BREEDING-STATIONS OF THE BLACK-HEADED GULL 143 



BREEDING-STATIONS OF THE BLACK-HEADED 

 GULL IN DUMBARTONSHIRE. 



By Alexander Cuthbertson. 



The collecting of the data on which this paper is based has 

 been exceedingly difficult owing to the paucity of published 

 records relating to the years 1850-1900, and to the inde- 

 finiteness of much of the available information. In the 

 Transactions of the Andersoniaft Naturalists' Society, in 

 The Glasgow Naturalist^ and in The Scottish Naturalist, 

 few, if any, data are to be found, while in Mr Robert 

 Gurney's paper on the " Breeding-Stations of the Black- 

 headed Gull in the British Isles," ^ there is no mention 

 of any of the colonies in Dumbartonshire. The remarks 

 following refer particularly to the area of the Kilpatrick 

 Hills. 



The large colony at Loch Humphrey existed many years 

 prior to 1875, and seems to have numbered several hundred 

 pairs in 1890, the gulls nesting on a large islet and on 

 a long peninsula. The authorities unwittingly forced the 

 birds from their breeding-sites, by raising the level of the 

 water, so that in 1895 or so, a movement to the marsh 

 at the south-east of the loch became general. Several 

 years later frequent raids occurred, and a concomitant decrease 

 was noted until 1910, when a steady recovery took place, 

 but in 1916 and 1917 signs were abundant that this colony 

 was again on the decrease. During 1918-1921 the numbers 

 of nesting birds varied from fifteen to thirty pairs, but as 

 they are taking to the moor close by the marsh a decrease 

 is imminent. 



North of Loch Humphrey lies Fyn Loch, which is asserted 

 to have been colonised about 1890 by great numbers of 

 gulls from Stirlingshire. I am inclined to believe, however, 

 that this colony is but an off-shoot from the large gullery, 

 then being slowly broken up, on Inch Moan in Loch Lomond. 



1 Joum. of N, H. Soc. of Glasgow. 



^ Trans. Norfolk Norwich Nat. Soc, vol. x. part xv., pp. 417-447, 



