The Bustards (Otis) are allied to the Gallinaceæ by their short back, their thick-set shape, and the general character of their habits; but their elongated tarsi, and their legs partly bare, give them a position among the Grallæ. They have short toes, and no back toe; they run with extreme rapidity, assisted by their wings. Their flight is heavy and awkward. They frequent dry and open plains, and make their nests on the ground. Their food consists of worms, insects, grasses, and even seeds; and they move about in large droves, although their range is rather restricted. The male birds being less numerous than the females, they are generally polygamous. These birds are shy and timid, and their flesh constitutes an excellent article of food.
There are three species of the Bustard—the Great Bustard, the Little Bustard ([Fig. 152]), and the Oubara Bustard (O. Denhami).
The Great Bustard (Otis tarda) is the largest of all European birds; its weight sometimes attains to sixteen kilogrammes. It is yellow on the back, with black streaks, and in front it is a greyish white. The head of the male bird is ornamented on both sides with curled feathers, which look something like moustaches, and have obtained for it the name of the Bearded Bustard. It flies with great difficulty, and will never make up its mind to take wing except in cases of absolute necessity. Its eggs, two or three in number, are laid in the corn or grass; the nest is nothing more than a hole scratched out in the earth, and with scarcely any lining on the inside.
Fig. 152.—Little Bustard (Otis tetrax, Gould).
The Great Bustard was formerly very common in Champagne, but has now become extremely rare. Nevertheless, it is the only province in France in which this bird is to be met with, and we might almost say that it has completely disappeared from French soil. Innumerable troops of them are to be seen in the steppes of Tartary and Southern Russia.
Brevipennes (Short-winged Birds).
The birds belonging to this family are distinguished from the rest of the Grallæ by such decisive characteristics that some naturalists have proposed to include them in a separate group, to be called Cursores, or Runners; an arrangement which has much in its favour, although the simpler arrangement of Cuvier best suits our purpose. In certain anatomical points, and especially in their habits, the Brevipennæ differ greatly from the other Grallatores. They have wings, it is true, but they are so slightly developed that they are entirely unfit for purposes of flight, and are only useful in accelerating the speed of their limbs. On the other hand, their legs are long and powerful, and capable of immense muscular effort, thus enabling them to run with extraordinary fleetness.
The deduction to be drawn from these facts is, that the Brevipennes are essentially land-birds. This limitation of their habitat necessitated certain modifications in the sternum, which, instead of a prominent edge of bone in the centre, as in other birds, only presents one uniform breast-plate. Again, most of the Brevipennes are birds of large size, and, in certain circumstances, manifest remarkable vigour.
This group comprehends the Ostrich (Struthio camelus), the American Nandou (Rhea americanus), the Cassowary (Casuarius emu), and the Apteryx.