The white-headed fruit pigeon (_Ptilopus cinctus_) is a very conspicuous bird when taken from its native haunts. It has a pure white neck and head, black back, yellow belly, and well-marked, deeply-curved black band across the breast, and black wings. It is a handsome as well as very conspicuous bird. It frequents trees that are a species of Eucalyptus in the island of Timor, and which have very open foliage and yellowish or whitish bark. The pigeons may be sitting motionless on exposed branches of the tree during the glaring heat of the day. The yellow and white bark of the tree, the deep blue sky seen through the openings of the leaves, with the intense tropical sunlight casting black shadows of one branch upon another, make color effects that harmonize so completely with the color patterns of the pigeons that they are entirely invisible.[8] Here again the complete color adaptation of the pigeons to their environment has been accomplished through the agency of Natural Selection,—Nature selecting those pigeons most frequently that varied most in the direction of useful color patterns, by concealing them from their enemies, the hawks. There are some birds that are not protectively colored, which therefore do not possess a local color adaptation. The common raven, which inhabits the Arctic regions, is black instead of being white. The raven is found as far north as any known bird or mammal. It is a powerful and fearless bird, and needs no protective coloring; and since it feeds on dead animals it needs no concealing coloration to enable it to secure its food.