Fam. VI. ARDEIDAE.–There are few persons in Britain who are not to some extent acquainted with the habits of the Common Heron or Hern, for it may be seen on the coast as well as on inland waters, and now breeds in more localities than formerly, though in smaller numbers; while of the remainder of the Family the Bitterns alone differ conspicuously in their mode of life. Herons are shy, solitary birds, frequenting lakes, fens, and rivers, where they {88}may often be seen standing ankle-deep in the water, and watching with untiring patience for the prey which never seems to satisfy their appetite. They rarely swim and walk but little. The majority breed in large colonies; but Bitterns (_Botaurus_), Little Bitterns (_Ardetta_), and Green Herons (_Butorides_) are notable exceptions, being, moreover, skulking and nocturnal in habit, and agreeing in the latter respect with Night-Herons (_Nycticorax_). The mud-flats commonly found on sandy shores provide excellent feeding ground, and thence old and young may be seen winging their way at considerable altitudes with leisurely flapping flight–rarely accelerated–to roost at night on the customary trees or rocks. Bitterns and their nearest allies are seldom seen far from marshes, flying noiselessly with laboured action and at a comparatively slow pace; they are, however, adepts at running or climbing among the water-plants, and perch with ease; while they often assume an upright position with the bill vertical, and thereby closely resemble the surrounding reeds, the deception being occasionally enhanced by the bird turning as if on a pivot and facing the spectator constantly.[90] Herons fly with the head drawn back, therein differing from the rest of the Order, and in some cases roost or bask in the sun on one leg; they are usually graceful and stately, the beautiful Egrets moving more easily on land than their kindred, and being somewhat less wary. The voice is a harsh croak or guttural sound, that of the Night-Heron verging upon a quack; while the Bitterns, besides the common cry, utter a booming or bellowing note in the breeding season, generally heard at night or early in the morning, the method of production of which is not at present quite clear. _Ardetta_ gives vent to a somewhat similar but weaker boom or grunt, and most species are noisy at the nest, hissing or screaming sharply. The diet consists largely of fish, but is varied by small mammals, birds, reptiles, amphibians, grasshoppers and other insects, molluscs, crustaceans, and worms, the digestion being very rapid and the birds seldom gorged. In the shallows the majority of the family stand motionless, and spear their prey with the beak as it passes, occasionally mauling it before swallowing; but some move from place to place, while the Buff-backed Heron (_Ardea bubulcus_) habitually picks insects from the backs or sides of the cattle. The nest, commonly situated {89}on lofty trees, though frequently on low bushes, ivy-covered cliffs,