The Naturalist on the River Amazons
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第170章

Gray.]-- all of whose members are fruit-eaters.On the Amazons, where these birds are very common, no one pretends ever to have seen a Toucan walking on the ground in its natural state, much less acting the part of a swimming or wading bird.Professor Owen found, on dissection, that the gizzard in Toucans is not so well adapted for the trituration of food as it is in other vegetable feeders, and concluded, therefore, as Broderip had observed the habit of chewing the cud in a tame bird, that the great toothed bill was useful in holding and remasticating the food.The bill can scarcely be said to be a very good contrivance for seizing and crushing small birds, or taking them from their nests in crevices of trees, habits which have been imputed to Toucans by some writers.The hollow, cellular structure of the interior of the bill, its curved and clumsy shape, and the deficiency of force and precision when it is used to seize objects, suggest a want of fitness, if this be the function of the member.But fruit is undoubtedly the chief food of Toucans, and it is in reference to their mode of obtaining it that the use of their uncouth bills is to be sought.Flowers and fruit on the crowns of the large trees of South American forests grow, principally, towards the end of slender twigs, which will not bear any considerable weight; all animals, therefore, which feed upon fruit, or on insects contained in flowers, must, of course, have some means of reaching the ends of the stalks from a distance.Monkeys obtain their food by stretching forth their long arms and, in some instances, their tails, to bring the fruit near to their mouths.

Hummingbirds are endowed with highly perfected organs of flight with corresponding muscular development by which they are enabled to sustain themselves on the wing before blossoms whilst rifling them of their contents.These strong-flying creatures, however, will, whenever they can get near enough, remain on their perches while probing neighbouring flowers for insects.Trogons have feeble wings, and a dull, inactive temperament.Their mode of obtaining food is to station themselves quietly on low branches in the gloomy shades of the forest, and eye the fruits on the surrounding trees-- darting off, as if with an effort, every time they wish to seize a mouthful, and returning to the same perch.

Barbets (Capitoninae) seem to have no especial endowment, either of habits or structure, to enable them to seize fruits; and in this respect they are similar to the Toucans, if we leave the bill out of question, both tribes having heavy bodies, with feeble organs of flight, so that they are disabled from taking their food on the wing.The purpose of the enormous bill here becomes evident; it is to enable the Toucan to reach and devour fruit whil remaining seated, and thus to counterbalance the disadvantage which its heavy body and gluttonous appetite would otherwise give it in the competition with allied groups of birds.

The relation between the extraordinarily lengthened bill of the Toucan and its mode of obtaining food, is therefore precisely similar to that between the long neck and lips of the Giraffe and the mode of browsing of the animal.The bill of the Toucan can scarcely be considered a very perfectly-formed instrument for the end to which it is applied, as here explained; but nature appears not to invent organs at once for the functions to which they are now adapted, but avails herself, here of one already-existing structure or instinct, there of another, according as they are handy when need for their further modification arises.

One day, whil walking along the principal pathway in the woods near Ega, I saw one of these Toucans seated gravely on a low branch close to the road, and had no difficulty in seizing it with my hand.It turned out to be a runaway pet bird; no one, however, came to own it, although I kept it in my house for several months.The bird was in a half-starved and sickly condition, but after a few days of good living it recovered health and spirits, and became one of the most amusing pets imaginable.Many excellent accounts of the habits of tame Toucans have been published, and therefore, I need not describe them in detail, but I do not recollect to have seen any notice of their intelligence and confiding disposition under domestication, in which qualities my pet seemed to be almost equal to parrots.Iallowed Tocano to go free about the house, contrary to my usual practice with pet animals, he never, however, mounted my working-table after a smart correction which he received the first time he did it.He used to sleep on the top of a box in a corner of the room, in the usual position of these birds, namely, with the long tail laid right over on the back, and the beak thrust underneath the wing.He ate of everything that we eat; beef, turtle, fish, farinha, fruit, and was a constant attendant at our table--a cloth spread on a mat.His appetite was most ravenous, and his powers of digestion quite wonderful.He got to know the meal hours to a nicety, and we found it very difficult, after the first week or two, to keep him away from the dining-room, where he had become very impudent and troublesome.We tried to shut him out by enclosing him in the backyard, which was separated by a high fence from the street on which our front door opened, but he used to climb the fence and hop round by a long circuit to the dining-room, making his appearance with the greatest punctuality as the meal was placed on the table.He acquired the habit, afterwards, of rambling about the street near our house, and one day he was stolen, so we gave him up for lost.But two days afterwards he stepped through the open doorway at dinner hour, with his old gait, and sly magpie-like expression, having escaped from the house where he had been guarded by the person who had stolen him, and which was situated at the further end of the village.