GULLS. 77 



BLACK-HEADED GULL. Larus ridibundus, Linnaeus. 

 A local resident, migratory in spring and autumn. 



KITTIWAKE. Larus tridactylus, Linnaeus. 



A local resident, to a certain extent migratory. 



COMMON GULL. Larus canus, Linnaeus. 



The same remark applies to this species as to the 

 last named. 



ICELAND GULL. Larus leucopterus, Faber. 

 A winter visitant, but not common. 



HEEEING GULL. Larus argentatus, Gmelin. 



Resident, and the most widely distributed of all our 

 Gulls. 



GLAUCOUS GULL. Larus glaucus, Gmelin. 



A winter visitant; more numerous in Shetland, 

 Orkney, and the east coast of Scotland. 



GEEATEE BLACK-BACKED GULL. Larus marinus, 



Linnaeus. 



Resident, but more particularly confined to the 

 north and west coasts. 



LESSEE BLACK-BACKED GULL. Larus fuscus, Lin- 

 naeus. 



Resident ; more numerous in the north. 



