70 A NATURALIST IN THE TRANSVAAL. 



the look out, so that the whole level country is thus 

 under constant supervision, and when a bird is seen to 

 descend or to be making off, that act serves as notice of 

 probable quarry for miles around, like the early signal 

 of the beacon-fire flashed from hill to hill. The usual 

 sailing motion of the hovering bird is at once changed 

 for a direct route, and its flight then, as far as I ob- 

 served, was always four or five strong flaps of the huge 

 wings, succeeded by a short straight motionless forward 

 movement caused by the impetus thus obtained, to be 

 followed by another four or five flaps as soon as the 

 former motive power was exhausted. Usually shy, 

 when gorged with food their habits are quite modified 

 and they are easily approached. I once came across 

 more than a hundred settled about two dead oxen. 

 On each carcass were ten or twelve vultures at 

 work, whilst the others in listless and gorged apathy 

 rested around. The naturalist who has skinned a full- 

 grown and full-fed vulture will not easily forget the 

 operation. Now that the vast herds of game which 

 once roamed over the veld are practically exterminated, 

 the vulture becomes more dependent for its provender 

 on the deceased domestic oxen bred by man, and the 

 body of an ox is much preferred to that of a horse. 

 Their food around Pretoria may become scarcer, as a 

 movement was on foot to form a commercial company 

 for gathering up these carcasses to boil down for soap. 

 About the town gardens a bird almost as common as 

 the sparrow in England is the Cape Wagtail (Motacilla 

 capensis), but which by its tameness and partiality for 

 the habitations of man reminded me of our robin, and, 

 like that bird, is as little molested, save by boys, the 

 natural enemies of all birds. Many entomologists have 

 recorded the fact that they have never seen a butterfly 

 attacked by a bird ; but I not only obtained an Arctiid 

 moth (Binna madagascariensis), which I surprised one 

 of these birds in the act of killing, but also saw another 

 actually pursuing a butterfly belonging to the genus 

 Acrcea, which is generally exempt from these attacks. 

 After an interval of some fifteen years Pretoria was 



