The Birds of Pembrokeshire. 115 
merged, only showing its head and neck above the surface, sink- 
ing again in a second at the flash of the gun before the shot 
can reach it, its pursuit is not easy, and, as we have ourselves 
witnessed on several occasions, it succeeds in making its escape, 
or does not succumb until after a long chase. The Great 
Northern Diver remains on the waters oft our coasts until the 
end of April; from the Tuskar Rock Lighthouse we have the 
report that the “ Black Divers” disappear about May rst, and are 
not seen again until the following October. 
BLACK-THROATED DIVER, 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 
acommon 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. 
RED-THROATED DIVER, Colymbus septentrionalis——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 
