The range extends throughout Tropical Asia, Africa, and America, and even slightly beyond those bounds in the two former; but America possesses only the large genus Capito and the two species of Tetragonops, whereas the other regions divide the remaining groups fairly evenly between them. Captain Shelley[[254]] admits nineteen genera and a hundred and ten species. The former are difficult to diagnose, and depend largely on colour; of the latter the subjoined are merely a few of the most typical or remarkable forms. Pogonorhynchus (including Erythrobucco and Melanobucco) and Tricholaema, including respectively some fifteen and ten species, are exclusively African groups, noticeable for the long, black bristles before the eye and below the beak. P. dubius of West Africa has bluish-black upper parts, with a little crimson on the wing-coverts and a white dorsal patch; the cheeks and ear-coverts are crimson, separated by a black line; the anterior under parts are crimson, the posterior scarlet, these being divided by a black pectoral band, and relieved by yellowish patches on the sides; the bill is reddish-yellow, the naked orbits are orange. Tricholaema leucomelan of South Africa is blue-black above, with plentiful yellow and scanty white markings, but white below with black throat. The forehead is crimson, the eyebrow and orbits are yellow, the bill is blackish. The breast-feathers have hair-like shafts. Gymnobucco calvus of West Africa is brown with paler streaks; having the bill and chin-bristles yellowish, and browner bristles round the nostrils in at least one sex. The naked head is blue. Barbatula, of the Ethiopian Region generally, contains a dozen small species, which exhibit soft loose plumage of black, varied with red, yellow, or white. B. minuta, extending from North-East Africa to Senegambia, has the forehead scarlet, the rump and under surface yellowish, the bill black, and somewhat scanty bristles. Stactolaema anchietae of Benguela, and S. olivaceum of East Africa, are respectively brown with yellowish head and throat, and olive-green with those parts blackish. The bill is black. Calorhamphus hayi, found from South Tenasserim to Sumatra, is yellowish-brown above and yellowish-white below, with black-shafted spiny crown-feathers, rufous throat, black bill, reddish orbits and no chin-bristles. C. fuliginosus of Borneo is similar. Megalaema, Chotorhea, Cyanops and Mesobucco, with about thirty members in all, extend from India and Ceylon to China, Formosa, Hainan, and the Great Sunda Islands. They are soft-plumaged green birds, having parti-coloured heads and throats tinted with blue, yellow, red, and black, or merely brown and white; the bill and feet are yellowish, greenish, or black. The bristles vary in their development. Psilopogon pyrolophus, of the mountains of the Malay Peninsula and Sumatra, is green, with a black forehead, a brownish head crossed by a greyish-white band, and a double belt of yellow and black below the green throat. The long nasal bristles are black, tipped with scarlet; the superciliary stripe and lower eye-lid are green; the upper eye-lid is yellow; the bill is yellowish-green with black central band; the legs and orbits are greenish. The unusually long tail is much graduated, and has pointed median rectrices, while these are square in some ten Ethiopian species of Trachyphonus, where the tail is similar. T. cafer of South-East Africa is bluish-black above with white markings; the rump being yellow; the upper tail-coverts scarlet; the forehead, sides of the head and lower parts yellow, with a tinge of scarlet on the throat, which is followed by a black and white gorget. The fine occipital crest is black, the beak green; the feet and orbits are dusky. T. margaritatus, of North-East Africa, has brown upper parts with round white spots; the upper and lower tail-coverts are crimson; the rump, head, neck, and under surface are yellow, except for the crown and marks on the hind-neck and throat, which are black, and for an indistinct chest-band of red, surmounted by one of brown. The beak is red, the feet are bluish. The exclusively Central and South American Capito is the only genus in which the sexes differ; the dozen or more species have, moreover, few bristles round the bill. C. niger of Guiana is black above, varied with yellowish and buff, and sulphur-yellow below with a few black spots, which become plentiful in the female. The forehead, cheeks, and throat are orange-scarlet, the bill is plumbeous. C. salvini of Costa Rica and Panama has green upper and yellow under parts; most of the head and the throat being scarlet, the flanks green and white, and a whitish band descending the sides of the neck. The female lacks the scarlet, but has a dull golden crown and nape, pale blue cheeks, and an orange gorget below the green throat. The bill is greenish-yellow, the orbits are yellowish. Tetragonops rhamphastinus of Ecuador, in which the nostrils lie in grooves, has the crown black, with white sides merging gradually into a blue-grey throat; a glossy black nuchal crest; a rufous-olive mantle; orange lower back and upper tail-coverts; blackish-blue wings and tail; scarlet breast with orange sides; and yellowish-green abdomen. The bill is orange-yellow with dusky tip. T. frantzii of Costa Rica, called "Gallinita" from its chicken-like cry, has greenish-olive upper and yellowish-green lower parts, with golden-orange forehead, cheeks and throat, a plumbeous bill, and a similar crest to its congener. This genus bears a certain resemblance to the Toucans.
Sub-fam. 2. Indicatorinae.–The Honey-guides are contained in the two genera Indicator and Prodotiscus, with nine and two species respectively, which were formerly placed among the Cuckoos. Their chief interest centres in the fact that they are said to conduct travellers to bees' nests, as will be seen below.
From the Capitoninae, Indicator differs in the stout Finch-like bill with ridged and laterally swollen maxilla, while that of Prodotiscus is more slender and pointed. Moreover, the metatarsi are short; the nostrils possess a narrow membrane and are not bristly; and the rectrices number twelve, save in the last-named genus, which has ten. The curiously interrupted range includes the whole Ethiopian Region, except Madagascar; the Himalayas; and the Malayan and Bornean mountains. The sexes are generally similar, while almost all the forms, which hardly exceed a Lark in size, are chiefly dull brown, with a yellow wash, and some white on the rump, tail, or wings.
Indicator xanthonotus of the Himalayas is blackish above, with golden forehead and orange rump-region, and greyish below; the latter colour merging into yellow on the throat and black on the abdomen. I. archipelagicus of the Malay Peninsula and Borneo, and I. sparrmani of Tropical Africa, except the western forests, exhibit a yellow shoulder-patch; while the males of the latter and of I. major of the same districts have black throats, which are whitish and yellow in the respective females. I. minor, and the remaining Ethiopian species, differ from the last two forms in having no white on the lower back. Prodotiscus regulus of Natal, and P. insignis, ranging from the Gaboon to East Equatorial Africa, are particularly dull.
Circumstantial accounts of eye-witnesses so clearly shew that bees' nests are found through the instrumentality of these birds, that their intention can hardly be doubted, and it has been said that not only man but the ratel (Mellivora capensis) is conducted; the object of attraction, however, occasionally turns out to be a leopard, cat, snake, or dog. Honey-guides call attention by a shrill cry or hiss, and will even fly in the face of a traveller, as if enraged at not being followed; they eat bees, grubs, and honey, and are asserted to lay white eggs in the nests of Barbets and the like.[[255]] Sir John Kirk writes[[256]] of the habits of Indicator minor–"The Honey-guide is found in forests, and often far from water, even during the dry season. On observing a man it comes fluttering from branch to branch in the neighbouring trees, calling attention. If this be responded to, as the natives do by whistling and starting to their feet, the bird will go in a certain direction and remain at a little distance, hopping from one tree to another. On being followed it goes further; and so it will guide the way to a nest of bees. When this is reached, it flies about, but no longer guides; and then some knowledge is needed to discover the nest, even when pointed out to within a few trees. I have known this bird, if the man after taking up the direction for a little then turns away, come back and offer to point out another nest in a different part. But if it do not know of two nests, it will remain behind. The difficulty is, that it will point to tame bees in a bark-hive as readily as to those in the forest. This is natural, as the bee is the same; the bark-hive, 'Musinga' as it is named, being simply fastened up in a tree and left for the bees to come to. The object the bird has in view is clearly the young bees. It will guide to nests having no honey, and seems equally delighted if the comb containing the grubs be torn out when it is seen pecking at it."
Fam. XVII. Rhamphastidae.–The Toucans[[257]] are easily recognisable by their huge beak, only paralleled by that of the Hornbills, of which some authors have considered them the Neotropical representatives; but whereas in the latter this beak is usually surmounted by a casque of varying size, in the Toucans it is shaped much as usual, though abnormally developed. It does not seem to interfere with the bird's powers of flight or feeding, and indeed the structure of both mandibles is admirably calculated to combine bulk with strength and lightness; the external walls being so thin and elastic that they are said in some species to be compressible by the fingers, while the inner cavities are filled with a network of bony columns, to which the air has constant access. Moreover, the maxilla is so perfectly hinged to the skull that the utmost ease in mastication is secured, the serrated edges further aiding in the process. In Aulacorhamphus the mandibles are grooved, and Andigena laminirostris has a square basal plate on each side of the culmen. The metatarsi are stout and scutellated on both aspects, the toes are papillose below, the claws sharp and curved. The somewhat weak wings have ten primaries and twelve secondaries; the square, rounded, or graduated tail of ten rectrices is capable of free vertical motion, and is frequently jerked up over the back. The furcula is U-shaped; the tongue is long, thin and narrow, with feather-like margins towards the tip; the nostrils open backwards behind the bill-sheath in Rhamphastus, upwards or sideways near the hind part of the culmen in the other genera; the syrinx is tracheo-bronchial; the aftershaft is rudimentary or absent; and neither adults nor nestlings shew any down.
The coloration of the long, loose plumage, and of the beak and naked orbits, is most brilliant and varied; the females are smaller and duller than the males, and quite unlike them in Selenidera; while the young resemble the former, but have softer and differently-tinted bills. The feet are grey or green. Pteroglossus beauharnaisi has the black shafts of the crown-feathers dilated and coalescent with the barbs, producing an appearance like curls of horn.
Toucans, except just after moulting, are shy and restless; they are more or less gregarious, and small flocks gather to feed or bathe in the morning or evening; at noon they sit motionless on some lofty tree, but at other times may be seen jumping about the branches. At night they roost with the tail thrown forward upon the back, and the head turned to meet it. Their flight is easy, graceful, and direct, accompanied by occasional noisy flaps of the wing, the bill being carried horizontally; they rarely seek the ground, where they hop about obliquely in awkward fashion. All the species live chiefly on fruits, including seeds; but Azara's statement that they destroy small birds, and devour both eggs and young, is possibly quite correct, as in captivity they exhibit great excitement and delight when furnished with meat, mice, reptiles, and so forth,[[258]] tearing the food to pieces and masticating it with their serrated mandibles. Should, however, the object be small, they throw back the head and swallow it at a gulp; while a curious habit has been observed of regurgitating the substances for further mastication. Caterpillars, ants, and the like are added to the diet in the breeding season. When feeding in company, Toucans, like Rooks, post a sentinel, whose harsh, chattering scream can be heard for at least a mile: they are especially noisy in the morning and evening, or in wet weather. The unmelodious cry seems to vary considerably in the different species; being described as a croak, a hoarse note, a clear yelp, or a jarring sound like that of a Mistletoe Thrush. Owls and diurnal Birds of prey are often surrounded by a noisy mob of Toucans, which jerk their tails as they follow. Two oval and somewhat glossy white eggs are deposited in hollow limbs of tall trees. These birds are frequently eaten by the colonists and natives, the latter using their plumage to decorate their bows or their persons, while the beaks make convenient powder-flasks. They are easily tamed, and become amusing pets. The various forms extend throughout the forests of Tropical America down to the mangrove swamps of the coast, some occurring at an altitude of from six thousand to ten thousand feet on the mountains; northwards Rhamphastus carinatus, Pteroglossus torquatus, Aulacorhamphus prasinus, and A. wagleri reach South Mexico; southwards, Rhamphastus toco ranges to Argentina; but westwards no species crosses the Andes south of the Gulf of Guayaquil. They are not represented in the Antilles, though Rhamphastus vitellinus extends to Trinidad. Dr. Sclater[[259]] recognises five genera, comprising fifty-nine species, the majority inhabiting Amazonia and Guiana.
Fig. 94.–Ariel Toucan. Rhamphastus ariel. × ⅓.