The Shag breeds in May. Its favourite nesting haunts are the caves and fissures in the cliffs, but where such are wanting, or not available, the bird will content itself with a cranny amongst the rocks of a low island. If plenty of accommodation exists many pairs of Shags will nest in company; where suitable sites are scarce the birds breed in scattered pairs along the coast. It is more than probable that the Shag pairs for life: it returns season by season to its old nesting-place. The nest of this species is either wedged into some crevice of the sides or roof, or made upon a ledge in a cave; sometimes a hole in the face of a wall-like cliff is chosen; less frequently a site is selected amongst the rough boulders on a reef; or even on a ledge of the cliffs where they overhang considerably. In most cases the nest is bulky and made of sticks, stalks of plants, and sea-weed, lined with straws, coarse grass, and turf, all more or less matted together with droppings, decaying fish, and slime, and smelling most unpleasantly. Many nests are enlarged and patched up year by year. The two, three, or four eggs are a little smaller than those of the Cormorant, of a delicate bluish-green where the thick coating of lime does not conceal it. The Shag shows more reluctance to leave its nest than the Cormorant does. The effect is most startling as the big birds dash out of the gloomy sea caves one after the other. The only note I have heard this species utter has been a low croak. GANNET.