6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I3I 



fruit and again she refused to take it. She finally touched the "cherry" 

 with her bill. The male then swallowed the fruit for the fourth and 

 last time. Although this "cherry" presentation was observed on six 

 evenings between September 25 and October 5, she accepted only 

 once. On other evenings the ceremony climaxed in a touching of 

 bills. There was never more than a single fruit involved. 



Presentation of a piece of bark, a stick, or a leaf was commonly 

 observed during the nesting period. It was almost always the male 

 who did the offering. On one day, November 20, I observed the re- 

 verse process. A male perched in Mpanga Forest was joined by his 

 mate who held a large winged insect in her bill. She gave it to him. 

 He then gave it back and she swallowed it. Possibly she simply liked 

 to have things handed over, even if she had to provide the objects 

 herself. 



Mutual preening was another late evening activity of the two horn- 

 bills in our garden. On September 15, the female sidled up to the male 

 on his perch. Preening now went on for 20 minutes. The male nibbled 

 at the feathers of his mate's head and neck. She appeared to enjoy 

 this attention. Her head moved slowly backward until the occiput 

 rested on her back and her bill pointed upward. The male meanwhile 

 kept nibbling at her exposed throat. Later it was his turn and she 

 went over the feathers of his head and neck. He did not put his head 

 way back as she had. I seldom saw males do this, once being on 

 March 7 in the Botanical Gardens. A pair of hornbills were together 

 for the first time in 4 months. The recently emerged female, in soiled 

 plumage, was perched close to her mate as she nibbled at the feathers 

 of his exposed throat. Mpanga and Zika, my captive hornbills, were 

 preening each other at 3 months of age. Zika has always enjoyed hav- 

 ing her throat tickled gently. Even when sitting in my lap, her head 

 has gone way back in the manner of the wild bird which roosted in 

 our garden. Mpanga has often invited preening. He does this by 

 turning the back of his head to Zika, then ruffling up the feathers. 

 In going over each other's feathers, hornbills take special delight in 

 finding small bits of horny material. They may stop to toss these 

 about, small as they are. 



Playing zvitJi sticks and bill zvhacking. — Bill whacking was pre- 

 dominantly a male activity. It was usually done after a male had fed 

 his mate on the nest, but might take place on waking up at dawn or 

 most any time of day. The huge bill would resound like a castanet 

 as it was whacked from side to side on a limb. Females scrape their 

 bills on a perch after feeding. 



A favorite occupation of resting male hornbills was to toss a stick 



