WHALE MARKING 257 



constitute the o-Group, and they have been returned after an average period of twenty- 

 one days and after times varying from a few hours, the whale having been taken the same 

 day as marked, to eighty-eight days. Around South Georgia marked Blue whales in this 

 o-Group (Plate XLVI) have not been taken after a longer interval than six days, but Blue 

 whales marked in the vicinity of South Georgia have been recovered a considerable time 

 later far to the southward on the edge of the pack-ice. Thus, one whale (No. 3853) was 

 taken after eighty-eight days and had travelled more than 500 miles south-westerly, a 

 second (No. 4563) after thirty-two days and at a distance of more than 300 miles to the 

 south-east. From this it appears conclusively that Blue whales found in the region of 

 South Georgia during that part of the season when marking took place are on the 

 move and presumably migrating, only passing the island on their way southwards. The 

 short movements of those whales marked and captured on the South Georgia grounds 

 show, in general, a southerly trend. Farther south, a mark, No. 10638, was fired into 

 a whale in a position almost on the indicated track of No. 4563 and near the edge of the 

 pack-ice, though in a subsequent season (Plate XLVII). In nine days this whale had 

 travelled 360 miles in an east-south-easterly direction. From these movements it seems 

 evident that, in general, Blue whales found around South Georgia move during the 

 whaling season in a southerly direction, and probably keep on moving in this way until 

 the edge of the pack-ice is reached, where they may turn either to the east or to the 

 west. 



Only on the pelagic grounds to the east, between 15 and 50 E, have enough recoveries 

 been made to show any definite trends of movement (Plate XLVII). In this region the 

 time between marking and capture varies from two to fifty-nine days and, as most of 

 these whales have been marked in a rather restricted portion of the area, their progressive 

 movement can be followed. Without exception the movement lies between west and 

 south-west and, further, all these whales, with but one exception, were marked in the 

 same season, 1934-35, and during January, to be recovered at various times up to the 

 end of March. 



A consideration of the movements of the factory ships during this season (1934-35), 

 as shown on the charts given by Hjort, Lie and Ruud (1935), is of considerable interest. 

 These show that after the initial search period during December, when ships were well 

 spread out over a large area, there occurred in the latter part of January a marked 

 movement of factory ships towards Enderby Land, and a concentration was formed there. 

 During February this concentration moved westwards and was joined by other factory 

 ships from the north, so that an area of the whaling grounds to the west of Enderby 

 Land, between 30 and 40 E, was subjected to a very intensive slaughter. This area was 

 still occupied during March, although at the beginning of that month a number of 

 factories broke back eastwards towards Enderby Land, only to return westwards later. 

 Large catches of Blue whales were made in this region during January (2229) and 

 February (2052). There can be no doubt that there was a very large number of Blue 

 whales off Enderby Land and a little to the west during January of this season, and 

 marking shows that this body of whales moved westwards during the course of the 



