GULLS AND TERNS. 21 



of this species that are sometimes witnessed are 

 chiefly due to such accidental causes as an 

 unwonted supply of food, or a continued spell of 

 boisterous weather, which often drives Gulls in 

 thousands into sheltered bays and estuaries. This 

 Gull is generally met with beating about in a 

 solitary manner ; less frequently three or four may 

 be seen together ; whilst even in the breeding 

 season, when most Gulls congregate into colonies 

 whose size seems only to be regulated by the 

 accommodation presented, it is certainly the least 

 sociable of all the British species. It is a great 

 nomad during the non-breeding season, often 

 wandering far from land, resting and sleeping oh 

 the sea. On the other hand, it is one of the least 

 frequent visitors of the Gull-tribe to inland districts, 

 and, as its specific name of marinus indicates, is 

 closely attached to the sea. The usual call-note of 

 this fine Gull is a loud, whining, oft-repeated ag- 

 ag-ag. Notwithstanding the purity of its plumage, 

 and the magnificence of its presence, the Great 

 Black -backed Gull is almost as unclean in its 

 habits as the Raven or the Vulture. No kind 

 of carrion is refused, either lying on the shore or 

 floating on the sea weakly, death-stricken lambs 

 or wounded birds, eggs or chicks left unguarded 

 by their owners, fish basking or sleeping near the 

 surface, offal cast from the fishing boats or quays, 

 animal refuse of all kinds, form the prey of this Gull. 

 The usual breeding place of this Gull is the top 



