Waterfowl make up in number and variety for the lack of life within the lake. The surface fairly swarms with them. Lieutenant Doane enumerates swans, pelicans, gulls, geese, brants, and many varieties of ducks and dippers; also herons and sand-hill cranes. The pelicans are very plentiful, immense fleets of them sailing in company with the majestic swan, and at nightfall the low, flat islands in the lake are white with them. The gulls are of the same variety as those of San Francisco Harbor. Eagles, hawks, ravens, ospreys, prairie chickens, grouse, mocking-birds and woodpeckers are common in and around the lake basin. Mention is also made of a guide-bird, whose habits correspond with its name. It resembles the blackbird, but is larger. Lieutenant Doane says: "I saw but one of these--the day I went to the bottom of the Grand Cañon; it hopped and flew along from rock to rock ahead of us during the whole trip down, waited perched upon a rock while we were resting, and led us clear to the summit again in the same manner, making innumerable sounds and gestures constantly to attract attention. Others of the party remarked birds of the same kind and acting in the same manner." Herds of deer, elk, and mountain sheep, throng the forests and mountain meadows about the lake. Buffalo signs, grizzly bears and California lions are far from uncommon, while the smaller lakes and creek-valleys of the basin are fairly alive with otter, beaver, mink, and muskrats. Lieutenant Doane observed several unnamed and undescribed species of squirrels and weasels, and doubtless there are many other new varieties of animal life peculiar to this little-known region. One department of natural history, however, is happily unrepresented in the basin. There are no snakes, though rattlesnakes are plentiful down the Yellowstone. There are but two considerable islands in the lake--Stephenson's and Frank's--each about a mile long, narrow and covered with a thick growth of pines. Dot Island, near Frank's, a small lozenge-shaped mud-bank, not over a third of a mile long, and half a dozen of smaller size, usually near the shore, complete the list.