7500 Birch. 



Blackheaded Gull, Larus ridibundus. 



Situation. In tussocks of sedge at Palisbourne in North umbeiland, 

 and in the fens of Lincolnshire. 



Materials. " The gnlls trample down the grass on the tops of the 

 tussocks, and thus form a place on which they deposit their eggs, and 

 sit isolated each on his own little island, about a foot or more above 

 the surface of the water or swamp. Thus raised from the surface, 

 they are seen at a considerable distance, and easily observe the 

 approach of an enemy." — Col. Montagu. *" 



E(/gs, 3, 4. Pale olive-green or pale umber-brown, blotched with 

 black-brown or dark gray. 



KiTTiWAKEj Larus tridactijlus. 



Situation. On sea- cliffs at Flamborough Head in Yorkshire, the 

 Fern Islands on the coast of Northumberland, Fowls Heugh near 

 Stonehaven, the Bass Rock and the Isle of May in the Firth of Forth, 

 Ailsa Craig in the Fivlh of Clyde, and many other similar situations. 

 At Fowls Heugh they are said to breed in vast numbers, but never in 

 the Isle of Wight, as Mr. Yarrell supposed. " At Binaforth, a fishing 

 station belonging to Mr. Edmonston,'' one of their breeding stations, 

 " the ledges of the rocks were to a great extent whitened with their 

 numbers, as much as they would have been by a fall of snow." — 

 Mr. Heivitson. 



Materials. The birds collect a little dry sea-weed and dry grass, 

 and arrange it very carelessly on narrow ledges on the face of the 

 cliiTs. 



Eggs, 2. Gray, blotched with darker gray and black-brown. 



Common Gull, Larus canus. 



Situation. " At St. Abb's Head, a bold and rocky headland of 

 Berwickshire, these birds are very numerous in the breeding-season, 

 and occupy the whole face of the cliff"." — Mr. Selhy. 



Materials. " The nest is formed of sea-weed, dry grass, &c." — 

 Mr. Selby. 



Eggs, 2, 3. " The eggs, two and sometimes three in number, are 

 of a pale oil-green or a jellowish white colour, blotched irregidarly 

 with blackish brown and gray." — Mr. Selby. 



Lesser Blackbacke;d Gull, Larus fuscus. 



Situation. On the ground or in hollows or depressions of the rocks 

 on the coast of Northumberland and St. Kilda. 



Materials. Dried grass, sometimes intermixed with sea-weed, ge- 

 nerally comprising altogether a considerable mass. 



