GREAT SPOTTED CUCKOO (_Oxylophus glandarius_).--A striking rakish form, this stranger from unknown Africa silently appears in Spain during the closing days of February or early in March. On the fifth evening of the latter month, while rambling in the bush on the watch for "some new thing," a hawk-like figure swept by and perched on the outer branches of a thorny acacia. When shot, the bird dropped a yard or so, then clutching a bough with prehensile zygodactylic claws, hung suspended with so desperate a hold that it was with difficulty released. Waiting a few minutes, a harsh resonant scream--_cheer-oh_, thrice repeated--announced the arrival of the male, which fell winged on a patch of bog beyond. Ere we could reach the spot the bird had run back, regained the outer trees, and was climbing a willow-trunk more in the style of parrot than cuckoo. The beak was used for steadying, and so fast did it climb that we had to ascend after it. The beak in this species opens far back, giving a very wide gape--colour inside pink, deepening to dark carmine. We sketched and preserved both specimens, see p. 41 and above. * * * * * As a rule this cuckoo disappears in early autumn, but we have an exceptional record of its occurrence in winter. One was shot at San Lucar de Barraméda, December 19, 1909. This cuckoo, like all its old-world congeners,[70] is parasitic in its domestic _ménage_--that is, it adopts a system of reproduction by proxy--relying, as Canon Tristram long ago put it, on finding a "foundling hospital" for its young. But even the keen intellect quoted was at first at fault. For the great spotted cuckoo differs in one essential point from that "wandering voice" with which we are familiar at home. The latter deposits a single egg in casual nest of titlark, hedge-sparrow, wagtail--in short, of any small bird, regardless of the fact that its own egg may differ conspicuously from those of its selected foster-parent. The spotted cuckoo is more circumspect. Everywhere it restricts the delegated duty to some member of the _Corvidae_,[71] and in Spain exclusively to the magpies. Moreover, whether by accident or evolution, the cuckoo has so admirably adapted the coloration of its own egg to resemble that of its victim, as to deceive even so cute a bird as the magpie. Earlier ornithologists (as above suggested) failed for a moment to distinguish the difference--it was, in fact, the zygodactylic foot of an unhatched embryo that first betrayed the secret (Tristram, _Ibis_, 1859). On close examination the cuckoo's eggs differ in their more elliptic form and granular surface; but, unless previously fore-warned and specially alert, no one would suspect that these were not magpies' eggs, any more than does the magpie itself.