High definition video loggers provide new insights into behaviour, physiology, and the oceanic habitat of marine top predators
Author and article information
Abstract
Camera loggers are increasingly used to examine behavioural aspects of free-ranging animals. However, often video loggers are deployed with a focus on specific behavioural traits for which it suffices to use cameras that are small but often have a limited field of view, poor light performance and video quality. Yet the rapid developments in consumer electronics provide new devices with much improved visual data which allows a wider scope for studies employing this novel methodology. We developed a camera logger that records full HD video through a wide-angle lens, providing high resolution footage with a greater field of view than other camera loggers. Main goal was the analysis of foraging behaviour of a marine top-predator, the Yellow-eyed penguin in New Zealand, with regards habitat characteristics. Yet, visual data recorded proved to contain much broader information than anticipated. Frame-by-frame analysis allowed accurate timing of prey pursuits and time spent over certain seafloor types. Similarly, it was possible to time breathing intervals between dives and quantify exhalation events during prey events, a previously undescribed behaviour. Using screen overlays we analysed flipper angles and beat frequencies throughout the various phases of a dive. The recorded video footage showed that prey species were associated with certain seafloor types, revealed different predator evasion strategies by benthic fishes, and highlighted varying energetic consequences for penguins pursuing certain types of prey. Flipper movements analysis confirmed decreasing effort during descent phases as the bird gained depth, and that ascent was principally passive. Breathing episodes between dives were short (<1 s) while the majority of the time was devoted to subsurface scanning with a submerged head. Video data recorded on free-ranging animals not only provides a wealth of information recorded from a single deployment but also necessitates new approaches with regards to analysis of visual data. In this paper, we demonstrate the diversity of information that can be gleaned from video logger data, provide various analysis approaches to visual data and highlight the importance of video quality and field of view significantly increase quality of the resulting data.
Cite this as
2017. High definition video loggers provide new insights into behaviour, physiology, and the oceanic habitat of marine top predators. PeerJ Preprints 5:e2765v1 https://doi.org/10.7287/peerj.preprints.2765v1Author comment
A methods paper describing various analysis approaches to visual data recorded with novel high definition video loggers. In preparation for submission with Methods in Ecology and Evolution.
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Additional Information
Competing Interests
Yolanda van Heezik is an Academic Editor for PeerJ.
Author Contributions
Thomas Mattern conceived and designed the experiments, performed the experiments, analyzed the data, contributed reagents/materials/analysis tools, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.
Michael D McPherson conceived and designed the experiments, contributed reagents/materials/analysis tools, wrote the paper, reviewed drafts of the paper.
Ursula Ellenberg performed the experiments, contributed reagents/materials/analysis tools, reviewed drafts of the paper.
Yolanda van Heezik performed the experiments, contributed reagents/materials/analysis tools, reviewed drafts of the paper.
Philipp J Seddon performed the experiments, contributed reagents/materials/analysis tools, reviewed drafts of the paper.
Animal Ethics
The following information was supplied relating to ethical approvals (i.e., approving body and any reference numbers):
University of Otago Ethics Comittee (Protocoll 69/15)
Field Study Permissions
The following information was supplied relating to field study approvals (i.e., approving body and any reference numbers):
Filed experiments were approved by the New Zealand Department of Conservation (45799-FAU)
Data Deposition
The following information was supplied regarding data availability:
The raw data consists of a 6gb video file which currently exceeds the upload allowance of our video hosting platform (vimeo.com). We are looking for alternative ways to make the raw video footage available prior to publication after peer review.
Funding
This work was supported by an Otago Research Grant issued to PJS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.