Abstract
Determining the foraging behaviour of free-ranging marine animals is fundamental for assessing their habitat use and how they may respond to changes in the environment. However, despite recent advances in bio-logging technology, collecting information on both at-sea movement patterns and activity budgets still remains difficult in small pelagic seabird species due to the constraints of instrument size. The short-tailed shearwater, the most abundant seabird species in Australia (ca 23 million individuals), is a highly pelagic procellariiform. Despite its ecological importance to the region, almost nothing is known about its at-sea behaviour, in particular, its foraging activity. Using a combination of GPS and tri-axial accelerometer data-loggers, the fine scale three-dimensional foraging behaviour of 10 breeding individuals from two colonies was investigated. Five at-sea behaviours were identified: (1) resting on water, (2) flapping flight, (3) gliding flight, (4) foraging (i.e., surface foraging and diving events), and (5) taking-off. There were substantial intra- and inter- individual variations in activity patterns, with individuals spending on average 45.8% (range: 17.1–70.0%) of time at sea resting on water and 18.2% (range: 2.3–49.6%) foraging. Individuals made 76.4 ± 65.3 dives (range: 8–237) per foraging trip (mean duration 9.0 ± 1.9 s), with dives also recorded during night-time. With the continued miniaturisation of recording devices, the use of combined data-loggers could provide us with further insights into the foraging behaviour of small procellariiforms, helping to better understand interactions with their prey.
Highlights
Understanding and assessing the foraging behaviour of free-ranging marine animals is fundamental for determining their habitat use and responses to environmental change
Information about foraging ecology, habitat utilisation or at-sea distribution related to the heterogeneity and the patchiness of prey resources has been published on a large range of seabird species [10,11,12,13]
The present study was conducted following the ethical guidelines of the Deakin University Animal Ethics Committee (Approval A61-2010) and in accordance with the regulations of Department of Sustainability and Environment (Victoria, Australia, Permit 10005531)
Summary
Understanding and assessing the foraging behaviour of free-ranging marine animals is fundamental for determining their habitat use and responses to environmental change. Information about foraging ecology, habitat utilisation or at-sea distribution related to the heterogeneity and the patchiness of prey resources has been published on a large range of seabird species [10,11,12,13]. Despite these major advances in biotelemetry, some challenges remain. The short-tailed shearwater (Puffinus tenuirostris) is a highly pelagic small-sized procellariiform It is the most abundant seabird species in Australia, with approximately 23 million individuals breeding annually during the austral spring/summer (September to April) [33]. Assuming that higher energy costs occurring during short trips are due to greater foraging intensity [42], the aims of the present study were to investigate: 1) how individuals allocate their time at sea; and 2) to describe their diving activity during these nutritionally demanding periods
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
