3o6 HERONS, STORKS, AND IBISES. 



appears to be generally found singly or in pairs. Resembling in many of its 

 general habits the ibises, the hammer-head when passing from lake to lake 

 flies strongly and ascends high into the air ; and is reported to utter a kind of 

 croaking cry. The most interesting feature connected with this singular bird is, 

 however, its nest. This is a huge, dome-like structure of sticks, so firmly built 

 that it will bear the weight of a man, and frequently from a yard and a half to 

 two yards or more in diameter. Generally placed in a fork of a tree near the 

 ground, although sometimes in a rocky cleft, the nest has a single entrance 

 situated on its most concealed side. Internally it contains three chambers — a hall, 

 a drawing-room, and a sleeping apartment, with entrances so small that the bird 

 can only creep in. The sleeping-chamber occupies the highest portion of the nest, 

 in order to be safe from floods, and in it, upon a bed of water-plants, are laid the 

 white eggs, which are from three to five in number and are incubated by each 

 parent in turn. The middle chamber serves for the young when they are too big 

 for the inner one, while the hall is used as a look-out station. In Angola the nests 

 of other birds are said to be taken by the hammer-head. The chief food of these 

 birds appears to consist generally of fish ; but in some districts, at least, river- 

 mussels, frogs, lizards, small snakes, and worms and insects, constitute a portion 

 of the diet. Although the two members of a pair do not always remain together, 

 they appear to be associated for life ; and at times the two birds, or occasionally 

 three, will go through a peculiar kind of dance-like performance. Everywhere 

 these birds are mainly crepuscular, and are but seldom seen in the full daylight. 



The Stork Tribe. 



Family GlCONIIDJE. 



The storks may be distinguished externally from the herons by the absence of 

 pectination on the inner edge of the claw of the third toe, by the metatarsus being 

 covered with reticulate scales, by the absence of powder-down patches on the 

 sides of the rump, and by the feathering on the under surface of the lower 

 mandible not extending in advance of the line of the nostrils. In the skeleton the 

 furcula, which is generally U-shaped, is characterised by the absence of any 

 median projection into its angle. All storks have short triangular tongues, 

 whereas herons (except the boat-bill) have long ones ; and, with the exception of 

 two genera, they are characterised by the rings of the bronchial tubes being 

 complete. There are certain other anatomical features, into the consideration of 

 which it will be unnecessary to enter. As supplemental characters, it may be 

 mentioned that in all the members of the family the body is plump ; the beak in 

 the form of a long compressed cone, with a sharp point, but may be either turned 

 up at the extremity, or gaping in the middle ; the leg is long, strong, and naked 

 for a considerable distance above the ankle ; the toes are short, and the three front 

 ones connected by a short basal web ; the wings large ; and the short and rounded 

 tail with twelve feathers. The contour-feathers of the head and neck may be 

 either narrow and elongated, or short and rounded ; while in some cases they maj' 

 become woolly or hairy, or even, in old age, with horny lance-like tips. The two 



