Colymbus septentrionalis (Gavia stellata) – A winter visitor; common.
Sometimes called the Speckled Diver, from its pretty spotted back, this is the commonest of the three large Divers that visit our bays and estuaries in the winter. Like the Black-Throated Diver, the Red-Throated Diver also nests on the Scotch lochs, where it is a familiar bird. It is common in the winter in Milford Haven, Fishguard Bay, &c.
Its spotted back makes it readily distinguishable from the immature Black-Throated Diver, whose back is without spots. In its full adult plumage it has a red throat, and the top of the head and sides of the neck are bluish grey, with white and black lines running down the back of the neck, and on the back the white spots of the winter dress have become so small as almost to have disappeared.
Our own acquaintance with the various Divers was made in the estuaries of Devonshire, where we have occasionally seen the Red-Throated Diver in flocks of a dozen or more. Writing from Aberystwyth, Mr. J. H. Salter informs us that on April 5th, 1893, he observed Red-Throated Divers passing northwards, and that he had nearly twenty in sight at once.