1833/01/01 by Gabriel Bayfield, Elizabeth Gould, John Gould +5 · 2 citations
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Plant and animal studies #Insect and Arachnid Ecology and Behavior #Botanical Research and Chemistry
paper · doi:10.5962/bhl.title.156984
openalex publication_date 1833/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/02
OF the birds illustrated in the present Monograph, so few species had been discovered in the days of Linnzeus, that that great naturalist was induced to include them all in one genus, under the name of Ramphastos; but subsequent research in this branch of ornithological science having produced many additional examples, M. Illiger has with the greatest propriety arranged them under two distinct and well marked genera, applying the established term Ramphastos to the true Toucans, characterized by their large bills and square tails, and throwing the Aracaris, having graduated tails and less disproportionate bills, into a new genus, which he has denominated Pteroglossus, thus forming from the Swedish naturalist's limited genus an extensive family, the members of which are strictly allied to each other in general form and habits, constitute a group at once natural and well defined, and are no less remarkable for the peculiarities of their habits and manners than for their beauty of plumage, and in many species, though the enormous size of their bills may seem to contradict such an assertion, for the elegance of their form and movements.In geographical distribution these birds are strictly confined to the tropical portions of America.According to the best information, they are a retiring and shy race, are mostly observed in small flocks or companies, and inhabit the dense woods and forests of that luxuriant country.In their choice of food they are perfectly omnivorous; and although their elastic bill and delicately feathered tongue would lead us to conclude that fruits constituted the greatest proportion of their diet, we have abundant testimony that they as readily devour flesh, fish, eggs, and small birds, to which, in all probability, are added the smaller kinds of reptiles, _ caterpillars, and the larva of insects in general. 1 INTRODUCTION.Most of the species, if not all, incubate in the holes of trees, laying two eggs at a time, of a delicate white.The true Toucans, unlike many of the Aracaris, offer no sexual difference in the colour of the plumage; but the females are rather less than the males in all their proportions.The young of both genera assume at a very early age the adult colouring: their large bills, however, as might naturally be expected, are not fully developed for a considerable period.Their flight is straight, and appears not to be effected without considerable exertion ; while, on the contrary, among the trees, &c., they are as quick and graceful as can well be imagined, leaping from branch to branch with the most elegant agility.Tn a state of repose, they turn their heads over their shoulders, the bill being completely hidden among the plumage of the upper parts and greater wing-coverts, and the tail raised vertically over the back, in which state the bird resembles a ball of feathers.The habits of these birds in confinement, as observed on two of the species, have been admirably delineated in two papers published a few years since in the " Zoological Journal,' by Mr. Broderip and Mr. Vigors.'The details given by the latter gentleman are particularly valuable: they were derived from the observation of an individual of the Ariel Toucan, kept by him for several years, and are almost universally known on account of the numerous reprints of them which have been induced by the graceful manner in which they are recorded, no less than by the interest of the facts themselves.With these few preliminary observations I dismiss the general subject, and proceed to offer some remarks on the distribution of the species which have fallen under my notice.I. The Toucans are distinguished among the Ramphastide by the very disproportionate size of their bills, and by the comparative shortness and square termination of the tail.The general colour of their feathering is black; but the throat and the upper and under tail-coverts assume, in all the species yet known, a colouring different from that of the ground.The colour of the under tail-coverts appears to be invariably crimson; that of the upper tail-coverts is either crimson, white, or yellow, according to the several species.The throat is either white or yellow; and is terminated behind by a crimson band, which is in some species very narrow, oe 2 INTRODUCTION.while in others it is so broad as to extend over the whole of the chest.The legs are of a slaty blue; and the naked space surrounding the eyes is usually of the same colour with the legs;in three species only is it crimson.The bill varies much in colour, and is subject to variation in this respect, even in the same species, according to the age of the individual: the general distribution of the colouring of the bill seems, however, to be constant.In its proportion to the size of the bird, the bill also varies with the age and sex of the individual, but seems to be constant in each species in the adult state.It also differs, according to the species, in the greater or less convexity of its sides; i the sharpness or roundness of its upper edge; and in the smoothness or jaggedness of its cutting edges.A. The first section of the Toucans comprehends those in which the upper tail-coverts are yellow.In the whole of these the throat is white, with a faint tinge only of yellow; and the crimson band by which it is separated behind from the black of the under surface is of small breadth.All of them have the upper edge of the bill yellow, and a broad band of the same colour surrounding its base, this band being separated by a narrow line of black from the adjoining parts of the head and face.This section comprehends three species:1. Ramph.culminatus ; with the mandibles compressed laterally and wholly black, except the culminal and basal bands, which are pale straw yellow.2. Ramph.Cuviert; with the bill more attenuated than in culmenatus ; the mandibles convex and blackish brown, except the greenish yellow culmen and basal belt of the same colour, which is bounded before by a broad, and behind by a narrow, band of black.3. Ramph.erythrorhynchus; with the entire bill red, except the yellow culmen and basal band, and the black borders of the basal band and cutting margins.B. In the second section of the Toucans but one species is comprehended.It is characterized either by the total absence of the scarlet pectoral band, or by having it so faint as to be scarcely perceptible.The upper tail-coverts are white, exceed the ordinary proportions, and equal in length about one half of that of the tail-feathers.The throat is white; the space surrounding the eyes is red, and the eyelids blue.Such are the characters of 4, Ramph.Toco; with the bill rich orange, banded at its base and broadly blotched at its tip with black.C. The third section of the Toucans comprehends two species, distinguished by the upper ADDENDA TO THE INTRODUCTION.~ Humboldt's Aragari belongs to section E, where it will range between Pter.viridis and Pter.mscriptus ; as, Pter.Humboldti ; with the bill yellow, black on its culmen at its tip and base, blotched with black at its serratures, and with the under mandible black.Langsdorff's, Natterer's, and Reinwardt's Aragaris belong to section F, with the following distinctive characters :Pter.Nattererz; with the bill red, marked at the base of each mandible with a large black spot, and having the culmen and five or six blotches along the edge of the upper mandible also black.Pter.Reinwardti ; with the bill reddish at the base, with several black spots near the cutting edge of the upper mandible, and with the culmen and terminal half blackish brown. .Pter.Langsdorffix ; with the bill throughout nearly black, becoming slightly grey towards its base.Pter. pavoninus, Derbianus, and hematopygus will range in the seventh or last section, G, and are thus characterized :Pter. pavoninus; with the under tail-coverts and tips of the tail-feathers brown, and the lower mandible and base and cutting edge of the upper black.Pter.Derbianus ; with the under surface green throughout, and the tips of the two intermediate tail-feathers chestnut.Pter. hematopygus; with the under surface green throughout, and the upper tail-coverts blood red.As all the species comprised in this latter section appear to possess characters sufliciently distinct to warrant their separation as a peculiar genus, I propose to regard them in that light, and to give them the generic title of Aulacorhynchus, with the following characters :Bill comparatively short, furrowed on the sides ; culmen broad and flattened ; base of the under mandible extending obliquely beyond the line of the eye.Wengs short and round, the fourth quill-feather the longest, the fifth, sixth, and seventh being nearly of the same length.Tail comparatively short and less decidedly graduated than in Pteroglossus-The whole of this group are characterized by a uniform green plumage, the feathers of which are loose and decomposed in their texture.