Cassell's book of birds; vol. 3

by Alfred Edmund Brehm

It will be at once evident that in the above account of the habits of the Cuckoo there is a great deal of truth, although much that is surmised is devoid of foundation. The main facts that have been established by trustworthy observation relative to the breeding of the Cuckoo are in themselves sufficiently curious, and have no need of fictitious circumstances to make them interesting. They may be briefly stated as follows:—The female Cuckoo undoubtedly deposits her eggs in the nest of some other bird, not of any particular species, but of several; indeed, upwards of fifty have been enumerated as entitled to the honour of rearing the young Cuckoos. Secondly, it has been observed that the eggs of the Cuckoo differ remarkably from each other; indeed, more so than is the case in any other known species; and, moreover, that a Cuckoo's egg taken from the nest in which it has been placed is found strikingly to resemble the eggs laid by the owner of the nest. Thirdly, the Cuckoo only lays a single egg in the selected spot, and this is invariably deposited in a nest already containing eggs belonging to its proper owner.

The behaviour of the females while thus employed in laying their eggs is peculiar. No sooner do these birds arrive in the early spring than the males begin to make the woods resound with their well-known call, where they are soon joined by their mates, of whose coyness under the circumstances they can have little cause for complaint, and as soon as the female has an egg ready for laying, away she flies in search of a nest in which to deposit her burden. On these expeditions she is not accompanied by the male Cuckoo, with whose company, indeed, she seems by no means desirous of being troubled. Her search after a suitable nest is always made on the wing, and her cleverness in finding the object of her journey, however well it may seem to be hidden from observation, is at least remarkable. Quite contrary to her usual shyness, at such times she will unhesitatingly approach quite close to human habitations, and even enter buildings, such as barns and outhouses. If the shape and situation of the discovered nest is such as to allow her to do so, she places herself upon it and lays an egg, but if such is not the case she lays her egg upon the ground, and then taking it in her beak drops it into the nest. Sometimes it happens that she has considerable difficulty in introducing her egg into the nest, owing to the smallness of the aperture, and occasionally the bird has been captured during her endeavours to overcome the difficulty. Sometimes it has happened that two Cuckoos' eggs, of different colours, have been found in the same nest.

THE CUCKOO (Cuculus canorus).

"It is wonderful to observe," says Bechstein, "what great apparent delight the birds show when they see a female Cuckoo approach their abode. Instead of leaving their eggs, as they do when disturbed by the approach of other animals, they seem quite beside themselves for joy. The little Wren, for example, when brooding over its own eggs, immediately quits its nest on the approach of the Cuckoo, as though to make room to enable her to lay her egg more commodiously. Meanwhile she hops round her with such expressions of delight that her husband at length joins her, and both seem lavish in their thanks for the honour which the great bird confers upon them by selecting their nest for its own use."

Although the above extract sounds very well, with all deference to Herr Bechstein, we are compelled to say that it is unfortunately not true. All the birds that we have seen who have had the very doubtful honour of having a Cuckoo's egg palmed upon them as their own, have seemed to testify in a striking manner their anguish at the threatened occurrence and their unmistakable desire to drive the Cuckoo away. So far from coming as a welcome visitor, the mother Cuckoo comes like a thief in the night; and no sooner has she laid her egg than she hastily takes her departure, as if quite conscious of the unfriendly character of her visit. However this may be, there is no doubt that the foster-parents brood over the Cuckoo's egg with the same assiduity as over their own; and it is only when the eggs of both are hatched that the real character of the intruder begins to show itself, doubtless to the great terror and dismay of the proper owners of the nest.

THE JAY CUCKOO (Coccystes glandarius).

"Two Cuckoos and a Hedge Sparrow," writes Dr. Jenner, "were hatched in the same nest this morning. In a few hours after, a combat began between the Cuckoos for the possession of the nest, which continued undetermined until the next afternoon, when one of them, which was somewhat superior in size, turned out the other, together with the young Hedge Sparrow and an unhatched egg. This contest was very remarkable. The combatants alternately appeared to have the advantage, as each carried the other several times to the top of the nest, and then sank down again, oppressed by the weight of its burden, till at length, after various efforts, the strongest prevailed, and was afterwards brought up by the pair of Hedge Sparrows."

"It is wonderful," continues Dr. Jenner, "to see the extraordinary exertions of the young Cuckoo when it is two or three days old, if a bird be put into the nest with it that is too weighty for it to lift out. In this state it seems ever restless and uneasy; but this disposition for throwing out its companions seems to decline from that time till it is about twelve days old, when, as far as I have seen, it ceases entirely. Indeed, the disposition for throwing out eggs appears to cease a few days sooner, for I have frequently seen the young Cuckoo, after it had been hatched nine or ten days, remove a nestling that had been placed in the nest with it, while it suffered an egg, put there at the same time, to remain unmolested. The singularity of its shape is well adapted to these purposes, for, unlike other newly-hatched birds, its back, from the shoulders downwards, is very broad, with a considerable depression in the middle. This depression seems formed by Nature for the design of giving a more secure lodgment to an egg or a young bird, when the Cuckoo is employed in removing either of them from the nest. When it is twelve days old, this cavity is quite filled up, and then the back assumes the shape of nestling birds in general."