274 THE SCOTTISH NATURALIST 



hundreds at a time of both Common and Arctic Terns on the 

 Clyde opposite Dumbarton Castle." Though not so common now, 

 the Arctic Tern is still familiar in the estuary. From information 

 supplied by Mr R. Oswald Blyth it seems possible that a few may 

 nest alongside the Common Terns at Loch Thom. 



The *Black-headed Gull is our commonest Gull, and annually 

 forms large nesting colonies at Loch Thom, Harelaw Dam, and 

 near Loch Goin, while small settlements may be found either 

 regularly or occasionally in many other localities. The *Common 

 Gull, not by any means so common as its name might suggest, is 

 well known in the estuary ; a few pairs nest at Loch Thom, and it 

 is frequently seen elsewhere. Where river merges into estuary, 

 between Erskine Ferry and Port-Glasgow, Gulls of several species 

 are to be numbered by the ten thousand on some autumn days. 

 In these great gatherings the Herring-gull predominates. At all 

 times well known on the firth, it is a feature of the winter months 

 inland, especially on manure-strev/n fields and refuse heaps, where 

 noisy flocks act as scavengers. The Lesser Black-backed Gull 

 is common from March till September, and the Great Black- 

 backed Gull is frequent in the estuary in winter, but unlike the 

 former, the latter is seldom seen inland. An example of the 

 Glaucous Gull, now in Kelvingrove Museum, Glasgow, was shot 

 on Gourock Moor on 20th March 1S72. Others were seen m its 

 company {Proc. Nat. Hist. Soc, Glasgow, ii., p. 188). The Kitti- 

 wake, at times common in the estuary, is occasionally seen inland, 

 where a few examples have been found dead after storms. An 

 Ivory Gull was shot near Greenock in 1858 (Gray). 



Stercorariid.^. 



In the autumn of 1879 some Great, or Common Skuas, are 

 said to have been seen in Gourock Bay in company with Poma- 

 torhines, but the record is not as convincing as we could wish. Of 

 the latter species, considerable numbers appeared in the same 

 autumn. Mr Clunie, naturalist, Greenock, passed about fourteen 

 through his hands. These had been killed at various points between 

 Cardross and Dunoon. One flock of twelve and another of eight 

 were seen in Gourock Bay, and a few birds were observed as late 

 as 14th February 1880 (Proc. Nat. Hist. Soc, Glasgow, iv., p. 278). 

 Dr Macfie watched a pair of Skuas, robbing Gulls, off Princes Pier, 

 Greenock, but he could not determine the species. 



