THE CUCKOO 



in the act. One was observed to quit a hedge-sparrow's nest with an 

 egg of this species in its beak, for which it had substituted its own. 1 

 Occasionally all are removed except one, the cuckoo's egg itself 

 being nomnfiafli among those ejected, a fact which gives little proof 

 of intelligent discernment" IB ftftittili eiecin the eggs of the victim- 

 ised species are left unremoved. 8 



The ejection by the cuckoo of one or more of its victim's eggs is 

 not the least remarkable of its habits, seeing that the necessity for 

 such a proceeding is by no means evident One could understand it 

 if the bird were in the habit of placing its egg in nests containing a 

 full clutch, for it might then be necessary to make room, but this is 

 not its usual course. Nor can I find any clear evidence to show that 

 if an egg were not removed the nest would be deserted. Again, the 

 removal of the egg would be intelligible if the cuckoo profited by the 

 occasion to eat it, but its habit is to leave it untouched. That it 

 occasionally eats eggs is proved by the discovery of fragments of shell 

 in its stomach, but such finds are rare. In fifteen specimens 

 examined by Mr. Newstead, one only contained fragments of shell, 

 which were recognised as those of a meadow-pipit 4 None were 

 found in the thirty-four examined by Eckstein. 5 The cuckoo found 

 with the remains of at least seven eggs in its stomach, of which 

 two were robin's, must have been a bird of abnormal tastes." 



The cuckoo does not confine itself to depositing its egg in nests 

 which already contain those of the species victimised. Its eggs are 

 found in old and deserted nests, 7 and also in those in which the ^gp 

 of the owner have not yet been laid, and sometimes before the build- 

 ing is completed. 8 There was no egg in the wren's nest in which the 



1 Field, June 0, 1008. 082 (P. Banister). See also Nelson, Bird* of For**., i. 289. 



' J. A. Link, op. dt.. p. 101. ' See p. 470, and note 2. 



Food ofsonte British Bird*, p. 07, No. 430. 



1 Naomann, Vogel Mitteleuropa*, iv. 401, where the stomach content* of the thirty-four 

 specimens are given in detail. * FieM, 1882, liz. M (H. L. Wilson). 



T J. A. Link, op. '/., pp. 100-01. The cuckoo lays also in doterted newt* which contain eggs. 

 An instance is given in British Bird*, i. 320 (J. F. (ireen), of a cuckoo depositing her egg in it 

 li.-.ik--'--p-ni-" - "'-t .-..t.UiM.,',,: ..i.i- w'. "!" I' I'.'i'l l ''-'i '! -! !.-.! I In.-, .-. -k- |.t. \ Insf) 



' Naumaan, Vogel MitUfatropa*. iv. 158 (in the hardly Hnixhed nest of Sylvia locntUlla ; 

 Journal fitr Ornithologir, 1800 (Homeyer) ; J. A. Link. op. cit., p. 153. 



