LARGE WHALES 



(40-85 feet [12-26 ml maximum overall length) 



With a Dorsal Fin 



All five species of large whales with a dorsal fin belong to 

 the same major baleen whale group, the balaenopterid 

 whales or rorquals. All are characterized by the presence of a 

 series of ventral grooves, usually visible on stranded 

 specimens and the length and number of which are diagnostic 

 to species. In addition, all species, with the exception of the 

 humpback whale, have at least one distinctive (though often 

 not prominent) ridge along the head from just in front of the 

 blowhole to near the tip of the snout. (The humpback whale, 

 on the other hand, is distinguished by numerous knobs, 

 some of which are located along the line of the head ridge, 

 with others scattered on the top of the head.) In Bryde's 

 whale, the single head ridge characteristic of the other ror- 

 quals is supplemented by two auxiliary ridges, one on each 

 side of the main ridge. 



At sea, these whales often appear very similar and must 

 be examined carefully before they can be reliably identified. 



In general, though the characteristics of behavior may 



vary from one encounter to the next, based on the activities in 

 which the animal is engaged, whales in this group may be 

 distinguished from each other on the basis of differences in 1) 

 the size, shape, and position of the dorsal fin and the timing of 

 its appearance on the surface relative to the animal's blow (in 

 general, the larger the whale, the smaller the dorsal fin— the 

 further back its position and the later its appearance on the 

 surface after the animal's blow); 2) the height of body in the 

 area of the dorsal fin, relative to the size of the dorsal fin, 

 which is exposed as the animal sounds; 3) sometimes the blow 

 rate and movement patterns; and 4) the shape and color of the 

 head. 



Despite variability in behavior by members of the same 

 species from one encounter to the next, an observer can 

 greatly increase the reliability of his identification by forming 

 the habit of working systematically through a set of 

 characteristics for the species rather than depending on any 

 single characteristic. 



Body very large, up to 85 feet (25.9 m) long.' 



Body basically bluish with mottlings of grayish white. 



Baleen all black. 



Head broad and nearly U-shaped, viewed from above. 



Head flat in front of blowhole, viewed from side. 



Dorsal fin small (to 13 inches (33 cm]), triangular to moderately 



falcate, in the last one-third of back. 

 Distribution primarily from temperate seas to pack ice; rare in 



tropics. 

 Distribution more northerly during summer. 

 Flukes occasionally raised slightly on long dive. 



Body large, up to 79 feet (24 m) long. 



Body mostly dark gray or brownish gray; undersides of flukes and 



flippers and belly white; grayish-white chevron frequently on 



back behind head. 

 Right lower lip white; right upper lip sometimes white; left lip dark. 

 Head V-shaped, viewed from above. 



Right front one-third to one-fifth of baleen plates, yellowish white. 

 Other baleen bluish gray with yellowish-white stripes. 

 Dorsal fin to 24 inches (61 cm), slightly more than one-third forward 



from tail; forms angle of less than 40° with back. 

 Distribution extensive but not very common near pack ice and in 



tropics. 

 Distribution more northerly during summer. 

 Flukes not raised on dive. 



Blue whale 



Balaenoptera musculus 

 p. 19 



Fin whale 



Balaenoptera phy solus 

 p. 26 



Body up to 62 feet (19 m) long. 



Body appears shiny; dark g^ay on back, often with ovoid 



grayish-white scars; white on front of belly; undersides of 



flippers and flukes dark. 



Sei whale 



Balaenoptera borealis 

 p. 32 



'These figures are all near maximum sizes recorded for the North Atlantic. For all species which have historically been ex 

 ploited by whale fisheries present maximum sizes may be significantly less than these figures. 



It should also be noted that differences in methods of measurements often account for discrepancies in reported lengths. 



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