ON THE NESTING OF CERTAIN HAWKS, ETC. 599 
the bank rendered descent to the nest too dangerous to be tried, I 
left the family to the care of the father, who, it is to be hoped, 
has since done more for his family than he did on the occasion just 
mentioned. 
The character of the embankments on which all these hawks 
nested may be perfectly indicated in the fact that they were also the 
resort of myriads of cliff swallows (Hirundo lunifrons). Thou- 
sands of the swallows’ nests patched the face of the banks in vari- 
ous places; one large cluster was noticed near a buzzard’s nest ; 
while another group was aflixed within a few feet of one of the 
falcon’s nests. I was not long enough on the spot to determine 
whether the swallows were fond of their bold and powerful neigh- 
bors or not. 
In speaking of this unusual association of swallows and falcons, 
I am reminded to note a somewhat similar arrangement between & 
pair of Arkansas flycatchers, and Swainson’s buzzard; their nests 
being in the same tree and but a few feet apart. Both birds were 
incubating at the time of my visit. 
The Arkansas flycatcher (Tyrannus verticalis), is one of the 
commonest of the small birds along the Upper Missouri and the 
Wooded parts of the Milk river and its tributaries. So far as I 
have observed, however, it will not go into an entirely treeless 
country. In travelling over the prairie, no sooner do we strike a 
“coulé” (ravine) with scattered cottonwoods and box-elders, than 
we hear the shrill cries of these birds; and the nest—or several 
of them— may usually be soon discovered, the nest being bulky, 
and the trees straggling, with thin foliage. These birds lay later 
than most species in this country. I have taken fresh eggs up to 
the middle of July, and am sure there was no previous brood. 
nests are in a fork or crotch, generally far out on the limb, 
but sometimes directly against the trunk ; and at any height from 
five or six to forty or fifty feet. The common kingbird is gener- 
ally Seen in company with this species; I have taken both nests 
from the same tree. The eggs of the two are indistinguishable ; 
nor can the nests be told apart with certainty ; though on an aver- 
age the Arkansas is the larger, softer and fluffier, with more weedy 
and downy material and fewer slender rootlets; it is also rather 
ea compactly built. The eggs run from three to six in number. 
With the same general habits, these two flycatchers may instantly 
ba recognized by the voice; that of the Arkansas is much harsher 
