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LORISES
and POTTOS
(Lorisinae)
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Stealthy creepers of the night:
Lorises and pottos are nocturnal and move slowly and deliberately,
hand-over-hand. They don't release a grasp until the next one is securely
in place. Unlike bush babies, they never leap.
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"Loris"
comes from the Dutch word "clown", referring to their often comical
frozen poses, and amusing faces.
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pottos appear to be closely related, DNA studies show pottos are actually
more closely related to bushbabies/galagos, the other nocturnal prosimian
found in Africa. Thus the similar form and behaviour of lorises and
pottos appear to be a result of convergent evolution. |
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How
is being slow an advantage? Being slow makes lorises and
pottos less obvious to predators, whose eyes and ears are often attuned
to quick moving prey like rodents. In fact, the first defence of a
loris or potto is to stay stock still. And they can freeze for hours.
Being slow also allows them to creep unnoticed toward their prey.
When they are within striking range, however, they can move quickly.
Lorises and pottos can make a lightning snatch by throwing themselves
forwards, and grabbing with their hands while their feet maintain
a firm grip on a branch. |
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 Lorises
and pottos have various adaptations to their slow-mo lifestyle. Their
hands and feet are modified for a very strong grip. Thumbs
and big toes are large and the
index finger is reduced to a nub. In this way, the thumb is often
at 90 degrees or even 180 degrees to
the remaining digits. This creates a powerful clamp-like grip between
the first and third digits.
They can move upright on top of as well as upside down under branches.
Hanging from their feet, they use their hands to grab food or prey
(like the slow loris on the left). A female Potto and Slow Loris in
fact signals that she is ready to mate by hanging from her feet. They
even mate upside down! |
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Freeze
frame: Both lorises and pottos can grip for a long time
without muscle fatigue because the arteries and veins in the arms
and legs subdivide extensively to form networks of intertwining
vessels which act as storage vessels (retia mirabilia). Thus the
exchange of oxygen and waste materials in the muscles continues
even though there is no bodily movement. Special blood vessel storage
channels in their hands and feet allows blood to flow freely.
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All digits have nails, except the second toe of the foot which has
a toilet claw used for grooming. |
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They
also have extremely flexible bodies. Lorises have more vertebrae in
their backs and the most vertebrae of primates, so they can twist
every which way to slip silently through thick undergrowth. Their
spine moves sinuously as they slowly change their grip. Their wrists
and ankles are more flexible. Their hip and ankles joints are also
more mobile than those of other primates. Because
they don't need to leap, their front and hind limbs of equal length.
All can stand and sit erect. They have a short tail or none at all. |
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| Loris
lunches: Lorises and pottos are omnivorous. Unlike other
primates, few rely on fruits. Probably because they lose out in competition
to other fruit eaters; primates during the daytime and bats at night.
The smaller ones eat more insects (up to 75% of their diet), while
larger ones eat more fruit and gum. All of them eat some amount of
insects. Because they are slow, they hunt slow-moving foul-smelling
or toxic caterpillars, beetles and millipedes. These are too slow
to run away, and too nasty to be eaten by other animals. Lorises and
pottos track these down by smell. They also eat whatever animal they
can catch, usually those which are asleep or can't run away: lizards,
small mammals, baby birds, bird eggs, bats, rodents. They snack on
any tasty edible vegetation: leaves, flowers. Lorises and pottos may
drink dew on vegetation. |
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Night
hunters: Lorises and pottos rely on their excellent night
vision and keen sense of smell to find and catch their prey. Like
other nocturnal creatures, they have vertical pupils which allows
them to better control the light coming into their huge eyes. In fact,
they see quite well in daylight as well. Lorises have large eyes compared
to their body size, less so for pottos. Because they don't rely on
hearing, their ears are small. |
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Attack
of the slow: Although
slow-moving, lorises and pottos are not defenceless. Their first
defence is to freeze and remain motionless. But when things get
desperate, they can fight back.
 The
neck of the potto (Perodicticus potto) (left) is protected
at the back by a shield created by spines (4 elongated vertebrae
that protrude through the shoulder blades in sleeves of skin) which
are covered by hard, cornified thickened skin. Usually, an attacker
has to approach the potto along the branch that it's on. When threatened,
a potto rolls up, with its head between its hands, presenting its
shield towards the attacker. Extra long fur (5-10cm) covers this
shield and is used to detect and dodge attempts to bite its neck.
The potto may suddenly bite its attacker, or use its spiny shield
as a battering ram to dislodge the attacker from the branch. Or
it may itself suddenly fall off into the undergrowth, particularly
if attacked by a snake.
The
Golden Potto (Artocebus calabarensis) lacks this shield and
instead, grips a branch firmly and curls up into a ball with its
jaws under an arm pit. As the attacker investigates the ball, the
potto suddenly delivers a painful bite to the attacker's snout,
often without letting go. Eventually, the predator will fling off
the potto, and the potto is then impossible to find again.
Pottos also have glands which emit toxic secretions. The noxious
scent of an alarmed potto often effectively warns off predators
who had previous nasty encounters with a potto. Potto mothers also
coat their babies with this secretion before parking them on a branch
while they forage.
The
Slow Loris and Pygmy Slow Loris also secretes a strong smelling
substance from well-developed glands under its forearms, which turns
toxic when combined with its saliva. It spreads this secretion on
its back as it rolls up into a ball. The toxin makes the loris a
distasteful mouthful and may even cause ill health in the attacker.
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Lonely
lorises: All the lorises and pottos are solitary. They
don't sleep or hunt together. Adults only meet when mating. To avoid
unpleasant encounters in the thick undergrowth, lorises and pottos
mark their territory with scents. Lorises and pottos "urine wash",
wiping their hands and feet in their urine so they automatically mark
their comings and goings. Lorises also have other scent glands. These
scents not only mark territory, but also identify the individuals
to each other, and inform males when a female is ready to breed. They
also make calls so they can keep their distance from each other. Females
have special calls to signal their readiness mate, and often emphasise
their status by hanging upside down! A male's territory is usually
larger and overlaps that of a few females.
During the day, lorises sleep alone, curled up into a ball with their
head between their legs. They may hide in a hollow tree or simply
cling to a branch. These small creatures need to conserve body heat
because they have low metabolic rates. So it is vital that they keep
their soft woolly fur clean. They groom themselves with a tooth-comb
formed out of their lower teeth, or with the grooming claw on their
second toe, or by licking themselves with their rough tongue. The
underside of the tongue has sharp, hard points and is used to clean
its tooth-comb.
 Babies:
A newborn can cling strongly to the mum's fur. A potto baby
clings onto mum until it is about 3 weeks old, but a loris baby
(left) will cling on until it is nearly as large as mum! Usually,
when the baby is a few weeks old, the mother will park it on a branch
while she hunts. At the end of the night hunt, she brings it back
to the sleeping nest where they snooze together during the day.
As it grows bigger, baby rides on her back, then moves on its own
as she teaches it what to eat and how to eat or hunt it. Babies
are usually weaned at 4-9 months. In captivity, up to half the births
are twins!
Status and threats: All lorises and pottos are CITES
2. Their habitats are threatened by destruction. Many are hunted
for food or for use of their body parts for traditional medicine
and charms. They are also captured for the pet trade.
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LINKS
to more lorises and pottos ...
 | Duke
Primate Centre fact sheets, photos, distribution map on
Slow loris, Pygmy slow loris, Slender loris
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| Creature
of the Dark: Loris tardigradus by Kimberley Anne-Isola Nekaris:
about lorids in general and the slender loris in particular,
lots of info, photos, video clips, links. |
| Animal
Diversity Web of the University of Michigan on loridae
in general with fact sheets on the Slender Loris (Loris tardigradus),
Slow Loris (Nycticebus coucang), and the Potto (Perodicticus
potto). |
| AZA
Species Survival Plan for Pygmy Loris: in the box "please
select a species" enter "Pygmy loris" |
| Minnesota
Zoo fact sheet on the slow loris |
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About prosimians in general
About lemurs in general
About
other prosimian families
Dwarf Lemurs
Tarsiers
Aye Aye
About specific prosimians
Black and White Ruffed Lemur
Ring-tailed Lemur
Fat-tailed Dwarf Lemur
Slow
loris, Slender Loris
Pottos
Galagos/bushbabies
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| Cleveland Metroparks
Zoo Education Division: fact sheets on the slow loris, slender loris
and lesser slow loris. |
| Anthropology
at College of the Siskiyous has pages on galagos
and bushbabies and lorises |
| Primate
Behaviour by Sean Flannery: fact sheets on Angwatibo or Golden
Potto (Arctocebus calabarensis) Slender Loris (Loris tardigradus),
Slow Loris (Nycticebus coucang), Lesser Slow Loris (Nycticebus pygmaeus),
Potto (Perodicticus potto). |
| Jim
Scarff's page on Lorises, Pottos, Galagos (Bush Babies) & Tarsiers:
info on all the potto and loris species. |
| Primates
as an adaptive array at the University of Texas Austin: info particularly
on the potto. |
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