FISHERY BULLETIN: VOL. 80, NO. 2 



B 



)^ 





Figure 3.— The seven types of bubbling behaviors associated with feeding in humpbacks. A 

 through D are structures using bubble columns, which are 1- 1'/ 2 m in diameter and composed 

 of nonuniform-sized bubbles (estimated at >2 cm). E through G are bubble cloud structures, 

 4-7 m in diameter, and composed of uniform-sized bubbles (estimated at<2cm). A. Bubble 

 row. B. Bubble row with "crook," whale feeding location shown. C.V or semicircle shaped 

 bubble curtain. Whale feeds in and through open side of the semicircle. D. Complete cir- 

 cular formation, or bubble net. E. Single bubble cloud. In this example, one of several 

 variations, whale lunge feeds through center. F. Triangular formation of multiple bubble 

 clouds. G. Linear formation of multiple bubble clouds. 



In the simplest configuration, bubble rows, 

 the whale creates a line of columns (generally 

 4-6). When this has been completed, the whale 

 turns sharply and feeds, open-mouthed, either at 

 or below the surface, at an acute angle to the 

 screen formed by the row of bubble columns. In 

 some cases, the whale continues to release bubble 

 bursts during its turn, so that the line of bubble 



262 



columns has a "crook" in the end where the whale 

 feeds. The behavior associated with a semicircle 

 of bubble columns is similar, in that once a semi- 

 circle (or "V") has been constructed, the whale 

 appears and feeds toward the concave portion of 

 the screen. 



Complete circles of bubble columns, termed 

 bubble nets (Jurasz and Jurasz 1979), have been 



