2i8 BRITISH SEA BIRDS. 



most remarkable fact that the drake of this species 

 assists the duck in bringing up the young, but not, so 

 far as I can learn, in incubating the eggs. During 

 the whole breeding season this Duck is remark- 

 ably tame, loth to take wing, and swimming out 

 into the centre of the lake for safety, if threatened 

 by danger. The winter migrations of this Duck 

 are not very extended, the Mediterranean Basin, 

 perhaps, marking the extreme southern limits. 



MERGANSERS. 



The Mergansers are a well-defined little group of 

 fish-eating Ducks, forming the sub-family Merginee. 

 They are characterised by their slender, narrow bill, 

 furnished on both upper and lower mandible with 

 saw-like lamellae or denticulations. The head is 

 always more or less crested ; in most other respects 

 they resemble the Diving Ducks, all the species 

 seeking for their food by diving. The sexes differ 

 in colour of plumage, but not, perhaps, to such a 

 marked extent as in some other divisions of the 

 ANATID^E. Six species of Mergansers are known to 

 science, of which four are included in the British 

 list one as a rare visitor from North America. 

 Of the remaining two species, one inhabits South 

 America, the other the Auckland Islands. The 

 young, as usual, are hatched covered with down, 

 and able soon to follow the female to the water 

 In their moulting and progress to maturity they 

 resemble preceding species. 



