THE WOOD HOOPOES. 359 



oesophagus and the trachea, aiicl apparently no organ at the entrance to the former that could modify 

 sound. What action, then, can this swallowed air be made to take in the production of the bird's 

 notes 1 Pigeons have strikingly large air-crops, which they empty with each coo, and refill before they 

 coo again. Many birds swell out the throat when calling or singing, and others move it up and down. 

 These actions must also be caused by the swallowed air in the oesophagus, and must modify the sounds 

 in some way, as variously used, adding power and richness in some cases, or giving veiitriloquistic 

 effect in others. This question seems never to have been enquired into before, and I throw out the 

 liint in hopes that others may help to elucidate the matter with their investigations." 



The length of the Common Hoopoe is about one foot ; the upper surface is greyish-brown, the 

 win "8 and shoulders black barred with white, the rump being pure white ; on the head, which is tawny- 

 coloured, is an enormous crest, the feathers of which have a black tip, before which is a narrow white 

 bar ; the tail is black, with a white band at about a third of its length from the end ; underneath the 

 body is pale cinnamon, white on the abdomen and under tail coverts, the flanks striped with brown. 

 The sexes are alike in colour, excepting that the female is a little paler. 



THE WOOD HOOPOES (Irrisor). 



All the birds belonging to this section of the Hoopoes are remarkable for their very long and 

 strongly graduated tails, for their brilliant metallic plumage, which is always dark, and inclining more 

 or less to black instead of a sandy colour, as in the true Hoopoes and most of them for their very 

 curved, scimitar-like bills. They are all natives of Africa, and have a remarkably loud, chattering 

 note ; and from its harsh and resounding voice the Red-billed Wood Hoopoe (7. erythrorhynchus) is 

 known among the Dutch at the Cape as " Cackala," or the " Chatterer." The late M. Jules Verreaux 

 told the writer that the noise made by these birds is tremendous, and that on one occasion he was 

 attracted by an uproar, which seemed to indicate that something unusual was the matter. On pro- 

 ceeding to the place whence the noise came, he was astonished to find on the low branch of a tree three 

 of these birds, perched one on the back of the other, betokening by their drooping wings and repeated 

 chatter-ings the utmost consternation and fright. The cause of this was not far to seek, for just below 

 the birds was a cobra, balancing himself in an erect attitude, and perfectly motionless, the only in- 

 dication of life being the incessant flicking of the animal's tongue. The cacklings of the birds became 

 feebler and feebler, until at last the bottom one fell off the perch and dropped into the extended jaws 

 of the snake, which were ready to receive it ; while the other two birds, apparently freed from the 

 spell of the reptile's eye, took to instant flight. Having his gun in his hand, M. Verreaux shot the 

 snake immediately ; but on going to rescue the bird, found that the latter was qiiite dead. Mr. Thomas 

 Ayres, who has studied the species in Natal, says : "The food of these birds consists almost entirely 

 of a species of cockroach, which they take from the crevices of rough-barked trees, and in search of 

 which they creep about the trunk and branches somewhat similarly to the Woodpeckers. In this 

 manner their tail-feathers frequently become much worn. From four to eight of these birds are 

 generally together, and frequent bushy country. They have a loud chattering note, and are extremely 

 restless in their habits. They have a peculiarly powerful and disagreeable smell." Mr. Andersson's 

 account of the species is as follows : " It lives in small flocks probably consisting of entire families 

 which frequent trees, chiefly of the larger kinds, and examine them most assiduously in search of 

 insects and their larvte, which they extract from crevices in the wood and from beneath the bark. 

 These birds climb like Woodpeckers ; and their long tails come into constant contact with the rough 

 surface of the trees, by which the tail-feathers are much injured. When they have finished their 

 examination of one tree they move to the next convenient one, but not all together, as a short interval 

 generally elapses after the departure of each individual. The moment flight is decided on, they utter 

 harsh discordant cries or chatterings, which are continued until they are all safely lodged in their new 

 quarters. These harsh notes are also heard when they conceive themselves in danger from either man, 

 beast, or bird ; and they thus often betray their presence." 



The present species measures about seventeen inches, the tail being about ten out of that 

 number, and being thus three inches longer than the body of the bird. The colour is black, glossed 

 with green on the head, back, and under surface, with blue on the throat, purple on the wings and tail, 



