208 OUR BIRD ALLIES. 
ever, this brown hue gradually gives place to pure 
white, and completely alters the appearance of the 
bird, whose principal distinguishing feature is now the 
bright vermilion colour of the legs. 
The black-headed gull is frequently seen inland, 
more especially during the breeding season, at which 
time it often repairs to fresh-water marshes at a con- 
siderable distance from the sea. Unlike the generality 
of gulls, it avoids high and rocky districts for its nesting 
operations, and always selects low, marshy ground 
teeming with sedges and reeds. These it tramples 
down into a slight hollow, and deposits therein three 
eggs of an olive colour spotted with brown. Asa great 
number of these birds always congregate together at 
this period of the year, the collection of their eggs 
for culinary purposes forms quite a small industry for 
the time; so much so, that in more than one case 
the breeding-ground 1s regularly leased at no incon- 
siderable rent. These eggs, by the way, like those of 
the lapwing, frequently do duty for the ‘ plovers’ 
eggs ” for which there is so great a demand. 
Last upon our list of specially valuable birds is the 
Common Gull, whose food is of much the same 
character as the preceding species, and which follows 
the plough in exactly the same manner. This bird 
well deserves its popular title, and there are few parts 
of the coast in which it is not to be commonly seen. 
As a general rule, the common gull resorts to some 
high cliff or inaccessible rock for family purposes, 
and there constructs a rough nest with sea-weed, 
