Other birds of the thrush family.—The redwing, wheat-ear, whin-chat, stone-chat, redstart, robin, nightingale, and hedge-sparrow are other members of the thrush family which can here be only referred to. They have many points of resemblance, one of the most interesting of which is that the young birds are invariably spotted. The bill is usually rather long, stout, and straight, the staple food being insects, worms, etc., though fruit is also eaten, especially in winter. The nests are typically cup-shaped, and the eggs greenish or blue, with or without spots. The young birds are quite helpless and almost naked when hatched, and can only open their mouths to be fed by the parents. Even after they have left the nest they need careful and continuous teaching by the parents before they can be made to understand that in future they will have to obtain their own food. Birds of this family, [Pg 310] on account of the variable character of their food, are not so markedly migratory as many others, although they generally move further southward in winter, as the supply of insects becomes scarce—their place being taken by birds which have spent the summer in more northerly regions. This habit is very obvious in the case of the fieldfare and redwing, which visit us for the winter and return to Norway and Sweden for the summer. The nightingale, on the other hand, arrives here from the south in April to build its nest and rear its young. 56. THE SWALLOW FAMILY, THE SKYLARK, AND CROWS. 1. The swallow.—(a) General appearance.—Notice, first of all, the bird’s colouration, as this readily distinguishes the swallow from the martins. The whole of the upper surface is steel-blue; the only white is on the ventral surface. A black band stretches across the breast; the throat and forehead are pink. Observe the long, deeply forked tail, and the broad, short bill. (b) Habits.—What are the earliest and latest dates on which you have seen swallows? Do the birds seem to prefer the neighbourhood of water? Have you ever seen them (i) perching on trees, (ii) on the ground? Why do swallows occasionally alight on the ground? Do they seem comfortable on the ground? Observe the small and weak feet; are these adapted to a terrestrial life? Do swallows feed on the ground? What do they eat? How are the insects caught? What is the advantage of the very wide gape? How would you describe the flight of the swallow? (c) Voice.—Does the swallow sing? Describe its voice. Have you heard it when the bird was on the wing, or only when it was at rest? What kind of sound is uttered by the swallow when it is alarmed or angry? (d) Nest.—In what situations have you found swallows’ nests? (Do not confuse the nest with that of the house-martin, which lays white, unspotted eggs.) How soon after their arrival do the birds begin to [Pg 311] build? What is the shape of the nest? Of what materials is it composed? How many eggs does it contain? What is their colour?