40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I3I 



fashion, the side of the end portion . . . beating against the surface, 

 to which the moist dung is appHed." Ranger has also noted that the 

 cement walls are built up in layers. 



Ranger has been fortunate in having many years in which to study 

 crowned hornbills. If I had had at least a second year to study 

 Bycanistes I should have been specially interested in finding out ( i ) 

 whether these hornbills remain paired from one season to another ; 

 and (2) whether the same pair returns to the same nest tree in suc- 

 ceeding years. Both of these situations, true for the Tockus albotermi- 

 natiis, presumably hold for casqued hornbills. 



Ground hornbills. — I had only casual views of the huge ground 

 hornbills in Karamoja and in Murchison Falls National Park. These 

 form the third main group of hornbills that occur in British East 

 Africa. The following unpublished account of Bucorvus cafer 

 (Schlegel) is contributed by Dr. Friedmann. It is of interest from the 

 point of view of comparative biology. 



This giant hornbill was seen in rather small numbers in the open bushveldt at 

 Taveta, Kenya Colony, during March and April. The birds were usually seen 

 walking around on the ground in loose groups of three to six individuals. They 

 really walk, not hop. In East Africa they are protected as scavengers and 

 are not molested by big-game hunters and settlers. Although they feed on the 

 ground they sleep high up in tall trees and can fly remarkably well for their bulk. 

 The original "take-off" seems to give them some little difficulty, but when once 

 under way they fly more directly than do most hornbills, their heavy wings 

 causing a very audible zvoof woof with every stroke. The call note is a deep 

 boom boovt, a rather hollow, and reverberating note. During the mating season 

 the birds become more vociferous and call to each other with great frequency. 



The natives in Kenya Colony have a story to the effect that the female ground 

 hornbill says, "boom boom, I'm going home; boom, I'm going home" and the 

 male counters with, "yoxi ahvays say that; boom, you ahvays say that; I'm tired 

 of hearing it; go on home; boom boom." It was, therefore, with considerable 

 interest that I learned from Mr. Rudyerd Boulton that the natives in Angola have 

 another interpretation of the calling of these birds. They say that the female 

 says, "boom, boom, I'm going home, I'm going home," while the male replies 

 with, "you must not do that, you must hold up the corn." 



Like all hornbills these birds feed by picking up bits of food with the bill, then 

 tossing it in the air and catching it far down in the bill or even in the open 

 mouth as it descends. 



DISCUSSION OF HORNBILL BIOLOGY 



An early impression at Entebbe was that many of the nonmigratory 

 tropical birds, from hadadas (Hagedashia hagedash) to red-bellied 

 shrikes {Laniarius erythrogaster) , remained paired throughout the 

 year. Casqued hornbills were usually encountered in pairs. They 

 are presumably mated for life and one would like to know when pair 



