112 THE ZOOLOGIST. 



outside eggs in under the body, and by the way it seats itself 

 on the nest. It squats at the edge, and then gradually, in a 

 sliding manner, works itself in, until it covers the eggs, dragging 

 in sand during the process, and thus silting up the nest. The 

 Ostrich, being a large, heavy, long-legged bird, when about to 

 squat, bumps with a hard jerk on to its "knees," and then gently 

 lets its body down to the ground. So, when getting on to a nest, 

 it carefully places its feet among the eggs, bumps down with its 

 "knees" outside the nest, clear of the eggs, and then works 

 itself in till the nest is covered. If this method were not pursued 

 the eggs would be broken by the sudden and violent impact with 

 the " knees " as the bird bumped down. 



Now the use of the bank, and the reason for its gradual, con- 

 tinuous formation after sitting begins, are apparent ; the nest is 

 thus kept hollow. Without it the nest would be liable to silt up 

 and the eggs roll away. That this is its use seems to be clearly 

 shown by the fact that the nest, though hollow, is at times 

 slightly raised above the original level. The embankment, lying 

 close to the bird's body, also serves to carry off some of the 

 rain that falls on the bird, as well as to partly prevent running 

 water entering the nest. 



Guarding the Nest. 



The cock is very vicious and pugnacious, and will attack any 

 bird or any person approaching the nest ; at times he will chase 

 and kick at bucks, jackals, porcupines, and other animals. If, 

 however, a person gets right up to the nest, especially if he kneels 

 or sits beside it, the cock seldom kicks, but puts his head down 

 to the ground, snaps his beak spasmodically, hissing violently 

 meanwhile, and tremulously flutters his wings (which click loudly 

 at the largest joint) in impotent excitement and distress. But if 

 one is only a few yards off he will kick and fight most deter- 

 minedly. The reason seems obvious : if he kicks at the nest he 

 will almost certainly break the eggs. 



The hen is not vicious, and does not fight, except when 

 she has chicks ; then the habits of the cock and hen change 

 to some extent ; the cock generally runs away with the chicks 

 (he will fight if necessary), while the hen advances to do battle. 



