The most striking characteristic of the Waders consists in the nakedness and length of their tarsi, which sometimes attain to really extraordinary dimensions: some of these birds look as if they were mounted on stilts. This peculiarity of conformation is, however, well adapted to their modes of life. They inhabit, for the most part, river-banks, lakes, and marshes, in which they find their sustenance; consequently, they are fearless of water and ooze. The Agami, the Bustard, and the Ostrich, as well as the Emu and other _Struthionidæ_, which are placed by naturalists with this family, are not aquatic; they inhabit the interior of the country, and are either herbivorous or granivorous. The bills of these birds assume very various forms. They are generally long; but, according to the species, they may be thick or slender, tapering or flat, blunt or pointed, strong or weak; and in some kinds, such as the Flamingo, the Spoonbill, and the Boatbill, they really defy all description. The neck is always slender, and in perfect harmony with the length of the legs. Almost all the Waders are birds powerful on the wing, and twice a year most of them undertake long journeys, which they perform in large flocks, like as do Ducks, Geese, and Swans. There are, however, exceptions to this rule. Some of them--the Bustard, for instance--move through the air with difficulty, although their inferiority in this respect does not reach to complete inability; others, as the _Brevipennæ_, are absolutely unable to fly at all: their wings being altogether rudimentary, are only useful for accelerating their pace in running, and thus assisted they are remarkably swift.