IJinh in Relation to their Prey. 57 



to 00 on eating any insect, however unpleasant, with a pause 

 between (it may be) every two or three or more, provided 

 no pleasanter food is forthcoming to carry the satisfaction 

 of his hunger well beyond the point at which the unpleasant 

 insect in question is normally refused. Actually these 

 Yellow-billed Hornbills did, on several occasions, if one 

 might judge by their discomfited manner, carry their eating 

 of nauseons insects beyond safety-point ; but this was only 

 to be expected in the case of just-fledged birds deprived of 

 parental guidance. And in any case they probably never 

 ate them to at all near real repletion-point. The key to a 

 proper understanding of all these experiments on L. leucom&Ias 

 is provided by experiment 541 on L. melanolennis (below). 



520. Feb. 16. — Two fully-fledged nestlings now able to 

 fly and picking up food for themselves. I have had them a 

 few days. I offered the extraordinarily conspicuous gre- 

 garious larva of (probably) a (Cuspidate moth. Brilliant 

 red-black-and-white, with a pungent smell and two yellow 

 filaments, which are waved when the larva is alarmed or 

 annoyed, and are brought over — with a strong increase in 

 smell — to touch the aggressor when the larva is seized, it 

 had been offered to my Kingfisher {Halcyon cyanolencus) and 

 been treated by him as he only treats the vilest of objects. 

 He had, on trying it, dashed it violently to the other side of 

 the cage and remained for long afterwards "shaking his 

 head, clapping his bill, rubbing the latter against the j)erch, 

 and showing generally greater signs of disgust than I had 

 ever previously seen him exhibit.'^ 



Lophoceros B pulled at the larva, and would have eaten it 

 had I allowed her. I then let A pull at it well and, finally, 

 swallow it. I offered a second larva immediately afterwards, 

 and he tugged at it greedily, and would have eaten it too (as 

 would B) had I allowed. 



I let ten minutes elapse for after-effects. Then I again 

 offered A the second larva. His manner had quite changed. 

 He rejected it with absolute fury, raising his crest and 

 hissing at me every time the larva was produced, and draw- 

 ing back from it, still angry and hissing, when I pressed it 



