NO. 9 CASQUED HORNBILLS — KILHAM I3 



lined by soldiers, showed where the hornbill had collected earth. On 

 October 27 the male again visited the stump. At 12 130 noon he flew 

 from his nest tree to the maize patch where I was able to observe him 

 from a distance of 25 feet by using a screen of corn stalks. This time 

 he picked up considerable earth from the stump and a little from the 

 ground. Then he flew back to his nest hole, where he spent some time 

 perched on the rim, moving his head about inside where his mate was 

 working. Both birds were silent. So far it appeared that his job was 

 to gather dirt and hers to build with it. However, at 8:20 a.m. on 

 October 31 both birds flew to the forest clearing. She flew to the 

 ground and hopped behind a mud-wattle hut. I moved around to see 

 her bounce up against the wall and knock off a piece of dry mud the 

 size of a plum, which she swallowed. She next hopped around a 

 corner and knocked off another piece. From here she flew up to rejoin 

 her mate. Shortly afterward she followed him to a distant pawpaw 

 tree, where he fed her some fruit. Within 15 minutes they were back 

 at the nest. By 9:10 a.m. the female was working on the nest wall, 

 making a rapid tapping noise like a woodpecker. The male flew away 

 for a short time, apparently to collect dirt. On his return, he perched 

 beside his mate outside the hole, then gave her 11 pellets which she 

 accepted at the tip of her bill and swallowed. She did not use them 

 immediately, for the pair flew away from the nest hole and were gone 

 for a half hour or more. 



These observations showed that female hornbills as well as males 

 collect dirt, although they probably do so less often. The female from 

 nest I did not always use pellets immediately after swallowing them. 

 Dirt might be retained in her gullet for half an hour or more. The 

 same was true of the male. Since earth was generally hard and dry 

 when collected, the period of retention would give it a chance to be- 

 come moistened by glandular secretions and by juices from such fruit 

 as paw-paws retained in the gullet at the same time. A larger part of 

 the moistening may be done by the male. I noticed with my captive 

 hornbills that the male could swallow more than twice as much as the 

 female. He is, of course, a third larger in size. It was of interest that 

 hornbills came to termite nests to gather building material, as these 

 nests are exceedingly durable ; each grain of earth is selected and 

 coated with a cement substance by the termites. I saw the birds from 

 nest I visit a termite nest on another occasion. The pair flew to the 

 edge of the forest clearing at 9 :o8 a.m. on November 7. The female 

 flew to a low tree, then over the shambas to the tall termite mound 

 shown on plate 4, figure i. Clinging to its steep sides, she took up 15 

 chunks of dirt and swallowed them. Finally her mate flew over to 



