NATURAL HISTORY OF BIRDS. 



wliilo one invades tlie Pala>arctic region, ami one, our nuldy duek {Erismatura ru- 

 biila), is jiceiiliar to North America. The birds of this family are especially cliarao 

 teri7.ed by the narrow and ri^id tail-feathers, which are only scantily protected with 

 coverts at the base. The strangest bird of tlie group is tlic Australian musk-duck 

 (Biziura loliata), the male of which has .1 large, compressed wattle nnderneath the 

 chin, very niucli like that which ,SiirIt-i(/iorni.<t has on the toj) of the bill. It very 

 seldom takes to the wing, even when hard ])ressed, but it dives with great ease and 

 can remain under water for an incredible space of time. Its chief mode of progi'es- 

 sion is by swinmiing with the head and part of the neck alone above the surface. 

 The male is nearly twice as big as the female, and the color of both sexes is a blackish 

 brown. During the pairing and breeding season the male emits a strong odor of 



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Fig. 73. — jUtT(/«»Mfr m-njnufrr, Kuroin-nn gooaaiuler. 



musk, which may be smelt long before the bird is seen, and hence the n.ime. The 

 eggs, which usually are only two in number, are comjiaratively large, and of a pale 

 olive color; the shell is rough and very strong. The peculiar voice of the musk-duck 

 is said to resemble "the sound caused bv a large drop of water fallin" into a dee]> 

 well." 



The last snl»-family consists of the mergansers, which are directly and closely 

 related to several of our sea-ducks, but adapted to a diet of living fish instead of the 

 molluscs wliich serve the sea-ducks for food. In coiLsecjuence the bill has been greatly 

 modified. The great width, being unnecessary, has been reduceil, the lameTla-, no 

 longer serving .as a sieve, liave been changed into .strong teeth which will i)rcvent the 

 escajie of the unfortunate victims, and the nail has assumed the character of a strong 

 hook. The result is that these birds are among the greatest destroyers of fish life. 



