zealand seabird, we deployed Global Positioning System devices and Time‐Depth Recorders on 26 birds in 2017 and 2018. We found Hutton's shearwaters traveled much further from their breeding grounds than previously considered, with trip durations averaging 5 days and over 1,000 km in length. Birds dived to depths of 30 m and foraged in locations characterized by higher chlorophyll a levels and shallower water depths. Mapping the distribution of Hutton's shearwaters at sea can reveal potential areas of conflict with fisheries and other users of the marine environment.