The members of this family as a rule frequent salt water, yet not uncommonly breed on inland lakes and swamps, especially in the proximity of trees; they are often to be seen in companies, and are decidedly shy and cautious in most cases. The heavy flight is strong, steady, and rapid, bearing a certain resemblance to that of the Duck-tribe, while the birds experience considerable difficulty in starting, and laboriously flap their wings until fairly launched in the air, when they rise to some height, or skim the waves, as fancy dictates. They swim and dive to perfection, remaining a long time submerged, and indulging in many a turn and twist as they pursue their slippery prey, both wings and feet lending their aid to the performance. Ordinarily a spring precedes the plunge from the surface, but in presence of danger they disappear more quietly. Though the gait on land is an awkward waddle, Cormorants perch with ease on rocks, posts, and limbs of trees, where their upright posture gives them the appearance of black bottles or objects hung out to dry; they are stated, moreover, to be able to cling to the face of a cliff, and certainly can climb among thick vegetation, as in the case of _P. pygmaeus_. Not unfrequently they roost in trees, with the head drawn back upon the shoulders. The food, normally of fish, is varied by crustaceans, or even frogs and newts; the young are fed by regurgitation, and, when old enough, thrust their heads into their parents' bills to help themselves.[81] The note, comparatively seldom heard, is a harsh guttural croak, while the female hisses during incubation, in which she is said to be assisted by the male. The nest, placed {79}in caves, on ledges of cliffs, tops of stacks, or low islands, and less commonly on trees, bushes or reeds, is a mass of sticks, grass, seaweed, rushes and the like, according to situation; the smaller species constructing a slighter platform when the trees are chosen, and a lining of green leaves being occasionally added. Early in spring colonies, often of very large dimensions, are formed by many–but not all–of the species for breeding purposes, the stench from the remains of decaying fish at such spots being decidedly unpleasant. Incubation lasts about four weeks. Cormorants were of old used in England for catching fish, and this has been a regular business from time immemorial in China and Japan; but with us it is a mere sport, the chief exponent of which is now Captain F. H. Salvin, whose chapters on "Fishing with Cormorants" will be read with pleasure by those interested in the subject.[82] The bird rises to the surface to swallow its prey, but a strap round the neck allows it to dispose of the smallest only of its captures, while it is forced by its master to disgorge the remainder before it is rewarded with a portion of the catch.