108 COLYMBID^. 



swimming, they are in the constant habit of dipping their 

 bill in the water, with a graceful motion of the head and 

 neck."* 



Since the above was written, the Black-throated Diver has 

 been found by Mr. Harvie-Brown and others to be even more 

 plentiful in the south-western portion of Sutherland than 

 the Red-throated Diver, although in the northern and eastern 

 districts the latter species preponderates. Mr. R. Gray adds 

 that a number of pairs take up their summer quarters on 

 the lochs of Argyllshire, Perthshire, Inverness-shire, and 

 Ross-shire ; and on almost every loch in the Outer Hebrides 

 there are to be found one or two pairs breeding. They seem 

 to come near the shore in May and remain a short distance 

 from land, travelling northwards, especially on the west 

 coast ; and he has seen both old and young birds on Ben- 

 becula in September. 



The Black- throated Diver occasionally breeds on some 

 narrow spit on the shore of a loch, but the favourite site is 

 a green grass-grown island. The nest is a hollow in the 

 ground, rarely with any lining, and situated near the water's 

 edge. Mr. Harvie-Brown says that when the female leaves 

 the nest she floats gently on the surface of the water when 

 undisturbed, but if alarmed, she almost instantaneously 

 dives, or should the water close to the shore be too shallow 

 to admit of this, she half swams, half dives, until she finds 

 sufficient depth, splashing up the water and making a noise 

 which can be heard at a considerable distance. On several 

 occasions with a good glass he has watched the female as 

 she sat on her eggs, whilst the male swam up and down at 

 no great distance, gracefully dipping his bill in the water, or 

 lying over on his side stretching out his leg the better to 

 preserve his balance, and then preening the feathers of his 

 breast and side with his long dagger-shaped bill. When 

 alarmed, he would raise his head sharply, and gradually sink 

 his body, till his back became level with the water, or 

 entirely disappeared beneath it, leaving only the long snake- 

 like head and neck exposed to view. If the danger then 



* Edinb. New Phil. Journ. xx. p. 293. 



