126 THE RAPTORIAL BIRDS OF IOWA 



insect remains, chiefly beetles.. Later in the day the stragglers of this 

 flock were noted feeding along the grasshopper-infested sandbars of 

 Cedar river. 



By far the greater number of specimens that have come to hand 

 have been immature birds. 



It is related that Audubon once removed a Broad-wing from the 

 nest, carefully measured and sketched it, then released it without the 

 bird's having given the least evidence of irritability. 



An immature bird of this species was brought to me, and was taken 

 in hand, posed on several perches, its plumage arranged. It even al- 

 lowed the full spreading of one wing while being photographed, with- 

 out resentment. 



Captain Bendire in summarizing its breeding habits says, "It is a 

 late breeder; in the more southern portion of its range nidification 

 begins about the second week in April and correspondingly later 

 northward. In the New England states, northern New York, Penn- 

 sylvania, Iowa and Minnesota generally in the latter half of May; 

 and in New Brunswick and the southern portions of Canada about 

 the beginning of June and sometimes later. Incubation lasts twenty- 

 one to twenty-five days, and the eggs are deposited at intervals of 

 one or two days. Both parents assist in incubation and in the care of 

 the young. A single brood is raised in a season." 



Rarely sets of four eggs are taken, two or three being the rule. A 

 set of two eggs taken at Duluth, Minnesota, measure respectively 2.20 

 by 1.73 inches and 2.07 by 1.65 inches, and are soiled whitish in 

 ground color with both bold and subdued spots of chocolate brown 

 and lilac tending to become confluent at the smaller end of each egg. 



Mr. Frank L. Burns in his "Monograph of the Broad-winged 

 Hawk" gives the summary of the food of this species as ascertained 

 by several observers. In 115 stomachs examined, 11 contained birds ; 

 31, mice; 17, other mammals; 17, reptiles; 22, batrachians; 45, in- 

 sects; 10, crayfish; 2, spiders; 1, thousand-legs; 2, earthworms; and 

 7 were empty. 



