Page:Ornithological biography, or an account of the habits of the birds of the United States of America, volume 1.djvu/516

488 others nearly black. The feathers change their colours as the pairing season advances, and in the first spring the bird is in its perfect dress.

After nearly thirty years of observation, I may say, hardly interrupted, I may be allowed to draw your attention to the following fact as highly curious. I have observed that every species of Owl which breeds in the Northern and Middle States is considerably more deficient in its powers of vision during the day or on moonlight nights, when the ground is covered with snow, than the species that breed in, and consequently may be considered as residents of, more northern countries, such as the Snow Owl, the Forked-tailed Owl, and the Hawk Owl, all of which shew no material difference in their power of vision, be the sun or moon shining ever so brightly on the snow. I have frequently approached the Great Horned Owl, as well as every other species that breeds in the United States, during what I call glaring snows, whilst, on the same day, my attempts to approach the Snow Owl or the Hawk Owl were ineffectual. Yet on examining the structure of the eyes of all these species, I have found little or no difference in them. I wish some competent anatomist would investigate this singular fact, and communicate the result of his inquiries, for the benefit of the scientific world, and that of the author of the Biography of the Birds of the United States.

The Mottled Owl rests or spends the day either in a hole of some decayed tree, or in the thickest part of the evergreens which are found so abundantly in the country, to which it usually resorts during the breeding season as well as in the depth of winter.

The branch on which you see three individuals of this species, an adult bird and two young ones, is that of the Jersey Pine (Pinus inops), a tree of moderate height and diameter, and of a scrubby appearance. The stem is generally crooked, and the wood is not considered of great utility. It grows in large groves in the state from which it has derived its name, and is now mostly used for fuel on board our steam-vessels. The Mottled Owl is often observed perched on its branches.

, Linn. Syst. Nat. vol. i. p. 132.—Lath. Ind. Ornith. vol. i. p. 54.—Ch. Bonaparte, Synopsis of Birds of the United States, p. 36.

, Lath. Synops. vol. i. p. 123.

, Wils. Amer. Ornith. vol. iii. p. 16. Pl. 19. fig. 1. Adult.

, Wils. Americ. Ornith. vol. v. p. 83. Pl. 42. fig. 1. Young.

Adult. Plate XCVII. Fig. 1.