406 ZOO-GEOGRAPHICAL NOTES. 



instance. It builds its sleeping nests of brandies and leaves 

 in the highest and strongest trees, and stays in them till late 

 in the morning. 



While it has been thus demonstrated that the boundary-lines 

 of the vegetation coincide for the most part with those of the 

 fauna, it is natural to expect that other facts relating to this 

 subject will be found in our territory. It is known that birds 

 of prey are rare in the proper forest region, and this has been 

 proved to correspond with their distribution towards the south. 

 Except in Uganda, where daily executions supply the neces- 

 saries of life to a considerable number of vultures, the regions 

 to the south of 4 N. lat. are poor in birds of prey, unless they 

 are steppe regions. In Monbuttu, where no cattle are kept, I 

 only saw a single vulture, which, on the bank of the Kibali, 

 was probably pondering over the competition of the population. 

 The commonest bird of prey there is Asturinula monogrammica, 

 Temm., which lives on Fringillidse. Already in Makraka 

 Milvus parasiticus, Forsk., is rare, though elsewhere it is one 

 of the plagues of our country. Where the forest region begins, 

 the carrion vultures, the eagles, Melierax, Poliornis, and others, 

 almost entirely disappear, because their food is only found in 

 open country. 



Were the boundaries between steppe and forest, as well as 

 between their connecting-links, everywhere sharply defined, we 

 should be able to draw direct inferences from the vegetation of 

 a country as to the nature of its fauna. But this is not the 

 case ; on the contrary, the various regions run so much into 

 one another that a real separation is impossible, and hence it 

 happens that in every locality which admits of it we find the 

 inhabitants of two different regions intermingled. Thus Mon- 

 buttu, belonging to the western region, besides harbouring the 

 purely western animals, supplies us with a number of animals 

 that have long been known to us in the East African region. 

 Thus, too, the inhabitants of the south and west push as far 

 north and east as the conditions of climate and sustenance 

 allow them, and the occurrence of such species comparatively 

 far to the north seems to depend only on the possibility of 

 their procuring suitable food, viz., on vegetation, climate, and 

 elevation. But why certain species of animals inhabit a well- 



