'214: MR. 0. F. M. SWYNNEilTON ON THE 



Suspicion o£ the food offered is another condition during the continuance 

 of: which any results that may be obtained must be duly discounted. Again, 

 judging simply from my own experience, it is likely, I believe, to be due usually 

 to lack oi" tact on the part of the experinaenter. Thus the offering of a number 

 of highly unacceptable insects without a good admixture of more acceptable 

 species to a bird that is just learning to take from the forceps would be a 

 mistake. My baboon afforded an extreme instance of this suspicion, the result, 

 apparently, of my having offered him unacceptable insects hidden in balls 

 of dough, and T have noticed that trickery in any form — such as disguise by 

 the attachment of another insect's wing — tends^ where detected, to produce 

 temporarily a suspicious frame of mind in previously confident birds. Usually 

 I have found such suspicion to be quite transient. It is also, as a rule, readily 

 recognizable and can be allowed for. 



Over-confidence is likely only to take place in an over-petted animal that 

 is continually being offered dainties by hand, and even in it only during the 

 first experiment or two in which any number of unpleasant insects are used. 

 It is, in any case, unlikely to be present in a bird that has already had ample 

 experience of unpleasant insects in the wild state. 



To sum up on these few points : — Fretting, ill-health, restlessness, fear of 

 the experimenter, suspicion of the food offered or over-confidence, are each 

 and all perfectly capable of vitiating the results of any experiment throughout 

 which they are present. This certainly constitutes an exceedingly strong- 

 plea for care in the treatment and selection of the animals to be experimented 

 on, but I am not at all sure that it is any more a valid argument against 

 "captive" experimentation generally than the fact that some charities are 

 undeserving of attention is an argument for refusing to contribute to charities 

 at alb 



Some individual animals are refractory under confinement, or otherwise 

 unsuitable for experiment. These should not be used (or, if they Jiave been 

 used, should not be regarded as necessarily reliable). Others, even though 

 captured when adult, take confinement very placidly, soon become thoroughly 

 friendly with the experimenter, feed well, and keep in excellent health and 

 condition. Birds of this stamp seem to me likely to be useful subjects 

 for experiment in captivity — always subject to the difficulties, yet to be 

 discussed, connected with food and exercise. Amongst others of this kind 

 were my chief European roller (B), my kingfisher, my shrike {L. coUaris), 

 and my drongos. 



4. The food dijfficulty. I have from the very first realized the importance 

 of this and have made it a point that the food should be abundant, varied, and 

 so far as possible natural. One special native always (occasionally two)— 

 chiefly when Diptera or hive-bees were wanted in special quantity, as for 

 the swallows, drongos, and bee-eaters — has done nothing else all his time but 

 catch various insects for the birds. This quite apart from any native (or 



