30 WATER FOWL OF INDIA AND ASIA. 
young resemble the female, and so does the male when 
in the undress plumage which he puts on for a time 
after breeding. 
At the lower end of the male’s windpipe there is a 
curious hollow enlargement, partly of bone and partly of 
membrane, the bulla ossea or drum ; and in the case of 
the Red-breasted Merganser, it has been noticed that in 
the pairing season the male alone emits a singular low 
hollow note. The ordinary voice of Mergansers is rather 
a croak than a quack. 
Mergansers are swift and powerful swimmers and 
excellent divers, most of their time being spent on the 
water. On shore they move about very little, but are 
more active than most diving Ducks ; their flight is swift 
and powerful, though the Goosander rises with difficulty. 
They are the most carnivorous of the family, feeding on 
fish and other water animals, and regarded as food 
themselves are but indifferent, though probably edible 
enough if the skin be removed ; I have only tried the 
Red-breasted. Their nests are placed under cover, 
either in holes of trees or on the ground ; their eggs are 
numerous, and creamy or greenish white or buff in colour. 
One species, the Goosander, breeds within Indian limits 
in the higher Himalayas, migrating in winter to the 
base of the range: but. the ‘other species; the iNed= 
breasted Merganser and Smew, are migrants only, 
breeding to the northward of our area. 
The Goosander and Smew are fairly common, but the 
Red-breasted Merganser is one of the rarest of Indian 
waterfowl, though probably commoner than is supposed. 
The Goosander and KRed-breasted Merganser very 
closely resemble each other and differ much from the 
Smew, for which reason these two are placed together 
in one group (genus), while the Smew, having no very 
near relative, occupies a genus by itself. The three birds 
are very easily distinguished by their beaks as follows :— 
