Sowerby's Beaked Whales, Mesoplodon bidens
Taxonomy Animalia Chordata Mammalia Cetacea Hyperoodontidae Mesoplodon bidens
Description & Behavior
Sowerby's beaked whales, Mesoplodon bidens (Sowerby, 1804), aka North Atlantic beaked whales, are slender cetaceans that measure between 4-5 m in length and weigh between 900-1,100 kg. They have 2 teeth in their lower jaws that protrude in males. Their dorsal fins are small and curved with rounded tips. Their flukes (tails) are dark in color and unnotched. The flippers of Sowerby's beaked whales are curved and relatively long compared to other Mesoplodon species. Sowerby's beaked whales are slate to blue-gray on their dorsal (upper) sides, lighter on their ventral (under) sides with occasional gray or white spots.
Little is known about Sowerby's beaked whales, however some have been observed surfacing head first at a steep angle after which the animal spends about 1 minute breathing. They then dive for 10-15 minutes, and have been observed resurfacing up to 800 m away.
Beaked Whales (Family Ziphiidae)
These medium-sized to moderately large whales have a single pair of grooves on their throats. They have distinct snouts, and often the few teeth present are visible only in adult males. They have a single nostril or blowhole. Beaked whales are generally slender with small dorsal fins toward the rear on their backs. The rear edge of their flukes (tails) usually lacks a well-defined notch. These whales are deep divers and are rarely seen. Many species are known only from a few specimens, and little is known about the life history and biology of the group. All members of this family, except Blainville's beaked whales, are difficult to distinguish from each other, and study by museum experts is usually necessary for identification.
World Range & Habitat
Based on data collected from strandings, Sowerby's beaked whales, Mesoplodon bidens, are found in temperate and subarctic waters in the eastern and western North Atlantic. The eastern population has been seen around Britain and Norway. The western population has been seen mainly off Newfoundland, Canada, and Massachusetts. Little is known about the migratory patterns of this species.
Feeding Behavior (Ecology)
Conservation Status & Comments
No warnings. Very little data is available for this species (as with all beaked whales).
References & Further Research
Texas Marine Mammal Stranding Network - Corpus Christi Region
Center for Cetacean Research and Conservation (CCRC) - Beaked whales (+ videos)
Jefferson, T.A., S. Leatherwood, and M.A. Webber, FAO species identification guide, Marine mammals of the world, Rome, FAO. 1993. 320 p. 587 figs.
Whale and Dolphin Conservation Society (WDCS)
Carwardine, Mark. Eyewitness Handbook Whales, Dolphins, and Porpoises. 1995.
Leatherwood, Stephen and Randall R. Reeves. The Sierra Club Handbook of Whales and Dolphins. 1983.
Wynne, Kate and Malia Schwartz. A Guide To Marine Mammals & Turtles of the U.S. Atlantic & Gulf of Mexico. 1999.
Research Mesoplodon bidens » Barcode of Life ~ BioOne ~ Biodiversity Heritage Library ~ CITES ~ Cornell Macaulay Library [audio / video] ~ Encyclopedia of Life (EOL) ~ ESA Online Journals ~ FishBase ~ Florida Museum of Natural History Ichthyology Department ~ GBIF ~ Google Scholar ~ ITIS ~ IUCN RedList (Threatened Status) ~ Marine Species Identification Portal ~ NCBI (PubMed, GenBank, etc.) ~ Ocean Biogeographic Information System ~ PLOS ~ SCIRIS ~ SIRIS ~ Tree of Life Web Project ~ UNEP-WCMC Species Database ~ WoRMS
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