WATER BIRDS. 79 



Distribution. — Eastern North America, west to the Mississippi Valley, 

 north to Labrador, breeding southward to the northern parts of the United 

 States. 



The Black Duck is similar in appearance and voice to the common 

 Mallard, for the female of which it is sometimes mistaken. It is not 

 uncommon throughout the state during the migrations, and doubtless 

 formerly bred in suitable places everywhere. 



It arrives from the south from three weeks to a month later than the 

 Mallard, an average date for the southern counties being not far from 

 April 10th. On the other hand its autumnal movement southward does 

 not begin until late in September, and numbers linger until after most of 

 the Mallards have gone. According to Swales it is occasionally found at 

 St. Clair Flats in winter, although very likely these birds may prove to 

 belong to the more northern form, the Red-legged Duck. At present it 

 seems to be only a migrant in the southern part of the Lower Peninsula, 

 but breeds sparingly throughout the remainder of the state. It is found 

 commonly in large flocks, flies and feeds much after dark, and is considered 

 just as good eating as the Mallard. The nest is placed on the ground not 

 far from the water, built of grasses and similar coarse materials, and more 

 or less heavily lined with down. The eggs are grayish white to greenish 

 buff, and average 2.43 by 1.75 inches. 



TECHNICAL DESCRIPTION. 



Resembles the Mallard in size and general appearance and might readily be mistaken 

 for the female or young of the year of that species. The sexes, however, are alike, and in 

 any plumage the Dusky Duck is always darker and less streaked than the Mallard. The 

 general color is a rich dark brown, the feathers usually with lighter edgings. The lower 

 back and rump are sometimes glossy black, but elsewhere the plumage is seldom darker 

 than a clear brownish-black. The head is deep brownish-black on top more or less mixed 

 with narrow streaks of ashy or brownish; tlie sides of the head, the throat, and the neck 

 all around are buffy white finely streaked with fuscous. The distinguishing mark of the 

 species is the speculum, which is deeper blue or violet-purple than in the Mallard, bordered 

 in front and behind by black, sometimes with a narrow white bar behind the black, but 

 none on the front edge. Bill greenish-black to olive-green; legs and feet brownish or 

 sometimes tinged with reddish. 



Length, 21 to 24.50 inches; wing, 10.50 to 11.50; culmen, 2 to 2.35. 



In the northern form, separated as a subspecies by Brewster in 1902 

 under the name Red-legged Black Duck, the tarsi and toes are bright 

 red and the bill yellow, while such individuals average somewhat larger 

 than those reared farther south. According to Mr. Brewster the Red- 

 legged form does not appear in New England as a rule before the middle 

 of October, his earliest record with a single exception being. October 8. 

 He is careful, however, to make it clear that by no means all the black 

 ducks which nest north of the United States belong to the Red-legged 

 form, Mr. C. F. Batchelder having collected many examples of the smaller 

 bird in Newfoundland in June and July. 



The colors of the bill and feet change very quickly after death so that 

 in museum specimens or dried skins the colors of these parts in the two 

 forms are not noticeably different. Mr. Brewster, however, states that 

 the two birds "are sufficiently unlike in respect to size and proportions, 

 as well as in coloring, to be distinguished, under favorable conditions, at 

 more than gunshot distance when flying, and when freshly killed and 

 placed side by side they may be separated at a glance. The larger bird 

 usually has the entire bill (excepting the nail) yellow, varying from chrome 

 to canary or sulphur yellow, the legs and toes bright red, varying from 



