The Sub-Order Ardeae contains the Families Ardeidae and Scopidae, in which the body is often compressed, the head and eyes are large, and the neck is long. Most members of the former have a long, straight, sharp bill with rounded culmen and flattened sides, the edges being commonly serrated and the maxilla notched; it may be comparatively small, as in Zebrilus, but is usually stout, and in Cancroma is extraordinarily broad and depressed, with prominent keel and somewhat dilatable skin beneath, the form resembling that of an inverted boat. Balaeniceps (Fig. 27) has a huge beak, which is not only flattened and swollen, but has a ridge on the culmen terminating in a hook, the maxilla having an undulating outline above and following the strong upward curve of the mandible below, while its sides are grooved. So peculiar, indeed, is this bird that it might well stand alone in a Sub-family Balaenicipitinae, as opposed to the Ardeinae, if not referred to the Storks, where many writers have placed it. In Scopus the bill is acute, keeled, greatly compressed, and laterally grooved, with a small hook at the tip. The tibia is usually bare below, though occasionally feathered, as in Ardetta and Zebrilus; the metatarsus being remarkably long, except in such forms as Nycticorax, Botaurus, and Ardetta. The latter member is covered anteriorly with transverse or hexagonal scales, which become smaller or reticulated behind, and show a decided tendency to fusion in many cases. The toes are long, with a distinct web between the middle and outer; the claws are generally short and curved, though elongated, slender, and nearly straight in Botaurus and Ardetta; that of the middle digit being toothed on the inner side, save in Balaeniceps. The wing is somewhat rounded, yet long, and has eleven primaries–reduced to ten in Scopus–and from eleven to eighteen secondaries; the fairly even tail is short or moderate, with from ten to twelve broad stiffish feathers, except in Botaurus and Ardetta, where the ten rectrices are soft and abbreviated. The tongue is usually long and pointed, but in Cancroma, Balaeniceps, and Scopus it is very short; the lores and orbits are naked, save in Scopus, as is the malar region in Tigrornis and Tigrisoma, while the last at times has the throat bare, or merely feathered centrally. The nostrils are impervious only in Cancroma and Balaeniceps. The nestlings are uniformly covered with sparse hair-like down. The state of the chick is unrecorded in Balaeniceps and Scopus. The furcula is generally V-shaped, the syrinx is tracheo-bronchial, and an aftershaft is present, the latter and the syringeal muscles being much reduced in Balaeniceps. Crests and decorative plumes are common, as will be seen below.
Of especial importance are the large, thick, "powder-down patches," or greasy yellow spaces covered with tufts of grey or black filaments, disintegrating into bluish or whitish powder. Balaeniceps has a big pair on the lower back, Botaurus and Ardetta an additional couple on the breast, and the remainder of the Ardeidae two more on the abdomen, except Cancroma which possesses still another pair on the upper back. In Scopus they are absent. The use is uncertain, and the occurrence quite irregular.
Fam. VI. Ardeidae.–There are few persons in Britain who are not to some extent acquainted with the habits of the Common Heron or Hern, for it may be seen on the coast as well as on inland waters, and now breeds in more localities than formerly, though in smaller numbers; while of the remainder of the Family the Bitterns alone differ conspicuously in their mode of life. Herons are shy, solitary birds, frequenting lakes, fens, and rivers, where they may often be seen standing ankle-deep in the water, and watching with untiring patience for the prey which never seems to satisfy their appetite. They rarely swim and walk but little. The majority breed in large colonies; but Bitterns (Botaurus), Little Bitterns (Ardetta), and Green Herons (Butorides) are notable exceptions, being, moreover, skulking and nocturnal in habit, and agreeing in the latter respect with Night-Herons (Nycticorax). The mud-flats commonly found on sandy shores provide excellent feeding ground, and thence old and young may be seen winging their way at considerable altitudes with leisurely flapping flight–rarely accelerated–to roost at night on the customary trees or rocks. Bitterns and their nearest allies are seldom seen far from marshes, flying noiselessly with laboured action and at a comparatively slow pace; they are, however, adepts at running or climbing among the water-plants, and perch with ease; while they often assume an upright position with the bill vertical, and thereby closely resemble the surrounding reeds, the deception being occasionally enhanced by the bird turning as if on a pivot and facing the spectator constantly.[[90]] Herons fly with the head drawn back, therein differing from the rest of the Order, and in some cases roost or bask in the sun on one leg; they are usually graceful and stately, the beautiful Egrets moving more easily on land than their kindred, and being somewhat less wary. The voice is a harsh croak or guttural sound, that of the Night-Heron verging upon a quack; while the Bitterns, besides the common cry, utter a booming or bellowing note in the breeding season, generally heard at night or early in the morning, the method of production of which is not at present quite clear. Ardetta gives vent to a somewhat similar but weaker boom or grunt, and most species are noisy at the nest, hissing or screaming sharply. The diet consists largely of fish, but is varied by small mammals, birds, reptiles, amphibians, grasshoppers and other insects, molluscs, crustaceans, and worms, the digestion being very rapid and the birds seldom gorged. In the shallows the majority of the family stand motionless, and spear their prey with the beak as it passes, occasionally mauling it before swallowing; but some move from place to place, while the Buff-backed Heron (Ardea bubulcus) habitually picks insects from the backs or sides of the cattle. The nest, commonly situated on lofty trees, though frequently on low bushes, ivy-covered cliffs, flat rocks, or reeds and herbage in swamps, is often a large fabric of sticks without lining or with a slight bedding of grass, leaves, and the like, but may be a mere mass of rushes and flags; the tree-building forms at times resorting to the ground and vice versâ. Bitterns generally crush down the aquatic vegetation and add softer materials on this substructure, depositing four or five olive-drab eggs; Ardetta in some cases does the same, but the eggs are bluish- or greenish-white; whereas those of the Herons proper are of a greenish- or whitish-blue colour of varying depth, and exceptionally amount to six or seven. Butorides not uncommonly lays only two. If the first set is removed a second is often produced after a short interval; but the young remain long in the nest. Incubation lasts from sixteen to thirty days. Herons were of old protected by law, as affording an excellent quarry for Falcons, while the flesh was highly esteemed; when wounded, however, they must be carefully approached, as they use the bill with deadly effect, and aim at the captor's eye. In India they are used as decoy-birds with the eyes sewn up.
The following will sufficiently shew the coloration; the largest species is Ardea goliath; Ardetta furnishes the smallest forms.
Botaurus stellaris, the Bittern, which bred so lately as 1868 in Norfolk, and occurs throughout the warmer parts of the Palaearctic and the whole of the Ethiopian Region, is buff, with black bars above and streaks below, black crown, nape, and stripes down the side of the neck, and chestnut bands on the primaries. B. lentiginosus, distinguished by the nearly uniform brown primaries, is rarely found in Britain, but inhabits North America, probably meeting about Nicaragua with B. pinnatus of tropical South America, which lacks the neck-stripes; while B. poeciloptilus of the Australian Region has much of the back brown. The neck-feathers in these birds form an elongated ruff. Ardetta minuta of Central and Southern Europe, Western Asia, and the northern half of Africa, formerly known to have bred in England, is greenish-black, with buff neck, wing-coverts, and under surface, the latter slightly streaked with dusky. These streaks are more decided in other species, which are often greyer, browner, or more ruddy above; A. cinnamomea of the Indian Region is almost entirely rufous, while all have a slight head-tuft. A fuller crest marks Zebrilus pumilus of northern South America, wherein the upper parts are black with fulvous undulations, and the lower parts correspondingly mottled. The "Tiger-Bitterns" (Tigrisoma) extend from Central America to North Argentina, the four or five forms varying chiefly in the amount of naked skin on the throat. T. brasiliense is blackish with rusty vermiculations above, and reddish-grey below, the head being mainly chestnut, and the tips of the remiges and spots on the breast white. Tigrornis leucolophus of West Africa has a narrow white crest, the neck-feathers hanging loosely down, as in Tigrisoma. Zonerodius heliosylus of New Guinea is black above with fulvous bands, and has white bars on the wing; the rump and fore-neck are white with dusky markings, the lower parts yellowish-white. The genus Butorides, connecting the Bitterns and the Herons, exhibits somewhat elongated plumes on the crown, fore-neck, and scapular region. These small birds, variegated with glossy green, black, grey, and chestnut, and often streaked with white, occur chiefly in the Neotropical and Australian Regions, though B. virescens at least inhabits North America and B. atricapilla the Ethiopian countries.
Nycticorax (Night-Heron) is an almost cosmopolitan genus, remarkable for the long linear blackish or white occipital feathers, from two to ten in number, apparently lost for a time after breeding. In our occasional visitor, N. griseus, of the Palaearctic, Indian, and Ethiopian Regions, and the barely separable N. naevius of America, the colour is greenish-black, with grey neck, rump, wings, and tail, white cheeks and lower parts. N. leuconotus of the Ethiopian Region has the neck rufous, the back white, and the under surface spotted with dusky; N. (Pilerodius) pileatus of tropical South America is white with black crown; N. (Nycterodius) violaceus of the same districts, which extends to the United States, is plumbeous, with yellowish-white crown and black stripes above, the scapulars being somewhat decomposed; N. pauper, confined to the Galapagos, is very similar; N. (Syrigma) sibilatrix of South Brazil, Chili, and Argentina, is grey, with blackish head and remiges, rufous markings on the face and wing-coverts, and yellowish-white breast; N. (Gorsachius) goisagi, ranging from India and the Malay countries to Japan, is red-brown, with buff and white lower parts, the whole plumage being marked with dusky; while N. caledonicus of the Australian Region has the upper parts rich buff, the lower parts white, and only the head black. Cancroma cochlearia, the Boat-billed Night-Heron of South America, is blue-grey with white on the forehead and neck; the head, crest, and flanks being black, and the belly cinnamon. C. zeledoni of Central America differs in its reddish fore-neck.
Ardea, another world-wide genus, may be subdivided as below if desired,[[91]] but the supposed generic characters are hardly satisfactory. A. (Buphus) bubulcus, the Buff-backed Heron of South Europe, Africa, and Asia to the Caspian, is white, with buff crown and nape, and elongated occipital, scapular, and jugular plumes of the same colour, developed in the breeding season; A. coromanda, with orange head, neck, and scapulars, replacing it from the Caspian eastward and reaching Japan. The former has once visited Britain, while A. (Ardeola) ralloides, the Squacco Heron, has done so frequently. This bird, which ranges from the Canaries and Central Europe to South Africa and Persia, is warm buff, with white wings, tail, breast, and belly, the darker back possessing long hair-like plumes which cover the tail, the jugulars being buff, and the head graced by a tuft of long white feathers, margined with black. A. (Lepterodius) gularis of tropical Africa and Madagascar, and A. asha, extending from the Persian Gulf to India, are dusky-slate with white throat, and have moderate scapular and pectoral plumes, with a nuptial crest. A. (Demiegretta) sacra, ranging from Bengal to Japan, Australia, and the Pacific, differs in having only a white streak down the throat, A. greyi being a white phase. A. (Melanophoyx) ardesiaca of the Ethiopian Region is almost entirely slaty-black, with elongated occipital, dorsal, and jugular feathers; A. (Notophoyx) picata of Australia, New Guinea, and the Moluccas, is bluer, and nearly white below; while A. pacifica of that country is greener, with white head and rufescent dorsal plumes. A. (Dichromanassa) rufa of the warmer parts of North America is plumbeous, with reddish head and neck, its white phase being denominated A. pealii; here nearly all the head- and neck-feathers are elongated, and the filamentous scapulars extend beyond the tail. A. (Hydranassa) tricolor, found from the Southern United States to Brazil, is grey-blue, purple, rufous, and white, with shorter seasonal plumes than the preceding; A. (Florida) caerulea, with a slightly more northern range, is slaty-blue, with maroon head and neck, a variable amount of white when immature, and extremely long scapulars; while A. (Agamia) agami of central and northern South America is metallic green, with rufous and white throat, rufous belly, black cheeks and nape; the very long occipital and dorsal plumes being grey, as is the fore-neck, and the recurved feathers of the sides of the neck reddish.
Fig. 26.–Common Heron. Ardea cinerea. × ⅐.
A. (Garzetta) garzetta, the "Little Egret," which has strayed to Britain, and extends from South Europe to the whole of Africa, India, and Japan, is entirely white, with long filamentous scapular and moderate jugular plumes and two lengthened crest-feathers, all of which are said to be temporarily lost after breeding. A. nigripes, ranging from Java to Australia, is barely distinguishable, but the American representative, A. candidissima, has a large occipital tuft. A. (Herodias) alba, the Great White Heron, another of our rare visitors, extends from the middle of Europe to most of Africa, Central Asia, and the Burmese countries, beyond which a doubtfully distinct species, with yellower bill, reaches Australia and New Zealand; the American A. egretta, however, differs in its black legs. The breeding adult is white, with very long decomposed scapular and lengthened jugular plumes, but no crest. The most typical forms of Ardea are large slaty-coloured birds, varied by black, rufous, and white, the head being commonly darker and the lower parts striped; while two slender occipital plumes are, in most cases, developed in the nuptial period, and the scapular and jugular feathers are elongated, though not decomposed. The Common Heron (A. cinerea), ranging through Europe, Africa, and Asia, to Japan and Australia, needs no description, but the Purple Heron, A. (Phoyx) purpurea, though it often occurs in Britain, is less well known. It is grey, with black crown and black stripes down the sides of the buff neck, chestnut scapulars, rufous, grey, and black jugular plumes, and maroon breast; the range being from Central and Southern Europe to South Africa, China, and the Philippines. A. herodias of North America meets in northern South America the white-necked A. cocoi, both species resembling A. cinerea, but the former having rufous thighs and edge of the wing. The white A. occidentalis, of Florida and Cuba,[[92]] was formerly thought to be an instance of dichromatism. The African A. goliath has the head and neck rufous and the under surface chiefly maroon.