National Geographic : 1912 Jun
Photo by George Shiras, 3rd TYPICAL VIEW OF SHEEP ON HIGH SLOPES BORDERING THE SNOW FIELDS, WHERE CONSIDERABLE FRESH VEGETATION ISFOUND FOR A SHORT PERIOD ON SPOTS RECENTLY COVERED WITH SNOW The writer is not a believer in the theory of protective coloration when applying to the larger animals ofthis country, whatever may have been the effect of laws of nature regulating survival in prehistoric times, when the pelage colors first became constant and characteristic. Some of the smaller animals and certain birds, fish, reptiles, and insects, whose enemies are largely the same today asinthepast, areun doubtedly preserved by obliterative or deceptive colors, as well as by concealing shapes. Confirming the first conclusion arethewhite sheep of Alaska, conspicuous for miles, and which never through apparent design sought the protection ofadjoining snowbanks, however great their anxiety to escape detection or pursuit. Keenness of vision, or occupancy of a favorable lookout, and wonderful aptitude ininferring danger from the action or the absence of other sheep, constitute their main reliance.