Taxonomy & Nomenclature
Physical Description / Field Identification
Gervais’ beaked whales are dark gray above and lighter gray below. In young animals, the belly is white. The teeth of adult males are found 1/3 of the distance from the snout tip to the gape. They are visible outside the closed mouth. The mouthline is relatively straight.
Males attain lengths of at least 4.5 m, and adult females reach at least 5.2 m. Newborns are about 2.1 m in length. Weights of at least 1200 kg are attained.
Can be Confused With
Gervais’ beaked whales are nearly impossible to distinguish from other mesoplodonts at sea. Genetic study or details of the morphology of the skull may be required for positive identification.
Distribution
Most records are from the east and Gulf coasts of North America, from New York to Texas, United States, but Gervais’ beaked whales are also known from several of the Caribbean islands. In the eastern Atlantic, they are known from the English Channel to Guinea-Bissau in West Africa. There is also a stranding at Ascension Island, in the central South Atlantic.
Ecology and Behavior
The favored habitat of Gervais’ beaked whales appears to be warm temperate and tropical waters. Little else is known of their biology.
Feeding and Prey
Like other members of the genus, they are known to feed on squid.
Threats and Status
Specimens of Gervais’ beaked whale have been entangled and killed in pound nets off New Jersey, United States. Currently, Gervais’ beaked whales are ‘Data Deficient’ (IUCN) and ‘Not Listed’ (ESA).
Links
References
Dalebout, M.L. 2002. Species identity, genetic diversity, and molecular systematic relationships among the Ziphiidae (beaked whales). Ph.D. dissertation, University of Auckland, New Zealand.
Mead, J.G. 1989. Beaked whales of the genus Mesoplodon. pp. 349-430 in S.H. Ridgway and R. Harrison, eds. Handbook of marine mammals, Vol. 4 River dolphins and the larger toothed whales. Academic Press.
Norman, S.A. and J.G. Mead. 2001. Mesoplodon europaeus. Mammalian Species 688:1-5.
Pitman, R.L. 2002. Mesoplodont whales Mesoplodon spp. pp. 738-742 in W.F. Perrin, B. Würsig and J.G.M. Thewissen, eds. Encyclopedia of marine mammals. Academic Press.
