Insights into the Underwater Diving, Feeding, and Calling Behavior of Blue Whales from a Suction-Cup-Attached Video-Imaging Tag (Crittercam)

Abstract

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.

Keeping momentum with a mouthful of water: behavior and kinematics of humpback whale lunge feeding

“…As the MSA reaches a peak an average of 2s before the drop in flow noise (Table3), we conclude that the mouth must begin opening a second or so before this and therefore some 3s earlier than predicted by the lunge-stop model of Goldbogen et al (Goldbogen et al, 2006). This conclusion is supported by Crittercam recordings of another lunging rorqual species, the blue whale, which show that the mouth opens before the flow noise begins to drop (Calambokidis et al, 2007).…”

“…But, although our understanding of rorqual foraging has increased recently thanks to technological advances (Goldbogen et al., 2006; Goldbogen et al, 2008;Goldbogen et al, 2011;Calambokidis et al, 2007;Ware et al, 2011;Doniol-Valcroze et al, 2011), the details of how lunges are performed at depth are largely based on inferences from low-resolution sensor data (Goldbogen et al, 2006). Here we use fast-sampling multi-sensor tags to provide a higher-resolution picture of the kinematics and behavior of rorqual lunge feeding.…”

Skull and buccal cavity allometry increase mass-specific engulfment capacity in fin whales

“…Although this approximation does not account for the space occupied by the thoracic cavity, the magnitude of that volume is relatively small when compared with the engulfed volume. Furthermore, the elevation of the skull that occurs during mouth opening (Koolstra & Van Eijden 2004;Calambokidis et al 2007) suggests that the influx of engulfed water is not hindered by the position of the thoracic cavity. We explored the effects of morphological variation on engulfment capacity by incorporating the data for each morphological parameter separately into the allometric equations that evaluate the engulfed mass ratio.…”

Foraging behavior of humpback whales: kinematic and respiratory patterns suggest a high cost for a lunge

“…Lunge feeding occurs not only at the sea surface, but also apparently at any depth where prey is particularly abundant (Calambokidis et al, 2008). However, regardless of depth, rorqual foraging dives are limited to very short durations despite their large body size (Croll et al, 2001;Croll et al, 2005;Dolphin, 1988;Goldbogen et al, 2006;Panigada et al, 1999), a characteristic that typically enables longer diving in a wide range of air-breathing vertebrates (Halsey et al, 2006;Schreer and Kovacs, 1997).…”