THE SOUTHERN SEA LION 305 



breeding rookery, attended by 68 harem and idle bulls; but at a distance of about 

 two miles there is a well-known hauling ground for bulls where there were 140 of them. 

 On this part of the coast the numbers of the sexes were more nearly equal than they 

 were at Cape Dolphin, since here there were 208 bulls to 271 cows. Other examples 

 of herds consisting almost entirely of males could be given, but enough has been 

 written to show that many of the idle bulls have their own beaches and hauling grounds 

 and that they may be found on them even in the breeding season. A few stray cows 

 may be found on the outskirts of such places and they have as a rule been taken charge 

 of by bulls (Plates V, VI, VII). 



MIGRATION 

 Whether or not any of the animals engage in a partial migration from the Falklands 

 is doubtful, since they may merely be spread about the very extensive coasts. They 

 certainly leave some places altogether for the winter, but not all, nor is every rookery 

 completely abandoned. There seems to be no certain rule; thus High Island and 

 Green Island in Salvador Waters, East Falkland, are only two miles apart; but the 

 former is altogether forsaken in winter, whereas the sea lions remain on the latter all 

 the year round. So far as I know both islands are breeding places and they are 

 completely sheltered, being many miles from open water. 



Devincenzi (1925) says that from Lobos Island, Uruguay, there is a migration to 

 the south in early winter, but that the sea lions return after a short absence, and he 

 further states that only the sick and aged are left behind. This is not so in the Falklands: 

 Otaria byronia is present in the islands in reasonable numbers throughout the year 

 and seldom abandons completely the recognized rookeries. 



Sea lions may be met with, as late as December, in an area of water roughly 120 miles 

 north of the Falklands — not on passage, but playing and feeding in a region which 

 must be a rich feeding place, since birds are numerous and one usually expects to see 

 whales there. Early in November, I have seen parties of sea lions apparently on a 

 passage south, when I have been approaching the Falklands from Monte Video. 

 Otaria may possibly be partly migratory so far as the Falklands are concerned, and it 

 at least goes a long way off shore to feed. 



LENGTH OF LIFE 

 Accurate information as to the length of life of Otaria byronia is sparse. Flower 

 (193 1 ) mentions two females which lived in the collection of the Zoological Society 

 for i6| and 17^ years respectively. The second animal was believed to be 2 years old 

 when it was brought to London, and this would bring her age to 19! years when she 

 died. He records the following ages for other Otariids in captivity: Eiimetopias, 17 years 

 (one specimen); Zalophiis, 12I-19 years (6 specimens); and Arctocephahis pusillus 12\ 

 and 20 years. Males of the northern fur seal, Callorhimis alascamis, are known to live 

 to 12 or 14 years, but branded cows which were 17 years old have been seen. The whole 

 family is obviously tolerably long lived. 



