DESCRIPTION OF THE ISLANDS 155 



It is probable that the volcanic eruptions gave rise to the South Sandwich Islands in 

 late Tertiar}' or early Quaternary times. This is the age attributed to the later eruptive 

 rocks of the South Shetlands and Graham Land. 



Seals. Only three species of seal were identified at the South Sandwich Islands. The 

 most abundant was the Leopard seal {Hydnirga leptonyx), which was very frequently 

 seen in the water, especially in the neighbourhood of penguin rookeries. In our attempts 

 to make landings we were often closely followed by these seal, which would come up 

 from behind to within a few feet, raise their heads from the water to look at us and then 

 swim alongside or dive underneath. In a small boat the manoeuvres of these large 

 animals may be a little disconcerting; but their motive is only curiosity, though it may 

 sometimes lead them, as we are informed by the whaling managers at South Georgia, 

 to lift their heads from the water on to the gunwale. The Leopard seal, as Matthews has 

 noted, 1 does not congregate in rookeries on shore like some other species, and for this 

 reason it is unlikely that it can ever be taken in sufficient quantity for commercial 

 purposes. At several of the islands one or two were seen hauled up on shore. 



The islands as a whole are very deficient in places where seal can form rookeries, and 

 even where beaches exist which appear suitable no great numbers were seen. The best 

 beaches are on Candlemas Island, in Cordelia Bay on Saunders Island, and near Beach 

 Point on Thule Island. Those on Candlemas were not examined closely, but appeared 

 to have very few seal on them. At Thule Island a landing was made, and Dr Marshall 

 reports that the seal here, about forty-five in all, were mainly Weddell seal (Leptonychotes 

 zoeddelli). About the same number was seen on Saunders Island and these in all prob- 

 ability were mainly Weddell seal also, though it was difficult to identify them with 

 certainty from a boat. Three Weddell seal were seen at Montagu Island, two on the 

 rocks and one on an ice floe. 



Elephant seal (Miroutiga leonina) can be distinguished with more certainty, but were 

 only seen in very small numbers: about six on the eastern side of Visokoi, one on 

 Vindication, perhaps a dozen in Cordelia Bay on Saunders, and two near Beach Point 

 on Thule. The existence of Elephant seal must have been known to the sealers who 

 visited the islands during the last century, but the species does not appear to have been 

 previously recorded from the group and it is not mentioned in Larsen's report. It 

 occurs in some abundance in the South Orkneys and in fonner times is said to have been 

 found in the South Shetlands. At the South Sandwich Is. there is a complete absence of 

 the tussac grass among which it forms rookeries at its headquarters in South Georgia, 

 and this, combined with the unsuitable foreshore and the fact that the islands are very 

 near the southern limit of its range, must be held to account for its scarcity. 



No Crab-eater seal {Lobodon carcinophagiis) were recognized with certainty, though 

 some at Cordelia Bay may have belonged to this species. We saw no Fur seal (Arctoce- 

 phalus australis), and Larsen, who made landings on a number of islands in order to look 

 for them, reports that he found none. It appears, however, that Fur seal must at one time 



1 Matthews, "The Natural History of the Elephant seal, with notes on other Seals found at South 

 Georgia", Discovery Reports, 1, p. 253 (1929). 



