Prey capture attempts can be detected in Steller sea lions and other marine predators using accelerometers
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We attached accelerometers to the head and jaw of a Steller sea lion (Eumetopias jubatus) to determine whether feeding attempts in a controlled setting could be quantified by acceleration features characteristic of head and jaw movements. Most of the 19 experimental feeding events that occurred during the 51 dives recorded resulted in specific acceleration patterns that were clearly distinguishable from swimming accelerations. The differential acceleration between the head-mounted and jaw-mounted accelerometers detected 84% of prey captures on the vertical axis and 89% on the horizontal axis. However, the jaw-mounted accelerometer alone proved to be equally effective at detecting prey capture attempts. Acceleration along the horizontal (surge)-axis appeared to be particularly efficient in detecting prey captures, and suggests that a single accelerometer placed under the jaw of a pinniped is a promising and easily implemented means of recording prey capture attempts.
KeywordsPrey capture Accelerometers Jaw movements Foraging activity Pinnipeds Steller sea lion
We gratefully thank Chad Nordstrom, Rebecca Barrick, and the trainers that helped us at the Vancouver Aquarium. This study was supported in part by grants to the North Pacific Universities Marine Mammal Research Consortium from the North Pacific Marine Science Foundation and the US National Oceanographic and Atmospheric Administration.
- Guinet C, Dubroca L, Lea M-A, Goldsworthy SD, Cherel Y, Duhamel G, Bonadonna F, Donnay JP (2001) Spatial distribution of foraging in female Antarctic fur seals Arctocephallus gazella in relation to oceanographic variables: a scale-dependent approach using geographic information systems. Mar Ecol Prog Ser 219:251–264CrossRefGoogle Scholar
- Naito Y (2007) A new animal-borne digital still camera (DSL): Its functions and applications to marine mammal science. In: Marshall G (ed) Proceedings of the 2007 animal-borne imaging symposium. National Geographic Society, Washington D.C., pp 201–207Google Scholar
- NMFS (2008) Recovery plan for the Steller sea lion (Eumetopias jubatus). Revision. National Marine Fisheries Service, Silver Spring, p 325Google Scholar
- R Development Core Team (2009) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://www.R-project.org
- Ropert-Coudert Y, Kato A (2006) Are stomach temperature recorders a useful tool for determining feeding activity? Polar Biosci 20:63–72Google Scholar
- Ropert-Coudert Y, Kato A, Liebsch N, Wilson RP, Müller G, Baubet E (2004) Monitoring jaw movements: a cue to feeding activity. Game Wildl Sci 20:1–19Google Scholar
- Trites AW, Larkin PA (1996) Changes in the abundance of Steller sea lions (Eumetopias jubatus) in Alaska from 1956 to 1992: how many were there? Aquatic Mammals 22:153–166Google Scholar
- Wilson RP, Cooper J, Plotz J (1992) Can we determine when marine endotherms feed? A case study with seabirds. J Exp Biol 167:267–275Google Scholar