LARIDA, 647 
THE COMMON TERN. 
STERNA FLUVIATILIS, Naumann. 
The Common Tern is deservedly so named as regards the southern 
and even greater part of the British Islands, but there is consider- 
able difficulty in sketching its northern summer-range with exacti- 
tude, owing to the fact that this over-laps the southern limits of the 
Arctic Tern. Broadly speaking, I believe that the Common Tern 
is the predominant species along the shores of the Channel and on 
the west side of Great Britain as far north as the Isle of Skye; 
while on the east it is found from Kent to the Moray Firth. 
Northwards, it yields numerically to the Arctic Tern, and often 
shows a liking for fresh-water lochs or estuaries rather than for 
exposed islands, though Mr. Harvie-Brown states that in 1885 it was 
nesting abundantly at the western end of the Pentland Skerries, while 
the eastern was occupied by a colony of Arctic Terns. There is no 
conclusive evidence of the occurrence of the Common Tern in the 
Shetlands, but several colonies are now known in the Orkneys and 
Outer Hebrides. When the two species inhabit the same area, they 
frequently shift their ground from year to year in a confusing 
manner, and this, no doubt, caused Booth to miss seeing the 
Common Tern on the Farnes, where large numbers undoubtedly 
