Highlighting when animals expend excessive energy for travel using dynamic body acceleration
Rory P. Wilson,
Samantha D. Reynolds,
Jonathan R. Potts,
James Redcliffe,
Mark Holton,
Abi Buxton,
Kayleigh Rose,
Bradley M. Norman
Affiliations
Rory P. Wilson
Biosciences, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, UK
Samantha D. Reynolds
School of Biological Sciences, The University of Queensland, St Lucia, QLD 4065, Australia; ECOCEAN Inc., P.O. Box 42, Serpentine, WA 6125, Australia
Jonathan R. Potts
University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, England, UK
James Redcliffe
Biosciences, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, UK
Mark Holton
Biosciences, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, UK
Abi Buxton
Biosciences, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, UK
Kayleigh Rose
Biosciences, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, UK
Bradley M. Norman
ECOCEAN Inc., P.O. Box 42, Serpentine, WA 6125, Australia; Harry Butler Institute, Murdoch University, Murdoch, WA 6150, Australia; Corresponding author;
Summary: Travel represents a major cost for many animals so there should be selection pressure for it to be efficient – at minimum cost. However, animals sometimes exceed minimum travel costs for reasons that must be correspondingly important. We use Dynamic Body Acceleration (DBA), an acceleration-based metric, as a proxy for movement-based power, in tandem with vertical velocity (rate of change in depth) in a shark (Rhincodon typus) to derive the minimum estimated power required to swim at defined vertical velocities. We show how subtraction of measured DBA from the estimated minimum power for any given vertical velocity provides a “proxy for power above minimum” metric (PPAmin), highlighting when these animals travel above minimum power. We suggest that the adoption of this metric across species has value in identifying where and when animals are subject to compelling conditions that lead them to deviate from ostensibly judicious energy expenditure.
