LOON. 85 them when leaving the nest. The young are born covered with down and can swim at birth. The Fied -billed Grebe is one of our most aquatic birds. When pursued, it pi-efers diving to flight, and the marvelous rapidity with which it can disappear from the surface of the water, to reappear in a quite unexpected place, justifies its reliance on its own natatorial powers. It can swim under water with only its bill exposed, when it becomes practically invisible. When on land Grebes progress awkwardly. They can, it is said, stand erect on their toes, but, when resting, support themselves on the whole length of the foot or tarsus (see Fig. 8, the Great Auk). On the wing Grebes resemble small Ducks, but their pointed bill and their feet stretched out behind the rudi- mentary tail will serve to distinguish them. LooNS. (Family Urinatorid^.) The Loon, like its small relative the Grebe, is known to almost every one hy name, but only those who have Loon visited its summer haunts among the Urinator imher. IS^orthcm lakcs and heard its vild call Plate III. ^^^ ]|jg g^-^ ^Q know it. Nuttall writes of its cry as "the sad and wolfish call of the solitary Loon, which, like a dismal echo, seems slowly to invade the ear, and, rising as it proceeds, dies away in the air." It " may be heard sometimes for two or three miles, when the bird itself is invisible, or reduced almost to a speck in the distance." The Loon is as aquatic in habits as the Grebe, but is much stronger on the wing. It migrates by day, and probably also by night, and we may some- times see it passing over — a large, ducklike bird — in March and October. When on land, it is nearly helpless, progressing awk-
