388 



COLUMB.I 



-BIRDS. COLUMBID.E. 



believed that when the birds found it impossible to get 

 access to the combs by their own exertions, they would 

 set off in search of human aid, and guide their allies to 

 the hive by flying before them from bush to bush. The 

 Hottentots are said always to leave a portion of comb 

 for the Honey Guides when they have been led by 

 them to the discovery of a hive. A peculiar mammal, 

 the Katel, which is as partial to honey and the other 

 contents of the hive as the Honey Guides themselves, 

 also avails himself of the instinct of these birds, and 

 is often conducted to a rich banquet by their cries. 

 The Honey Guides fly heavily, and only for short dis- 

 tances, but they run upon the trunks and branches of 

 trees with great agility in the manner of the Wood- 



peckers, to which Mr. Blyth considers them as more 

 nearly allied than to the Cuckoos. Their mode of 

 breeding has long been a matter of dispute some 

 ornithologists asserting that they deposit their eggs in 

 holes of trees, and others that they form a pensile nest ; 

 but, from the observations of M. Verreaux, it would 

 appear that they have the parasitic habits of the common 

 Cuckoo, introducing their eggs sometimes into the nests 

 of Woodpeckers, and sometimes into those of Orioles, 

 which would account for the discrepancy in the state- 

 ments above alluded to. The species are principally 

 found in Africa, and indeed in the southern parts of 

 that continent, but one or two occur in the forests of 

 India, and in the island of Borneo. 



OEDER IV. COLUMB^E. 



THE Order of the Columbse or Pigeons stands as it were 

 in an intermediate position between the Passerine birds 

 and the Gallinse, between the two sections of Inses- 

 sores and Autophagsc, into which, as already stated 

 (p. 235), the class of birds has been divided. With the 

 former they agree in their niditication and in the help- 

 lessness of their young, which remain in the nest for a 

 considerable time, and require to be carefully tended 

 and fed by the parent birds ; whilst they approach the 

 latter to a considerable extent in their structure. In- 

 deed, by some ornithologists the Columbae are amal- 

 gamated with the gallinaceous birds to form a single 

 order. There is, however, one important peculiarity 

 which seems to distinguish the Pigeons from all birds ; 

 the walls of that dilatation of the oesophagus which 

 usually goes by the name of the crop, are furnished 

 with a number of glands, from which during the breeding 

 season a milky juice exudes ; this mingles with the 

 food in the crop, soaks into it and softens it, so that, as 

 the young birds are fed with substances regurgitated 

 from the crops of their parents, they may be regarded 

 as partially nourished by a secretion produced by the 

 latter, just as the young Mammals are supported upon 

 their mother's milk. 



The principal distinctive character of the Columbae 

 is furnished by the structure of the bill. The upper 

 mandible consists of a horny apical portion, which is 

 often of considerable length and strength, but its base 

 is formed by a convex cartilaginous plate, in the ante- 

 rior portion of which the nostrils are situated. The 

 skin covering the cartilaginous portion of the bill is of 

 a soft texture, very different from that of the rest of the 

 bill ; it is sometimes smooth and clothed with a sort of 

 scurf, but in other cases it is warty, or even developed 

 into a fleshy wattle. This is especially the case in 

 some domesticated varieties of the pigeon. 



The Columbae are provided with short tarsi and 

 moderately long toes, all scutellated. The toes are four 

 in number, three in front and one behind ; the anterior 

 toes are not united by a membrane at their base ; the 

 hinder toe is placed in the same plane as the anterior 

 toes, and the whole sole of the foot is formed by soft 

 papillated pads, which are usually a good deal wider 

 than the scutellated upper portion of the toes. The 



wings, which are generally long and pointed, contain 

 ten primary quills, and the tail usually consists of 

 twelve feathers, although in some cases there are six- 

 teen. An important distinctive character of the birds 

 of this order as compared with the Gallinse, is to be 

 found in the fact that their feathers are destitute of the 

 plumules or accessory plumes (p. 232), which are greatly 

 developed in the gallinaceous birds. 



The form of the wings in the Pigeons is sufficient to 

 indicate that they are birds of rapid and powerful flight, 

 and many of them are remarkable for the speed with 

 which they traverse the air, especially when engaged 

 in those migrations which some species perform; Most 

 of them are arboreal in their habits, and nestle in the 

 holes of trees ; others frequent rocks ; but all perch 

 with great facility, although they generally seek their 

 food upon the ground, and walk or run with consider- 

 able ease. They are also remarkable in their mode of 

 drinking, in which they differ from all other known 

 birds. The general practice of birds in drinking is, as 

 is well-known, to take up a small portion of water in 

 the bill, and then, by raising the head, to allow it to 

 flow down into the throat ; the Pigeons, on the con- 

 trary, dip their bills into the water and hold them there 

 until they have quenched their thirst. 



In Mr. Gray's arrangement the Pigeons form only a 

 single family, that of the Columbidse ; and as the birds 

 all exhibit a very close resemblance to each other, we 

 may follow his example in this respect, merely separat- 

 ing the species into certain subordinate groups which 

 appear .to be indicated by peculiar characters. These 

 birds are inhabitants of the warmer and temperate 

 regions of the earth, but they are found in most abun- 

 dance in hot climates, where also their plumage attains 

 a brilliancy of which that of our native species gives 

 us no idea. 



FAMILY I. COLUMBID^). 

 PIGEONS. 



The section of the True, Pigeons, to which our British 

 species of this group belong, may be regarded as the 

 most typical of the order. The birds of this section 

 have a rather small and slender bill, the base of which 



