NON-INDIGEXOUS BRITISH BIRDS. 149 



breeding grounds in the Arctic regions as soon as they are 

 free from ice, following the breaking-up rivers north- 

 wards in May. The favourite haunts of this Goose are 

 tundras and treeless plains, especially such as are studded 

 with pools and traversed by rivers. The Bean Goose 

 is gregarious and social enough whilst on passage, but 

 appears to breed in scattered pairs. It probably mates 

 for life, as so many other Geese are known to do. The 

 nest is either placed amongst the tall grasses and sedges 

 by the margin of a pool, in the long vegetation clothing 

 an island, or on a hillock on the shore. It is merely a 

 hollow lined with dry grass and other vegetable frag- 

 ments and lined with down and a few feathers from the 

 old bird's body. 



Range of egg colouration and measurement : 

 The eggs of the Bean Goose are three or four in number. 

 They are rather coarse in grain, and creamy-white. 

 Average measurement, 3-2 inches in length by 2' 15 

 inches in breadth. Incubation Is performed almost if 

 not entirely by the female, but the duration of the period 

 is unknown. 



Diagnostic characters : The eggs of the Bean 

 Goose cannot always be distinguished from those of 

 the Gray Lag Goose in colour or in size, but are lighter 

 in shell weight. I know of no character whatever by 

 which they may be separated from those of the Pink- 

 footed Goose and the White-fronted Goose. It will 

 thus be seen of what vital importance correct identifica- 

 tion is. 



