Whales, Dolphins, and Porpoises of the Western North Atlantic A Guide to Their Identification

Anglický jazyk

Whales, Dolphins, and Porpoises of the Western North Atlantic A Guide to Their Identification

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Excerpt: ... length or less. (Photo by J. G. Mead.) Pg 94 SHORT-FINNED PILOT WHALE (T) Globicephala macrorhynchus Gray 1846 Other Common Names Blackfish (see also p. 84 , 91 , and 94 ). Description Male short-finned pilot whales of the western North Atlantic reach lengths of at least 17.5 feet (5.3 m). Females are reportedly slightly smaller than males (recorded only to 15.5 feet 4.7 m). The head, somewhat like that of the Atlantic pilot whales (p. 91 ), is thick and bulbous, a characteristic which reaches its extreme in the development of a flattened or squarish appearance to the front of the head in mature males (see Fig. 101). In very old males the melon may overhang the mouth up to several inches. The flippers are shorter than those of the other pilot whale species of the western North Atlantic (thus the common name short-finned pilot whale), reaching only one-sixth of the body length or less. The tail is dorsoventrally thickened just in front of the flukes. The dorsal fin, like that of the Atlantic pilot whale, is one of the species' most distinctive characteristics. It is low in profile, has a long base, and is set far forward on the animal's back. Short-finned pilot whales are all black on the back sides and most of the belly with an anchor-shaped patch of gray on the chin and a gray area of varying extent and intensity on the belly. These areas are less vivid and extensive than those on Atlantic pilot whales. Younger animals are lighter, often medium gray. Natural History Notes Short-finned pilot whales are known to occur in groups of 60 animals or more, though smaller groups are more common. They have been reported pitchpoling (spy-hopping), lobtailing, and-rarely-breaching. Short-finned pilot whales feed on squid and fish. May Be Confused With In the tropical portion of their range, short-finned pilot whales may be confused with pygmy killer whales (p. 138 ) and many-toothed blackfish (p. 142 ). They may be distinguished from both species...