CH. IV] BIRDS OF KERGUELEX. 193 



The Fauna of Kerguelen. 



The island of Kerguelen is situated in the southern 

 ocean in lat. 50, about half way between Australia and 

 the Cape of Good Hope. It is a large island of irregularly 

 indented form measuring in greatest diameter some 80 

 miles. The island is moreover situated on a plateau 

 which extends for a distance of more than 150 miles. 



The island is entirely built up of volcanic rocks ; it is 

 chiefly formed of basalt ; but trachyte and phonolite enter 

 also into its composition. 



Our information as to the fauna of Kerguelen is 

 apparently fairly complete. It was investigated by an 

 English expedition some years ago, the results of whose 

 discoveries were published by the Royal Society in 1875. 

 Later the " Challenger " stayed for some time at various 

 parts of the coast, and the German ship " Gazelle '" during 

 its voyage in the years 1874 76 touched at the island 

 and collected a quantity of material. 



In spite of the large size of the island, there is no 

 indigenous mammal ; the only mammal indeed which 

 occurs there, apart of course from marine forms, is the 

 ubiquitous Mus musculus. As the island is visited by 

 whale fishermen it is easy to understand how the common 

 mouse may have been introduced in ships. The only 

 land bird is the duck, Querquedula eatoni, a species 

 peculiar to this island and to the not very remote Crozets ; 

 the bird lives in marshes. Of the marine birds Sterna 

 virgata is also peculiar to Kerguelen and to the Crozets. 



B. Z. 13 



