HAMNER ET AL : FEEDING BEHAVIOR OF SOUTHERN RIGHT WHALES 

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Figure 3. — Echogram of krill school on 3 March 1986 on which right whale stopped swimming and began 



feeding bout. 



ther north, as confirmed by comparing video 

 recordings of both sightings. Photographs of these 

 four individuals were subsequently compared 

 with the catalog of southern right whales that 

 overwinter near Peninsula Valdes, Argentina 

 (Payne and Rowntree 1984), but none of the 

 Antarctic individuals were in that compendium of 

 some 623 individuals. 



DISCUSSION 



Our observations of southern right whales 

 along the Antarctic Peninsula suggest that 

 coastal Antarctica may have been (and may well 

 become again) a regular part of the summer feed- 

 ing range of the species. These sightings indicate 

 a more extensive distribution in the Southern 

 Ocean than heretofore reported, an extension cor- 

 roborated by the comparison of recent and his- 

 toric summer distributional patterns by Ohsumi 

 and Kasamatsu (1986). Southern right whales 

 were hunted almost to extinction in the shallow 

 coastal embayments where they overwinter more 

 than 100 years before whaling began in the 

 Southern Ocean (Harmer 1928; Townsend 1935). 

 It is not surprising, therefore, that there are only 

 a few scattered records of southern rights in 

 Antarctic waters, fluke observations so to speak. 

 During the past 50 years southern rights have 



been protected, and several domes of southern 

 right whales have increased (Best 1981; Ohsumi 

 and Kasamatsu 1986; Whitehead et al. 1986), and 

 a commensurate extension of the summer feeding 

 range into areas formerly occupied by these 

 whales may be occurring. 



It is interesting that none of the 4 individual 

 whales for which we have photographic identifi- 

 cations appear in the catalog of 623 individual 

 southern rights for the Valdes, Argentina breed- 

 ing population (Payne and Rowntree 1984). We 

 believe that the right whales we encountered in 

 Antarctic waters probably winter elsewhere, per- 

 haps along the Chilean coast, which has been less 

 well surveyed than has the east coast of South 

 America (Cardenas et al. 1986). 



Payne (1976) described tail-sailing among the 

 Valdes population of southern right whales and 

 suggested that this may be a form of play behav- 

 ior. In Antarctic waters this behavior may be a 

 method used to forage on krill. The right whale 

 that we observed tail-sailing had three fur seals 

 in attendance, constantly darting about its head, 

 apparently feeding on the same prey as the 

 whale. Furthermore, tail-sailing occurred next to 

 a grounded iceberg at a specific location that was 

 repeatedly transected by the whale, the only spot 

 in the vicinity where krill were detected on the 

 ship's sonar. 



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