While these additions to the substance of the egg are going on, the germinal disc undergoes the remarkable process known as segmentation, in which it becomes divided into two, four, eight, sixteen, thirty-two (and so on) masses, which arrange themselves in two distinct layers, the presence of which has been already noted in the laid egg.
This is not the place in which it is possible to follow out the various future changes undergone, but the condition of the young birds on escaping from the egg is widely different in some of the larger groups of birds. Some young birds, on their exclusion from the egg, are able to shift for themselves, and are covered with down; while others are born naked and helpless, and require food from their parents for some time after they are hatched. Of the first section, an ordinary chicken is a familiar example, while a young Thrush or a Sparrow illustrates the second. There are, however, manifest exceptions to this rule, as in the Herons, for instance, where the young are densely clothed with feathery down, but are helpless for a long time after they are hatched.
Finally, it must be stated that all birds possess an oil-gland (known as the uropygial), situated near the tail, with which they clean and dress their feathers. Attention has already been called to this gland in the foot note on p. 245.
Before commencing the special part of the present article, it may be useful to give a slight sketch of the classification which it is proposed to follow throughout its course.
CLASS AVES. |
DIVISION I. CARINATÆ: CARINATE BIRDS. |
ORDER I.—ACCIPITRES: BIRDS OF PREY. |
SUB-ORDER I.—FALCONES: FALCONS. |
Family I.—Vulturidæ | Vultures. |
„ II.—Falconidæ | Hawks. |
Sub-Family I.—Polyborinæ | Caracaras. |
„ II.—Accipitrinæ | Long-legged Hawks. |
„ III.—Buteoninæ | Buzzards. |
„ IV.—Aquilinæ | Eagles. |
„ V.—Falconinæ | Falcons. |
SUB-ORDER II.—PANDIONES: OSPREYS. |
SUB-ORDER III.—STRIGES: OWLS. |
Family I.—Bubonidæ | Owls proper. |
„ II.—Strigidæ | Barn Owls. |
ORDER II.—PICARIÆ: PICARIAN BIRDS. |
SUB-ORDER I.—ZYGODACTYLÆ: CLIMBING BIRDS. |
Family I.—Psittaci | Parrots. |
a. Psittaci proprii. |
Sub-Family I.—Camptolophinæ | Cockatoos. |
„ II.—Androglossinæ | Fleshy-tongued Parrots. |
„ III.—Conurinæ | Conures. |
„ IV.—Platycercinæ | Parrakeets. |
„ V.—Strigopinæ | Owl Parrots. |
b. Psittaci orthognathi. |
„ VI.—Trichoglossinæ | Brush-tongued Parrots. |
Family II.—Cuculidæ | Cuckoos. |
„ III.—Indicatoridæ | Honey-guides. |
„ IV.—Musophagidæ | Touracoes. |
„ V.—Picidæ | Woodpeckers. |
„ VI.—Rhamphastidæ | Toucans. |
„ VII.—Capitonidæ | Barbets. |
SUB-ORDER II.—FISSIROSTRES: WIDE-GAPING BIRDS. |
Family I.—Galbulidæ | Jacamars. |
„ II.—Bucconidæ | Puff Birds. |
„ III.—Alcedinidæ | Kingfishers. |
„ IV.—Bucerotidæ | Hornbills. |
„ V.—Upupidæ | Hoopoes. |
„ VI.—Meropidæ | Bee-eaters. |
„ VII.—Momotidæ | Motmots. |
„ VIII.—Coraciadæ | Rollers. |
„ IX.—Trogonidæ | Trogons. |
„ X.—Caprimulgidæ | Goatsuckers. |
„ XI.—Cypselidæ | Swifts. |
„ XII.—Trochilidæ | Humming-birds. |
ORDER III.—PASSERIFORMES: PERCHING BIRDS. |
SECTION A.—ACROMYODI: SINGING BIRDS. |
SUB-ORDER I.—TURDIFORMES: THRUSH-LIKE. BIRDS. |
GROUP I.—COLIOMORPHÆ: CROW-LIKE. PASSERES. |
Family I.—Corvidæ | Crows. |
Sub-Family I.—Corvinæ | Crows proper. |
„ II.—Fregilinæ | Choughs. |
„ II.—Paradisiidæ | Birds of Paradise. |
„ III.—Orioliidæ | Orioles. |
„ IV.—Dicruridæ | Drongos. |
„ V.—Prionopidæ | Wood-shrikes. |
GROUP II.—CICHLOMORPHÆ: THRUSH-LIKE PASSERES. |
Family VI.—Campophagidæ | Cuckoo-shrikes. |
„ VII.—Muscicapidæ | Flycatchers. |
„ VIII.—Turdidæ | True Thrushes. |
Sub-Family I.—Turdinæ | Thrushes. |
„ II.—Sylviinæ | Warblers. |
Family IX.—Timeliidæ | Babbling Thrushes. |
Sub-Family I.—Troglodytinæ | Wrens. |
„ II.—Brachypodinæ | Bulbuls. |
„ III.—Timeliinæ | Babblers. |
„ IV.—Cisticolinæ | Grass-warblers. |
„ V.—Miminæ | American Babblers. |
Family X.—Laniidæ | Butcher-birds. |
„ XI.—Vireonidæ | Greenlets. |
„ XII.—Paridæ | Titmice. |
GROUP III.—CERTHIIMORPHÆ: CREEPERS. |
GROUP IV.—CINNYRIMORPHÆ: HONEY SUCKERS. |
SUB-ORDER II.—FRINGILLIFORMES: FINCH-LIKE BIRDS. |
Family I.—Motacillidæ | Wagtails. |
„ II.—Mniotiltidæ | American Warblers. |
„ III.—Cærebidæ | American Creepers. |
„ IV.—Diceidæ | Flower-peckers. |
„ V.—Ampelidæ | Chatterers. |
„ VI.—Hirundinidæ | Swallows. |
„ VII.—Tanagridæ | Tanagers. |
„ VIII.—Fringillidæ | Finches. |
„ IX.—Icteridæ | Hang-nests. |
SUB-ORDER III.—STURNIFORMES: STARLING-LIKE BIRDS. |
Family I.—Ploceidæ | Weavers. |
„ II.—Sturnidæ | Starlings. |
„ III.—Artamidæ | Wood-swallows. |
„ IV.—Alaudidæ | Larks. |
SECTION B.—MESOMYODI: SONGLESS BIRDS. |
Family I.—Menuridæ | Lyre-birds. |
„ II.—Pteroptochidæ | Bush-wrens. |
„ III.—Dendrocolaptidæ | Spine-tails. |
„ IV.—Formicariidæ | American Ant-thrushes. |
„ V.—Pittidæ | Old-World Ant-thrushes. |
„ VI.—Tyrannidæ | Tyrant-birds. |
„ VII.—Cotingidæ | American Chatterers. |
„ VIII.—Pipridæ | Manakins. |
„ IX.—Eurylæmiidæ | Broadbills. |
„ X.—Phytotomidæ | Plant-cutters. |
ORDER IV.—COLUMBÆ: PIGEONS. |
ORDER V.—GALLINÆ: GAME-BIRDS. |
Family I.—Cracidæ | Curassows. |
„ II.—Opisthocomidæ | Hoatzins. |
„ III.—Phasianidæ | Pheasants. |
„ IV.—Meleagridæ | Turkeys. |
„ V.—Tetraonidæ | Grouse. |
„ VI.—Pteroclidæ | Sand-grouse. |
„ VII.—Turnicidæ | Hemipodes. |
„ VIII.—Megapodidæ | Megapodes. |
ORDER VI.—GRALLÆ: WADING BIRDS. |
Family I.—Rallidæ | Rails. |
„ II.—Scolopacidæ | Snipes. |
„ III.—Charadriidæ | Plovers. |
„ IV.—Otididæ | Bustards. |
„ V.—Gruidæ | Cranes. |
„ VI.—Psophiidæ | Trumpeters. |
ORDER VII.—HERODIONES: HERONS. |
Family I.—Ardeidæ | Herons proper. |
„ II.—Ciconiidæ | Storks. |
„ III.—Plataleidæ | Spoonbills. |
„ IV.—Phænicopteridæ | Flamingoes. |
ORDER VIII.—ANSERES: GEESE. |
Family I.—Palamedeidæ | Screamers. |
„ II.—Anatidæ | Ducks. |
ORDER IX.—STEGANOPODES: PELICANS. |
Family I.—Fregatidæ | Frigate-birds. |
„ II.—Phæthontidæ | Tropic-birds. |
„ III.—Pelecanidæ | Pelicans. |
ORDER X.—GAVIÆ: SEA-BIRDS. |
Family I.—Laridæ | Gulls. |
„ II.—Procellariidæ | Petrels. |
ORDER XI.—PYGOPODES: GREBES. |
ORDER XII.—IMPENNES: PENGUINS. |
ORDER XIII.—CRYPTURI: TINAMOUS. |
DIVISION II.—RATITÆ: STRUTHIOUS BIRDS. |
DIVISION III.—SAURURÆ: LIZARD-TAILED BIRDS. |
It has been already stated that birds are divisible into three great sections, and attention is now directed to those which have a keel to the sternum, and which are good flyers—the Carinate Birds (CARINATÆ).
CHAPTER III.
DIVISION I.—THE CARINATE BIRDS (CARINATÆ).
THE ACCIPITRINE ORDER—BIRDS OF PREY.
VULTURES AND CARACARAS.
The Birds of Prey—Distinctive Characters—The Cere—How the Birds of Prey are Divided—Difference between a Hawk, an Owl, and an Osprey—The three Sub-orders of the Accipitres—[Sub-order FALCONES]—Difference between the Vultures of the Old World and the Vultures of the New World—[THE OLD WORLD VULTURES]—Controversy as to how the Vultures reach their Prey—Waterton on the Faculty of Scent—Mr. Andersson’s, Dr. Kirk’s, and Canon Tristram’s Views in Favour of Sight—[THE BLACK VULTURE]—[THE GRIFFON VULTURE]—Its Capacity for Feeding while on the Wing—[THE EARED VULTURE]—One of the Largest of the Birds of Prey—Whence it gets its Name—[THE EGYPTIAN VULTURE]—A Foul Feeder—[THE NEW WORLD VULTURES]—[THE CONDOR]—Its Appearance—Power of Flight—Habits—[THE KING VULTURE]—[THE TURKEY VULTURE]—[THE CARACARAS]—Distinctive Characters—Habits—[THE SECRETARY BIRD]—How it attacks Snakes—Habits—Appearance—[THE ÇARIAMA].