Year-round distribution, activity patterns and habitat use of a poorly studied pelagic seabird, the fluttering shearwater Puffinus gavia.

Martin Berg,Susanne Åkesson,Stefanie M H Ismar-Rebitz,Matt J Rayner,Chris P Gaskin,Jannie F Linnebjerg,Mike Bell,Graeme Taylor

doi:10.1371/journal.pone.0219986

Abstract

We present the first study to examine the year-round distribution, activity patterns, and habitat use of one of New Zealand’s most common seabirds, the fluttering shearwater (Puffinus gavia). Seven adults from Burgess Island, in the Hauraki Gulf, and one individual from Long Island, in the Marlborough Sounds, were successfully tracked with combined light-saltwater immersion loggers for one to three years. Our tracking data confirms that fluttering shearwaters employ different overwintering dispersal strategies, where three out of eight individuals, for at least one of the three years when they were being tracked, crossed the Tasman Sea to forage over coastal waters along eastern Tasmania and southeastern Australia. Resident birds stayed confined to waters of northern and central New Zealand year-round. Although birds frequently foraged over pelagic shelf waters, the majority of tracking locations were found over shallow waters close to the coast. All birds foraged predominantly in daylight and frequently visited the colony at night throughout the year. We found no significant inter-seasonal differences in the activity patterns, or between migratory and resident individuals. Although further studies of inter-colony variation in different age groups will be necessary, this study presents novel insights into year-round distribution, activity patterns and habitat use of the fluttering shearwater, which provide valuable baseline information for conservation as well as for further ecological studies.

Highlights

Procellariform seabirds are known to undertake long migrations to exploit seasonally favourable feeding areas far from their breeding grounds [1, 2, 3]
Foraging ecology of the fluttering shearwater and all permissions for work on Long Island were from the Department of Conservation and their Animal Ethics committee
The oceanic features of the Hauraki Gulf region and the Cook Strait are influenced by a high primary production enhanced by nearshore upwelling [43], and it is possible that the outstanding oceanographic features in these areas allow the fluttering shearwaters to successfully forage in New Zealand waters year-round

Summary

Introduction

Procellariform seabirds are known to undertake long migrations to exploit seasonally favourable feeding areas far from their breeding grounds [1, 2, 3]. The funder provided support in the form of salaries for authors [JFL, GT, SMHI, MBELL, CPG, SÅ, MJR], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section in the manuscript

Methods

Results

Discussion

Conclusion