The Cuckoo (Cuculus canorns), Fig. 47, belongs to the family Cuculidae (Cuckoo kind) and sub-family Cuculinae. It is characterized by a bill of moderate size, short tarsi, and tail composed of ten feathers, bill compressed and slightly arched. The plumage is not attractive, the colour being shades of slatey-grey and brown with darker markings, white spots on the tail feathers, the under-parts whitish with brown markings. It arrives in this country during the last fortnight of April, and the male arriving first pours forth from a bare bough its monotonous song - cuckoo !

The Cuckoo and Gooseberry Caterpillar.

Fig. 47. - The Cuckoo and Gooseberry Caterpillar.

The Cuckoo is especially distinguished by the habit of the female in placing her eggs solitary in the nests of birds, always much smaller than itself, such as that of the Hedge-sparrow, Meadow-pipit or Titlark and Tree-pipit. The eggs of the Cuckoo are extremely small, varying in weight from 43 to 55 grains, and the colour is extremely variable. Some, both in ground and pencilling, very much resemble the house-sparrow's; some are distinctly covered with bran-coloured spots, and others are marked with lines of black. The egg is laid on the ground and, taken in the mouth, placed by the cuckoo in the nest of the foster-parent, usually the hedge-sparrow's, incubation not taking place before the middle of May. A fortnight is taken up by the sitting bird in hatching the egg, and soon afterwards the nest is found to contain only the young cuckoo, which continues therein (or rather on) for three weeks, and if disturbed at the latter part of that time sets up its feathers, such as they are, after the manner of a peacock and makes a sort of hissing in order to disconcert the intruder. When the foster-parent appears with a caterpillar the young cuckoo opens its mouth wide, displaying its red throat and fluttering its feathers in joy for the repast.

After leaving the nest the young cuckoo loiters about the place of its incubation and is fed by the foster-parents for a monthor more, and then, full feathered, provides for itself, anon taking its departure, and after the old cuckoos, never acquiring the cuckoo note before departing, but utters a sort of screech now and again in its flight. The parent cuckoos feed entirely upon insects, taking many larvae, such as wire-worms and leather-jackets from the ground on their first arrival, caterpillars not being sufficiently ample for their dietary; but when these, especially the hairy caterpillars, are abundant, they feed almost exclusively upon them, and are particularly fond of those infesting gooseberry-bushes, the cuckoos visiting gardens and clearing the bushes of the leaf-devouring pests. The old cuckoos, about 14 in. in length, depart from Britain early in July, though possibly some, "cuckoo-noteless," remain to pilot the young cuckoos over the "silver streak."