The Great Skua resorts to its breeding grounds in April, and the eggs are laid in May. As it returns yearly to the same places, it very possibly pairs for life. The nests are made upon the ground of the high moorlands, amongst the heath and grass, and are mere hollows in the moss, sometimes lined with a little dry grass. The eggs of this Skua are two in number, and vary from pale buff to dark olive-brown in ground colour, sparingly spotted and speckled with dark brown and grayish-brown. These eggs are large in size, and very closely resemble those of the Herring Gull. But one brood is reared in the year, and by the end of August the young birds and their parents desert the nesting colony, and adopt their pelagic habits. Few birds are so courageous in defence of their nests as the Skua. Even such predaceous creatures as Eagles, Ravens, and dogs are driven off; whilst human intruders are screamed at and approached within a few feet, the birds wrathfully extending their legs as if they would strike, and skimming to and fro in rage. Many tales of this bird’s daring at its nesting places are current in Shetland, where it is known almost universally as the “Bonxie.” Our second species is Richardson’s Skua, the _Stercorarius richardsoni_ of some systematists, the _S. crepidatus_ of others. Although not quite so local as the preceding species, its breeding area is remarkably restricted, so far as the British Islands are concerned. It breeds on the Hebrides, in Caithness and Sutherlandshire, and on the Orkneys and Shetlands. Richardson’s Skua is a more gregarious species than its larger relative, but its habits generally are much the same. It is, for its size, equally daring and rapacious; is also remarkable for its powers of flight; but differs from the Great Skua in being more gregarious. Richardson’s Skua is for the most part a summer migrant to the British Islands, and numbers of birds pass along our coasts in spring to their northern breeding-grounds. It is only during the seasons of passage that the visitor to our southern coasts may hope to fall in with this bird, and even then it does not approach the land much. Like the other Skuas, the present species is a relentless robber of the Gulls and Terns, chasing them up and down until they disgorge their fish, and repeating the process at every opportunity. Eggs, young birds, and carrion, are also eaten. It is said to capture weakly birds, but I do not think it is so much addicted to this Hawk-like habit as the preceding species. During summer insects and ground fruits are eaten, whilst it has been known to take worms and molluscs. The note of this Skua is described either as a plaintive _mee_ or _kyow_, and when in chase of a bird it has been likened to the syllable _yah_, oft repeated.