MEDIUM-SIZED WHALES
(13-32 feet [4-10 m] maximum overall length)
With a Dorsal Fin
There are 11 species of medium-sized whales with a dorsal fin known from the western North Atlantic. These species, taking many diverse forms, range in maximum adult size from about 13 feet (4.0 m) (grampus) to about 33 feet (10.1 m) (the minke whale). This group includes such widely distributed and frequently encountered species as the pilot whales, false killer whales, and minke whales, and such rarely encountered and poorly known species as the various "beaked whales" (Mesoplodon spp. and the goosebeaked whale).
Aside from their common inclusion within the stated size range and the presence of a dorsal fin in all species (which ranges from only a small nubbin in some of the beaked whales to a substantial 5- to 6-foot [1.5- to 1.8-m] sail on adult male killer whales), these species have no diagnostic field characteristics in common. Therefore, each is discussed in detail and is placed in the text in near proximity to those species with which it is likely to be confused in the field.
Minke whale
Balaenoptera acutorostrata
p. [63]
- Body to 30 feet (9.1 m), or more, long.
- Body black or dark gray; area of gray shading on each side just in front of and below dorsal fin.
- Flippers have transverse white band.
- Head very sharply V-shaped viewed from above.
- Dorsal fin falcate and distinct; usually appears simultaneous with blow.
- Blow often low and indistinct.
- Distribution polar, temperate, and tropical; frequently coastal.
- Often curious about boats.
- Flukes not raised on dive.
Northern bottlenosed whale
Hyperoodon ampullatus
p. [67]
- Body to 32 feet (9.8 m) long.
- Body of young uniformly chocolate brown; body of adults brown with cream or yellow blotches.
- Head bulbous in adults and white in larger animals; has distinct beak.
- Dorsal fin falcate and distinct, in last one-third of back.
- Distribution north temperate and Arctic-offshore.
- Often curious about boats.
- Flukes large, rarely notched; occasionally raised on long dive.
Goosebeaked whale
Ziphius cavirostris
p. [70]