How Do Slow Lorises Work?

The slow loris is the world's only venomous primate, but it looks like a cuddly plush toy. Learn why you shouldn't go in for a snuggle in this episode of BrainStuff, based on this article: https://animals.howstuffworks.com/mammals/slow-loris.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio, Hey brain Stuff
Lauren vogelbaumb Here. Slow lorises are small primates with fuzzy
fur round heads, a small snout in ears, and wide
saucer like eyes that make them look like nothing more
than toys from the Thai beanie line come to life.

(00:23):
But as with wild animals in general, you shouldn't go
in for a cuddle. Slow lorises are the only genus
of venomous primates. When threatened, they raise their arms and
licked the oils secreted from glands in their armpits, which
then mixes with their saliva and pools in grooves on
their specialized comb like lower front teeth. Their resulting venomous

(00:47):
bite can cause necrosis or anaphylactic shock in humans, leading
to a nasty wound or even death. There are nine
or so species of slow loris that all live in
the forests of South and Southeast Asia and spend most
of their lives up in the trees. They have compact
bodies with only a small stump of a tail, and
all four limbs have long fingers and toes that let

(01:10):
them grasp branches, vines, and other objects. They have dense,
short fur in shades ranging from brown to reddish to
tan to white, often with a distinctive pattern on their face,
with lighter cheeks and forehead markings surrounding darker fur around
their eyes and making their eyes appear even bigger than
they are. The word loris comes from a Dutch word

(01:32):
meaning clown, alluding to those facial markings. The slow part
is fairly literal. A lorius can hang still from branches
for long periods of time to hide from prey or predators,
a thanks in part to specialized blood vessels in their
wrists and ankles, though their side varies by species. They
tend to range from about seven to fifteen inches long

(01:54):
from nose to butt that's about eighteen to thirty eight centimeters,
and they can weigh from just nine ounces to over
four and a half pounds that's about two hundred and
fifty grams to over two kilos, so we're talking about
kitten sized if cats are a familiar unit of measurement
for you, light cats, slow Loris's eyes have what's called

(02:15):
a tapitum lucidum that is a light reflecting surface behind
the retina that helps them see better in the dark
because it gives their retina another chance to sense the light.
Humans and other Haplerini primates lack this feature, which is
why our eyes don't appear to shine in the dark
the way that cats or dog's eyes do. This is
because humans are mostly active during the day, but slow

(02:38):
lorises are mostly nocturnal. They live in the branches of
bamboo and hardwood forests, usually sleeping during the day in
crevices or hollows. For water, they lick dew off of leaves.
Loriuses are considered opportunistic hunters. They use their excellent sense
of smell to hunt for insects and other small prey,

(02:59):
making slow, deliberate movements. They'll also eat fruit, nectar, and
tree gum, which is a sugary sap that they extract
from trees using that lower jaw tooth comb that I
mentioned a minute ago. In their natural habitats, lorises are
thus an important part of the food chain. They help
control insect populations, and they spread pollen between flowers and

(03:22):
seeds through their poop, which they deposit on the forest floor,
which is pretty much the only time they spend out
of the trees as so to avoid predators, but they
do serve as prey for larger arboreal animals like snakes, eagles,
and orangutans. Slow Loris's venom system is thought to be
one of the most complex on Earth. It's the only

(03:43):
one we know of that has two components that the
animal has to mix the oil from its underarm gland
and its saliva, both of which are each unpleasant alone,
but together they're potentially deadly to invertebrates and mammals, including
other slow lorises. It's thought that their diet, and perhaps
especially those tree gums, is how they obtain these toxic compounds.

(04:07):
Competition amongst low lorises seems to be the primary use
of their venom, though it may also help them prevent
attack from parasitic insects and arachnids. For the article, this
episode is based on How Stuff Works check down with
researchers at the Duke Lemur Center at Duke University. Although
they no longer house lorises at the center, how Stuff

(04:27):
Works spoke via email Anna Lie, an education technician there.
She said, when two lorises cross paths, interactions are generally positive,
grooming instead of fighting. In the wild, males and females
will occasionally remain in the same space while their offspring
are young, forming small family groups until the offspring get
older and disperse. These groups groom each other and sleep

(04:51):
in contact with one another, but they frequently forage alone
and there doesn't seem to be a clear dominant structure
in the wild. That family time can last up to
three years of a total of a ten to twenty
year lifespan, but lorises seem more territorial in captivity. It's
difficult to find and follow loris' in their remote rainforest

(05:13):
habitats because they're endangered. Duke researchers were interested in following
their life history, studying questions like how long female animals
nurse their young and how long they live in human care.
Ali said learning how to care for and eventually breed
them successfully in human care is important for their continued survival.

(05:33):
All breeding was done at the recommendation of a species
survival plan, which helps avoid overbreeding and maintains healthy genetics
for all slow lorises in human care. While we no
longer house them ourselves, what we learned during the years
we did keep slow lorises continues to help the colony
in human care at other facilities Today. How stuffworks also

(05:54):
spoke by email with Lee's colleague Jody Stark, an animal
care technician who worked with the slow loss when they
were at the Duke Glamer Center. She said that they
exhibited distinctive personalities quote. Some are very shy or stand offish,
while others are outgoing, curious and interactive with the staff.
The biggest threats to the survival of slow lorises are

(06:15):
twofold and man made, the degradation of its habitat, and
direct human interaction such as hunting or attempting to domesticate them.
Because of these and other threats, all species of slow
loris are listed somewhere from vulnerable to critically endangered by
the International Union for Conservation of Nature. A note here

(06:36):
that non human primates, including slow lorises, don't make good pets,
and trying to domesticate them isn't fair to them. Lorises
are meant to live with other lorises, not people. Lisaid.
Slow lorises rely on undisturbed rainforests to live in something
that's in short supply in our ever changing world. Some

(06:57):
are hunted for bush meat or use in tradition medicines,
while other slow lorises are kept as props for tourists
or sold into the international pet trade. With their distinctive
giant eyes and slow speed, lorises are frequent viral video stars,
driving up the practice of keeping them. As always, social
media doesn't tell the full story. Lorises taken from the

(07:19):
wild frequently have their teeth removed to prevent dangerous bites,
and their arm raising behavior seen in videos of tickling,
is a defensive posture used against threats like humans. I
would add here that due to the toxins and slow
lors saliva, humans who have handled or pet alorus have

(07:40):
been known to experience symptoms like numbness in their hands
and feet and even blood in their urine. Furry animals
often have heavy traces of their own saliva on their
fur from grooming. There are some programs working to help
slow lorises out in the wild. For example, on the
Indonesian island of Java, natural habitat has shrunk by as

(08:01):
much as ninety percent, so primate research groups are building
and installing loris bridges using irrigation tubing to connect spots
in the treetops so the lorises aren't isolated from their
home ranges. Today's episode is based on the article slow
Loris is a cuddly looking primate with a toxic bite

(08:24):
on how stuffworks dot Com, written by Patty Rasmusen. Brain
Stuff is production of iHeartRadio in partnership with how stuffworks
dot Com and is produced by Tyler Klaang. For more
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