360 BULLETIN 135, UNITED STATES NATIONAL MUSEUM 



Nesting. — The same observer says in regard to nest building: 



In building, the female arranged the dead stems of the round stalked Scirpus 

 occidentalis to form a platform, bending them over and striking them repeatedly 

 with her bill to make them stay in position, causing a peculiar knocking, ham- 

 mering noise that at this season was to be heard in the rushes on all sides. Fre- 

 quently the first one or two eggs of a set were laid on a mere platform and the 

 completed nest built up later, depending perhaps upon the need of the female 

 for a place to deposit her eggs. A complete set of seven eggs with incubation 

 begun was seen on June 7 and after this sets were common. The males seemed 

 to take no part in nest building, but stood about in the rushes a few feet awaj'. 

 This guard continued as the eggs were laid and incubation began. When the 

 females were on the nest it was amusing, as I approached slowly in the boat, to 

 see the males stalk truculently down and slide into the water, eyeing me closely 

 all the while. Frequently at this season they rose on the surface of the water, 

 treading heavily for a few strokes, making a loud turmoil in the water and driv- 

 ing themselves backward for a foot or more with the force of the effort, appar- 

 ently a threatening act intended to frighten away an intruder. 



I made my first acquaintance with the nesting habits of the coot 

 in Nelson and vSteele Counties, North Dakota, in 1901; since then I 

 have seen many coots' nests, for it is an abundant bird in all suitable 

 prairie sloughs. The nests are usually partially, or well, concealed 

 in the bulrushes (Scirpus) or flags ( Typhus) about the borders of the 

 sloughs or marshy ponds; sometimes the nests are in plain sight near 

 the edge, or in an isolated clump; occasionally one is seen in an en- 

 tirely open situation with no concealment whatever. The nest is 

 usuall}'' a floating structure, under which one could pass the hand 

 without obstruction, but it is generally firmly attached to gro^ving 

 reeds or flags, to prevent drifting. Whatever material is most read- 

 ily available, bulrushes, flags, reeds, or grass, is used and firmly 

 woven into a substantial basket; the inner cavity, which is hollowed 

 just enough to hold the eggs, is neatly lined with pieces of dry flags 

 or other smooth material. An average nest, well concealed in a 

 thick clump and containing 10 eggs, measured 14 inches in outside 

 and 7 inches in inside diameter, the rim being 8 inches above the 

 water. A larger nest, in a more open situation and containing 15 eggs, 

 measured 18 inches outside and 7 inches inside, but the rim was only 

 about 4 inches above the water. The largest nest I ever measured 

 contained only 9 eggs but it was 20 by 15 inches in outside diameter 

 and built up 7 inches above the water. These are normal types. 



John G. Tyler writes to me that he found about 15 pairs of coots 

 nesting in a shallow pond of about 40 acres, near Fresno, Cahfornia, 

 on June 18, 1917; the nests were "all built of green wire-grass stems 

 and anchored in patches of grass in water averaging a foot deep." 



Robert B. Rockwell (1912) describes several other types of nests 

 found in the Barr Lake region, Colorado, as follows: 



In the large number of nests examined were found wide variation in construc- 

 tion and location. Most of the nests were built well out toward the edge of the 



