440 



FAMILY BUCERIDJE, OR HORNBILLS. 



between which are filled with air. All the bones of these 



remarkable Birds are more per- 

 meated by air than are those of 

 any other known species ; even 

 the phalanges of the toes being 

 penetrated by it. The Hornbills 

 are confined to the warm parts 

 of Asia and Africa. In their 

 general habits, they seem to bear 

 a considerable resemblance to the 

 Crows ; their flight is sailing, 

 like that of the Corvidae; and 

 on the ground they advance by a 

 sort of leaping action, in which 

 they are assisted by the wings. 

 The larger species are very shy 

 and difficult of approach ; and 

 they perch on the branches of 

 lofty trees, where their vision can 

 command a wide range. They 

 are omnivorous in their diet; chasing mice, small birds, and 

 reptiles ; not disdaining carrion ; and resorting to soft vegetable 

 matter when no other is to be had. Like the Toucans, which 

 resemble them in the enormous size of the bill (Fig. 265), they 

 swallow their food whole, throwing it up into the air, and catch- 

 ing it as it falls. They breed in the hollows of decayed trees. 



FIG. 240. HORNBFLL. 



TRIBE II. DENTIROSTRES. 



398. In this division of the order, the upper mandible has a 

 notch on either side of the tip, like that of the Noble Birds of 

 Prey ; and the diet is almost or completely restricted to animal 

 food, these Birds being chiefly supported upon insects, worms, 

 c., but the larger of them feeding also upon small birds, 

 reptiles, &c. The notch is not always deep, and is sometimes 

 altogether wanting ; in that case the place of the Bird is known 



