98 BRITISH BIRDS. 



which are the home of a flourishing- and well-known colony 

 of Black-headed Gulls. It lies a little out of the way of 

 the ordinary visitor to the Gull pits, and the watcher 

 himself seldom visits it. 



On May 27th, this year, he took me to inspect the nest, 

 liaving seen it for the first time himself only a day or two 

 before. As we aj^proached, two birds flew away from the 

 shingle near the margin of the pool, and a subsequent 

 closer view of them convinced me that they were quite 

 young birds of the year. 



I found the pit to be about a hundred yards long by 

 thirty broad, roughly oval in outline, considerably depressed 

 ])elow the surrounding beach, and containing only a small 

 area of open water at the south end. On the north, east, 

 and half of the west sides it was choked up with treacherous 

 floating bog, supporting a dense growth of bulrushes and 

 reeds, the old brown stems of which were about five feet 

 liigh, while amongst them were new green ones of half 

 that height. The bog also formed a margin six or eight 

 yards wide at the south-west end, but the reed growth 

 was here scanty. 



In the open water, about two yards distant from this 

 margin, the nest was situated, supported by and completely 

 covering a clump of vegetation of the same character as 

 the surrounding bog. 



It was built entirely of the long, dark brown stems of 

 the common dock, many of them up to three-quarters of 

 an inch in diameter, and projecting a foot or more from 

 the main wall of the nest. Its diameter, viewed at a 

 distance of six feet, appeared to be fully three feet, and 

 its height from the surface of the water two and a half 

 feet. The hollow in the centre was about six inches deep, 

 and was lined with the finer twigs of the same plant. 



The old birds have been seen by the watcher (who is a 

 thoroughly reliable man) in the neighbourhood of these 

 pits for several summers past, but knowing that Herons 

 usually build in trees, he had never thought to look for a 

 nest in the pits before. 



