What a jerk: prey engulfment revealed by high-rate, super-cranial accelerometry on a harbour seal (Phoca vitulina). Ydesen, K. S., Wisniewska, D. M., Hansen, J. D., Beedholm, K., Johnson, M., & Madsen, P. T. The Journal of Experimental Biology, 2014.
What a jerk: prey engulfment revealed by high-rate, super-cranial accelerometry on a harbour seal (Phoca vitulina) [link]Paper  doi  abstract   bibtex   
A key component in understanding the ecological role of marine mammal predators is to identify how, where and how much prey they capture in time and space. Satellite and archival tags on pinnipeds generally only provide diving and positioning information, and foraging is often inferred to take place in particular shaped dives or when the animal remains in an area for an extended interval. However, fast movements of the head and jaws may provide reliable feeding cues that can be detected by small low-power accelerometers mounted on the head. To test this notion, a harbour seal (Phoca vitulina) was trained to wear an OpenTag (sampling at 200 or 333 Hz with ±2 or ±16 g clipping) on its head while catching fish prey in front of four underwater digital high-speed video cameras. We show that both raptorial and suction feeding generate jerk (i.e., differential of acceleration) signatures with maximum peak values exceeding 1000 m/s3. We conclude that reliable prey capture cues can be derived from fast-sampling, head mounted accelerometer tags thus holding a promising potential for long-term studies of foraging ecology and field energetics of aquatic predators in their natural environments.
@ARTICLE{Ydesen2014,
  author = {Ydesen, Kristina S. and Wisniewska, Danuta M. and Hansen, Janni D.
	and Beedholm, Kristian and Johnson, Mark and Madsen, Peter T.},
  title = {What a jerk: prey engulfment revealed by high-rate, super-cranial
	accelerometry on a harbour seal (Phoca vitulina)},
  journal = {The Journal of Experimental Biology},
  year = {2014},
  abstract = {A key component in understanding the ecological role of marine mammal
	predators is to identify how, where and how much prey they capture
	in time and space. Satellite and archival tags on pinnipeds generally
	only provide diving and positioning information, and foraging is
	often inferred to take place in particular shaped dives or when the
	animal remains in an area for an extended interval. However, fast
	movements of the head and jaws may provide reliable feeding cues
	that can be detected by small low-power accelerometers mounted on
	the head. To test this notion, a harbour seal (Phoca vitulina) was
	trained to wear an OpenTag (sampling at 200 or 333 Hz with ±2 or
	±16 g clipping) on its head while catching fish prey in front of
	four underwater digital high-speed video cameras. We show that both
	raptorial and suction feeding generate jerk (i.e., differential of
	acceleration) signatures with maximum peak values exceeding 1000
	m/s3. We conclude that reliable prey capture cues can be derived
	from fast-sampling, head mounted accelerometer tags thus holding
	a promising potential for long-term studies of foraging ecology and
	field energetics of aquatic predators in their natural environments.},
  doi = {10.1242/jeb.100016},
  eprint = {http://jeb.biologists.org/content/early/2014/04/01/jeb.100016.full.pdf+html},
  file = {:Ydesen et al 2014.pdf:PDF},
  owner = {Tiago Marques},
  timestamp = {2014.07.23},
  url = {http://jeb.biologists.org/content/early/2014/04/01/jeb.100016.abstract}
}

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