WHALE MARKING 267 



Although it is fully recognized that whale-marks can only be returned from those 

 places where whaling is carried out and that the positions and movements of the 

 factory ships have a considerable bearing on the picture rendered by the returned marks, 

 it is also true that the factory ships do not remain long in areas where whales are not to 

 be found. It does, therefore, seem reasonable to suggest that the part of the mouth of 

 the Weddell Sea lying between 35 and 50 W has, for some reason, a strong attraction 

 for Fin whales, which congregate there from a wide area extending to the east and west. 

 In addition there seem to be strong grounds for considering the region between 30 W 

 and o° to be more sparsely populated with Fin whales. The reasons for this are obscure 

 and a discussion of the possibilities beyond the scope of this paper, but it might be 

 suggested that the influence of the submarine topography along the southern verge of the 

 Scotia Sea on the hydrology of that region sets up conditions favouring the production 

 of rich food stores which attract the whales. 



On the grounds to the east, off Enderby Land, three returns (Nos. 2982, 3261, 5941) 

 in this group show that here also Fin whales continue to frequent the same region from 

 season to season. 



The 2-Group of Fin whales is composed of twenty-one recoveries taken after intervals 

 varying between 694 and 797 days and after an average lapse of 746 days. It is at once 

 obvious that these recoveries reinforce very strongly the general outline of Fin whale 

 movements deduced from the i-Group returns (Plates LVII, LVIII). They show the 

 return of Fin whales to the same region, and at times to the same locality, in which they 

 were marked ; and further, they show the infiltration between one region and another, a 

 movement now on the whole more pronounced after a period of two years than after 

 one year, a result naturally to be expected. One whale (No. 1034) shows how closely 

 Fin whales on the South Georgia grounds will return to the same locality even after 

 two years ; three weeks later in the season than when marked it was captured twenty-two 

 miles from its position of marking in 1934-35. Similarly, on the easterly grounds off 

 Queen Mary Land a Fin whale (No. 5436) was taken a fortnight earlier in the season less 

 than 200 miles from the marking position. Further, a number of whales marked near 

 South Georgia and the Shag Rocks were returned from the pelagic grounds to the 

 south and are, of course, returns from the same region, for their apparent movements 

 are those demonstrated to take place during the course of a season. These whales were 

 marked in three different seasons and they give the same picture as the 1 -Group 

 movements. There can be no doubt that many Fin whales normally return to the South 

 Georgia- Shag Rocks- Weddell Sea region annually, though this cannot be regarded 



as a rigid rule. 



The dispersal movement in the group is shown most clearly by whales marked on the 

 Enderby Land grounds. Three whales (Nos. 5834, 5848, 5861), marked on the same day 

 in March 1936 within a few miles of each other, all show a return to a position westwards 

 of the marking position. Two (Nos. 5848, 5861) may be considered to have returned to 

 the same grounds, the distances of the places of recovery from the marking position 

 being 352 miles and 517 miles respectively, but the third (No. 5834) was taken 1150 



