CASPIAN TERN. 
21 
appearance on fresh-water lakes or rivers is consequently 
very rare. They roost on the ground. They are very shy 
birds, always on the look out, and difficult to be approached, 
except when engaged with their nest and young, but sociable 
among themselves. 
Like the Swallows, these, as all the other Terns, true to 
their ‘nom de guerre,’ are incessantly on the wing, and 
nothing can be more interesting than to watch them hawking 
for their prey. 
They swim buoyantly on the water, but do not dive, 
beyond the plash made in plunging from their stoop. 
They fly, for their size, in a peculiarly buoyant manner, 
and hover over a quarry like a hawk, pouncing down and 
catching it in an instant. They swim about occasionally, 
and run with ease and swiftness. 
They feed on fish, especially those of the herring tribe, 
or any chance eatable that floats on or near the surface, 
and even the young of other birds: the former they appear 
to swallow head foremost. 
The note is only a harsh cry. 
The nest is a mere hollow scratched in the sand. 
The eggs are two or three in number, of a yellowish 
stone or pale olive green colour, spotted with grey and 
reddish brown or blackish brown. They are hatched in 
about twenty days; soon run about, and are fed by the 
parents with small fish. ‘Although the birds use great 
exertions to prevent an intruder from approaching the nest 
and eggs, by flying over his head, and making a consider¬ 
able noise, yet it has been remarked that when they are 
once ^disturbed, they do not easily return to their nest, and 
are said even not to revisit the same spot the following year 
if they are fired at.’ Several hundreds of pairs build 
together. 
Male; length, one foot nine or ten inches; bill, vermilion 
red, paler towards the tip; iris, dusky reddish brown; head 
on the crown, neck on the, back, and nape, velvet black, 
the feathers elongated towards the last-named, and ended 
in a rounded point. In winter, white, or with a few dark 
feathers on the hind parts; the sides of the head below the 
eyes are white; chin, throat, and breast, white; back, blue 
grey. The expanse of the wings in this species is four feet 
three inches and a half: they extend considerably beyond 
the end of the tail. The first quill feather is the longest; 
