Nest and Young
Like the kestrel, the sparrow-hawk is content with a slovenly nest, which it builds of dead twigs on the ruins of other nests—usually those of magpies, crows, or pigeons. Or it uses a squirrel's drey as a foundation, or comes year after year to its own old home. Usually the chosen site is not very high in a tree—larches and oaks are favourites—and the nest will be found near the trunk: in short oaks it may be in the cup formed where several branches spread away. We have found a nest within ten feet of the ground. The nest, when you climb to it, is much larger than it appears from below, and only a man with long arms could encircle it. There may be five eggs, pale white, blotched with dark chestnut-brown, the markings of eggs in one clutch sometimes showing a beautiful variation, while the markings of the clutches of different birds differ considerably. The shells, like those of the kestrel's eggs, are very thick—even the hawk's sharp claws would hardly puncture them without intentional effort.
Should you hear a soft whistling in a wood—not unlike the whistling of the farmer's wife when she calls her chickens to meals, but much subdued—you may know there is a sparrow-hawk's nest not far away. A glimpse of the whistler gives rise to a general alarm-cry among blackbirds. If the whistling leads to the discovery of young hawks, on your approach they will assume attitudes suggestive of disgust and resentment. In their poses and markings there is something owl-like about young hawks: and, as with young owls, there is a good deal of difference in the size of the fledglings, and in the state of their feathering. The strongest young one has the pick of the food, and quickly outgrows his brothers and sisters. Should the mother bird be killed, the cock will rear the family unaided on the small birds on which they thrive. The preservation of woods has meant a steady increase in the hosts of small birds, and hawks in consequence are under no necessity to prey on game-birds. Some sparrow-hawks will acquire the game-feeding habit: others will pounce by chance on a small game-bird; but sparrow-hawks are in no way dependent on game, living for the most part on finches and the like, thereby helping to preserve the balance of scales of which the gamekeeper and his master take little heed.
