That shaggy-haired creature, which may be seen hanging from the boughs
of the lofty cecropia--the much-abused sloth--is generally described as
a type of laziness, doomed to a helpless and wretched existence; but
such an animal the all-beneficent Creator has not placed on the earth.
To each animal that he has formed he has given an instinct and
organisation specially adapted to their mode of life and the part they
are destined to perform in the economy of nature. The sloth is formed
to pass its time in trees, and to feed on the superabundant leaves,
which would otherwise impede the circulation of the air, retard their
growth, or bring on premature decay. This duty it shares with
numberless other animals of the luxuriant forests of Tropical America.
Place the sloth out of its natural position, and, as would be the case
with other animals, it finds itself in a difficulty. Its destiny is to
live in the dense forest, where, the branches of the trees meeting each
other, it can move along from bough to bough, and make its way for
considerable distances without difficulty, or having to descend to the
ground. When by force or accident placed on the ground, it is unable to
move along except at a slow and toilsome pace. When by any chance thus
seen, its arms appear much too long, while its hind-legs, which are very
short, look as if they could be bent almost to the shape of a
cork-screw. Both fore and hind-legs, by their form, and the manner in
which they are joined to the body, are incapable of acting in a
perpendicular direction, or in supporting its body. Hence its belly
touches the ground. Even could the animal thus raise itself, it would
be in pain, as it has no soles to its fore-feet, and its claws are very
sharp, long, and curved. Thus, were its body supported by its feet, it
would be on their extremities; just as a man would be were he to go on
all-fours, and try to support his body on the ends of his toes and
fingers. "Were the ground polished like glass," says Waterton, "the
sloth would actually be quite stationary; but as it is generally rough,
the sloth moves its fore-legs in all directions, in order to find
something to lay hold of; and when it has succeeded, it pulls itself
forward, and is thus able to travel onwards, though in a slow and
awkward manner. Indeed, as its looks and gestures betoken its
uncomfortable situation, and as a sigh every now and then escapes it, it
may be concluded that it actually is in pain."
Thus it is evident that the sloth is formed, not to live on the ground,
but in trees; and on further observation it will be seen that, unlike
most other arborial animals, it lives, not on the branches, but under
them. It moves, suspended from the branch; it rests, suspended from the
branch; and sleeps, suspended from the branch. "Hence its seemingly
bundled position is at once accounted for," adds Waterton; "and in lieu
of the sloth leading a painful life, and entailing a miserable existence
on its progeny, it is but fair to conclude that it enjoys life as much
as any other animal, and that its extraordinary formation and singular
habits are but further proofs to engage us to admire the wonderful works
of Omnipotence."
In proportion as the sloth's organisation unfits it for terrestrial
progression, it is wonderfully adapted for climbing trees. With its
long arms it reaches right up, and clings to the branches with its long
and crooked claws. It has thus the power of grasping a tree which no
other mammal possesses. It is indeed the best climber among mammals,
while it is the only mammal that can neither walk nor stand. When
sleeping, the sloth does not hang head downwards, like the vampire, but
supports itself from the branch parallel to the earth. It first seizes
the branch with one arm, and then the other, and then brings up both its
legs--one after the other--to the same branch, so that all four are in a
line.
It is almost tailless. Had it a tail it would be at a loss to know what
to do with it in this position. Were it to draw it up between its legs,
it would interfere with them; and were it to let it hang down, it would
become the sport of the winds.
Waterton observes that he has never seen a tree entirely stripped of its
leaves; indeed, he believes that by the time the animal had finished the
last of the old leaves, there would be a new crop on the part of the
tree it had stripped first, ready for him to begin again, so rapid is
the process of vegetation in that region. In calm weather it remains
tranquil, probably not liking to cling to the brittle extremities of the
branches, lest they should break with it in passing from one tree to
another; but as soon as the wind rises, the branches of the neighbouring
trees become interlocked, and then the animal seizes hold of them, and
pursues his journey in safety, travelling at a good round pace--showing
that he does not deserve the name of sloth.
The head of the sloth is short, the face small and round, the hair
coarse and shaggy. There are several species, differing considerably in
colour, but resembling in general dry, withered grass, or moss. The
species vary in size from two feet to the size of a rabbit. Its face
resembles the human countenance as much as that of the monkey, but with
a very sad and melancholy expression. It brings forth its young and
suckles them like ordinary quadrupeds. The infant sloth, from the
moment of its birth, adheres to the body of its parent, until it
acquires sufficient size and strength to shift for itself. Its cry is
low and plaintive, resembling the sound of "ai." Hence the three-toed
sloth has obtained the name of the ai.
Mr Bates says that the natives consider the sloth the type of laziness,
and that it is very common for one native to call another--reproaching
him for idleness--"beast of the cecropia tree;" the leaves of the
cecropia being the food of the sloth. "It is a strange sight," he adds,
"watching the creature's movements from branch to branch. Every
movement betrays not indolence, but extreme caution. It never loses its
hold of one branch without catching the next; and when it does not
immediately find a branch to grasp with the rigid hooks which serve it
for paws, it raises its body, supported by its hind-legs and claws, and
feels round in search of a fresh foothold." In one of their voyages, he
and Mr Wallace saw a sloth (Bradypus infuscatus) swimming across a
river, at a place where it was probably three hundred yards broad. It
is not generally known that this animal takes to the water.