File(s) under permanent embargo

Testing optimal foraging theory models on benthic divers

journal contribution
posted on 2016-02-01, 00:00 authored by D Foo, J M Semmens, John ArnouldJohn Arnould, N Dorville, Andrew Hoskins, K Abernathy, G J Marshall, M A Hindell
Empirical testing of optimal foraging models on diving air-breathing animals is limited due to difficulties in quantifying the prey field through direct observations. Here we used accelerometers to detect rapid head movements during prey encounter events (PEE) of free-ranging benthic-divers, Australian fur seals, Arctocephalus pusillus doriferus. PEE signals from accelerometer data were validated by simultaneous video data. We then used PEEs as a measure of patch quality to test several optimal foraging model predictions. Seals had longer bottom durations in unfruitful dives (no PEE) than those with some foraging success (PEE. ≥. 1). However, when examined in greater detail, seals had longer bottom durations in dives with more PEEs, but shorter bottom durations in bouts (sequences of dives) with more PEEs. Our results suggest that seals were generally maximizing bottom durations in all foraging dives, characteristic of benthic divers. However, successful foraging dives might be more energetically costly (e.g. digestive costs), thus resulting in shorter bottom durations at the larger scale of bouts. Our study provides a case study of how the foraging behaviour of a central place forager foraging in a fairly homogeneous environment, with relatively high travel costs, may deviate from current foraging models under different situations. Future foraging models should aim to integrate other aspects (e.g. diet) of the foraging process for more accurate predictions.

History

Journal

Animal behaviour

Volume

112

Pagination

127 - 138

Publisher

Elsevier

Location

Amsterdam, The Netherlands

ISSN

0003-3472

eISSN

1095-8282

Language

eng

Publication classification

C Journal article; C1 Refereed article in a scholarly journal

Copyright notice

2015, Elsevier