New publication on stereotyped movements and sex differences in killer whale foraging behavior

[Jennifer Tennessen - NOAA Affiliate <>]

Dear Bioacoustics community,

My co-authors and I are pleased to share with you our recent paper in the Journal of Experimental Biology. We used acoustic data from biologging tags to validate a method to detect prey capture based on subsurface movement, and to investigate foraging behavior in resident-type killer whales. 

Tennessen, J.B., Holt, M.M., Hanson, M.B., Emmons, C.K., Giles, D.A., Hogan, J.T. 2019. Kinematic signatures of prey capture from archival tags reveal sex
differences in killer whale foraging activity. Journal of Experimental Biology 222, jeb191874. doi:10.1242/jeb.191874

Studies of odontocete foraging ecology have been limited by the
challenges of observing prey capture events and outcomes
underwater. We sought to determine whether subsurface
movement behavior recorded from archival tags could accurately
identify foraging events by fish-eating killer whales. We used
multisensor bio-logging tags attached by suction cups to Southern
Resident killer whales (Orcinus orca) to: (1) identify a stereotyped
movement signature that co-occurred with visually confirmed prey
capture dives; (2) construct a prey capture dive detector and validate it
against acoustically confirmed prey capture dives; and (3)
demonstrate the utility of the detector by testing hypotheses about
foraging ecology. Predation events were significantly predicted by
peaks in the rate of change of acceleration (‘jerk peak’), roll angle and
heading variance. Detection of prey capture dives by movement
signatures enabled substantially more dives to be included in
subsequent analyses compared with previous surface or acoustic
detection methods. Males made significantly more prey capture dives
than females and more dives to the depth of their preferred prey,
Chinook salmon. Additionally, only half of the tag deployments on
females (5 out of 10) included a prey capture dive, whereas all tag
deployments on males exhibited at least one prey capture dive (12 out
of 12). This dual approach of kinematic detection of prey capture
coupled with hypothesis testing can be applied across odontocetes
and other marine predators to investigate the impacts of social,
environmental and anthropogenic factors on foraging ecology.

You can obtain a copy of the article online:

http://jeb.biologists.org/content/222/3/jeb191874

or from me

Kind regards,

Jennifer, Marla, Brad, Candice, Giles and Jeff

--

Jennifer B. Tennessen, Ph.D.

Postdoctoral Scientist
Marine Mammal & Seabird Ecology Team, Conservation Biology Division
NOAA/NMFS Northwest Fisheries Science Center
2725 Montlake Blvd East
Seattle, WA 98112

Phone: (206) 860-3473