Mr. Dall found this the most common species of Owl about Nulato. Many of both sexes were obtained, and on the 16th of April he took from the ovary of a female an egg ready for laying. On the 5th of May Mr. Dall obtained six eggs which were laid on the top of an old birch stump, and fifteen feet from the ground. There was no nest other than that the rotten wood was somewhat hollowed out, and the eggs laid directly upon it. As he was climbing to the nest, the male bird which had been sitting on the nest attacked Mr. Dall, and knocked off his cap. The female did not appear. Mr. Donald Gunn states that these Owls hunt in the daytime, and feed chiefly upon mice; and Mr. Dall seldom found anything but mice in their crops, and adds that it is very fond of flying, towards dusk, from the top of one tall spruce to another, apparently swinging or balancing itself, calling to its mate at intervals, while chasing or being chased by it. Captain Drummond states, in “Contributions to Ornithology” (p. 37), that he noticed a bird of this species, on the wing, within a few yards of him, in the Bermudas. Mr. Dresser, who had ample opportunities of observing the Hawk Owl in New Brunswick, where he found it by no means uncommon, describes it as a true day Owl. It was often seen by him hawking after prey in the strongest sunshine, or seated quietly blinking on the top of an old blasted tree, apparently undisturbed by the glare of the sun. In its general appearance, and particularly in its flight, it appeared to him to have considerable affinity to the Sparrow Hawk. In New Brunswick it affected the open plains or so-called blueberry barrens, where the open country is covered with low bushes and an occasional scathed tree. It would sit on one of these trees for hours in an upright hawk-like position, occasionally hunting over the ground, like the Kestrel of Europe, in search of small field-mice. It showed but little fear, and could be easily approached within gun-shot. When shot at and missed, it would take a short flight and return to its former perch. On one occasion Mr. Dresser, firing at one with a rifle, cut the branch close under the bird, which returned almost immediately to another branch, was a second time missed, and finally fell under a third shot. Its note is said to be a shrill cry, similar to the call of the European Kestrel, and generally uttered on the wing. The stomach was generally found filled with small field-mice, and rarely contained any remains of small birds. They appeared to hunt after food chiefly early in the forenoon and in the evening. During the day they rested on some elevated perch. In the night they retired to rest like other diurnal _Raptores_.