340 EASTERN ETHIOPIA xxvm 



The Ibis is generally found along the shores of lakes 

 and rivers, hunting for shell-fish, worms, and crabs : it 

 also frequents mud-banks, probing the mud with its 

 long bill. In Lower Egypt the shape of the beak has 

 won for this bird the name of " Father of a Sickle." It 

 is common around the margins of lakes and the banks 

 of the Nile in the Equatorial Provinces. (See p. 178.) 



Horn bills are abundant in Uganda and in the Man 

 forests, and are sure to attract attention from the most 

 casual observers, for they are big birds with great beaks 

 of curious shape, fly in a clumsy manner, and make 

 a great noise in the forest. The natives do not eat 

 these birds and as their black and white plumage is 

 not attractive, hornbills are common and force them- 

 selves on the attention of travellers. In spite of the 

 size of the beak the hornbill shows great dexterity in 

 using it, for almost every morsel of food it picks up 

 is tossed in the air, caught, and swallowed. The neat- 

 ness with which these birds can catch with the beak 

 may be tested any day at the Zoological Gardens, and 

 the birds often hold a grape in their beak by means 

 of its thin stalk. In the wild state hornbills live 

 on fruit, flowers, berries, insects, eggs, and probably 

 many other things. 



As if to atone for the heavy and apparently clumsy 

 structure of hornbills, Nature seems to have done her 

 best to make amends by lightening the heavy beak, for 

 she has filled it with air-cells. It is well-known that, in 

 birds, the air-cells of the lungs communicate with 

 cavities in some of the bones ; such bones are said to be 

 pneumatic ; in the hornbills more bones are filled with 

 air than is comiron in birds ; air also permeates the 

 muscular interspaces and the subcutaneous tissues. 

 These birds are devoid of fat beneath their skins. In 

 many birds there is a curious gland near the root of 

 the tail, known as the oil-gland. When birds preen 

 themselves they are supposed to dip their beaks into 

 this natural pomatum pot and rub it over their feathers. 



