The Crested Black Tit breeds throughout the Lower Himalayas west of
Nepal, at elevations of from 6000 to 8000 feet.
The breeding-season lasts from March to June, but the majority have laid, I think, for the first hatch by the end of the first week in April, unless the season has been a very backward one. They usually rear two broods.
They build, so far as I know, always in holes, in trees, rocks, and walls, preferentially in the latter. Their nests involve generally two different kinds of work—the working up of the true nests on which the eggs repose, and the preliminary closing in and making comfortable the cavity in which the former is placed. For this latter work they use almost exclusively moss. Sometimes very little filling-in is required; sometimes the mass of moss used to level and close in an awkward-shaped recess is surprisingly great. A pair breed every year in a terrace-wall of my garden at Simla; elevation about 7800 feet. One year they selected an opening a foot high and 6 inches wide, and they closed up the whole of this, leaving an entrance not 2 inches in diameter. Some years ago I disturbed them there, and found nearly half a cubic foot of dry green moss. Now they build in a cavity behind one of the stones, the entrance to which is barely an inch wide, and in this, as far as I can see, they have no moss at all.
The nests are nothing but larger or smaller pads of closely felted wool and fur; sometimes a little moss, and sometimes a little vegetable down, is mingled in the moss, but the great body of the material is always wool and fur. They vary very much in size: you may meet with them fully 5 inches in diameter and 2 inches thick, comparatively loosely and coarsely massed together; and you may meet with them shallow saucers 3 inches in diameter and barely half an inch in thickness anywhere, as closely felted as if manufactured by human agency.
Six to eight is considered the full complement of eggs, but the number is very variable, and I have taken three, four, and five well-incubated eggs.
Captain Beavan, to judge from his description, seems to have found a regular cup-shaped nest such, as I have never seen. He says:—"At Simla, April 20th, 1866, I found a nest of this species with young ones in it in an old wall in the garden. I secured the old bird for identification, and then released her. The nest contained seven young ones, and was large in proportion. The outside and bottom consists of the softest moss, the nest being carefully built between two stones, about a foot inside the wall; the rest of it is composed of the finest grey wool or fur. Diameter inside 2·5; outside about 5 inches. Depth inside nearly 3 inches; outside 3·6."
Captain Cock told me that he "found several nests in May and June in Cashmere. The first nest I found was in a natural cavity high up in a tree, containing three eggs, which I unfortunately broke while taking them out of the nest. The interior of the cavity was thickly lined with fur from some small animal, such as a hare or rat. I found my second nest close to my tent in a cleft of a pine, quite low down, only 3 feet from the ground. I cut it out and it contained five eggs of the usual type—broad, blunt little eggs, white, with rusty blotches."
Colonel G.F.L. Marshall writes:—"I have only found two nests of this species in Naini Tal, both had young (two in one nest, in the other I could not count) on the 25th April; they were at about 7000 feet elevation, built in holes in walls, the entrance in both cases being very small, having nothing to distinguish it from other tiny crevices, and nothing to lead any one to suppose that there was a nest inside. It was only by seeing the parent birds go in that the nest was discovered."
The eggs of this species are moderately broad ovals, with a very slight gloss. The ground-colour is a slightly pinkish white, and they are richly blotched and spotted, and more or less speckled (chiefly towards the larger end), with bright, somewhat brownish red.
The markings very commonly form a dense, almost confluent zone or cap about the large end, and they are generally more thinly scattered elsewhere, but the amount of the markings varies much in different eggs. In some, although they are thicker in the zone, they are still pretty thickly set over the entire surface, while in others they are almost confined to one end of the egg, generally the broad end.