she was a Cuckoo with a special predilection for Yellow Wagtails' nests, and nothing else would suit her.
Cuckoos would probably be less likely to meddle with Hawfinches' eggs than those of most birds, because the nest of the Hawfinch is very rarely selected by them to lay in. Jays and Jackdaws were more probably the thieves which robbed the thirty-two nests alluded to by Mr. Calvert, assisted perhaps in their depredations by mice, which are very destructive little pests.
Mr. P.N. Emerson, in his 'Birds, Beasts, and Fishes of the Norfolk Broadland' (1895), writes:—"The evidence I have collected from [Norfolk] fenmen and others quite satisfies me that the Cuckoo does suck eggs; and, though I have never caught him, I have found eggs sucked that were whole before the Cuckoo hopped about them.... I have opened several Cuckoos' crops at the beginning of the season, and have upon some occasions found a yellowish substance which looked to me like nothing but egg." With this quotation I leave the much vexed question to those who have better opportunities than I have now of watching this inveterate nest-hunter.
We have had two nests this year with two Cuckoos in each; one belonged to a Pied Wagtail, and the other to a Spotted Flycatcher, but from what I can learn one Cuckoo only was reared in each nest.
