Nesting Status of the Black-headed Gull in Yorks. 163 



near Lake Bala, Merionethshire, is reported from ' the Hebden 

 Bridge Gullery ' {British Birds, Vol. VIII., page 217), and is 

 no doubt referable to this breeding station. 



Keighley Moor Dam. — From information received, and 

 from what I can remember, the Black-headed gulls first nested 

 here in 1902 or 1903. Their eggs have often been raided, it 

 has never been a thriving colony, and has decreased rather 

 than increased. Mr. F. H. Edmondson estimates the numbers 

 during the last half-dozen years as between ten and twenty 

 pairs. Relating to this nesting station, Mr. H. B. Muff 

 wrote in The Naturalist (1900, p. 304) : ' On 27th July last 

 (1900) I noticed about a dozen Black-headed gulls here, 

 and amongst the rushes at the west end of the reservoir I 

 found a young bird unfledged. I do not know of any record 

 of the species breeding in that locality.' 



The above appears to have been an exceptional incident, 

 as the gulls were not there the following season. July 27th 

 is certainly an exceptionally late date for a Black-headed 

 Gull to be unfledged. 



Upper Bar den Reservoir, Barden Moor, Upper Wharf e - 

 dale. — The Duke of Devonshire's gamekeeper (Stephen Birch) 

 informs me that although there were several Black-headed 

 Gulls about for a year or two before 1900, he never found any 

 nests or eggs before that year. After that they increased very 

 rapidly for about twelve j^ears. In 1912 and 1913 he estimated 

 their numbers roughly at about 150 pairs. Afterwards they 

 decreased year by year, owing, as Mr. Birch thinks, to being 

 disturbed by people taking their eggs. Mr. Rowan {The 

 Naturalist, 1920, page 153) estimated the number nesting 

 in 1918 as between 40 and 50 pairs. It is rather a significant 

 fact that in the great ' caterpillar year ' of 1917 the gulls 

 failed to put in any appearance at this colony {The Naturalist, 

 1920, page 153) whilst higher up the same valley and in the 

 heart of the caterpillar country, it was the record year of the 

 Oughtershaw colony ! 



At this colony the gulls nest in a swamp close to the 

 Upper Badern Reservoir, or High Dock as it is known locally. 

 In late years a small offshoot from this colony has been estab- 

 lished at the small Lodge at the top of Gill Beck, and close 

 to Barden Fell. Mr. Birch estimated that about six pairs 

 nested there in 1920, and presumed their eggs would be taken 

 by passers by. 



{Grassington Moor, Upper Wharfedale. — This nesting 

 colony has been extinct for about ten years. It ceased with 

 the draining off of the water from Priest Tarn for lead-working 

 purposes, although on one occasion since a few pairs of Black- 

 headed Gulls endeavoured to nest on some flood-water there. 

 This has never been a thriving colony, and I should say it 



1921 May 1 



