44 DECEPTIVE COLORATION. bird became a conspicuous dark object against a white background, it took wing on the first suspicion of danger. I coukl mention many other similar instances, but the careful observer will soon find them included in his own experience. Deceptive, or, as Poulton terms it, " aggressive " col- oration is perhaps best illustrated by common Flycatchers {TyrannidiE). Although these birds live in and about trees, they are, as a rule, quietly attired in olive-green or olive-gray, and are quite unlike the brilliantly clad, y)'?«'^- eating Tanagers, Orioles, Parrots, and other l)irds that may be found near them. Insects are therefore more likely to come within snapping distance than if these birds were conspicuously colored. In the same manner we may exjDlain the colors of Hawks, which are never brightly plumaged. It is well known that many arctic animals become white on the approach of winter. With Ptarmigans this is doubtless an instance of protective coloration, but the Snowy Owl, who feeds on the Ptarmigan, may be said to illustrate deceptive coloration. Recognition, signaling, or directive colors have, with more or less reason, been made to include many different types of markings, of which I shall mention only those that are conspicuously shown in flight or by some move- ment. Such are the white outer tail-feathers of Juncos, Meadowlarks, Towhees, and many other birds, and cer- tain wing and rump patches, which are noticeable only when the bird is on the wing. Markings of this kind are supposed to aid birds in recognizing others of their kind, their special use being to keep the individuals of a family or flock together, so that when one starts the others can readily follow. The theory is open to objections, but these so-called recognition marks are so often found among birds that they doubtless are of some use, though their
