CUCKOO. 



191 



herself) insectivorous ; and it is one of the most curi- 

 ous facts in natural history, that many of the smaller 

 finches, which never themselves touch any sort of in- 

 sect food, and even bring up their own young exclu- 

 sively upon softened vegetable food ejected from their 

 own craws, will, notwithstanding, rear np the young 

 cuckoo upon caterpillars and othe.r insects. A case is 

 mentioned in the " Magazine of Natural History," o'f 

 a young cuckoo being brought up by a pair of com- 

 mon linnets ; and another, in which a pair of green 

 grosbeaks were the foster parents. In the " Field 

 Naturalist's Magazine," also, for January, 1834, the 

 following highly interesting fact, bearing on this sub- 

 ject, is recorded. "A cuckoo was foundjust feathered, 

 in the nest of a hedge-chanter. It was immediately 

 taken from thence, and placed in a cage containing a 

 hen canary. The birds agreed perfectly well ; but 

 what is most singular, when the proper food for the 

 cuckoo (small caterpillars, &c.) was placed in the cauv, 

 the canary fed its young charge with that, although 

 she herself kept to the hempseed, &c., to which she 

 had been accustomed." It would appear, however, 

 from the results of a great number of experiments 

 which the writer of this has instituted upon this sub- 

 iect, and in which, from the great difficulty of procur- 

 ing a number of cuckoo's eggs, those of the skylark 

 were cruelly employed, as being both in colour and 

 size somewhat similar to them, that an alien egg, sur- 

 reptitiously introduced into a nest, is very frequently 

 ejected from it. by the rightful owners. The writer of 

 this has tried this experiment upon a very great num- 

 ber of species ; has placed the alien egg along with 

 other eggs, has taken the latter away and substituted 

 it singly in their place, and has placed it in many 

 newly-finished nests, before any other eggs had been 

 deposited in them, and he has continually observed 

 the same result. He thinks, therefore, he may fairly 

 conclude that the cuckoo's egg also is very frequently 

 turned out by the birds into whose nests it is depo- 

 sited. He can only thus account for the excessive 

 rarity of its occurrence, although the birds are every- 

 where seen abundantly, and though he has counted 

 upwards of fifty eggs, of different sizes, in the ovarium 

 of a single cuckoo. 



It is indeed stated oy Mr. Hoy of Norfolk, a gentle- 

 man well known to naturalists as a most accurate and 

 clo?..' observer, that " it appears to be usual for the 

 birJs, in whose nests the cuckoo may have deposited 

 a't egg before they may themselves have begun to 

 'ay, to cast out the cuckoo's egg;" and as that gentle- 

 man has bestowed particular attention upon the 

 phenomena of this interesting bird, he has doubtless 

 observed some instances to warrant this remark. He 

 mentions, however, one case in which the contrary 

 was observed. " On one occasion," he says, " I had 

 observed a cuckoo during several days anxiously 

 watching a pair of wagtails building ; I saw the 

 cuckoo fly from the nest two or three times before it 

 was half completed ; and at last the labour of the 

 wagtails not going on, I imagine, so rapidly as might 

 be wished, the cuekoo deposited its egg before the 

 lining of the nest was finished. The egg, contrary to 

 my expectation, was not thrown out ; and on the 

 following day the wagtail commenced laying, and as 

 usual the intruder was hatched at the same time with 

 the rest, and soon had the whole nest to itself." This 

 instance seems to favour the opinion that the cuckoo 

 possesses the power of retaining her egg in the oviduct 

 considerably longer than is the case with birds in gene- 



ral ; and it is possible, as has been suggested to the 

 writer of this article by a distinguished physiologist, that 

 the nervous excitement of the bird, whilst wanting to 

 lay, may have the effect of preventing the immediate 

 development of the egg next in succession. There is 

 not the slightest reason, however, to suppose with 

 some that the egg is ever quickened in the oviduct by 

 the heat of the parent bird ; for were such ever the 

 case, it would of course be necessary that it should 

 be deposited in a nest upon which the owner hud 

 begun to sit, which the cuckoo of course would be 

 unable to do, as she never drives a bird off its nest, 

 but sneaks into it during its absence. It is hardly 

 necessary perhaps here to remark, that after the vital 

 action within an egg has once commenced, a very 

 short suspension of the necessary degree of warmth is 

 sufficient to destroy the embryo. No instance, how- 

 ever, has been yet recorded of the cuckoo's egg having 

 been found addled. 



The common cuckoo's egg has been known to 

 occur in the nests of the following British species, 

 viz., the blackbird, songthrush, skylark, green grosbeak, 

 linnet, chaffinch, hedge-chanter, different pipits and 

 wagtails, yellow and reed bunting, redstart, robin, 

 reed warbler, hedge warbler, and grasshopper warbler; 

 but in at least nine cases out of ten, it is found either 

 in those of the common or the shore pipit (Anthus 

 pratensis and A. obscurus), or in that of the pied water- 

 wagtail (Motacilla domcstica, M. alba of Linnaeus), 

 and somewhat less frequently in that of the hedge- 

 chanter (Accentor modularis); the chief reason of 

 which, in the opinion of the writer of this, is that 

 these birds are not so much in the habit of turning 

 out an alien egg as the others are ; he has known, 

 however, the hedge-chanter to eject a lark's egg that 

 was placed along with its own, and also to eject 

 another which was placed alone in the nest, its own 

 eggs having been taken away. Some birds, as the 

 blackcap, most usually forsake a nest into which the 

 egg of another species had been introduced. Others 

 will turn out the alien egg, and even then desert their 

 nest. 



Nothing is more certain than that the number of 

 cuckoos' eggs that are found is out of all proportion 

 small, considering the number of birds that are heard 

 and seen. Unlike all other birds also, the number of 

 young cuckoos that are ever seen in autumn is very 

 considerably smaller than that of the old ones ; 

 although, from their being very much buffetted and 

 persecuted by swallows and many other small birds, 

 they are little likely to escape observation. It is, 

 therefore, very difficult to conceive how the species is 

 continued so abundantly ; perhaps they live a great 

 number of years, but the following fact seems hardly 

 to warrant this supposition, that there is not, when 

 they arrive in spring, the same proportion of indivi- 

 duals of the preceding year that we find in other birds. 

 The writer has noticed that the greater number of 

 cuckoos, which he has examined in spring, were birds 

 of the preceding season, these always having a rem- 

 nant of the immature plumage upon the wings, two 

 or three of the quill-leathers, and of the greater 

 coverts impending over them, not having been shed ; 

 but it is possible that these are more frequently shot, 

 from their being less suspicious and vigilant than the 

 old birds. 



We do not think it very probable that, as some 

 persons have imagined, the cuckoo's egg is ever suf- 

 fered to perish, from the bird not having been success- 



