This species is too well known to need a description. The female lacks the black on the throat and the grey and chestnut on the crown, and her colours generally are much duller. The young approach the female in general coloration, but young males often show traces of black on the throat. Length 6 in.; wing 3 in. TREE-SPARROW Passer montanus (Linnæus) [Illustration: TREE-SPARROW _Passer montanus_] Although so closely allied to the preceding pest, the Tree-Sparrow is a bird of very different temperament and habits, and worthy to be numbered among our bird friends. Many spend the winter with us, but it is partially migratory, and their numbers are increased each spring by arrivals from abroad. It is a rather local and scarce bird, but even in places where they are common they are so shy that they are hardly ever seen, and are considered in consequence much rarer than really is the case. It shuns the habitations of man, whether because of the overpowering insolence of its larger relative or not is a debatable point, but the fact remains that if we want to see it we must find some secluded and undisturbed spot. Holes in pollard willows or in some hedgerow tree are generally chosen for a nesting-site, inside which a substantial nest of grass abundantly lined with feathers is formed. Five eggs form the clutch. These are greyish in ground colour, delicately but thickly mottled with brown, and it is an almost invariable rule that one egg of a clutch should be conspicuously lighter than the others. Little is known of the habits of this bird; its food consists chiefly of seeds and berries, but in summer insects form a large part of its diet and the young are almost entirely reared on them. Its notes and song very closely resemble those of its commoner relative but are slightly more musical and less harsh. The adult has the crown and nape dark chestnut, rest of upper parts chestnut with darker centres to the feathers; upper and lower wing coverts tipped with white and forming two distinct bands. Cheeks white with a triangular black patch in the centre. Chin and throat black; rest of under parts greyish white passing to brown on the flanks. Length 5·6 in.; wing 2·75 in. The sexes are alike in plumage. The young are similar to their parents but duller. It is a scarce and local species but widely distributed, and doubtless from its retiring habits and resemblance to the House-Sparrow it is often overlooked. THE CHAFFINCH Fringilla cœlebs, Linnæus