SOME NOTES ON THE COLOURATION OF REPTILES 

 AND AMPHIBIANS FOUND NEAR KIMBERLEY, C.P. 



By I. H. Power. 



The colouration of an animal may generall}' be explained 

 in terms of one or more of those well-known principles included 

 under the expressions " warning colouration," " protective re- 

 semblance." " alluring colouration," etc. So far as I can ascer- 

 tain, these ]jrincii)les have been established mainly from studies 

 on insects, birds, and mammals, wdiilst the colouration of rep- 

 tiles, with few exceptions, has been neglected. In this paper 

 I endeavour to offer a rational explanation of the colouration of 

 some of the reptiles found in the neighbourhood of Kimberley. 

 It must be understood that the colouration of a particular reptile 

 may not be fully explained in terms of any one principle, and, 

 indeed, we must be prepared to find several principles illustrated 

 in the same animal. 



The most prevalent type of colouration amongst reptiles is 

 protective, the colours of the animal harmonizing with those of 

 its surroundings. Along with this, or replacing it, we commonly 

 find colours which serve quite an opposite puipose, tending to 

 make the animal conspicuous in its natural surroundings. These 

 may frequently be described as " courtship colours," for they are 

 specially characteristic of adults during the breeding period, and 

 may enable the opposite sexes of a species to recognize each other. 



In his book on the " Colours of Animals," Prof. Poulton 

 says that : 



Courtship colours rarel}- usurp the whole surface of the body ; they in- 

 clude everything that is most beautiful in nature, and are carefully con- 

 cealed when the animal is at rest, while, on the other hand, warning colours 

 can be distinguished l)y the subordination of every other feature to that of 

 conspicuousness. Crude patterns and startling, strongly contrasted 



colours are eminently characteristic of a warning appeanmce. 



One of the commonest lizards of Kimberley, called Ac/ama 

 acitleota, sjiends the winter on the open veld, where it lies in bur- 

 rows, under stones or tins, or in deserted termite heaps. At that 

 season of the year it is i:)rotectively coloured to a high degree. 

 The colours of the dorsal surface harmonize well with the pre- 

 vailing colours of the surroundings, and are modified as those of 

 the environment may change in different localities. On the other 

 hand, in sunnner it Ijecomes arboreal in habit, and is a A-erv con- 

 spicuous, gay-coloured object on the thorn-trees in the neighbour- 

 hood of Kimberley. In the case of the male, the shoulders, sides, 

 and breast become a brick-red, and the throat a deep-blue, border- 

 ing on black, about the beginning of the breeding season. These 

 coknu's diminish somewhat in intensity towards the end of the 

 breeding season, and finally disappear altogether. 



A closely related lizard, Agaiiia afra, is confined to rocky 

 habitats, being found on the kopjes, where it sits on the dark 

 stones. In this species also, the colours of the dorsal surface 



