REDHEAD 233 



affect it directly. The serious droughts of recent years have taken ex- 

 cessive toll of this and other slough-nesting species. 



In courtship, the females are the ones which appear to take the in- 

 itiative, but after marriage the males assert their rightful superiority 

 and enforce it by stern disciplinary measures when necessary. Wetmore 

 (1920) relates having witnessed the display of these ducks on several 

 occasions and describes an instance as follows: "A party of four males 

 and three females were swimming in open water, two of the birds ap- 

 parently being mated. Suddenly one of the females began to display, ap- 

 proaching one of the males with her head held high, sometimes jerking 

 it up and down and again holding it erect, and at intervals calling quek, 

 que-e-ek, the last a peculiar rattling note. The male chosen extended his 

 neck, holding his head erect, frequently whirling quickly to show the 

 female his back, or again sank down with his head drawn in while the 

 female bowed before him. At short intervals she opened her mouth and 

 bit at him gently or, if he was swimming, sprang quickly in front of 

 him with her head erect and back partly submerged. She transferred her 

 attention from one male to another in turn, even approaching the one 

 who apparently was mated. The males showed considerable jealously 

 over these favors and drove each other about in fierce rushes. At inter- 

 vals they called, the note being a curious drawn-out groaning call, re- 

 sembling the syllables whee-ough given in a high tone. As it was given 

 the male sometimes raised his breast, elevated his head, and erected his 

 crest. Again he threw his head straight behind him so that it touched 

 his dorsum above the rump, with the throat and the bill pointing to- 

 ward the tail. The bill was then throw r n up and head brought again to 

 the erect position as the call was made. The curious actions of the male 

 in calling continued after he was mated, and the strange call note was 

 heard often. Mated males were seen driving savagely at their mates and 

 biting at them while they escaped by diving." 



The Redhead breeds no further north than the central portions of 

 the Canadian provinces of Alberta, Saskatchewan and Manitoba. Its 

 nest is most often found among the flags, reeds, bulrushes, and cat-tails 

 of the sloughs and swampy areas, comparatively close to deep water, 

 and usually is placed in a clump of such vegetation slightly above the 

 level of the water. It is a handsome structure, well made of reeds, deeply 

 hollowed, and plentifully lined with down, which accumulates as incu- 

 bation proceeds and is often formed into a blanket with which to cover 

 the eggs. The nest is similar to that of the Canvas-back but the down 

 in it is whiter. The number of eggs varies from 6 to 27 but the larger 

 sets are probably the product of more than one female, as Redheads are 

 very prone to lay their eggs promiscuously in the nests of other species 

 as well as in the nests of others of their own kind. The usual clutch 

 is from 10 to 15 eggs, of a pale olive buff or cream-buff colour, and an 

 average size of 2.41 by 1.71 inches. The shell of the egg is exceptionally 

 hard and tough. Incubation is performed by the female alone and takes 

 from 24 to 28 days. 



