GULLS AND TERNS. 4I 
birds that continue to replace their taken eggs, but 
one brood is reared in the season. 
THE SKUAS. 
These birds may be readily distinguished, even 
when on the wing, by the cuneiform or wedge- 
shaped tail, and by the dark upper plumage. The 
bill is also much stouter and hooked at the point, 
whilst the claws are sharp and curved. Skuas are 
only exceptionally seen by the ordinary visitor to 
the sea-side. In the first place, they only breed in 
our islands in the extreme north or west of 
Scotland, and in the second place they are decidedly 
oceanic in their habits, after the nesting season is 
passed. Occasionally Skuas may be seen on 
migration, especially in autumn, and along our 
eastern and southern seaboard; occasionally they 
are driven shorewards by protracted stormy 
weather, and under these circumstances have 
frequently been known to visit inland localities. 
Odd birds are generally seen, perhaps a party of 
half a dozen, but on very exceptional occasions 
large flocks make their appearance — witness the 
thousands of Pomarine Skuas that visited the 
coast of Yorkshire during the autumns of the 
years 1879 and 1880. 
The Skuas are birds of remarkably powerful 
flight, displaying marvellous command over them- 
selves in the air, turning and twisting with great 
speed. These birds are the Raptors of the sea; 
