High definition video loggers provide new insights into behaviour, physiology, and the oceanic habitat of marine top predators
- Published
- Accepted
- Subject Areas
- Animal Behavior, Ecology, Environmental Sciences, Marine Biology, Zoology
- Keywords
- marine top-predators, animal-borne video loggers, diving behaviour, benthic habitat, penguins, predator-prey interactions
- Copyright
- © 2017 Mattern et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. High definition video loggers provide new insights into behaviour, physiology, and the oceanic habitat of marine top predators. PeerJ Preprints 5:e2765v2 https://doi.org/10.7287/peerj.preprints.2765v2
Abstract
1. 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 utilizing small cameras with a limited field of view, poor light performance and video quality. Yet rapid developments in consumer electronics provide new devices with much improved visual data allowing a wider scope for studies employing this novel methodology.
2. 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, in the context habitat characteristics. 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. Screen overlays facilitate analysis of flipper angles and beat frequencies throughout various stages of the dive cycle.
3. 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 movement 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.
4. 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. Here, we demonstrate the diversity of information that can be gleaned from video logger data, if devices with high video resolution and wide field of view are utilized
Author Comment
Updated version following reviewer comments.