British Sea Birds

by Charles Dixon

RED-BREASTED MERGANSER.

This handsome sea-bird, the Mergus serrator of Linnæus and most modern ornithologists, is unfortunately a winter visitor only to English waters. In Scotland and Ireland, however, it is one of the most familiar coast birds all the year round. The Red-breasted Merganser cannot readily be confused with any other Duck. The crested head and upper neck are black, shot with green and purple, the lower neck and upper breast are buff, streaked with black, the feathers on the sides of the breast having broad black margins, the flanks are strongly vermiculated with black, the back is black, vermiculated with gray on the lower portions, the inner scapulars are black, the outer ones white, the speculum is white, barred with black, and the underparts (except the flanks) are white. The female has the head and neck reddish-brown, and the upper parts brown, the black-bordered feathers on the sides of the breast are absent. Although found in many inland districts, the favourite resorts of the Red-breasted Merganser are wild, rocky coasts, such as contain plenty of quiet bays and creeks, and lochs studded with islands. Waters where the bottom is sandy or rocky, are preferred to those in which it is composed of mud. Many birds of this species visit our coasts for the winter from more northern haunts, whilst some of those dwelling in Scottish waters draw southwards at that season. This Merganser is more or less gregarious, and may be met with in flocks out at sea, or during rough weather sheltering nearer the land in lochs. Early in spring, and onwards through the summer, the Red-breasted Merganser lives closely in pairs, flying and feeding in company. I have noticed that this bird visits certain spots to feed very regularly, according to the state of the tide; almost to the minute I could depend upon certain pairs passing certain spots on their way to these feeding-grounds. I know of few prettier sights than the actions of a pair of Mergansers in some quiet, deep sea loch in early summer. The birds swim side by side close inshore below the rocks, first one diving, and then another, rarely, if ever, both descending at the same time when feeding; but when engaged in courtship, the drake will pursue the duck, and splash about in the water in a most uproarious way, often diving after her in the eagerness of his chase. The bird swims well, if rather low in the water, and dives head foremost with a leap just like the Shag. The food of this species consists largely of fish, but crustaceans, crabs especially, and molluscs are also devoured. Most of this food is obtained whilst diving, each capture being brought to the surface to be swallowed, the bird drinking after doing so, and not unfrequently rising three parts out of the water and flapping its wings. The note is a guttural kurr, heard chiefly during flight. The bird flies well and rapidly when once free from the water, but often flaps along the surface for several yards before that is accomplished.

The Red-breasted Merganser breeds in May, the eggs being laid during the latter half of that month, and the first half of June. Although not gregarious during this period, it is, at any rate, social, for several pairs may be found nesting very close together, if keeping somewhat to themselves. An island is always preferred to the mainland. The nest is placed under a rock or bank, in a rabbit burrow, or amongst dense heather and gorse at no great distance from the water. In many cases the eggs are laid upon the bare ground, in others a few dry vegetable fragments are collected into a slight hollow, but a plentiful bed of down gradually accumulates around them. From eight to twelve olive-gray eggs are laid, upon which the female alone sits. The male, however, is in attendance on the water near by, and the duck joins him there during the short periods that she leaves her charge to feed and to bathe. If alarmed, the hen bird slips off very quietly. When the young are hatched the drake retires to moult, and the female brings them up unaided. Outside our islands this Merganser is widely distributed over the northern parts of Europe, Asia, and America, drawing southwards in winter.