224 THE SCOTTISH NATURALIST 



have favourite roosting-places, usually on some rocky point on the 

 sea-shore, to which they flock in the evenings. 



Whimbrel {Numenius phceopus). These birds begin to arrive, 

 and pass north about the end of April, and continue passing in 

 flocks of varying numbers during the whole of May. I have often 

 wondered how these birds could keep the direction in all weathers. 

 I remember being on the north side of the island on a very foggy 

 day, and I watched for some time small flocks of Whimbrel passing 

 out to sea. They all went due north, although they could not see 

 two hundred yards ahead of them. Only a few scattered birds 

 occur when on the passage south, towards the latter end of August 

 and first half of September. 



Sandwich Tern {Sterna cantiacd). This Tern is very rare. 

 One was shot and identified, and I have noticed a few others at 

 long intervals, always about the month of August. 



Common Tern {Sterna fluviatilis). A numerous summer 

 visitor. They begin to arrive usually about the middle of May, 

 although a few odd birds may sometimes arrive earlier. They 

 breed on rocks on the shore and inland, and on the shingle above 

 high-water mark. They also breed on the reef pastures, where they 

 make no nest, but just lay two eggs, and sometimes three, on the 

 short grass. There are one or two places where they breed in 

 colonies, such as the Island Loch, Loch a Phuil, etc. Within 

 recent years they have become much more numerous than the 

 Arctic Tern, which used formerly to be the more plentiful. 



Arctic Tern {Sterna macrura). Arctic Terns have been 

 decreasing of late years as a breeding species, and their place has 

 been taken by an increase in the Common Tern. They still nest 

 on small islets on Loch-a-Rioghan, and Soay, and a few other 

 places. Their habits and mode of feeding are much the same as 

 the Common Tern, with which species they associate a good deal. 



Little Tern {Sterna minutd). This species usually arrives 

 about a week later than the Common Tern. They breed in small 

 colonies on different parts of the island. When the young are 

 hatched, the old birds are very pugnacious, and will not hesitate to 

 swoop down and strike the intruder with their beaks. All the Terns 

 can protect eggs, and will attack with vigour, and drive away, 

 Hoodie Crows and Common Gulls, both of which are great egg- 

 stealers. 



{To be continued.) 



