GULLS AND TERNS. 19 
especially during the breeding season, are by no 
means exclusively marine ones. Almost every kind 
of coast is frequented by these birds—rocky head- 
lands, precipitous downs, sandy dunes, mud-flats or 
slob-lands, and marshes; whilst every harbour 
round the shore of our islands is periodically visited. 
Gulls are not very pronounced migrants. They 
wander about a good deal during the non-breeding 
season, and many Arctic species draw southwards 
during winter, but all the indigenous British forms 
are residents on and off the coasts throughout the 
year. With these few words of introduction we 
will now proceed to give a more detailed account of 
the strictly British species. 
GREAT BLACK-BACKED GULL. 
This, the largest of the Gulls, and scientifically 
known as Larus marinus, is one of the least 
common British species, most locally distributed 
during the breeding season. It is not known to 
breed anywhere on the east coast of England, and 
but very locally on the south coast, in Dorset. It 
becomes more numerous in the wilder districts, in 
Cornwall, the Scilly Islands, and Lundy, and thence 
locally along the Welsh coast and in the Solway 
district. In Scotland it becomes more common, 
especially among the islands of the west coast, 
including St. Kilda, and on the north coast to the 
Orkneys and Shetlands. It is also widely dis- 
tributed in Ireland, but there, as everywhere else, 
