WHALE MARKING 259 



Subsequently Blue whales were marked farther west, but none of these were reported 

 as killed that season ; it may be that this marking was done outside the main stream of 

 whales, possibly on its northern fringe. 



That this body of Blue whales was subjected to considerable persecution is also 

 shown by the capture of a marked female Blue whale only 69 ft. long (No. 2910) ; when 

 marked it had been estimated to be 60-65 ft- m length. At this length, 10 ft. below the 

 average of the season for the whole Antarctic, the whale appeared, when free at sea, to be 

 comparatively diminutive. 



The experience of the manager of a factory ship a year earlier, recorded by the late 

 Sigurd Risting (1935), suggests that a movement similar to this had taken place that 

 season, 1933-34. ^ n January this manager had searched southwards in a catcher and 

 had met the ice-edge near Prinsesse Ragnhild Land, almost 250 miles from his ship, 

 but had seen no whales. In February, however, many Blue whales were to be found 

 here where there had been none the previous month. The region must have been situated 

 between 10 and 30 E and the arrival of Blue whales in February corresponds with the 

 movements of marked whales the next year ; it is very probable that some of them had 

 come here from waters to the east, off Enderby Land. 



One other mark (No. 7705), from a later season (1936-37), has been recovered in this 

 area. It was fired early in the season, in December, and recovered in February, and 

 indicates a general south-westerly trend of movement. One is inclined to think that 

 after being marked the whale may have proceeded eastwards, later turning to make the 

 westerly movement so marked in the earlier season. On the other hand, the movements 

 of the factory ships during this season (1936-37) show a contrast to their usual move- 

 ments as outlined above, to which they had held for several seasons. No concentration 

 was formed off Enderby Land and consequently no movement from there to the west- 

 ward was made. The weekly positions of factory ships as shown by Hjort, Lie and Ruud 

 (1938) are much more widespread, and their movements greater and more erratic. The 

 movement in the longitudes in which the whale was marked and killed is, in general, 

 southerly. Whilst the movements of the factory ships are different from those of previous 

 seasons, there is also a very marked decrease in the catch of Blue whales in this area 

 during February as compared with those of former seasons. This may be due to over 

 fishing in this region and the breaking up of regular whale movement by excessive 

 harrying and slaughter, reflected in the need of a wider search for fewer whales. 



The 1 -Group of recovered marks contains eight returned after an average period of 

 375 days. Although the number is small and the tracks between the positions of marking 

 and capture diverse, several points at once come to light. Three recoveries have been 

 made on the South Georgia ground (Plate XLVIII) and two (Nos. 903, 3771) suggest 

 that Blue whales return to this region from season to season, although, as explained above, 

 little time is spent there during the season itself. The third of these recoveries (No. 1 0427/3 1 ) 

 is of great interest, for the whale bearing these marks had come to South Georgia from 

 the vicinity of Bouvet Island, a distance of 1180 miles, and with the former indicates 

 an identity of stock over 40 of longitude. Another recovery (No. 3023), only 155 miles 



