CLIFF SWALLOW IN WESTERN IOWA 
61 
camp opposite Black Bird Hill. The next morning, he relates, he 
passed under cedar-covered bluffs containing clusters of nests which, 
he believed, belonged to Cliff Swallows. Fred J. Pierce refers to this 
in his article entitled ‘When Audubon Visited Iowa’, in Vol. VI of Towa 
Bird Life', pp. 4(3-48. 
Audubon’s records almost definitely establish the age of this colony 
of cliff dwellers at not less than 98 years. Quite likely it existed before 
Lewis and Clark; before Marquette and Joliet; before white men had 
rossed the Alleghenies, and when the vast territory to the west was 
little more than a myth. It serves as a connecting link between the 
past and the present. 
Early on the morning of June 13, 1937, we started out to make a 
survey of the colony. Our party included Dr. T. C. Stephens of Morn- 
ingside College, Slate Conservation Officer W, W, Tvusell, and myself. 
Going down the Iowa side, we launched our motor boat opposite the 
bluffs and cruised for several miles up and down the west bank of the 
river. 
The colony of Cliff Swallows is scattered out along the cliff for about 
a mile. We counted the nests as well as we could and concluded there 
were 2,600 nests in the colony. At one point of concentration there 
were over 1,500 nests in little more than 100 yards. The air was filled 
with the birds, which were at the peak of their nesting activities. Both 
eggs and young were in the nests. Across the face the light-colored 
bands gave them the appearance of wearing goggles. The retort-shaped 
nest is made of mud with the spout pointed downward to protect the 
inside from the weather. The eggs are white, finely speckled with 
brown. 
The beauty of this historic spot is now being ruined by the U. S. Army 
engineers who have erected huge pile-dikes against the base of the cliff 
in an effort to slow down the current and move it out away from its 
rock channel. This is a part of the work to make the river navigable 
for boats that will never use it. 
I visited the place on April 23, 1941, and found the colony to be 
greatly reduced, probably disturbed by the construction work. It is 
not likely that the spot will be entirely abandoned by the swallows, 
but I doubt if it will ever again regain its former size. Will they scatter 
out and find other suitable nesting sites? That they may do this is 
possible. 
In 1939 I first noticed 20 or 30 Cliff Swallow nests on the stone 
abutments of the Illinois Central railway bridge crossing the Missouri 
River at Council Bluffs. In 1940 there were about 100 and in 1941 
the colony increased to more than 200 nests. State Conservation 
Officer John F. Holst has informed me that recently a colony of Cliff 
Swallows has established itself on the stone abutments under the Blair 
Bridge on the Missouri River west of Missouri Valley, Iowa. It may 
be that some of this increase came from the area above Black Bird Hill. 
As late as 1937 there was a small colony nesting in the bluffs on the 
west side of the Missouri River about 10 miles above Sioux City. 
L. Nelson Nichols, writing about the Cliff Swallow in Pearson's 'Birds 
of America', says: "One very conspicuous place where there was an 
immense colony was on the face of the high bluffs near the confluence 
of the Niobrara and Missouri Rivers. ” This spot is about 100 miles 
above Sioux City. As I have not seen it in a number of years, I am 
unable to make a report on its present status, but in my memory it 
was never as large as the colony above Black Bird Hill. 
In conclusion I will say that the Northern Cliff Swallow has increased 
in numbers in western Iowa during the past decade, but it will be in- 
teresting to note what effect the loss of the great colony above Black 
Bird Hill will have on the future population here. 
