Beaked whale diving behavior study published

For more information contact Robin W. Baird at rwbaird (at) cascadiaresearch.org

Adult female Blainville's beaked whale with suction-cup attached tag. The white oval scars visible were caused by cookie-cutter sharks. Photo taken April 20, 2006. (c) Robin W. Baird 2006. Not to be used without permission.

A paper published on-line in the Canadian Journal of Zoology on September 15, 2006, reveals information on the underwater behavior of two species of poorly known whales, the Cuvier’s and Blainville’s beaked whales. Beaked whales are one of the largest families of whales and dolphins, yet one of the least known groups due to their typically open-ocean distribution, long dive times, and sometimes avoidance of boats. Over the last five years a team of researchers led by Dr. Robin Baird of Cascadia Research in Olympia, Washington, have studied these two species off the west coast of the island of Hawaii. These researchers have used suction-cup attached tags containing a small computer (a Time-depth recorder) and a radio-transmitter to study the underwater behavior of these species. In the paper in the Canadian Journal of Zoology, the researchers report that both species are regularly diving to depths greater than 800 m (2,624’), with maximum depths documented of 1,408 m (4,619’) for Blainville’s beaked whales and 1,450 m (4,757’) for Cuvier’s beaked whales. Cuvier’s beaked whales were documented holding their breath for up to 87 minutes. The researchers report that while most species of whales and dolphins ascend to the surface at the same speed at which they dive, both species of beaked whales had significantly slower ascent rates than descent rates. Dr Baird notes that “this may be a mechanism to cope with gas bubble formation associated with such regular long and deep dives”. The researchers relate their results to the mass strandings of both species which have occurred in response to high-intensity naval sonars. In recent years these mass strandings have occurred off the Bahamas and off the Canary Islands associated with NATO or US Navy exercises. Based on the results of their tagging study, Baird and colleagues suggest that the two species may be susceptible to impacts from sonars due to behavioral reactions which cause the whales to ascend too rapidly.

This study was funded by the Southwest Fisheries Science Center of the National Marine Fisheries Service, the U.S. Navy, and the Wild Whale Research Foundation.

A pdf copy of the paper will be available at www.cascadiaresearch.org/robin/hawaii.htm

Adult male Blainville's beaked whale showing erupted teeth and scars from fighting with other males. Photo taken April 22, 2006. (c) Robin W. Baird 2006. Not to be used without permission.

Adult male Cuvier's beaked whale showing scars from cookie-cutter sharks. Photo taken November 28, 2004. (c) Greg S. Schorr 2004. Not to be used without permission.

Adult female Cuvier's beaked whale with suction-cup attached tag, showing scars from cookie-cutter sharks. Photo taken November 28, 2004. (c) Robin W. Baird 2004. Not to be used without permission.

Adult male Cuvier's beaked whale with erupted teeth and barnacles growing on teeth. (c) Daniel J. McSweeney 2006. Not to be used without permission.

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