Oct. 14, 1911.] 
FOREST AND STREAM. 
589 
The Cooper’s Hawk. 
Though very anxious to know the bird inti¬ 
mately, never until this summer have I found 
the nest of a Cooper’s hawk, the bird being rather 
rare in Iowa. On June 8 of this year I found 
a nest in a bit of woodland bordering the Nish- 
nabotna River about a half mile from my home. 
It was cleverly hidden under Virginia creeper 
in a crotch of a walnut tree about thirty-five feet 
from the ground. The nest was composed of 
rather small twigs, much like those used by the 
house wren in making her habitation. I think 
that it is doubtful whether a single twig in the 
NEST AND EGGS OF COOPER S HAWKS. 
entire structure had a diameter larger than a 
lead pencil. It was about the size of the nest 
made by the crow, but very nearly flat on top, 
being not much deeper than an ordinary saucer. 
There was no lining other than a few scales of 
bark which show in the pictures. The eggs were 
three in number, white, with a slight bluish tinge. 
On June 20 all three eggs hatched. The con¬ 
duct of the parent birds was very different from 
that of other birds of prey that have come under 
my observation. The mother would always slip 
away on my approach, and seldom did I see her 
at all; in fact, until the young birds were nearly 
mature I was under the impression that the nest 
was that of her near relative, the sharpshin. 
Once or twice, while the young were quite small, 
did she remain near at hand, though hidden 
among the branches. Usually she left the 
vicinity, evidently having little concern as to 
what should be going on at the nest. The male 
bird was not once seen. I have approached the 
nest of the sparrow hawk when the young were 
hatching, and the mother refused to leave, though 
I was within two feet of her. Screech owls 
have even permitted me to lift them from the 
nest under the same circumstances, and have 
attacked me when later I visited the nest. Not 
so the Cooper’s hawk. She is one of the shyest 
birds that I know and never allowed more than 
a fleeting glimpse through the trees. The few 
times that she remained near at hand she kept 
herself hidden from view. 
Of special interest to me are the food habits. 
The Cooper’s hawk being universally condemned, 
this nest was watched with unusual interest. 
Being absent from home for a few days shortly 
after the young had appeared in the nest, I had 
no opportunity to observe them until they were 
about a week old. From that time, until the 
young left the nest, with few exceptions I 
visited them one or more times daily. These 
birds never seemed to have a surplus. Other 
hawks observed nearly always left some frag¬ 
ments about to indicate what they were eating. 
Not so much as a handful of feathers was to 
be found on this nest. The only way that I 
could tell anything of what they were feeding 
upon was by frequently visiting the nest, and 
compelling the young birds to disgorge their 
meal; a disagreeable task. The parent birds 
were so shy that I was unable to catch them 
in the act of feeding. I had never known the 
Cooper’s hawk to take anything but birds or 
young poultry, nor have I noted them with being 
credited with any appreciable service, though 
they are said to feed to some extent upon squir¬ 
rels. For some time while the birds were young, 
there was no indication of other foods than 
pigeons, poultry or birds, and after making a 
number of visits to the nest I made the remark 
that if they were doing any good I had not been 
able to catch them at it. 
About the 12th of July a change was notice¬ 
able in the fare. Prairie gray squirrels and 
striped ground squirrels (spermophiles) began 
to furnish a considerable portion of the food. 
The birds would have ground squirrel for a 
couple of days and then make a meal on chicken, 
followed by more ground squirrel. The haying 
was about over, and the grain was being cut at 
this time, thus exposing the spermophiles to view 
and making them easy prey. No trace of tree 
squirrels or other small mammals was found. 
Seldom, however, did more than two days elapse 
between the chickens, so that it is easy to see 
that these birds are a source of considerable 
loss to a community, in spite of the fact that 
they destroy a considerable number of ground 
squirrels. There was, however, evidence of a 
much greater service than I have ever known 
them to be given credit for. The birds that they 
kill are perhaps a source of even greater loss 
than the poultry. The birds consumed were so 
badly mutilated that I could not, in most cases, 
identify the species with certainty, but birds of 
COOPER’S HAWKS EIGHTEEN DAYS OLD. 
the size of robins and flickers seemed to fur¬ 
nish the bulk of the captures. Whether or not 
any insects were eaten I was unable to tell. 
On July 8 the young began to show feathers 
through the down. The photograph shows them 
well at this stage, when about two and a half 
weeks old. From then on the development was 
very rapid, the other picture being taken only 
ten days later. 
As soon as one of the birds left the nest he 
was captured, and together with the two remain¬ 
ing in the nest was confined to a cage and fed 
with meat scraps. Though I had visited the nest 
daily from the time the birds were a few days 
old, and now they were constantly near to human 
beings, these birds showed not the least sign of 
becoming tame. I have noticed that among the 
Sioux Indians, hawks are quite commonly kept 
as pets, and have seen them unrestrained about 
COOPER'S HAWKS TWENTY-EIGHT DAYS OLD. 
their homes. However, I never chanced to find 
a Cooper’s hawk kept in this manner, and doubt 
very much whether they could be tamed to the 
point of remaining near their captors once they 
were given their liberty. 
Our birds did not seem to be on friendly terms 
even with each other, and while left in the care 
of others during my absence, one was devoured 
by its nest mates, though they were plentifully 
supplied with raw beef. Possibly had they been 
fed on chicken instead, such a tragedy had not 
occurred. An adult Cooper’s hawk has visited 
us almost daily for weeks at a time and caused 
great commotion among the fowls in the barn¬ 
yard just at daybreak. I have never noted its 
appearance at any other time, as it always comes 
before we leave the house. The bird would re¬ 
main quiet among the leaves until a favorable 
opportunity offered, then make a sudden dart 
among the chickens. I have watched it from 
the kitchen door and noted its position in the 
treetop near at hand, but on turning away could 
hardly locate it again a moment later. So 
motionless did it remain and so natural was the 
mimicry that it looked like a dead branch. 
Though Dr. Fisher has given out detailed 
statements of the results of stomach examina¬ 
tions on which he has based his conclusions of 
the economic status of the birds of prey, he has 
been severely criticized by small caliber writers 
who are unable to rise above the level of their 
prejudice in the agricultural press. In my opin¬ 
ion the Cooper’s hawk, and its relative, the sharp- 
shin, are responsible for much of the widespread 
prejudice against the birds of prey. The daily 
