76 The Ottawa Naturalist. [October 



their habit of not leaving food nearby. Thus, unless one kills the birds 

 and examines their stomachs, it is necessary to rely almost wholly upon 

 the disgorged pellets overlooked by the parents, which unfortunately 

 are practically absent during the early stages of the existence of the 

 young. Details of pellets examined in 1917 are: 



July 2 14 pellets collected beneath the nest of a pair of young; 

 two made up of feathers and weed seeds from one or more vesper 

 sparrows; four containing hair of voles and mice and odd bones of 

 these rodents; the remaining pellets containing ground squirrel hair 

 and a few bones chiefly of the striped species, Cetillus tridecemlineata: 

 a few aspen leaves were also present. 



July 10 Six pellets beneath the nest of a single nestling, chiefly 

 made up of vole hair and with three sets of teeth of these animals, also 

 bones and feathers of a young crow. Pellets from another nest taken 

 on the same day, five in all, showed a few bird feathers, parts of two 

 voles, much hair of the same rodents, ground squirrel hair and three 

 tail tips of Franklin's ground squirrel. 



July 31 Three pellets gathered containing hair and bones of 

 ground squirrels, the former of C. richardsoni and franklinii. Odd 

 bones and a tail of the last species were also located upon the ground. 

 The young hawk had left this nest about ten days. Another nest from 

 which the young had departed was examined on October 5 ; it con- 

 tained broken pellets consisting of ground squirrel hair and bones. 



These studies, as was mentioned above, relate to a single 

 season's observations. Similar studies, covering a number of years 

 show little variation in the kind of food consumed. The situation of 

 the hunting grounds naturally influences the results inasmuch as these 

 are apt to be frequented by a greater number of animals of one species 

 in one place and another kind elsewhere. A shortage of some par- 

 ticular animal, such as ground squirrels, will have to be made up by 

 the collecting of some other such as mice or birds, all of which have to 

 be taken into consideration before we can arrive at a true knowledge 

 of any hawk's food habits. 



With regard to the relation of Red-tailed hawks to poultry, I have 

 yet to learn of a single instance of these hawks having attacked 

 poultry of any kind, though it is not at all an uncommon event to find 

 them nesting within a few hundred yards of barnyards and poultry 

 runs. Such is the evidence brought out by this investigation. The 

 destruction of a few sparrows may be used against the hawks. The 

 killing of a vastly greater number of noxious rodents leaves a large 

 balance in the bird's favour. We can, therefore, come to but one con- 

 clusion, namely, that it is not only a friend to the farmer but also a 

 useful ally as a conserver of our food supply. 



