title: Dive characteristics can predict foraging success in Australian fur seals (Arctocephalus pusillus doriferus) as validated by animal-borne video.
abstract: Dive characteristics and dive shape are often used to infer foraging success in pinnipeds. However, these inferences have not been directly validated in the field with video, and it remains unclear if this method can be applied to benthic foraging animals. This study assessed the ability of dive characteristics from time-depth recorders (TDR) to predict attempted prey capture events (APC) that were directly observed on animal-borne video in Australian fur seals (Arctocephalus pusillus doriferus, n=11). The most parsimonious model predicting the probability of a dive with ≥1 APC on video included only descent rate as a predictor variable. The majority (94%) of the 389 total APC were successful, and the majority of the dives (68%) contained at least one successful APC. The best model predicting these successful dives included descent rate as a predictor. Comparisons of the TDR model predictions to video yielded a maximum accuracy of 77.5% in classifying dives as either APC or non-APC or 77.1% in classifying dives as successful verses unsuccessful. Foraging intensity, measured as either total APC per dive or total successful APC per dive, was best predicted by bottom duration and ascent rate. The accuracy in predicting total APC per dive varied based on the number of APC per dive with maximum accuracy occurring at 1 APC for both total (54%) and only successful APC (52%). Results from this study linking verified foraging dives to dive characteristics potentially opens the door to decades of historical TDR datasets across several otariid species.
authors.affiliation: School of Life and Environmental Sciences, Deakin University Burwood, Victoria 3125, Australia byou@deakin.edu.au.
authors.forename: Beth L
authors.initials: BL
authors.lastname: Volpov
authors.affiliation: Marine Mammal Research Unit, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
authors.forename: David A S
authors.initials: DA
authors.lastname: Rosen
authors.affiliation: School of Life and Environmental Sciences, Deakin University Burwood, Victoria 3125, Australia.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Hoskins
authors.affiliation: School of Life and Environmental Sciences, Deakin University Burwood, Victoria 3125, Australia.
authors.forename: Holly J
authors.initials: HJ
authors.lastname: Lourie
authors.affiliation: School of Life and Environmental Sciences, Deakin University Burwood, Victoria 3125, Australia.
authors.forename: Nicole
authors.initials: N
authors.lastname: Dorville
authors.affiliation: School of Life and Environmental Sciences, Deakin University Burwood, Victoria 3125, Australia.
authors.forename: Alastair M M
authors.initials: AM
authors.lastname: Baylis
authors.affiliation: School of Life and Environmental Sciences, Deakin University Burwood, Victoria 3125, Australia.
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Wheatley
authors.affiliation: Remote Imaging Department, National Geographic, Washington, DC 20036, USA.
authors.forename: Greg
authors.initials: G
authors.lastname: Marshall
authors.affiliation: Remote Imaging Department, National Geographic, Washington, DC 20036, USA.
authors.forename: Kyler
authors.initials: K
authors.lastname: Abernathy
authors.affiliation: Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania 7001, Australia.
authors.forename: Jayson
authors.initials: J
authors.lastname: Semmens
authors.affiliation: Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania 7001, Australia.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hindell
authors.affiliation: School of Life and Environmental Sciences, Deakin University Burwood, Victoria 3125, Australia.
authors.forename: John P Y
authors.initials: JP
authors.lastname: Arnould
keywords: Animal-borne video; Crittercam; Dive profile analysis; Foraging behaviour