I cannot conclude this article better than by inserting the observations which the Marquis de Montmirail communicated to me concerning the unau, which had been above three years in his menagerie. “The fur of the unau is much softer than that of the aï. It is probable that what travellers have said of the excessive slowness of the sloths, only belongs to the aï. The unau, although very heavy, and of an excessively aukward motion, ascends and descends the highest tree many times in a day: he is most active in the evening and during the night, which makes it probable that he sees but badly in the day, and that his eyes are of no use to him but in the dark. When I bought this animal at Amsterdam, it was fed with sea-biscuit, and I was told, that when the winter was over, and the verdure began to appear, it would require nothing but leaves. We supplied him with leaves which he ate freely while they were green and tender; but the moment they began to be dry, shrivelled, or worm-eaten, he refused them. During the three years that I preserved him in my menagerie, his common food was bread, apples, and roots; and his drink always milk. He always took his food in one of his fore-claws, but with difficulty, and which was increased in proportion to the size. His cry, though plaintive and melancholy, does not resemble that of the aï; it is short, and seldom uttered. The most natural situation of the unau, and which he prefers to all others, is suspending himself on a branch of a tree, with his body downwards. He sometimes even sleeps in this position, his four claws fastened on the same point, and his body describing the figure of a bow. The strength of his muscles is incredible; but it becomes useless to him when he walks, for his motion then is not the less constrained or tottering. This formation alone seems to be the cause of the slowness of this animal, who besides has no violent sensation, and does not recognize the hand that feeds him.”
SUPPLEMENT.
We have been informed by M de la Borde, that in Cayenne there are two species of sloths, whose principal differences consist in the length of their bodies, the one, which is called the sheep sloth, being nearly twice as long as the other, known by the name of the bashful sloth. The first has bushy hair of a dirty white; he weighs about twenty-five pounds; he climbs to the tops of trees, from whence he throws himself down in a very aukward manner. The latter does not weigh more than twelve pounds; he has some black spots on different parts of his body, and his hair is not so rough as the other. Both species produce but one young at a time, and which they carry with them on their backs; and there is some reason to believe the female brings forth on the trees; the leaves of which, form the general food of both species, and which are equally common. They frequently suspend themselves by their claws from the branches of the trees, and when so situated they may be taken at pleasure, as they will suffer the branch to be cut asunder without letting go their hold. They ascend the trees by sticking in their fore claws alternately, and so drag up their bodies, but the slowness of their motion, is almost incredible. When kept in the house, they climb up the sides of a door or post, and never rest upon the ground; and if a stick is put to them, they will climb to the top and cling to it with their whole body.
It is plain from the above description, that the sheep sloth is the same as that we have spoken of under the name of the unau, and that this bashful sloth of our aï.
M. Vosmaër has denied the assertion in my history of these animals, that they are unable to descend from a tree, but allow themselves to drop down like inanimate blocks; I had the fact from eye-witnesses, and it is now supported by the testimony of M. de la Borde.[AN] With respect to my other assertion, that the sloths have no teeth, I readily admit my mistake and feel myself indebted to M. Vosmaër for correcting the error.
[AN] Ulloa also in his voyage to Peru, says, that the unau climbs up the tree which is the most laden with fruit; and that when he has done, he rolls himself up into a round ball, and lets himself fall plump down, to avoid the trouble of descending.