The Nuthatch (Sitta casta or europaea), Fig. 24, upper figure, included in the Tenuirostres (slender billed) section of the order Insessors or Perchers, forms a sub-family Sittinae, of the Certhidae or Creepers. It averages about 5 in. in length, the body of robust make, bluish-grey in colour in the upper portion, and light reddish-yellow on the lower parts. The sides are brown, and the throat and cheeks white. A black streak passes from the base of the bill to the shoulders. The nest is constructed in the hole of a tree, sometimes in a former habitation of the woodpecker, and is lined with oak-leaves, in which the female lays six or seven eggs of a white colour spotted with brown. The birds defend their nest vigorously, abiding by it in face of persecution. Indeed, the nuthatch is fearless and assiduous in searching for prey in stems and branches of trees, often head foremost when descending trunks. They occur chiefly in pairs, agile and active. The female is not so brilliant or definite in her colours as the male. The food consists chiefly of insects and their larvae. Nuts - cob, filbert, and hazel-also form part of the dietary, the bird, fixing the nuts in the crevices of trees, opens them by repeated strokes of its bill. Acorns and beech-mast are likewise appropriated.

Nuthatches, generally in solitary pairs, may occasionally be seen in the neighbourhood of London.