WHALE MARKING 275 



5. The manner in which marks are found and returned is explained. 



6. The movements of whales as indicated by marking methods are discussed for Blue, 

 Fin and Humpback whales, and these movements are shown on a series of charts 

 illustrating the movements that had taken place after a given period of time. 



7. Blue whales found around South Georgia are shown not to be a stationary 

 population. Blue whales found off Enderby Land are demonstrated to move in a westerly 

 direction during the latter part of the whaling season, and the movements of factory 

 ships are considered to support this view. 



Marks recovered after periods of one year and longer show that Blue whales return to 

 the same region, but are also dispersed around the Antarctic Continent. This dispersal 

 appears to be limited, for movements after four years have no greater amplitude than 

 those after one year, but there is no evidence that Blue whales found in any one region 

 of the area covered are segregated from the rest. 



8. Fin whales found around South Georgia are shown not to be a stationary popula- 

 tion, but they may loiter in the neighbourhood of the island longer than Blue whales. 

 The movement from South Georgia during the whaling season is towards the south, 

 and although large numbers of Fin whales pass close to the Shag Rocks none appears to 

 move eastwards into the ambit of the South Georgia whalers. It is suggested that Fin 

 whales pass southwards in this region on different tracks in different seasons. On other 

 parts of the whaling grounds the direction of movement during the season appears to be 

 generally to the south. 



After one year Fin whales are shown to return very largely to the same area frequented 

 the previous season, but a dispersal movement similar in many ways to that of Blue 

 whales takes place. This dispersal movement provides connecting links between the 

 Fin whales of the Bellinghausen Sea and those off Queen Mary Land. Fin whales 

 originally found around the Shag Rocks may visit South Georgia. 



These two movements of return and dispersal continue, but, as with Blue whales, 

 dispersal is limited and not necessarily in itself progressive. In consequence, there 

 appear to be large provinces between which very little interchange of Fin population 

 takes place, but within which movement is considerable. 



Migration from Antarctic waters to the Cape regions of South Africa has been shown 



to occur. 



9. Humpback whales are shown to migrate, probably annually, from Antarctic waters 

 to tropical regions off the north-west coast of Australia and off Madagascar. There is a 

 return to the same region, but there appears to be no movement comparable to the 

 dispersal demonstrated for the other two species; "provincial" stocks of Humpback 

 whales are thus thought to be much more limited and self-contained than among 



Blues and Fins. 



10. The percentage of marked whales killed shows that Humpback stocks are suffer- 

 ing very heavily in comparison with the other species because of recent expansions of 

 Humpback whaling in tropical waters, and that the Blue whale stock is being depleted 

 much faster than the Fin stock. 



