2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I3I 



rapidly and quietly from one nest tree to another. Most of the nest 

 trees I discovered were within a quarter mile of the headquarters 

 clearing. There were undoubtedly more at a greater distance. The 

 forest covers 1.75 square miles and is 2^ miles long. An African 

 ranger and his assistants who lived at the headquarters clearing (pi. i, 

 fig. i) were most helpful in putting up ladders and erecting scaffolds. 

 Life in Mpanga Forest. — A remarkable feature of the tropical 

 forest was that during many hours I saw and heard few living things, 

 whether I was sitting or moving quietly about. Throughout the day, 

 especially in the first part of the nesting season, casqued hornbills were 

 noisy and conspicuous. Other wildlife activity reached a crescendo 

 early in the morning and again late in the afternoon, set off by the 

 screaming of gray parrots (Psittaciis erithaciis) . Great blue turacos 

 (Corythaeola cristata) often came to feed on fruit of the same trees 

 as the casqued hornbills. Their rolling calls were tremendous in vol- 

 ume. On the other hand black-billed turacos {Tauraco schiittii), run- 

 ning squirrel-like along high branches, were quiet and difficult to find. 

 Two other, smaller hornbills {Tockus alboterminatiis and Tockus 

 fasciatus) occasionally came through the forest in small groups. I 

 never saw or heard an owl at Mpanga. Hawks and eagles were not 

 frequent, but they raised a commotion among hornbills whenever they 

 appeared. Most magnificent was the crowned hawk eagle {Stcpha- 

 noaetus coronatus) . The harrier hawk (Polyboroides typiis), some- 

 what vulturine in appearance, would search crevices and holes of dead 

 trees for birds' nests and other prey. Lastly, I encountered the great 

 sparrow hawk (Accipiter melanoleiiciis) for some weeks in the horn- 

 bill area. It made a continual shrill call, "ker-kee-kee." I had a strong 

 suspicion, but could not prove, that this powerful bird sometimes 

 preyed on casqued hornbills. Smaller birds were rather retiring. It 

 usually took some searching to see such birds as the West African 

 nicator (Nicator chloris), the yellowbill {Ceuthmo chares aereiis), 

 and Narina's trogon {Apaloderma narina). Among mammals, troops 

 of redtail monkeys {Cercopitheciis ascanius schmidti) were much in 

 evidence at the extremes of the day. 



METHODS 



Finding nests. — Knowledge of hornbill habits facilitated the finding 

 of nests. The various ways in which 16 nests were located, with the 

 number of nests discovered by each method, may be summarized as 

 follows : Search for the largest tree in an area where hornbills were 

 suspected of nesting (5 nests) ; chance observation of a male at the 



