4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I3I 



servations were all made by myself except in two instances, both of 

 which I was able to check to some extent on a subsequent occasion. 



Captive hornbills. — Field studies have been supplemented with ob- 

 servations on four young captive hornbills, three of which were re- 

 moved from nests when approximately 6 to 7 weeks of age. A male 

 (pi. 2, fig. i) and a female (pi. 2, fig. 2), named "Mpanga" and 

 "Zika" respectively, were both taken from nests and have lived in 

 my house for a year. This paper does not present full observations 

 on these captive birds. It is hoped to make a more complete study 

 over a number of years. 



GENERAL HABITS OF HORNBILLS 



Flight. — Casqued hornbills, with large bills and black and white 

 plumage, were conspicuous birds in the vicinity of Entebbe, especially 

 when they flew over open spaces. They were usually in pairs, the male 

 flying about 20 feet in front of the female. Occasionally she took the 

 lead. Their flight was remarkable. There would be a series of wing- 

 beats, then a glide with head and bill held well up. These glides could 

 be without apparent loss of altitude. If a bird was going downhill, 

 as from our hilltop garden toward the lake, a glide might extend 200 

 or 300 yards. Either phase of flight was noisy. The wingbeats made 

 a "wush, wush" noise and the glide a prolonged "woo-oosh." These 

 noises were helpful, especially in Mpanga Forest, as they enabled me 

 to know, even at some distance, when a male hornbill was returning to 

 his nest. 



Roosting. — There were several opportunities within the Institute 

 Compound for observing roosting habits. From August, when we 

 arrived, until October, a pair of hornbills spent every night in a tree 

 in our garden. They would come in with fair regularity at about 

 6:50 p.m. and sit together for 10 or 15 minutes in the dusk. Then 

 they would separate to roost on individual perches. These perches 

 were at the periphery of the tree where branches were about one 

 inch in diameter. They were about 20 feet apart and 25 feet above 

 the ground. The male always used his own perch and the female 

 hers. In the period of perching together, either one of the two perches 

 might be used. During my first nights at Entebbe, I was mystified by 

 strange noises coming from the tree, not knowing that they came 

 from hornbills. There would be an occasional "woof" or a whacking 

 of bills on bark. By dawn at 6 a.m. noises increased, especially the 

 bill whackings. The hornbills again perched side by side but were 

 in no hurry to leave. They would finally move to other branches of 



