370 Mr. A. L. Butler on the 



but that night the mosquitoes made skinning an impossibility 

 and I did not preserve it. I think, from memory, that it 

 belonged to this species. 



216. Circus macrurus (Gin.). 



a. S ad. Khartoum, Oct. 28, 1902. 



b. $ jr. „ Oct. 29, 1902. 



The Pale Harrier is common in the winter and spring, 

 keeping mostly to the neighbourhood of the rivers. I have 

 repeatedly seen it capture the Wagtails which swarm on 

 the White Nile. Its modus operandi is to glide low and 

 swiftly along the banks with the frightened Wagtails dashing 

 up underneath it, until some bewildered bird flutters almost 

 into its claws. 



217. Circus .^ruginosus (Linn.). 

 a. ?. Khartoum, Feb. 1903. 



The Marsh- Harrier is a common cold-weather visitor. At 

 Khartoum, just at suuset, the birds come in from the White 

 Nile in steady succession to roost in the bean-crops. At 

 that hour I have frequently seen twenty-five or thirty in a 

 few minutes. 



218. Serpentarius secretarius (Scop.). 



1 have never come across the Secretary-Bird myself. This 

 is lather curious, as, though scarce, it seems to be widely 

 distributed. I have had it brought to me alive from the 

 White Nile and from Kordofan, and 1 know that it occurs 

 in the Kassala district. 



219. Vultur monachus Linn. 



The Black Vulture is most ofte~ seen in the northern 

 parts of the Soudan. It seems to be much less numerous 

 than the two following species. 



220. Otogyps auricularis (Daud.). 



The Sociable Vulture is common, but less so than the 

 next species. It also seems to be a more shy bird. 



221. Gyps rueppelli (Brehm). 



This seems to be the commonest large Vulture in the 

 country. 



