Sir John Richardson met with this Hawk and procured several specimens in the Arctic regions, and Captain Blakiston also met with it in the valley of the Saskatchewan. He states that it ranges throughout the interior from Hudson’s Bay to the Rocky Mountains and Mackenzie River. He found it breeding on the Saskatchewan, and one of his specimens was shot on its nest. The Goshawk was obtained at Sitka by Bischoff; and a pair was taken by Mr. Dall, April 24, 1867, within a few miles of Nulato Fort, on the Yukon River. The nest was on a large poplar, thirty feet above the ground, and made of small sticks. No eggs had been laid, but several nearly mature were found in the ovary of the female. The nest was on a small island in a thick grove of poplars, a situation which this species seemed to prefer. Mr. Dall adds that this was the most common Hawk in the valley of the Yukon, where it feeds largely on the White Ptarmigan (_Lagopus albus_), tearing off the skin and feathers, and eating only the flesh. Mr. Dall received skins from the Kuskoquim River, where it was said to be a resident species. Dr. Suckley speaks of this Hawk as bold, swift, and strong, never hesitating to sweep into a poultry-yard, catch up a chicken, and make off with it almost in a breath. Its manner of seizing its prey was by a horizontal approach for a short distance, elevated but a few feet from the ground, a sudden downward sweep, and then, without stopping its flight, making its way to a neighboring tree with the struggling victim securely fastened in its talons. For strength, intrepidity, and fury, Dr. Suckley adds, it cannot be surpassed. It seems to display great cunning, seizing very opportune moments for its attacks. In one instance it was several days before he was able to have one of these birds killed, although men were constantly on the watch for it. So adroit was it in seizing opportunities to make its attacks, that it regularly visited the poultry-yard three times a day, and yet always contrived to escape unmolested. He found these birds much more plentiful during some months than at other times, and attributed it to their breeding in the retired recesses of the mountains, remaining there until their young were well able to fly, and then all descending to the open plains, where they obtain a more abundant supply of food.