The SKUAS (_Lestres_), although resembling the Gulls in shape and plumage, differ from them in so many particulars that they must be regarded as forming a separate family. The principal points of difference between these birds and the true Sea Gulls are found in the structure of the beak and feet, as also in the peculiarity of their colours, and in their mode of life. In the Skuas the body is strongly built, the neck short, the head small, the beak moderately short but strong, thick, and towards the apex compressed. The upper mandible is vaulted above, strongly hooked, and provided at its base with a cere. The tarsus is moderately high, the toes short, but with a very complete web, and furnished with crooked, sharp-pointed, and sharp-edged claws. The wings are long, narrow, and pointed, the first quill being the longest. The tail consists of twelve feathers, of moderate length, and has the central tail-feathers prolonged. The plumage is rich and thick, upon the under surface fur-like; its prevailing colour is a dusky brown. The Skuas, or Parasite Gulls, are most abundant in the Arctic Regions. They live principally in the open sea, but at their breeding-time seek the neighbourhood of coasts and islands. Occasionally they wing their way into more southern latitudes, and sometimes are to be seen far inland. In strength of wing they are superior to the Gulls, and they swim well, but prefer flying to swimming. In a certain sense, they might be said to hold a middle position between Sea Gulls and birds of prey. They attack all animals that they are able to subdue, and persecute their weaker brethren until they oblige them to yield up whatsoever prey they may have caught. Indeed, it was recently generally believed that they were unable to catch prey for themselves, but were obliged to live the life of freebooters, and depend upon thieving for their support; modern observations have, however, shown that this is not altogether correct. It is, however, quite true that their power of diving is not such as to enable them to catch fishes at any great depth; they can only procure such as may be swimming close to the surface. They are, however, by no means confined to a fish diet; they devour birds and their eggs, kill small quadrupeds, and prey upon shell-fish of every kind. They will even attack young lambs, hack out their eyes and brains, and, in short, prey upon everything that offers itself, whether living or dead. Generally, however, they live by the labour of other diving birds. They watch the Gulls, Terns, Guillemots, and other predatory species, and whenever they perceive that they have caught a fish, hasten after them with all speed, and so torment and worry them as to compel them to disgorge their already swallowed prey, and let it drop from their mouths. No sooner do their pursuers see it fall than, swooping after it with the speed of a Falcon, they catch it before it reaches the water, and appropriate it to their own use.