ORCID Profile
0000-0002-7518-3548
Current Organisations
Dalhousie University
,
University of Oxford
,
University of St Andrews
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Publications
Best practice recommendations for the use of external telemetry devices on pinnipeds
Publisher: Springer Science and Business Media LLC
Date: 04-10-2019
DOI: 10.1186/S40317-019-0182-6
Abstract: Pinnipeds spend large portions of their lives at sea, submerged, or hauled-out on land, often on remote off-shore islands. This fundamentally limits access by researchers to critical parts of pinniped life history and has spurred the development and implementation of a variety of externally attached telemetry devices (ETDs) to collect information about movement patterns, physiology and ecology of marine animals when they cannot be directly observed. ETDs are less invasive and easier to apply than implanted internal devices, making them more widely used. However, ETDs have limited retention times and their use may result in negative short- and long-term consequences including capture myopathy, impacts to energetics, behavior, and entanglement risk. We identify 15 best practice recommendations for the use of ETDs with pinnipeds that address experimental justification, animal capture, tag design, tag attachment, effects assessments, preparation, and reporting. Continued improvement of best practices is critical within the framework of the Three Rs (Reduction, Refinement, Replacement) these best practice recommendations provide current guidance to mitigate known potential negative outcomes for in iduals and local populations. These recommendations were developed specifically for pinnipeds however, they may also be applicable to studies of other marine taxa. We conclude with four desired future directions for the use of ETDs in technology development, validation studies, experimental designs and data sharing.
Images as proximity sensors: the incidence of conspecific foraging in Antarctic fur seals
Publisher: Springer Science and Business Media LLC
Date: 29-09-2015
Fur seals do, but sea lions don't — cross taxa insights into exhalation during ascent from dives
Publisher: The Royal Society
Date: 14-06-2021
Abstract: Management of gases during ing is not well understood across marine mammal species. Prior to ing, phocid (true) seals generally exhale, a behaviour thought to assist with the prevention of decompression sickness. Otariid seals (fur seals and sea lions) have a greater reliance on their lung oxygen stores, and inhale prior to ing. One otariid, the Antarctic fur seal ( Arctocephalus gazella ), then exhales during the final 50–85% of the return to the surface, which may prevent another gas management issue: shallow-water blackout. Here, we compare data collected from animal-attached tags (video cameras, hydrophones and conductivity sensors) deployed on a suite of otariid seal species to examine the ubiquity of ascent exhalations for this group. We find evidence for ascent exhalations across four fur seal species, but that such exhalations are absent for three sea lion species. Fur seals and sea lions are no longer genetically separated into distinct subfamilies, but are morphologically distinguished by the thick underfur layer of fur seals. Together with their smaller size and energetic es, we suggest their air-filled fur might underlie the need to perform these exhalations, although whether to reduce buoyancy and ascent speed, for the avoidance of shallow-water blackout or to prevent other cardiovascular management issues in their ing remains unclear. This article is part of the theme issue ‘Measuring physiology in free-living animals (Part I)’.
Drivers and constraints on offshore foraging in harbour seals
Publisher: Springer Science and Business Media LLC
Date: 22-03-2021
DOI: 10.1038/S41598-021-85376-2
Abstract: Central place foragers are expected to offset travel costs between a central place and foraging areas by targeting productive feeding zones. Harbour seals ( Phoca vitulina ) make multi-day foraging trips away from coastal haul-out sites presumably to target rich food resources, but periodic track points from telemetry tags may be insufficient to infer reliably where, and how often, foraging takes place. To study foraging behaviour during offshore trips, and assess what factors limit trip duration, we equipped harbour seals in the German Wadden Sea with high-resolution multi-sensor bio-logging tags, recording 12 offshore trips from 8 seals. Using acceleration transients as a proxy for prey capture attempts, we found that foraging rates during travel to and from offshore sites were comparable to offshore rates. Offshore foraging trips may, therefore, reflect avoidance of intra-specific competition rather than presence of offshore foraging hotspots. Time spent resting increased by approx. 37 min/day during trips suggesting that a resting deficit rather than patch depletion may influence trip length. Foraging rates were only weakly correlated with surface movement patterns highlighting the value of integrating multi-sensor data from on-animal bio-logging tags (GPS, depth, accelerometers and magnetometers) to infer behaviour and habitat use.
Related Organisations
University Of Oxford
Location: United Kingdom of Great Britain and Northern Ireland
University Of St Andrews
Location: United Kingdom of Great Britain and Northern Ireland
Related Funding Activities
No related grants have been discovered for Sascha Hooker.