284 MIMICRY AND NATURAL SELECTION 



clean off; unfortunately I had no net and failed to capture 

 the insect. 



Swynnerton shot a hobby (Falco subbuteo), which had 

 in its stomach an almost complete Terias. The thorax 

 and abdomen were quite uninjured, but the tips of the 

 fore-wings were gone. 



April 26. I was watching a drongo hawking insects 

 from the top of a dead tree ; there were many Pierinae 

 about, chiefly Teracolus and Belenois, but the bird paid 

 not the least attention to them. At last a Belenois came 

 by which had its wings very much shattered, so that its 

 flight was weak and erratic ; the drongo observed it at 

 once, and swooped down on it, but I saw the butterfly 

 drop into the long grass. Whether it was injured by the 

 bird I could not say, as I was unable to find it, and I did 

 not see it rise again. This episode would point to the 

 conclusion that the fact that birds refrain from pursuing 

 butterflies may be due rather to the difficulty in catching 

 them, than to any widespread distastefulness on the part 

 of these insects. 



1900. C. F- M. Swynnerton wrote from Gazaland: 

 ' In March [1900] I saw a Pratincola torquata [South 

 African stonechat] in chase of Tarucus plinius. Had it 

 not been frightened off by coming face to face with me, 

 it would undoubtedly have caught it. I think I told you 

 long ago of having found the wings of a lot of butterflies, 

 chiefly P. corinneus, below the branch of a tree on which 

 some swallows were constantly settling.' 



May 13. Salisbury. Saw a drongo {Buchanga assi- 

 milis) swoop from a tree and catch what I took to be 

 an injured Belenois, which it dropped almost at once, 

 I marked the insect down, and found it to be a common 

 white moth of the distasteful genus Diacrisia {D. macu- 

 losa). 



1901. December 17. Melsetter, 5,500 feet, Gazaland. 

 A specimen of the large, conspicuous Hypsid moth Calho- 

 ralis bellatrix was seized and rejected by a drongo, 

 undoubtedly a young bird, judging by its plumage. [The 

 moth, which is now in the Hope Department, has lost 

 most of the head, but is otherwise uninjured. — E. B. P.] 



