Underwater Behavior of Large Whales Using Suction-cup Attached Tags
- John Calambokidis
Cascadia Research Collective
- John Hildebrand
Scripps Institution of Oceanography
- John Francis
National Geographic Society
This project examined underwater movements, behavior, and vocalizations of individual blue, fin, and humpback whales using suction-cup tags. Tags included a variety of instrument packages.
Summary to DateWe have more than 40 deployments on blue whales of three different types of suction-cup attached tags including Crittercams, Burgess Bio-acoustic probes, and WHOI dTags. Results to date have provided valuable new information on both the feeding and vocal behavior of blue whales (Calambokidis et al. 2003).
Key findings on the feeding behavior of blue whales include:
1)Blue whales dive to a wide variety of depths some deeper than suspected (300m)
2)Whales often approach prey from underneath, inverting to open the lower jaw into a prey field
3)Confirmation that the series of upward lunges made by blue whales are into prey
4)Dramatic diurnal patterns in diving behavior and apparent shallow resting at night
5)Pairs of blue whales are not engaging in cooperative feeding
6)Blue whales, like other deep diving animals, largely glide when they are diving deep making use of negative buoyancy created by compression of air spaces (Williams et al. 2000).
Key findings on the vocal behavior of blue whales from both the tag data as well as collaborative research with Scripps Institute of Oceanography (Oleson et al. 2003) include:
1)Most blue whales were not producing long patterned calls especially during feeding
2)Even though much of the remote acoustic data describes and documents regular callers, irregular call behavior may be a more common behavior even though it is under-represented in the acoustic records
3)Only males have been documented so far to produce long calls
4)There appear to be differences in social/behavioral contexts of non-callers, irregular and regular callers
5)These findings complicate the goal of determining the relationship between acoustic detections and whale density.
- Trophic association
Study MethodsTag descriptions
Crittercam: A package developed by National Geographic and termed “Crittercam” was deployed on blue whales (Marshall 1998, Williams et al. 2000, Francis et al. 2001). The instrument packages deployed contained a combination of 1) hydrophone and recording system for underwater vocalizations, 2) Pressure sensor to record water depth, 3) Sensor to monitor and record water temperature, 4) Conductivity switch to control surface and underwater instrument activation, 5) VHF tag to provide local positioning information, and 6) Underwater video camera to record behavior and prey
Burgess Bio-Probe: An acoustic tag deployed developed by Bill Burgess of Greeneridge Scientific Services (with support from ONR) an deployed as part of a collaboration with Scripps Institute of Oceanography. The tag recorded underwater sound and dive depth. The tag sampled acoustics with 16-bit resolution at bandwidths up to 14 kHz, as well as temperature and depth with 12-bit resolution.
WHOI (Woods Hole Oceanographic Institute) digital tag: The WHOI digital tag has been developed in recent years and successfully tested on a number of species. A graduate student at WHOI, Becky Woodward, collaborated with us in conducting deployments in the Santa Barbara Channel. The digital tag consists of hydrophone, pressure sensor, a thermistor both for water temperature and to correct the pressure sensor readings, 3-axis accelerometers to measure pitch and roll, 3-axis solid-state magnetometers to measure heading.
Figures and Images
Dive behavior of blue whale tagged with Burgess Bio-tag on June 30, 2002 off San Diego, CA.
Whale swimming with attached suction tag.
Acoustic tag being placed on a whale.