i 4 AFRICAN NATURE NOTES CHAP. 



from enemies or for the purpose of mutual recogni- 

 tion by animals of the same species in times of 

 sudden alarm. Sexual selection and the influence 

 of environment must, I think, have been equally 

 potent factors in the evolution of colours in mammals, 

 birds, reptiles, and insects. 



In all recent articles which I have read by well- 

 known naturalists on these subjects, it appears to 

 be assumed that both carnivorous and herbivorous 

 animals trust entirely to their sense of sight, the 

 former to find their prey, and the latter to detect 

 and avoid the approach of their enemies. Yet 

 nothing is more certain than that all carnivorous 

 animals hunt almost entirely by scent, until they 

 have closely approached their quarry, and usually 

 by night, when all the animals on which they prey 

 must look very much alike as far as colour is 

 concerned. 



The wild dogs of Africa and the wolves of 

 northern latitudes are not so completely nocturnal, 

 it is true, as the large Felidae, but the former I 

 know, and the latter I have every reason to believe, 

 hunt, as a rule, by night and only occasionally in the 

 daytime. In both these animals the sense of smell 

 is enormously developed, and must be of far greater 

 use to them in procuring food than the sense of 

 sight, however acute that may be. In all my 

 wanderings I have only seen African wild dogs 

 chasing game in the daytime on four occasions. I 

 once saw a single wild dog chasing a sable antelope 

 in the daytime. This wild dog which was, however, 

 then too far away to enable me to see what it was 

 first ran past the sable antelope and behind it from 

 where I was watching. It must then have been 

 running on the trail, with its nose on the ground, 

 and must have passed quite close to the animal it 

 was pursuing without seeing it. Its nose, however, 

 kept it on the antelope's tracks and soon brought it 



