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Mammalian Species DISCLAIMER 
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Beaked Whales (Ziphiidae)
This diverse family of whales is represented in Canadian waters by four genera: Berardius, Hyperoedon, Ziphius, and Mesoplodon. Ziphiids, or beaked whales, are typically pelagic in distribution and rarely sighted on the continental shelf. Most appear to be deep divers, and squid or deep-sea fish comprise the bulk of their diet. All beaked whales in the Northern Hemisphere have a pair of deep grooves on the throat, which partially converge to form a forward-pointing V. Their flukes are not normally separated from each other by a well-formed notch. The beak, which can be short and ill-defined as in Cuvier's beaked whale (Ziphius cavirostris) or long and cylindrical as in Baird's beaked whale (Berardius bairdii), is equipped with usually 2 but no more than 4 functional teeth, situated toward the front of the lower jaw. In Mesoplodon, only adult males have erupted teeth, and in some of these the teeth protrude outside the closed mouth, serving as formidable tusks that are probably used during fights between males. Baird's beaked whale, measuring nearly 13 m in length, is the largest of the beaked whales. It lives only in the North Pacific, where it is known from as far south as northern Baja California, Mexico, to as far north as the central Bering Sea. Shore-based whalers frequently encountered groups of 10-20 Baird's beaked whales, mainly adult males, on the whaling grounds west of Vancouver Island. The whales were seen during all months from May to September, but most regularly in August. The only other beaked whale that has been of any commercial significance in Canada is the northern bottlenose whale (Hyperoddon ampultatus). It is endemic in the North Atlantic, where it is widely distributed in cold temperate and subarctic regions. Off North America, the two best-known areas of concentration are at the mouth of Hudson Strait and in a deep canyon east of Sable Island, called The Gully. It is in the latter area that 67 bottlenose whales were caught during the 1960s by whalers out of Blandford, Nova Scotia. Bottlenose whales were also hunted in Davis Strait by British arctic whalers during the nineteenth century, and 818 of them were taken off Labrador during 1969-1971 by Norwegian pelagic whalers. Bottlenose whales dive for longer periods than most other whales; timed dives lasting 90 minutes or more have been reported. The other beaked whales that occur in Canadian waters have not been hunted here, and they are rarely seen alive at sea. Most of what is known about their distribution in Canada comes from the few stranded specimens which have come to the attention of scientists. Cuvier's beaked whale and Blainville's beaked whale (Mesoplodon densirostris) are cosmopolitan in temperate and tropical seas, and they can be expected to occur irregularly on both the Atlantic and Pacific coasts of southern Canada. In addition, Sowerby's beaked whale (M. bidens) and Gervais' beaked whale (M. mirus) are known from the east coast; Hubbs' beaked whale (M. carlhubbsi) and Stejneger's beaked whale (M. stejnegeri), from the west coast. |
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SOURCE: Communications Directorate Department of Fisheries and Oceans Ottawa, Ontario K1A 0E6 © Minister of Supply and Services, Canada Cat. No.: Fs 41-33/59-1988E ISBN: 0-662-16501-2 Reprinted 1993 |
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