nestling, and by the presence of numerous hairs stretching from
the forehead over the nostrils. These hairs lie horizontally, and
in all cases reach beyond the nostrils, and not unfrequently nearly
to the end of the bill. They are not to be confounded with the
rictal bristles, which are stiff and strong and lie laterally, nor are
they to be confounded with the lengthened shafts of the frontal
feathers, which in some of the Thrushes resemble hairs. These
latter, moreover, are never horizontal, nor do they extend over the
nostrils except in cases where this is brought about by accident,
such as careless preparation of the preserved specimen.
The amount of mottling or squamation in the plumage of the nestling varies considerably, but is present in every species in a more or less marked degree. This character is perhaps least developed in the genus Terpsiphone, the most typical of Fly- catchers so far as structural characters are concerned ; but even in this genus the mottled breast is unmistakable.
The Flycatchers may further be recognized by their very feeble tarsi and feet, which quite incapacitate them from walking on the ground; and this character will by itself be sufficient to separate them from the Thrushes, in which the tarsi are long and the feet strong. Young Flycatchers moult into adult plumage in most cases the first autumn ; but Terpsiphone differs in this respect, the males retaining an intermediate plumage for two or more years. Those Flycatchers which have abandoned their migratory habits and have become resident are well differentiated by generic characters ; but others which are still migratory resemble each other structurally very closely, and generic characters by which to separate them into convenient groups are not easy to be found. In the following key, therefore, I have had recourse to types of colour, which appear to work well and to bring allied birds together into natural groups. The Flycatchers feed on insects, which they either catch on the wing, starting from a perch to which they usually return several times, or by running with the aid of their wings along the limbs of trees. They seldom or never descend to the ground. The majority construct their nests in holes of trees or banks, and some of the species build very beautiful cup-shaped nests in the branches of trees. Few of these birds have any song, and on the whole the Flycatchers are remarkably silent. They are found solitary or in pairs, and they are frequently familiar birds.
Key to the Genera.
a. Tail considerably shorter than wing.
a’. Second primary equal to the fifth.
a". Closed wings not reaching- beyond middle of tail MUSCICAPA, p. 4.
b". Closed wings reaching nearly to tip of tail HEMICHELIDON, p. 5.
