SAND-MARTIN. 187 
I have never heard the Sand-Martin sing, but it is said to twitter occa- 
sionally. Its call-note is a loud and harsh cry, almost a faint scream. 
Naumann represents it by the word share; but the consonants, to my ears, 
are imaginary. 
The food of the Sand-Martin is composed entirely of insects, chiefly the 
smaller ones, such as gnats, which fly most abundautly over water. Gilbert 
White, however, states that the young are sometimes fed on large dragon- 
flies. The inside of the mouth of the Sand-Martin is full of a viscid saliva, 
which aids it in capturing its prey, the little flies sticking to it as the bird 
courses through the air. 
As soon as the young of the first broods can take care of themselves 
they unite into large flocks, and flit all day long over the fields and waters, 
feasting upon the boundless store of insect food. These young birds 
probably never visit the nest again, and roost at night in reed-beds, 
marshy plantations, and other suitable places; they are the earliest birds 
astir in the morning, and almost the last to retire to roost at night. ‘After 
the young have flown, they and their parents often desert the sand-banks 
altogether, and wander about in search of the best localities for food; 
they gather in immense flocks, skimming over the large rivers and lakes, 
or sometimes perching on the telegraph-wires. Stevenson gives some 
interesting particulars of these autumn flights of Sand-Martins, which 
roost like Starlings in the reed-beds. 
The Sand-Martin is a very sombre-coloured little bird. The general 
colour of the upper parts and a broad band across the chest are an almost 
uniform mouse-brown, very slightly darker on the head and somewhat 
paler on the rump. The wings and the somewhat forked tail are blackish 
brown ; the underparts generally, except the chest-band already alluded 
to, are dull white. Biull black; legs, toes, and claws dark brown ; irides 
hazel; at the back of the tarsus are a few feathers. The female does 
not differ from the male in colour, nor is there any seasonal change of 
importance. Young in first plumage resemble the adults, but have most 
of the feathers of the upper parts, especially the wing-coverts, the inner- 
most secondaries, the feathers of the rump, and the upper tail-coverts 
tipped with pale buff, and the chin and throat are suffused with buff ; but 
in many examples this buff fades into almost white, even before the birds 
leave this country. This species is easily distinguished from the House- 
Martin by its bare feet, and both from this bird and the Swallow by its 
dingy-brown plumage. 
It has been said that examples from Siberia and Arctic Europe are 
somewhat darker above and whiter below than our birds. This idea has 
probably arisen from the excessive cleanness of the underparts of birds 
living in very thinly populated districts where no coal is burnt. 
