LARUS RIDIBUNDUS 363 



This species, luisleadingly called the Black-headed instead of 

 Brown-headed Gull, is very plentiful in Tunisia, particularly in the 

 north, throughout the winter months and periods of passage. Accord- 

 ing to Blanc the species may also occasionally be observed in summer 

 off the south-east coast of the llegency, not near the shore as a rule, 

 but flying out at sea, or in the neighbourhood of the small islands 

 off that coast. Most of the individuals observed at that season appear 

 to be young birds. The bulk of the winter visitors arrive in November 

 and leave again in March, and during the period between those 

 months may be found in considerable numbers on all the shores and 

 lagoons of North Tunisia. 



The species is abundant in Algeria and Marocco in winter and on 

 passage. 



Its range appears to extend throughout Europe, a considerable 

 portion of Asia, and Northern Africa. Its nesting-grounds are chiefly 

 in the north, but it has been known to breed as far south as the 

 island of Sardinia and in Asia Minor. 



Large numbers of the species are to be found throughout a con- 

 siderable portion of the year on some of the Swiss lakes, and according 

 to good authorities a few nest in Switzerland. 



This Gull is far less a marine species than most of its congeners, 

 and may frequently be found on the borders of lakes, rivers and other 

 inland waters, and occasionally even in localities far distant from the 

 sea. For its breeding quarters it usually selects marshy spots and 

 fresh-water localities in preference to the sea-coast. It may con- 

 stantly be observed on cultivated fields, and is fond of following the 

 plough in search of food, exhibiting no fear of the ploughman and 

 other labourers in its vicinity. The numbers of noxious insects and 

 grubs destroyed by the vast assemblages of these Gulls is enormous, 

 and of great benefit to the farmer. In the vicinity of Syracuse I have 

 seen the fields lohite with these birds. 



Like other GuUs, the present species is voracious and almost 

 omnivorous, for besides feeding on all sorts of insects, worms and 

 larvae it preys on small fish and crustaceans, and, in captivity, will 

 eat anything that may be given to it in the way of "scraps." Some 

 of these Gulls have lived for years in my garden on a mixed diet of 

 fish and maccaroni. 



On Lake Leman in Switzerland large flocks of this species 

 accompany the steamers plying from place to place, and feed 



