Figure 1.— Schematic representation (not to scale) illustrating the sequence of the killer whale-fin whale interaction. Dark 

 squares in light circles = the three killer whales; light squares in dark circles = fin whales; the two numbers inside squares 

 = the boat with observers at initial and final positions; solid and dashed lines with arrows = movements of the principal 

 fin whale pair and the three killer whales, respectively. 



and the killer whales were still headed directly 

 towards the boat at an estimated speed of 30-40 

 km/h. Aware of the risk of staying in the path of 

 these whales, we started the motor and moved 30 

 m east. Just after starting the motor, the pair of 

 fin whales changed direction by about 110° and 

 headed towards open sea (Fig. 1), probably as a 

 result of our movement. The fin and killer whales 

 continued west for 50 m and were now approximate- 

 ly 80 m ahead of us. During this encounter, we heard 

 at least six clear, high pitched whistling sounds that 

 each lasted about three seconds. 



We then observed one of the killer whales turn 

 towards the pair of fin whales. At this moment, the 

 fin whales turned approximately 180° and headed 

 back towards the boat, in the direction of land. The 

 pair, with the three killer whales close but slightly 

 behind them, continued towards the boat. When 

 they were 5 m away and parallel to the boat, we saw 

 the head of one of the fin whales disappearing below 

 the water. At that same moment, the head of one 

 killer whale appeared above the fin whale. At this 

 time we observed a great amount of splashing 

 created by both species. The pair of fin whales then 

 continued swimming east, with many short surface 



dives each lasting between 5 and 10 seconds. The 

 killer whales continued their pursuit. All whales 

 were travelling too fast for us to follow them, and 

 they were soon out of sight. 



During the time of the killer whale-fin whale 

 interaction, the other fin whales that were not 

 directly involved were all swimming very slowly out 

 towards open sea, showing almost no parts of their 

 bodies and with no visible or audible blows, possibly 

 to avoid detection. We followed them and finally 

 counted at least 13-15 whales, still in pairs or 

 triplets, that after 10 minutes had resumed their 

 feeding activities 0.5 km from the killer whales 

 incident. 



Discussion 



It appears that marine mammals are successful- 

 ly attacked and eaten mainly by the larger, usually 

 adult male killer whales (Nishiwaki and Handa 1958; 

 Hancock 1965; Rice 1968; Jonsgard and Lyshoel 

 1970; Tarpy 1979). Apparently, most attacks on 

 baleen whales, where only females or immature 

 killer whales participate, are unsuccessful (e.g., 

 Morejohn 1968; Cummings et al. 1972; this paper). 



371 



