BLACK DUCK. 315 



BLACK DUCK. 



DUSKY DUCK. DUSKY MALLARD. 



Anas obscura. 



Char. General plumage blackish brown, paler on under parts ; head 

 and neck lighter ; wing-patch purplish green, bordered with black ; lining 

 of wings white ; bill greenish yellow ; legs red. Length about 23 inches. 



Nest. On the ground in a wet meadow or marshy border of lake or 

 stream, — sometimes under a bush or amid rushes ; a large but well-made 

 structure of grass and weed-stems lined with feathers. 



Eggs. 6-12 (usually about 8) ; pale buff or bullish green ; 2.40 X 1.70. 



This species seems to be an exclusive inhabitant of America, 

 being met with from Labrador to Florida, but is not found in 

 the higher boreal regions of the continent. It is generally 

 known by the improper name of the " Black Duck," though it 

 is merely dusky, and both sexes, nearly alike in plumage, have 

 a great resemblance to the female of the Common Mallard. It 

 is a numerous and common species in the salt-marshes, as well 

 as freshwater rivers and lakes. It is only partially migratory, 

 many birds often wintering in the Middle and Southern States, 

 where they also pass the summer and breed from the Carolinas 

 to Labrador in retired places in the freshwater marshes, or in 

 the sea islands, making a nest of rank weeds. 



Many of these birds migrate north as well as into the inte- 

 rior at the approach of spring. Their principal food in autumn 

 and winter appears to consist of minute shell-fish, particularly 

 those univalves which are so abundant in the salt-marshes. 

 They also at times in great numbers visit the sandy beach in 

 quest of small bivalves and other shelly mollusca, and occa- 

 sionally feed on seeds of aquatic and bog plants, such as those 

 of the Scheutzeria ; and, as usual, swallow gravel with the rest of 

 their fare. They roost in the shallow ponds and islands, where 

 many are caught by the minx and fox, and are extremely shy 

 during the day, being at that time very seldom seen, except 

 when surprised in their retreats or alarmed by the report of the 

 gun, when they often rise from the marsh in great numbers and 



