(110) Sitta castaneiventris castaneiventris.
THE CHESTNUT-BELLIED NUTHATCH.
Sitta castaneiventris Frank., P. Z. S., 1831, p. 121 (Vindhyan Hills) Blanf. ft Oates, i, p. 304.
Vernacular names. Siri (Hind.); Chor-parki (Beng.). Description.— Adult male. A black streak from the nostril through the eye to the shoulder; lores, cheeks, ear-coverts and chin white; "the whole upper plumage and visible portions of closed wing slaty-blue ; middle tail-feathers ashy-blue ; the next two black, edged and tipped with ashy-blue; the others with a subterminal white patch on the inner webs and generally with a white band on the outer web of the outermost feathers ; whole lower plumage uniform dark chestnut-bay; under tail-coverts chestnut, centred with ashy; under wing-coverts black; a white patch on the base of the primaries visible from below.
Female is a paler chestnut below and the white on the face is ill-defined.
Colours of soft parts. Iris dark brown ; bill greenish or bluish plumbeous, the terminal half black and lower mandible and base paler; legs and feet greenish plumbeous. In some specimens nearly the whole bill is black.
Measurements. Length about 130 mm.; wing 74 to 70 mm.; tail about 37 mm.; tarsus about 17 to 18 mm.; culmen about 15 to 17 mm.
Distribution. The whole of the northern plains of India as far south as the Wynaad, as far west as Umballa and Khandesh and as far east as Calcutta. I obtained it both in Nadia and the 24th Parganas, where however it is very rare. In Behar it is extremely common to the east.
Nidification. This little Nuthatch breeds principally in February and March throughout its range, making its nest in small holes in trees at any height from 10 to 30 feet from the ground. A very favourite nesting-site is in mango-trees in branches between 8 and 12 feet from the ground, and the natural hollow is always cemented round with clay to reduce the entrance to about 30 mm. This masonry work is also often continued well down inside the hollow and on the bark outside the tree as well and, even when the natural entrance to the hole is in no way too big, it is nearly always made neat and tidy with a clay finish. The nest is generally nothing but chips of dried bark and soft tinder-wood with a few leaves and rarely a little dried moss. The eggs number anything from two to six, most often five and are rather fragile, broad oval in shape and of the usual white ground with red specks. They average about 17.0x13.2 mm. Many birds must breed twice in the year, as nests may be taken in May and June and even as late as September.
Habits. The Chestnut-bellied Nuthatch is entirely a plains' bird and is very common in all well-wooded parts, though it is not a forest bird. Mango-topes both in the vicinity of, as well as away from, villages are very favourite resorts and two or more pairs may often be found in the same orchard. They have the usual restless habits of the genus and feed on the same kind of food.