https://www.nature.com/articles/s41598-019-50942-2
Tennessen, J. B., Holt, M. M., Ward, E. J., Hanson, M. B., Emmons, C. K., Giles, D. A., & Hogan, J. T. (2019). Hidden Markov models reveal temporal patterns and sex differences in killer whale behavior. Scientific Reports, 9(1), 1-12.
Abstract
Behavioral
data can be important for effective management of endangered marine predators,
but can be challenging to obtain. We utilized suction cup-attached biologging
tags equipped with stereo hydrophones, triaxial accelerometers, magnetometers,
pressure and temperature sensors, to characterize the subsurface behavior of an
endangered population of killer whales (Orcinus
orca). Tags recorded depth, acoustic and movement behavior on fish-eating killer
whales in the Salish Sea between 2010-2014. We tested the hypotheses that (a)
distinct behavioral states can be characterized by integrating movement and
acoustic variables, (b) subsurface foraging occurs in bouts, with distinct
periods of searching and capture temporally separated from travel, and (c) the probabilities
of transitioning between behavioral states differ by sex. Using Hidden Markov
modeling of two acoustic and four movement variables, we identified five temporally
distinct behavioral states. Persistence in the same state on a subsequent dive had the greatest
likelihood, with the exception of deep prey pursuit, indicating that behavior
was clustered in time. Additionally, females spent more time at the surface
than males, and engaged in less foraging behavior. These results reveal
significant complexity and sex differences in subsurface foraging behavior, and
underscore the importance of incorporating behavior into the design of
conservation strategies.
Please contact me with any questions.
Cheers,
Jennifer Tennessen
--
Jennifer B. Tennessen, Ph.D.
Postdoctoral Scientist, contractor with Lynker, LLCMarine Mammal & Seabird Ecology Team, Conservation Biology Division
NOAA/NMFS Northwest Fisheries Science Center
2725 Montlake Blvd East
Seattle, WA 98112