New publications on underwater behavior of blue whales
The article below summarizing the underwater behavior of blue whales from suction-cup attached Crittercams was recently published:
Calambokidis, J., G.S. Schorr, G.H. Steiger, J. Francis, M. Bakhtiari, G. Marshall, E. Oleson, D. Gendron and K. Robertson. 2008. Insights into the underwater diving, feeding, and calling behavior of blue whales from a suction-cup attached video-imaging tag (CRITTERCAM). Marine Technology Society Journal 41(4):19-29.
We examined the underwater behavior of blue whales using a suction-cup-attached video-imaging
instrument (CRITTERCAM). We made 13 successful deployments (defined as tag
duration of >15 min and successful recovery of the tag and data) totaling 19 hours of
CRITTERCAMs on blue whales off California and in the Sea of Cortez from spring through fall
(26 February to 30 September) between 1999 and 2003 . Whale diving depth and behavior
varied widely by region and period, although deployments on different individuals in the
same area and period often showed very similar feeding behavior. One deployment extending
into night showed a diurnal shift in diving behavior with progressively shallower
feeding dives as it became dark, with shift to shallow, apparently non-feeding dives during
the night. Data and video from tags demonstrated that the characteristic series of vertical
movements blue whales make at depth are lunges into dense aggregations of krill. These
krill were visible streaming by the camera immediately before these lunges and more clearly
when the whales’ forward motion stopped as a result of the lunge. The progression of events
leading up to and during the lunge could be documented from the head movement of whales
and occasional views of the expanding throat pleats or lower jaw, and by changes in flow
noise past the tag, indicating a rapid deceleration. One set of deployments in the Southern
California Bight revealed consistent feeding at depths of 250-300 m, deeper than has been
previously reported for blue whales. A loud blue whale vocalization was heard on only one
deployment on a male blue whale in an interacting trio of animals.
*The article is for personal use only, and is not to be distributed in any format. The Marine Technology Society is a not-for-profit, international, professional association. Founded in 1963, the Society believes that the advancement of marine technology and the productive, sustainable use of the oceans depend upon the active exchange of ideas between government, industry and academia. See www.mtsociety.org.