The Common Iora (the genus, though possibly nearly allied, is too
distinct from _Chloropsis_ to allow me to adopt, as Jerdon does, one
common trivial name for both) breeds in different localities from May
to September. I have taken nests and eggs of typical examples of both
supposed species, and have had them sent me with the parent birds by
many correspondents; and though both vary a good deal, I am convinced
that all the variations which occur in the nests and eggs of one
race occur also in those of the other. If one gets only two or three
clutches of the eggs of each, great differences, naturally attributed
to difference of species (see Captain Cock's remarks, _infrà_), may
be detected; but I have seen more than fifty, and, so far as I am
concerned, I have no hesitation in asserting that, as in the case of
the birds so in that of their nests and eggs, no constant differences
can be detected if only sufficiently large series are compared.
The birds build usually on the upper surface of a horizontal bough, at
a height of from 10 to 25 feet from the ground. Sometimes, when the
bough is more or less slanting, the nest assumes somewhat more of a
pocket-shape. Occasionally it is built between three or four slender
twigs, forming an upright fork; but this is quite exceptional.
As a rule nests of the Iora very closely resemble those of
_Leucocerca_, so much so that when I sent a beautiful photograph of a
nest, which I had myself watched building, of the latter species to
Mr. Blyth, he unhesitatingly pronounced it to be a nest of the former.
There is, however, a certain amount of difference; the Iora's nests
are looser and somewhat less compact and firm. My experience does not
confirm Mr. Brooks's remarks (_vide infrà_) that they are usually
shallower; on the contrary all those now before me are, as indeed all
the many I can remember to have seen were, deep, thin-walled cups,
which had been placed on more or less horizontal branches, not
uncommonly where some upright-growing twig afforded the nest
additional security. The egg-cavity averages about 2 inches in
diameter, and varies from an inch to 1¼ inch in depth; the walls,
composed of vegetable fibres, and varying in different specimens
from only one eighth to three eighths of an inch in thickness, are
everywhere thickly coated externally with cobwebs, by which also the
nest is firmly attached to the branch on which it is seated, as well
as, where such adjoin the nest, to any little twig springing from that
branch. Interiorly they are more or less neatly lined with very fine
grass-stems. The bottom of the nest in its thinnest part is rarely
above one eighth of an inch in thickness, but running, as it so often
does, down the curving sides of the branch, it becomes a good deal
thicker, and where placed on a small branch, say not exceeding an
inch in diameter, the lateral portions of the bottom of the nest are
sometimes more than half an inch in thickness.