^°^m4~^^] Saunders, An Ecological Bird Study. 207 



the Least Flycatcher and one of the Western Wood Pewee. The 

 Goldfinches evidently did not begin nesting until late in July, just 

 before I left for the mountains and I found no nests. During June 

 there were often more than three pairs on the area, there being a 

 small band of birds roving about the vicinity that were evidently 

 not mated. By July, however, the birds had evidently chosen 

 mates and I was able to find the three pairs regularly. 



Concerning the Cowbirds, the same remarks are true here as in 

 the cinquefoil brush association. I found more eggs of this species 

 in the cottonwoods, but did not observe the birds themselves there 

 so frequently. I found nine eggs of this species in nests of this 

 association; four in nests of the Yellow Warbler, two in a nest of 

 the Chipping Sparrow, and one each in nests of the Least Fly- 

 catcher, Cedar Waxwing and Black-headed Grosbeak. 



Of the remaining six species, I found the nests of all except the 

 Nighthawk, so have undoubtedly a correct count of them. The 

 Chipping Sparrow and Black-headed Grosbeak are usually rare in 

 this association, the former being common only in the evergreen 

 forests of the mountains in this region. The latter belongs more 

 properly to the willow brush association, where it is much commoner 

 than in cottonwood groves. The Cedar Waxwing often occurs in 

 greater numbers in this association than my count of one pair 

 would indicate, but since this species varies in abundance from year 

 to year, and is very irregular in occurrence and nesting, my count 

 per acre would no doubt be accurate if applied to a larger area. 



I am not quite sure that the Nighthawks nested in this associa- 

 tion. I found them there all through the latter part of June and 

 all of July, and observed both birds, resting and sleeping on the 

 horizontal limbs of the cottonwoods. I have never found a nest 

 of this species in this association, however, but have always found 

 them on the prairie benches, or in the mountains along barren ridge- 

 tops. Why they frequented the cottonwoods so much unless they 

 nested there, I cannot say, for there were no prairie benches within 

 half a mile. These birds had certain favorite spots on the cotton- 

 wood limbs on which to rest, and after I had learned where these 

 were I could locate both birds any day that I wished to. They 

 were certainly mated, for their plumage showed that they were 

 male and female, and I had observed courtship early in the season. 



