BLACK-THROATED DIVER 239 



winter-plumai^c the bird is much Hkc the great northern diver, from the 

 female of which it may be distinguished by its shorter beak. 



A far less common visitor to the British Isles than either the great 

 or the under-mentioned red-throated species, and seldom seen so far 

 south as the English Channel, the black-throated diver has been 

 generally regarded as having a circumpolar distribution, although of 

 late years the tendency has been to distinguish its Japanese and 

 American representative as C. pacificus. If this view be admitted, the 

 breeding-range of the present bird will be restricted to northern Europe 

 and continental northern Asia, and the limits of its winter-range to the 

 Mediterranean, the Black, and the Caspian Seas. Somewhat curiousl)% 

 this species seems to be unknown in Iceland, although it breeds not 

 only in Scandinavia, but likewise in the OrkncN's, the Outer Hebrides, 

 and parts of Scotland, especially Sutherlandshirc, Caithness, Inverness- 

 shire, Perthshire, Ross, and Arg\'llshire. For a long time it was 

 supposed to be unknown in the Shetlands, but it is now ascertained to 

 occur in those islands, although it does not appear to nest there. To 

 the rest of the British Islands the black-throated diver is only an 

 occasional winter-visitor, generally represented by birds of the year. 

 Up to the close of the last century only about five-and-twenty 

 individuals had been recorded from Ireland. 



Practically, the habits of this species are identical with those of its 

 larger cousin ; but it is stated to be peculiar in that all the flight- 

 feathers are shed simultaneously, so that during the summer-moult at 

 least the bird is for a time utterly incapable of flying. Sometimes the 

 nest is built in the water, and then consists of dried grass, together 

 with reeds and other water-plants ; but the eggs may be deposited on 

 land, where they are laid merely on a little carpet of green reeds 

 without anything that can be called a nest. In size the larger specimens 

 of the eggs of this species exceed the smaller ones of the great northern 

 diver, so that the distinction depends upon colouring. The ground- 

 colour in those of the present species is olive-brown or clay-brown, 

 sometimes dark and sometimes light ; and the deep-seated markings are 

 black and almost indistinguishable from the superficial spots. Like 

 the other members of the group, this diver is an exceedingly shy and 

 wary bird, which is very difficult to approach within gunshot range ; 

 the sportsman's difficulty in this respect being increased by the circum- 

 stance that when approached these birds swim very low in the \\ater, 

 submerging the base of the neck, and thus offering a very small mark. 



