MOVEMENTS BETWEEN THE ANTARCTIC AREAS 375 



demonstrated yet since very little whaling has taken place in Area I and no marked whales have been 

 captured there. Since movement in both directions has been demonstrated in the case of the other 

 areas it seems very probable that this movement westwards does in fact take place. The amount of 

 movement between the Areas II and III, and III and IV, appears to be about equal — the high 

 percentage of whales crossing from Area IV into Area III probably being accounted for by the small 

 numbers of marked whales involved. 



Movements of Blue whales. Blue whales have been marked in each of the four Areas I-IV (Table 5) 

 but of the forty-five marked whales recovered, the seven showing dispersal from one area to another 

 have all crossed the boundary between Areas III and IV. Five whales have moved in the eastward 

 direction from Area III into Area IV, and two westwards from Area IV to Area III. 



Only six Blue whales have been marked in Area I and it is thus extremely unlikely that a dispersal 

 eastwards into Area II will be demonstrated by the recovery of one of these marks. This movement 

 may well take place, however, as it has been shown to do so in Fin whales. It is interesting that no 

 Blue whale has yet been recovered after crossing the boundary between Areas II and III, although 

 about 300 of this species have been marked in each of these areas. So far as the small number of 

 returns allow any conclusion to be drawn, it seems that for Blue whales the separation between 

 Areas II and III is more distinct than that between Areas III and IV. 



The results of this comparison of the movements shown by marked whales between the Areas I-IV 

 seem to indicate that there is probably a more distinct separation between Areas II and III than 

 between Areas III and IV, a conclusion suggested by Mackintosh (1942) who used the earlier smaller 

 number of recoveries of marked whales. There would appear to be considerable movement of Fin 

 whales from at least the eastern part of Area I into Area II and it seems likely that the reverse move- 

 ment also takes place and that there may be a significant exchange of the members of the populations 

 in these two areas. 1 



SUMMARY 



1. Over 5000 whales were marked by the Discovery Committee in the Antarctic between 1932 

 and 1939. 218 marks have been returned from 208 Fin whales, and 50 marks for forty-five Blue 

 whales up to the close of the 1951-52 Antarctic whaling season. A list of these returned marks is 

 given, with details of the positions of marking and recovery, and of sex and length of the whale 

 where this is known. 



2. The distribution of the whales marked is shown diagrammatically, and the boundaries of the 

 Antarctic whaling areas indicated on a chart. 



3. The dispersal of whales is defined as the ultimate movement of whales eastwards or westwards 

 from the position in which they were marked. A study of dispersal involves the proportion of whales 

 showing dispersal and the range or distance to which they disperse, and the changes in this pro- 

 portion and range of dispersal over a period of time. Dispersal in Fin and Blue whales is shown on 

 ' time-charts ' and by means of histograms, and is discussed separately. 



4. Many Fin whales are shown to return from their migrations year after year to somewhere near 

 the place where they were marked. One whale was found after seventeen years less than i° of 

 longitude away from the position of marking. 



In Fin whales the range of dispersal appears to be limited to within 50 east or west of the position 

 of marking, and the dispersal is not necessarily in itself progressive. Within this limit, however, the 



1 Schubert, in a recent paper (1953), expresses the opinion that there is a movement of whales between Areas I and II. 

 This appears to have been based only on the direction in which some whales (seen between 6o° and 70 \V) were observed 

 to be moving, but his inference is now corroborated. 



