2 2 Barrett, Cuckoo Notes. [ist^jHiy 



kept under close observation, and at length had our patience 

 rewarded, for on visiting the nest one morning we beheld a blind 

 and naked nestling, easily recognized by its larger size as the 

 Cuckoo, in the act of ejecting one of its foster-brothers from the 

 nest ; the other unfortunate young Wren already lay dying on the 

 ground beneath. The Cuckoo we judged to be about 30 hours old, 

 while the young Wrens had probably been hatched a few hours 

 earlier. We were able to secure a good picture of the young 

 murderer at work, because on one of the Wrens being replaced 

 in the nest, the Cuckoo at once proceeded to throw it out again, 

 with the result that, during the two hours of our watching, he 

 accomplished this feat no less than six times. Struggling despera- 

 ately until it succeeded in getting the feebly resisting Wren into 

 the hollow of its back, and balancing it there with extended embryo 

 wings, the young Cuckoo, with head bowed between its strong legs, 

 which, with claws firmly fixed in the sides, were straddled across 

 the nest, worked its way gradually to the entrance, and on this 

 being reached, suddenly raised the head and with a sharp upward 

 lift of the body pushed the unfortunate nestling over the edge. 

 His work accomplished, the young usurper gave a final shrug of the 

 body, as if to make certain his burden was gone, and subsided 

 exhausted to the bottom of the nest. It has been suggested [Emu, 

 vol. iv., page 172) that the chief factor which operates on the young 

 Cuckoo, and causes it to throw out its foster-brethren, is probably 

 involuntary muscular action, incident on local irritation of the 

 nerves of the skin when in contact with a naked nestling. I 

 scarcely think the facts warrant us in accepting this theory without 

 some reservation, for, if it has m.uch in its favour, it still leaves 

 unexplained a most important point — viz., thereason why a distinct 

 hollow should be present in the back of a Cuckoo during the nestling 

 period, and disappear in the adult bird, if not specially adapted 

 by natural selection for the function it so admirably performs. 

 Again, no one who has not actually witnessed the scene can realize 

 the deliberate and apparently reasoning manner in which a young 

 Cuckoo commits his crimes. 



Cuckoo nestlings are very voracious. I have often watched them 

 being fed, and found it no uncommon thing for the devoted little 

 foster-parents to make over thirty visits within an hour to the 

 nest with food for their charge. The menu is varied, but the larvae 

 of lepidopterous insects form an important item, as far as my 

 observations go. The young bird develops rapidly on this diet, 

 and the nest soon becoming too small for his increasing girth, 

 expands to nearly twice its original size, and even then is filled 

 to bursting point. The Cuckoo is fed by the foster-parents long 

 after it has quitted the nest, in the vicinity of which it remains for 

 some time, its plaintive cry for food being always responded to 

 by its anxious guardians. While in the nest the Cuckoo displays a 

 viciousness in keeping with its general character, for if one's finger 

 be placed within reach it will be fiercely pecked until withdrawn. 



The list of foster-})arents for our Cuckoos is a long one, but in 



