The intrinsic muscles of the syrinx fixed to the ends of the bronchial semi-rings ; the edges of both mandibles smooth, the upper one simply notched; hinder aspect of tarsus smooth, composed of two entire longitudinal laminae; wing with ten primaries; tongue non-tubular; nostrils clear of the line of the forehead, the lower edge of the nostril nearer to the commissure than the upper edge is to the culmen; plumage of the nestling spotted or squamated ; nostrils more or less covered by long curly hairs; rectrices twelve; tarsi short and rather weak; an Autumn moult only.
The Muscicapidae, or Flycatchers, constitute a very large family of birds found all over the world and very well represented in India. Some are resident but many are migratory to a greater or less extent.
The Flycatchers may be known by the mottled or squamated plumage of the young 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, in some genera reaching almost to the end of the bill. They must not be confounded with the rictal bristles, which are stiff and strong and lie laterally, nor should they be confounded with the lengthened shafts of the frontal feathers, which in some 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 to some extent in every species. It is, perhaps, least developed in the genus Terpsiphone, the most typical of Flycatchers in other respects; even in this genus, however, the mottled breast and spotted wing-coverts are unmistakable.
The Flycatchers may further be recognized by their very feeble tarsi and feet, which incapacitate them from walking freely on the ground. This character is in itself sufficient to separate them from the Thrushes, in which the feet and tarsi are long and strong.
Young Flycatchers moult into adult or semi-adult plumage the first Autumn but many take two years or more to acquire the fully adult plumage and breed freely in immature garb.
In working out a key to the genera, Oates' resource to colour in addition to structural and other characteristics has been adhered to and it is noteworthy that science as it advances is finding that colour, more especially colour-pattern, is an older, more permanent character than many others hitherto so considered.
Of the genera included by Oates in the first edition of the 'Avifauna', one genus, Muscitrea, has had to be removed, as Mr. B. B. Osmaston has shown that the young are not mottled or squamated but pale replicas of the adult. Their proper place seems to be with the Warblers, Sylviidae.
Key to Genera.
A. Tail decidedly shorter than wing.
a. Second primary equal to fifth.
a1. Bill about twice as long as broad at
forehead Muscicapa, p. 201.
b1 Bill about equal in length and breadth
at forehead Hemichelidon, p. 203.
b. Second primary much shorter than fifth,
c1. Frontal feathers normal and not concealing nostrils.
a2. Rictal bristles short and few in number.
a3. Sexes different.
a4. Upper plumage brown or rufescent with black upper tail- coverts and white on base of
tail……………Siphia, p. 207.
b4. Males above blue or black, females brown or rufescent, but tail-coverts never black and no white on tail. a5. Bill strong and wide at
base Cyornis, p. 213.
b5. Bill narrow and feeble………….Nitidula, p. 237.
c4. Both sexes blue throughout ……..Stoparola, p. 238. b3. Sexes alike; plumage plain brown or rufescent through¬out.
d4. First primary never less than
half second Anthipes, p. 243.
e4. First primary much less than
half second Alseonax, p. 248.
b2. Rictal bristles very long and numerous.
c3. Tail rounded; first primary
longer than half second Ochromela, p. 252.
d3. Tail even; first primary less than
half second Culicicapa, p. 254.
d1. Frontal feathers dense and long, con- cealing nostrils.
c2. Bill carina ted and narrow; a brilliant blue neck-spot………Niltava, p. 256.
d2. Bill broad and flat; no neck-spot…………Philentoma, p. 261.
B. Tail as long as, or longer than, wing.
c. Head crested Terpsiphone, p. 264.
d. Head not crested.
e1. Tail about equal to wing.
e2. Bill about twice as long as broad
at base Hypothymis, p. 269.
f2. Length of bill about equal to
breadth at base Chelidorhynx, p. 274.
f1. Tail considerably longer than wing,. Rhipidura, p. 276.