Knowing that the bird dwells in "the wilderness," he has assumed that the wilderness in question is a sandy, arid desert, far from water, and consequently from vegetation. Such being the case, the nurture of the Pelican's young is evidently a difficult question. Being aquatic birds, the young must needs require water for drink and bathing, as well as fish for food; and, though a supply of both these necessaries could be brought in the ample pouches of the parents, they would be wasted unless some mode of storing were employed. Accordingly, the parent birds were said to make their nest in a hollow tree, and to line it with clay, or to build it altogether of clay, so as to leave a deep basin. This basin the parent birds were said to use as a sort of store-pond, bringing home supplies of fish and water in their pouches, and pouring them into the pond. The wild beasts who lived in the desert were said to be acquainted with these nests, and to resort to them daily in order to quench their thirst, repaying their entertainers by protecting their homes. In real fact, the Pelican mostly breeds near water, and is fond of selecting little rocky islands where it cannot be approached without danger. The nest is made on the ground, and is formed in a most inartificial manner of reeds and grass, the general mass of the nest being made of the reeds, and the lining being formed of grass. The eggs are white, of nearly the same shape at both ends, and are from two to five in number. On an average, however, each nest will contain about two eggs. The parent birds are very energetic in defence of their eggs or young, and, according to Le Vaillant, when approached they are "like furious harpies let loose against us, and their cries rendered us almost deaf. They often flew so near us that they flapped their wings in our faces, and, though we fired our pieces repeatedly, we were not able to frighten them." When the well-known naturalist Sonnerat tried to drive a female Pelican from her nest, she appeared not to be frightened, but angry. She would not move from her nest, and when he tried to push her off, she struck at him with her long bill and uttered cries of rage. In order to aid the bird in carrying the heavy weights with which it loads itself, the whole skeleton is permeated with air, and is exceedingly light. Beside this, the whole cellular system of the bird is honeycombed with air-cells, so that the bulk of the bird can be greatly increased, while its weight remains practically unaltered, and the Pelican becomes a sort of living balloon.