ov4 LARIDAi 
migration, the majority are immature, and with the excep- 
tion of an occasional straggler, they move on in October. 
Like most of its race, the Black Tern is a fearless, unsuspect- 
ing little bird, and can be observed from close quarters. 
Flight.—This species spends most of its time on the 
wing, and its flight is remarkably buoyant and graceful. 
When ‘hawking’ for insects, it can swerve adroitly and 
swoop to the ground with great speed. 
Food.—Various insects, including dragon-flies, are cap- 
tured on the wing, and grasshoppers, beetles, and other 
insects, are picked off the ground. This Tern also alights 
on the water, after the manner of Gulls, feeding on sub- 
stances floating on the surface (Farran). Small fish and 
aquatic worms are also snatched up. 
Voice.—The note, which is frequently uttered, is shrill 
and powerful for the size of the bird. It sounds like 
creek-crick. 
Nest.—This species is gregarious at its breeding-haunts. 
It resorts to marshy ground, making a nest of grasses, 
rushes, and odd bits of aquatic herbage, but on some swamps 
the nest may be found almost, if not entirely, surrounded 
by shallow water. The eggs, three in number, are dull 
olive-green or brownish-green in colour, marked with large 
blotches and spots of dark brown. 
As a breeding-species in the British Isles, the Black 
Tern has not been recorded since 1858, at which date the 
egos were taken in Norfolk, a county where the bird bred 
in considerable numbers fifty years previously. In 1855 
it is believed to have bred on the marshes of Solway 
(Saunders). 
Geographical distribution.—Abroad, it nests numerously 
in Central and Southern Europe, also in North Africa ; 
northward its range extends to the Baltic; eastward to 
Turkestan. On migration in autumn and winter it has 
been traced along both sides of Equatorial Africa. 
Its geographical distribution is more restricted than that 
of the next species. 
DESCRIPTIVE CHARACTERS. 
PLUMAGE. Adult male nuptial.—Top of head and back 
of neck, black; rest of head and neck, dark greyish-black ; 
back, wings, and tail, dull bluish-grey ; tail, slightly forked ; 
under wing-coverts, light grey ; throat, breast, and abdomen, 
dark slate-grey ; under tail-coverts, white. 
