Occasional J\'otes. 149 



oppoi'tunit}' o£ studying the habits of this beautiful bird. 

 About two years ago, although a pair returned to the old 

 nest, they did not lay there, and it was only last month that 

 I discovered the new nest on a ledge in a krantz about 

 200 ft. in height. It contained two half-grown young ones. 

 I have four eggs in my collection, and in 1912 I sent a tame 

 bird down to the Durban Zoo. It was one of the nicest pets 

 I have ever had. T have seen the Black Stork repeatedly in 

 Basutoland. R. E. Symons." 



Game Lodge, Tabainhlope, 

 P.O. Estcourt, Natal. 



9. To the Editor^ Journal of the S.A.O.U., Pretoria. 



A discussion took place at the April meeting of the 

 B.O.C. on the possibility that eaters of birds' eggs possess 

 preferences. The point is of interest, for the explanation 

 that preference would afford us of much that is now puzzling 

 in the coloration of eggs. 



A detailed account of the subject will appear shortly in 

 the ' Ibis.' I write here, however, in case any of my fellow- 

 members of the S.A.O.U. should have any observations for 

 or against the view, or should come across anything bearing 

 on it during the remainder of the present season. 



Points to be borne in mind are : (1) that in other classes 

 of prey, at any rate, it is apparently relative indigestibility 

 rather than taste that is the basis of preference ; (2) that a 

 hungry enough animal can digest and will readily accept 

 and eat the most indigestible species of prey ; (3) that a 

 recent shortage of a particular class of prey in an animal's 

 diet sometimes produces a temporary special craving, under 

 the influence of which even species that are normally quite 

 low-grade will be accepted and digested as readily as a high- 

 grade species. 



It follows from all this that mere acceptance is no proof 

 that the species of prey accepted is eaten normally to reple- 

 tion-point — is })ractically never refused. Nor is the fact 

 that a particular species of enemy has been known to eat all 

 kinds of eggs a proof that he never refuses any of them. 



