^°'i o^^^] Bent, Nesting Habits of Anaiida: in N. Dakota. 1 65 



NESTING HABITS OF THE ANATID.^ IN NORTH 



DAKOTA. 



BY A. C. BENT. 



Flates V and VI. 

 {Concluded from f. 12.) 



Aythya affinis {Eyt.). Lesser Scaup Duck. 



Although not universally abundant the Lesser Scaup Duck can 

 undoubtedly be found during the breeding season in the immediate 

 vicinity of all the larger lakes, and in certain localities is so very 

 abundant as to form what might be regarded as breeding colonies. 

 The centre of its abundance seems to be the Devils Lake region, 

 but we also met with it occasionally elsewhere in Nelson County 

 and on Fullers Lake in Steele County. Its larger relative, the 

 American Scaup Duck, probably breeds sparingly in North Dakota, 

 but I have no evidence to prove it and am inclined to think that 

 if it occurs there at all it is extremely rare. The difficulty in 

 distinguishing the two species in the field might, however, lead one 

 to overlook the rarer species in many cases. These two Scaups can 

 of course be easily separated from all other ducks in the field by 

 the conspicuous white speculum which shows very plainly in fiight, 

 and by the short stout build of the bird. The eggs can also be 

 easily identified by their darker and richer color, which I should 

 describe as a rich olive buff; the lightest types approach some- 

 what the darkest types of the Mallard's eggs, and the darkest types 

 are rich dark buff or deep coffee-colored. The measurements of 

 26 eggs before me show the following figures: length, 2.36 to 

 2.10; breadth, 1.64 to 1.53, and average 2.26 by 1.59. 



The nests we found were all placed on dry ground but never 

 more than fifty yards from the water. They were generally rather 

 poorly concealed in the prairie grass but in some cases, where the 

 grass grew thick and high, they were fairly well hidden. The 

 nest consisted of a hollow scooped in the ground, profusely lined 

 with very dark colored, almost black down, mingled with a little: 



