are only found in tropical forest regions of the
New World. They belong with anteaters and armadillos to the family
of Edentata (also called Xenarthra) which evolved entirely on the
South American continent when it was an isolated islands. They are the
only survivors of those South American old timers. Presently there are only
five species of sloths divided into 2 genera left
in South and Central America (where they migrated after the Panama
isthmus arose).Both species of
two-toed sloths of the genus Megalonychidae (to which also the
extinct Giant Ground Sloth belong) are found in Ecuador. The Western
Two-toed Sloth is at home in the coastal tropical region whereas the
Amazon Two-toed Sloth is as its name suggests can be found in the rainforests
of the Amazon. Only one
of the three existing species of the three-toed sloth,
the Brown-throated
Three-toed Sloth,
is in Ecuador but it is the most abundant and encountered in
the coastal and Amazonian forest regions.
Sloths
are good swimmers and can be seen doing so in rivers.
We encountered this
three-toed sloth crossing the Tiputini river in the
Amazon. However most of their
time is spent on trees. There they
move surely but very slowly up and down the main tree trunks
and along strong side branches. Hanging down and holding
on with their long and strong limbs with
claw-like toes shaped into
hooks, they take their time giving the
impression of being dull and lethargic. Each day or two
they climb down and move to another tree.
Their metabolic rate
is very low for mammals and thus they do not need a
large food intake. Their body temperature while
active is between 30 -34° Celsius
and even lower while resting. New studies show that they
may sleep for ten hours a day. Baby sloths stay with their mothers
for the first six to seven months clinging to her back.
Sloths are arboreal and solitary animals
consuming mostly leaves of many tree species. They are
able to eat greens that other mammals cannot digest and so
forged out an almost uncontested habitat for themselves. Their
stomach is long and multi-chambered like in ruminants and full
of bacteria which help it to break down the cellulose
and unwanted defensive plant chemicals. Sometimes you may notice a
greenish sheen in their fur. That is a product of algae living
in their hairs giving it a better camouflage. For those
reasons they are often difficult to spot and easily
overlooked. Unlike other tree dwellers sloth descend to the
ground to defecate and urinate making a hole and covering their feces with
dirt.
Sometimes a big surprise awaits you while
traveling through the country. Driving from Puyo to Tena
we observed from far away something moving in the sky
and it was not flying. Getting closer we saw then an
animal suspended on a high voltage cable. It
turned out to be the common brown-throatedthree-toed sloth which must of gotten on it
climbing up the huge steel towers from where the cables
are suspended. But why it would
do so, escapes me. Surely being an arboreal animal
it ought to know the difference between artificial and
natural structures. But it apparently it does not and
climbs anything up resembling a trunk. Electric shock is
a leading cause of death among them. I just hope that it got off
safely again
and found a real tree.
Sloths have few natural predators, its most formidable being
the harpy eagle which can pick it off right from a
tree. Once on the ground it is also prey to jaguars. But as for most animals their main threat is from man.
They are hunted for food and also being caught for making
shrunken heads for ceremonial purposes. But more detrimental
are the secondary actions by man, especially the clearing
of forests.
