FEEDING BEHAVIOR OF THE HUMPBACK WHALE, 

 MEGAPTERA NOVAEANGLIAE, IN THE WESTERN NORTH ATLANTIC 



James H. W. Hain, 1 Gary R. Carter, 1 Scott D. Kraus, 2 Charles A. Mayo, 3 and Howard E. Winn 1 



ABSTRACT 



Observations on the feeding behavior of the humpback whale, Megaptera novaeangliae, were made 

 from aerial and surface platforms from 1977 to 1980 in the continental shelf waters of the north- 

 eastern United States. The resulting catalog of behaviors includes two principal categories: Swim- 

 ming/lunging behaviors and bubbling behaviors. A behavior from a given category may be used 

 independently or in association with others, and by individual or groups of humpbacks. 



The first category includes surface lunging, circular swimming/thrashing, and the "inside loop" 

 behavior. In the second category, a wide variety of feeding-associated bubbling behaviors are 

 described, some for the first time. The structures formed by underwater exhalations are of two 

 major types: 1) bubble cloud— a single, relatively large (4-7 m diameter), dome-shaped cloud formed 

 of small, uniformly sized bubbles; and 2) bubble column— a smaller (1-1.5 m diameter) structure 

 composed of larger, randomly sized bubbles, used in series or multiples. Both basic structures are 

 employed in a variety of ways. 



Many of these behaviors are believed to be utilized to maintain naturally occurring concentrations 

 of prey, which have been identified as the American sand lance, Ammodytes americanus, and 

 occasionally as herring, Clupea harengus. 



This paper reports on the feeding behavior of the 

 humpback whale, Megaptera novaeangliae, in 

 the continental shelf waters of the northeastern 

 United States. We describe several feeding be- 

 haviors reported for the first time, as well as a 

 number of behaviors known from other areas but 

 not previously reported for these waters. Our col- 

 lective observations provide the beginning of a 

 more complete catalog than has previously been 

 available. 



Early observations of humpback feeding be- 

 havior were made by Ingebrigtsen (1929) from 

 the Norwegian Sea near Bear Island: 



"It [the humpback] employed two methods of 

 capturing 'krill' when the latter was on the sur- 

 face of the water. One was to lie on its side on 

 the surface and swim round in a circle at great 

 speed, while it lashed the sea into a foam with 

 flukes and tail and so formed a ring of foam. 

 The frightened 'krill' gathered together in the 

 circle. This done the humpback dived under 

 the foam-ring and a moment later came up in 

 the center to fill its open mouth with 'krill' and 



■Graduate School of Oceanography, University of Rhode 

 Island, Kingston, RI 02881. 



2 Present address: New England Aquarium, Central Wharf 

 Boston, MA 02110. 



3 Provincetown Center for Coastal Studies, P.O. Box 826, 

 Provincetown, MA 02657. ^n . « 



water, after which it lay on its side, closed its 

 mouth, and the catch was completed. 



"The other method was to go a short distance 

 below the surface of the water, swimming in a 

 ring while at the same time it blew off. The air 

 rose to the surface like a thick wall of air bub- 

 bles and these formed the 'net'. The 'krill' saw 

 this well of air bubbles, were frightened into 

 the centre, and then the manoeuvre of the first 

 method was repeated." 



Some 45 yr later, "bubblenetting" was reported 

 from Alaskan humpbacks by Jurasz and Jurasz 

 (1978), and later described in detail (Jurasz and 

 Jurasz 1979). With the exception of the work of 

 Watkins and Schevill (1979), accounts of feeding 

 behavior of this species in the waters of the west- 

 ern North Atlantic are few and largely anecdot- 

 al. 



MATERIALS AND METHODS 



Observations were made from dedicated air- 

 craft (a Cessna 337 Skymaster and a Beechcraft 

 AT-11 4 ), from dedicated surface vessels (the 27.5 

 m Dolphin III and the 21.3 m Tioga), from plat- 

 forms-of-opportunity, and from shore stations. 



Manuscript accepted November 1981. 

 FISHERY BULLETIN: VOL. 80, NO. 2, 1982. 



"Reference to trade names does not imply endorsement by 

 the National Marine Fisheries Service, NOAA. 



259 



