VoL i9i9 XVI ] Taverner, Birds of Red Deer River, Alta. 19 



eight specimens were secured including both adults and juveniles. The 

 latter differ from the former in being more creamy yellow. After identify- 

 ing these birds we realized that we had met them before on the river but 

 had thought them to be light plumaged Duck Hawks. They were usually 

 seen bathing in the shallows of the river shore. At least two were seen 

 between Camp 8 and 9 and one just above Steveville; all in arid country. 



70*. Falco peregxinus. Duck Hawk. — Though several of the 

 birds we ascribed to this species during the last days of our trip were 

 probably Prairie Falcons, a number previously observed were Duck Hawks. 

 Friends about Camp 1 spoke of what they called Stone Hawks that nested 

 on the adjacent cliffs, and one morning from our tent we saw a Duck Hawk 

 feinting or making actual attacks on a Red-tail along the high cliffs across 

 the river. The latter hastily took refuge in a tree-top and assumed the 

 defensive while the Duck Hawk circled about chattering loudly and making 

 frequent dashes at it, though as far as we could see no blows actually struck 

 home. Shortly the falcon retired to an observation point on the cliff 

 near by and waited, but at the first movement of the Buteo, returned to the 

 attack and again drove it into a tree-top. It was half an hour or more 

 before the Red-tail was allowed to slip away on its business. Just above 

 Camp 2, and it was this that largely decided our stop, we discovered what 

 was probably the same bird. It flew about us screaming loudly and was 

 much disturbed at our presence. Parts of the cliff were liberally sprinkled 

 with excrement and we were confident that a nest was nearby. The next 

 day's careful search, however, failed to reveal it and upon collection the 

 bird itself proved to be a non-breeding female. As when first seen it had 

 one primary feather shaft broken as if by a shot we concluded that its 

 mate had been killed and it having been unable to find another in time 

 for breeding, still lingered and took a proprietory interest in the site of its 

 old eyrie. Between Camps 5 and 6 a nest was found containing three 

 downy young and with both parents in evidence. We collected one of the 

 nestlings. A few miles below this nest another was found containing 

 four nearly grown young and one parent present. In endeavoring to 

 get a photograph of nest and young the better grown nestling took fright 

 and left the nest. It flew up the river for nearly a quarter of a mile and 

 finally came down in the river but soon scrambled ashore where we added 

 it to our collection. Both these nests were on ledges on cliffs overlooking 

 the river. In fact every Duck Hawk nest I have so far seen has been 

 overlooking water and usually with water washing the base of the cliff 

 upon which it was situated. Little or no nesting material was used and 

 the eggs were laid upon the bare shelf. About them were scattered re- 

 mains of various birds, the most conspicuous among which were the wing 

 feathers of Franklin's Gull which from this evidence seem to be the favor- 

 ite quarry of the Duck Hawks of this section in the nesting season. There 

 were no indications of mammal remains and I conclude that this noble 

 bird prefers feathered to furred game. 



71.* Falco columbarius. Pigeon Hawk. — This species was one of 



