Explanation of form and colouring. 227 



I have several times seen Coracias caudatus take up its position on successive 

 low trees close to a grass-fire and thence dash in often successful pursuit o£ 

 the various insects that were flying desperately from the flames ; and I have 

 seen C. garrulus display such dexterity in capturing an active insect on the 

 wing th:it I should not be entirely surprised were future observation to confirm 

 Mr. Bryden's statement (' Nature and Sport in South Africa,' p. 64) that 

 " Rollers are great hawkers of flying insects, especially butterflies." Marshall 

 (Trans. Ent. Soc. 1909, pp. 360 and 369) gives four separate instances, 

 including the quotation from Bryden, of attacks on butterflies by wild 

 individuals of this genus and I shall myself be able to add slightly to these 

 records. Then " Seventeen," my black superintendent, an intelligent native 

 of Inyambane who has been with me for many years, when I asked him the 

 question " Do birds generally feed much on butterflies ? " replied that he was 

 less sure about the others but that rollers at any rate did — greatly. He stated 

 that he had seen instances himself and that it was in any case a matter of 

 common knowledge amongst the natives of his tribe, who acted on the know- 

 ledge to the extent of sometimes baiting their roller-traps with butterflies ; 

 and he gave me the definite and unusually interesting record that I shall include 

 in a later section of this paper — of a roller that day after day frequented 

 the same dead branch for the purpose of attacking therefrom the butterflies 

 passing to and from some fruit close by. Furthermore, my captive rollers 

 showed, I think, no special repugnance to butterflies as against insects of 

 other orders. It may be objected to this that neither did my captive lemur 

 show any great repugnance to porridge-and-milk — which, nevertheless, con- 

 stitutes no proof that he had been in the habit of eating porridge-and-milk in the 

 wild state. True, but it may constitute an indication that he would possibly 

 have eaten porridge-and-milk in the wild state had he met with it and been 

 able to obtain it ; and there can be no reasonable doubt that my rollers had 

 thus met with butterflies and were, moreover, probably quite capable of 

 often capturing on the wdng even such active insects as the larger Charaxes 

 {vide my wild bird records). C, the only roller on whom I suflSciently tested 

 the point, displayed what could only, I thought, be interpreted as a very 

 good previous knowledge of his butterflies, while, to reinforce my reply to 

 the lemur argument, I may add that during two separate periods a wild lemur 

 of the same species as n)y caged one {Galago crassicaiidatus, GeofE.) formed 

 the habit of nightly visiting our verandahs and stealing from the shelves and 

 tables non-indigenous fruits and the cream from my wife's milk-basins. 

 The first visitations were at a time of year when Galago's natural food was 

 especially abundant, and the whole incident (and others 1 could quote) seems 

 to me perhaps somewhat to weaken the possible contention that it was only 

 under conditions of captivity that mj lemur would have shown no repugnance 

 to such food — or my rollers to butterflies. 



On the whole, I feel fairly satisfied that Coracias garrulus was a sufficiently 



