Colymbus arcticus
A winter visitor. The Black-Throated Diver, a very beautiful bird in its full breeding plumage, nests on some of the lochs in Scotland, and comes south in the autumn and winter. It is by no means a common bird on the south west coasts, and our only authority for giving it a place among the Birds of Pembrokeshire is its being included by Mr. Mathias in his list. It is considerably smaller than the Great Northern Diver, and although immature birds of both species are alike in plumage, the Black-Throated Diver may be always recognised by its smaller size. As we have frequently shot the Black-Throated Diver in the winter months on the North Devon tidal rivers, the Taw and Torridge, we have no doubt that it visits Milford Haven, where it may have been obtained and confounded with the commoner species of which we have next to write.