172 On Insects supposed to be distasteful to Birds. 



at once attack Cossus ligniperda, and although it is evidently 

 not relished by them, my blackbird devoured one and thereby 

 made his cage offensive for weeks. There must, I think, be 

 something startling to birds in the violent black and white 

 contrasts in the colouring of the moth which makes them 

 hesitate to touch it. 



The idea that metallic colours are a protection to insects is 

 a mistake ; they are rather the reverse. A bird knows 

 nothing of the nature of metal, but whatever is brilliant and 

 shining he makes for at once, to see whether it is good to eat ; 

 all insectivorous birds, excepting, I think (but Mr. Poulton 

 has my notes and can correct me if I am wrong), the Wryneck, 

 will eat the golden chrysalides of Vanessa urticoe^ and as for 

 those bright metallic moths, the Phisice, they are devoured 

 immediately, as I found quite recently when I turned P. chry- 

 sitis into my outside aviary and the Grey Wagtail seized 

 and tore him to pieces directly he settled. 



As a rule it may be taken for granted that finches, omitting 

 birds with such bunting-like habits as the type of Fringilla 

 and the Waxbills, are very slightly insectivorous, and there- 

 fore are very particular as to what they eat. Thus the 

 Linnet group, including the Canary, will occasionally eat 

 small green caterpillars, the Goldfinch group, including the 

 Siskin, will eat aphides in abundance and probably also green 

 caterpillars; the Chaffinch and Brambling, on the other 

 hand, which more nearly resemble the Buntings in their mode 

 of progression, are both ravenous insect-eaters, quite as much 

 so as the Nonpareil, Indigo Finch, or Weaver-birds. 



Of truly insectivorous birds the Thrushes and their allies 

 the Robins, including the Nightingale, are the least parti- 

 cular, the Missel-Thrush and Blackbird even eating without 

 hesitation the most hairy of hairy caterpillars, merely waiting 

 to rub ofii" the bristles before swallowing them ; the Wryneck, 

 on the other hand, is extremely dainty. 



It therefore appears to me that certain species of Lepido- 

 ptera and of other insects may become abundant in certain 

 years owing to the temporary scarcity of their particular 

 enemies, but that never do they enjoy perfect immunity from 

 destruction. 



Before closing these remarks I wish to disabuse entomolo- 

 gists of the notion that the spider-like appearance of the larva 

 of Stauropus is intended as a protection against birds. If 

 there is one thing that all insectivorous birds love it is a 

 spider ; unless he is at the point of death the sight of a spider 

 will rouse even a sick bird to activity ; the shout of pleasure 

 which a Bulbul gives when you otfer him a spider is alone 



