(685) Niltava macgrigoriae (Burton).
THE SMALL NILTAVA.
Niltava macgrigorioe, Fauna B. I., Birds, 2nd ed. vol. ii, p. 260.
This small species of Niltava has a far wider range than either of the larger species. It occurs in the breeding season from Mus¬soorie to Eastern Assam at elevations from 3,000 to 6 000 feet, sometimes being found another 1,000 feet higher, while in the Naga Hills it has been met with at 8,000 feet. In Sikkim Stevens gives its breeding elevation as 3,000 to 5,000 feet and up “to 6,000 feet or thereabouts.” It is common in the Chin Hills, Kachin and Bhamo Hills of Burma South to Tenasserim while, on the East, it extends to the Shan States and Siam.
These little Flycatchers keep very closely to evergreen forest for breeding purposes, but they choose lighter patches, with not too dense an undergrowth, and undoubtedly prefer the edges of open glades, banks of rivers and streams and other partly open spaces where sunlight and ample insect-food can be obtained. The nest is nearly always placed by or near water, though this may be no more than a tiny streamlet trickling on from one boulder to another.
Of the sites chosen by Niltavas for their nests I have not noticed that this particular species makes use of one more than another. If, however, it has any predilection it is, I think, for small clefts in rock-faces on the banks of streams or for niches under the same rocks. In Shillong several pairs built annually on the banks of the Umiam stream, where one side rose above the stream very steeply for some 100 feet, the whole of this being covered with rocks and boulders between which grew Azaleas and Rhododendrons in dense masses. No searching in such a place would have revealed the nests, but the little cock birds could be noticed haunting one particular spot, sometimes singing cheerily on a projecting branch of Azalea, sometimes hawking flies. If one worked carefully round these points it was generally possible, with patience, to put the female off her nest and so find it.
When found, the nest is just like that of its bigger cousins, differing only in being smaller, Hume’s nest of 5 inches across probably representing the biggest made. I have found them as small as 3.1/2 inches in diameter, though they are deeper in proportion than the nests of either the Great or the Beautiful Niltava.
The egg-cavity, compactly lined with matted moss and roots, generally measures slightly under 2 inches in diameter by 1.1/2 inch in depth, but Hume mentions a nest measuring “2.3/4 inches in dia¬meter by 1.3/4 inch in depth.”
The breeding months are May and June and nine out of ten eggs are laid in these two months, but I have taken an occasional clutch in the last week in April and again in the first week in July.
Both birds assist in building the nest, though the male seems to do little more than bring the materials ; both sexes also incubate but, I think, the male does so only for a short time in the mornings and evenings. The period of incubation is either eleven or twelve days, probably the latter.
The full clutch of eggs is four, though I have taken five and have occasionally seen three incubated.
The eggs differ considerably from those of the other species and, as a series, are much duller greyish or yellowish-red rather than pinkish-red, as in the bigger bird’s eggs. The ground-colour varies from the faintest creamy white to a pale greyish-yellow or, very rarely, a creamy pink. Many eggs are profusely blotched or freckled all over with pale dull reddish, the markings always more numerous at the larger end and often forming an indefinite ring or cap. Other eggs are less thickly covered and show more of the pale ground-colour. One clutch of four in my series has an almost white ground marked with red blotches, one egg being almost as boldly marked as a Tit’s egg.
In shape the eggs are regular ovals and the texture is fine and close, and either quite or very nearly glossless.
One hundred eggs average 18.1 x 13.6 mm. : maxima 19.1 x 14.1 and 18.0 x 14.2 mm. ; minima 16.0 x 13.1 and 19.0 x 12.9 mm.
685. Niltava macgrigoriae
(685) Niltava macgrigoriae (Burton).