294? Habits of the Cuckoo. 



and others in VIII. 285. 287., in which the wagtail had not 

 discarded one of its own eggs to make room for that of the 

 cuckoo. From a remark by our ornithological correspondent, 

 Mr. Hoy, in V. 278., it appears to be usual for the birds in 

 whose nests the cuckoo may have deposited an egg, before they 

 themselves have begun to lay, to cast out the cuckoo's egg. 



Another view remains open : the parent cuckoo may itself 

 sometimes reduce the number of the eggs of the bird to whose 

 eggs it deposits its own. This suggestion seems to be but 

 reviving a notion which is, it appears, deemed not true. In 

 Rennie's Mont. Orn. Diet., p. 117., will he found the reasons 

 which had convinced Montagu " that the eggs of the foster- 

 parent could not be destroyed by the old cuckoo." The fol- 

 lowing fact, communicated by Mr. Hoy, in V. 278., tends to 

 an opposite conclusion : — "I once observed a cuckoo enter 

 a wagtail's nest, which I had noticed a short time before to 

 contain one egg : in a few minutes the cuckoo crept from the 

 hole, and was flying away with something in its beak, which 

 proved to be the egg of the wagtail, which it dropped on my 

 firing a gun at it. On examining the nest, the cuckoo had 

 only made an exchange, leaving its own for the one taken." 

 Mr. Hoy's known skill in ornithology makes this fact one of 

 real value. Mr. J. D. Salmon, another correspondent skilled 

 in ornithology, has alluded, in V. 675., to the cuckoo's de- 

 stroying the eggs of the pied wagtail as a matter known to him. 

 If it destroy those of the pied wagtail, it will, doubtless, destroy 

 those of any species of bird in whose nest it may lay its own 

 eggs. Mr. Mudie, in his British Naturalist, has, as appears 

 by an extract in our V. 63., spoken of the cuckoo's making " a 

 meal of the eggs" of the bird whose nest it may appropriate. 

 The context shows, however, that he has not any practical 

 ground for this notion : but still it shows that the notion has 

 been extant ; and we remember a couplet, which was in use 

 with our schoolfellows, which expresses a similar idea. The 

 evidence of schoolboys on the distinctions of the species of 

 eggs of birds might be admitted ; but, on a disputed point in 

 economy, like the present, is not of avail, farther than to show 

 that such an imputation on the cuckoo has prevailed. 



We may next consider the hatched young cuckoo in the 

 course of being sustained by the foster-parent of it. 



Birds will frequently breed up the young of another species 

 exchanged for its own, provided they are of the same age, 

 and not very large, when the experiment is made. (Montagu, 

 in Rennie's Mont. Orn. Diet., 161.) The conditions stipu- 

 lated show that the substituted young are not committed to 

 the elective affection of the foster-parent, but imposed upon 



