HUMMING-BIRDS. 
2 r 
fly off together. Their food generally consists of fruit and berries, occasionally 
insects being taken, when their other sustenance is scanty. 
At the Cape the white-backed coly ( C. capensis ) is not uncommon in gardens 
during the fruit-season, ranging about in small families of from six to eight 
individuals. They fly with a rapid, though laboured flight, generally at a lower 
level than the object at which they aim, and on nearing it they rise upward with 
a sudden abrupt curve. They creep about the branches like parrots, and hang, 
head downwards, without inconvenience; indeed, it is said that they invariably 
sleep in this position, many of them congregated together in a ball. In Natal 
Mr. Ayres states that the white-backed coly lives entirely on fruits, as does Mr. 
Andersson, who gives some information as to the flight and nesting-habits of the 
species. The flight, he says, is short and feeble, seldom extending beyond the 
nearest bush or tree, on reaching which the bird perches on one of the lower 
branches, and then gradually glides and creeps upwards through the foliage, 
using both bill and feet for that purpose. The nest he found in a small bush; it 
was composed externally of grass and twigs, lined internally with soft grass; the 
eggs were white, and three in number. Another well-known representative of 
the genus is the South African coly (G. striatus), which is brown above with 
numerous dusky cross-lines on the plumage, the head being crested and a little 
more ashy, while the forehead and lores are reddish, the sides of the face, throat, 
and breast ashy brown, the latter with blackish cross-lines; the rest of the under 
surface being ochrey buff. The total length of the typical form is about 14 inches; 
but there is considerable local variation in this respect. Large at the Cape, the 
bird becomes smaller as it approaches Abyssinia, but is of about the same size 
in Senegambia, and then gradually decreases in size in its west coast habitats; 
this variation in size being an invariable rule with African birds. The South 
African coly breeds in Natal, building its nest in the thick fork of a mimosa or 
other low tree, well sheltered by creepers and foliage above. 
The Humming-Birds. 
Family Trochilibm. 
Mainly confined to Central and South America, where they range from the 
steaming tropical forests of Brazil to the cold and barren rocks of Tierra del Fuego, 
but also extending into Mexico, humming-birds are now regarded, in spite of their 
difference in form and habits, as near allies of the swifts. To a certain extent, 
indeed, the difference in the two groups is not so strongly marked in the young as 
in the adult condition, seeing that, while in the full-grown humming-bird the beak 
is always long and slender, in the nestling it is short and wide like that of a swift. 
In the structure of their palate, according to recent researches, both groups conform 
to the Passerine type. Having the keel of the breast-bone well developed, in 
accordance with their marvellous power of sustained flight, the humming-birds are 
characterised by the presence of ten feathers in the tail, and the same number of 
primary quills in the wing; while the secondaries are reduced to six, and are thus 
very different to those of the perching birds. The three forwardly-directed toes are 
