HUMPBACK WHALE (B) 



Megapteranovaeangliae (Borowski 1781) 



Other Common Names 



Humpbacked whale, bunch, hump whale, or hunchbacked 

 whale. 



Description 



Humpback whales reach a length of 53 feet (16.2 m). 



The body is robust, narrowing rapidly on the tail stock. 

 The head is quite broad and rounded, somewhat like that of 

 the blue whale. The head ridge characteristic of other 

 balaenopterid species is indistinct and is replaced in 

 prominence by a string of fleshy "knobs" or protuberances, 

 many more of which are randomly distributed on the top of 

 the head and on the lower jaw. There is a distinctive rounded 

 projection near the tip of the lower jaw. Humpback whales 

 carry many barnacles and whale lice. The baleen plates are all 

 black with black or olive-black bristles. 



The flippers are very long (nearly a third as long as the 

 body), are scalloped on at least the leading edge, and are 

 nearly all white. 



The dorsal fin, located slightly more than two-thirds of the 

 way back on the back in approximately the same position as 

 that of the fin whale, is small and varies in size and shape from 

 a small, triangular nubbin to a more substantial, sharply 

 falcate fin. The dorsal fin frequently includes a step or hump, 

 which is quite distinct when the animal arches its back to 

 begin a dive and from which the species derives its common 

 name. 



Humpback whales are basically black in color with a white 

 region of varying size on the belly, which upon close 

 examination may often be seen to be crosshatched with thin 

 dark lines; the flippers and the undersides of the flukes also 

 are white. 



Natural History Notes 



The blow of humpback whales is from 8 to 10 feet (2.4 to 

 3.1 m) tall and has been described as balloon-shaped. It is 

 wide relative to its height. Feeding humpback whales 

 habitually blow 4-8 times at intervals of 15-30 s after a long 

 dive. In the tropics they habitually blow 2-4 times in 

 succession when beginning a long dive. In diving, humpback 

 whales throw the tail flukes high into the air, exposing the 

 sometimes white undersurface and the rippled rear margin. 



Humpback whales often leap clear of the water, raise a 

 flipper, and slap it against the water, or "lobtail," raising the 

 tail high into the air and bringing it crashing back to the water 

 in a loud report. Often, particularly when they are 

 encountered on their tropical breeding grounds, humpback 

 whales will be found lying on their sides with a long flipper in 

 the air. 



Humpback whales feed on krill and schooling fish. 



May Be Confused With 



From a distance humpback whales may be confused with 

 any of the other large balaenopterid (rorqual) whales— blue. 



fin, sei, or Bryde's. Although it is highly variable, the dorsal 

 fin most closely resembles that of the blue whale. However, it 

 is located farther forward on the back. Humpback whales 

 distinguish themselves from the remainder of the rorquals by 

 their habit of raising the flukes high into the air when starting 

 a long dive. (In very shallow water they may not raise the 

 flukes at all.) The only other rorqual to do so — the blue 

 whale — raises the flukes slightly or not at all. 



Under some conditions humpback whales may be 

 confused with sperm whales at a distance. When arching the 

 back to begin a dive, both may show a distinct hump. Both 

 species frequently raise their flukes nearly vertically when 

 beginning a long dive but differ in several ways. The flukes of 

 humpback whales show varying amounts of white beneath, 

 are pointed on the tips, and are distinctly concaved and 

 irregularly rippled on the rear margin. Those of sperm 

 whales are all dark and more flattened and even along the 

 rear margin. Further the species can be distinguished in the 

 following ways: 



Humpback Whale 



Sperm Whale 



BLOW 



Projects upwards from cen- 

 ter of head. Usually blows 

 4-8 times (2-4 times in 

 tropics) before diving. 



Projects obliquely forward 

 from left side of tip of snout. 

 Usually blows many times 

 (20-50 or more) beforediving. 



Raised area around blow 

 holes, knobs on upper sur 

 face. 



HEAD 



Blunted, long, smooth. 



FLUKES 



Often white underneath. Smooth, 

 concaved and scalloped on margin, 

 rear margin, deeply notched. 



FLIPPERS 



all black on rear 



Extremely long (to one-third 

 of body), white and scalloped 

 on leading edge. 



Short; all black. 



DORSAL FIN (OR HUMP) 



Triangular to falcate fin, 

 including a step or hump in 

 front of the dorsal fin; 

 smooth. 



Rounded hump, two-thirds 

 back on back followed by 

 knuckles or crenulations. 



When they can be examined at close range, humpback 

 whales can be easily distinguished from all other large whale 

 species with a dorsal fin by the tuberosities or knobs on the 

 head, by the long white flippers scalloped on the leading edge, 

 by the small distinctive dorsal fin, and by their distinctive tail 

 flukes. 



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