The Sharp-shinned Hawk is brave and full of dash and spirit. It does not hesitate to attack birds fully as large as itself and in one instance it was known to strike down a night heron, which obtained its liberty only because its discordant squawks so disconcerted its ordinarily cool and collected enemy that it was frightened away. Even though its wings are short and seemingly not fitted for rapid progress, its flight, when in the pursuit of prey, is very swift and direct. “No matter which way the selected victim may turn and double, his untiring pursuer is equally prompt, and only rarely will it miss capturing its quarry. Once struck, death fortunately follows quickly, as it fairly transfixes its victim’s vitals with its long and sharp talons.” Audubon well describes the habits of this bird. He says: “While in search of prey, the Sharp-shinned Hawk passes over the country, now at a moderate height, now so close over the land, in so swift a manner that, although your eye has marked it, you feel surprised that the very next moment it has dashed off and is far away. In fact, it is usually seen when least expected and almost always but for a few moments, unless when it has procured some prey and is engaged in feeding upon it. The kind of vacillation or wavering with which it moves through the air appears perfectly adapted to its wants; for it undoubtedly enables this little warrior to watch and to see at a single quick glance of its keen eyes every object, whether to the right or to the left, as it pursues its course. It advances by sudden dashes, as if impetuosity of movement were essential to its nature, and pounces upon and strikes such objects as best suit its appetite, but so very suddenly that it appears quite hopeless for any of them to try to escape.” The nest of this species is usually built in dense hemlock or other cone-bearing trees, though a deciduous tree is sometimes selected. It prefers also a site not more than twenty to forty feet from the ground. It is said that the nest is sometimes built in the crevices of cliffs or in hollow trees. This may be the case in Arctic regions, but it is not the usual habit of the bird within the borders of the United States. The nests are very large, as compared with the size of the bird, varying in diameter from twenty to thirty inches, outside measurement. The walls are usually constructed with twigs and lined with smaller ones and strips of the fibrous inner bark of coniferous trees. Instances have been reported in which the walls were nearly eight inches in thickness. As a rule the Sharp-shinned Hawk does not defend its nest from the attack of intruders. There are, however, a few instances recorded in which both the male and female birds fought a person who was climbing to their nest, by repeatedly striking at the intruder.