Slow loris venom can kill humans

Field biologist and conservationist George Madani describes his near-death experience with a slow loris. This account is soon to be published as a medical case study written by Madani and Nekaris in the Journal of Venomous Animals Including Tropical Diseases. Without medical intervention, George almost certainly would have died…

As a field biologist working in Australia I’ve had my fair share of perilous creatures to contend with. Deadly snakes with venom potent enough to kill a man several times over. Bone crunching, limb tearing crocodiles lurking in billabongs and rivers of the north . Even our toilets aren’t safe with the infamous Redback spider lurking in their favourite haunt of the noble outback dunny.

So when I visited Borneo a couple of years ago I thought the greatest danger I might face would have perhaps been with one of their legendary vipers or cobras. Maybe I would end up as lunch from an elusive neck seizing clouded leopard or perhaps being trampled by a herd of startled stampeding jungle elephants. Little did I think that I would be undone by a small, cute and furry little mammal.

Having been afflicted with a desire to catch and admire most critters from a young age I met my match in Borneo by what I thought to be the most unlikely of candidates. It was with considerable excitement that I came across my first wild slow loris, which inadvertently led to too close an encounter and ultimately the teeth of this nocturnal primate sunk deeply into my finger.

Loris Bite by George Madani

George after a young Nycticebus kayan deeply bit into his finger

Following a painful and frightening adventure into anaphylaxis I had a crash course into understanding that these cute little forest gremlins pack quite the punch being one of the worlds very few venomous mammals. The photos speak for themselves and if I can’t serve as a good example then I can certainly serve as warning! Leave the loris alone!


Read more about slow loris venom here

Lorises, tigers and bears –Oh my!

by Grace Fuller
Lately my work with lorises in Java has led me to spend a lot of time with the other residents of Cikananga Wildlife Center. One of the possible functions of slow loris venom is to repel predators, and I have been testing this hypothesis by observing behavioural reactions of potential loris predators to samples of venom collected from the Little Firefaces. So far, I have conducted tests with Malayan sun bears, orangutans, and three species of eagles: Javan hawk eagles, changeable hawk eagles, and crested serpent eagles. There are confirmed cases of orangutans and changeable hawk eagles predating on slow lorises in the literature, so the lorises have reason to be wary of these species!

To conduct these tests, I offer a sample of the venom with a piece of food, which ensures that the predator is motivated to explore the test item. For the bears, this means wrapping a venom sample collected on a tissue around a piece of rambutan (a tasty local fruit) and sealing it with a drop of honey. In the future, I will be testing Javan leopards and other felid species at Cikananga, and I am hoping to venture outside the rescue center to conduct further tests with other potential predators including tigers, civets, and snakes. I have also been working with the sun bears to collect saliva samples (see photo) which I plan to use to measure hormones to determine if the loris venom elicits a stress response in the bears. Stay tuned for what I hope will be some interesting results!

Why do lorises produce toxic compound

One of the most interesting facts about the slow loris is that it is the only venomous primate. Slow lorises produce a toxic compound from their brachial glands (a patch of bare skin from their inside elbow up to their armpits), which they lick to combine with their saliva and “activate” the venom. The reason why slow lorises are venomous is still somewhat of an unsolved mystery.


As part of my postdoctoral research with the Little Fireface Project, I am exploring some of the hypotheses for why slow lorises produce such toxic compounds. Is it to ward off ectoparasites, tiny bugs that live in their fur and potentially could transmit diseases to them? Is it to deter predators of the night, including owls, hawks, and eagles? Could the venom serve multiple purposes?

In order to answer these questions, myself and LFP volunteer Anna Zango have been conducting two separate phases of research. First, we have been conducting a series of experiments testing the responses of various insects to the venom of slow lorises, using a combination of saliva and brachial gland secretions. Second, we have been playing the sounds of predators to the lorises as they forage at night, to see if they have any interesting behaviors that might be related to using their venom. We have to carefully study their reactions, and some of the lorises actually move quite fast! Good thing Anna has such sharp eyes!


This project has been incredibly interesting. I never imagined to see such specific responses. So far, the data suggest that slow lorises are a lot more complicated, unique, and special than many people realize. So, I am really excited to continue this research exploring how slow lorises use venom as an adaptation.

Loris venom investigated

Slow lorises are unique amongst primates in being the only group of venomous primates. Though special in this way, much research remains to be done to understand the role of venom in the ecology of the slow loris. Why are they venomous? Prof. Nekaris recently proposed a series of hypotheses as to the venom function of the slow loris:

1. Anti-predator behaviour
2. Defense against eco-parasites (parasites living on the skin/fur)
3. Communication between slow loris individuals
4. To help in catching prey

How do lorises catch insects and what role does their venom play?

These amongst other venom related questions are being answered by new team member and post doc Grace Fuller. Grace has joined the LFP team in January studying the role of loris venom on the captive slow lorises housed at Cikananga Wildlife Rescue Centre.

Grace is performing experiments in which she presents the lorises with a range of different insects of various sizes and toxicity and records the lorises reaction. She looks at how they catch the insects, how long it takes them to catch the insect, as well as what types of behaviours occur before and after catching an insect. For example does the loris start grooming once it has caught the insect prey?

All of these interesting experiments will help us to understand why lorises are venomous and aid in reintroduction of ex-trade lorises to the wild.

Many slow lorises are found in Asia’s illegal wildlife markets. Their teeth are regularly removed to make them “safe” to keep as pets. Removal of the teeth also removes the ability to use their venom. These individuals can not be returned to the wild, even if saved from the horrible trade markets. They spend the rest of their lives cared for by wonderful staff at Asia’s rescue centres. Those, however, that have fortunately been spared the cruel pulling of their teeth with nail clippers can potentially be reintroduced. The work done by Grace and the LFP team is vital to understand what these lorises need for reintroductions to be successful!

‘Cute’ slow loris victim of own internet stardom


Decline in rare primate linked to viral videos

(paper at above link)


The results of new research published today in scientific journal Plos One show that unwitting watchers of YouTube videos are indirectly responsible for the demise of one of the world’s rarest primates, the slow loris (Nycitcebus spp.). The illegal trade in wild slow lorises, fuelled by their demand as pets in Asia and elsewhere, appears to be influenced by people watching clips of the primates on popular video-sharing site YouTube.


A team of researchers from Oxford Brookes University, with additional funding from the People’s Trust for Endangered Species, measured the public’s perceptions of the rare slow loris by analysing over 12,000 comments posted over a three-year period in response to a single video on YouTube featuring one of the primates as a pet. One in ten viewers who left a comment wrote that they wanted a ‘cute’ slow loris as a pet, suggesting a direct link between the illegal trade in slow lorises and their presence on YouTube videos.  Furthermore, over 100 individual slow lorises were recorded in videos on YouTube, more than are currently found across accredited zoos.


Professor Anna Nekaris, lead author of the paper and an international expert on slow lorises says:  “Videos of wild animals such as slow lorises that portray them as cute and cuddly pets in a home-setting can serve to reinforce people’s likelihood to want to acquire one.  Without further context to the video, it may not be obvious to the general public that these primates are in fact protected species and that in all likelihood they have been caught in the wild and traded illegally.”


Slow lorises are a group of eight species of nocturnal primate found throughout South and Southeast Asia; all species are protected in each of the 13 range countries where they occur.  They are unique amongst primates in that they have a toxic bite.  For this reason, traders clip the teeth of captured slow lorises with wire cutters, nail clippers or pliers before they are sold illegally in markets.  Sadly, these animals often die in transit from infection or stress even before reaching the market.


“The number of slow lorises making an appearance on the internet is increasing – a reflection of the rampant illegal international trade,” adds Nekaris.  “Without a shadow of a doubt, the slow lorises we see in most videos on YouTube are derived directly from the wild and not the result of captive breeding facilities.  The reproductive success of captive slow lorises in accredited breeding facilities such as zoo is extremely low, making it unlikely that any captive lorises have been bred commercially.  Illegal wildlife trade is committed on a massive scale worth billions, rivalling drug and arms trafficking.  Yet there is currently no recourse on unregulated social media sites such as YouTube to flag up wildlife crime.”


The study also analysed the effect of celebrity endorsement on people’s desire to acquire a slow loris as a pet.  Celebrity endorsement is a well-known technique used by marketers to influence consumer behaviour and the way products are perceived.  In this case, celebrities who suggested their followers watch slow loris videos on YouTube because they found the creatures ‘cute’ or ‘irresistible’, led to thousands of additional people watching them.


In addition to the illegal trade for pets, other major threats to slow lorises include the rise in the number of slow lorises used as ‘photo props’ in popular tourist destinations in Thailand, hunting for their body parts which are used in traditional medicine practices in Asia, and habitat loss.





Notes for Editors

  • People’s Trust for Endangered Species has been helping to ensure a future for many endangered species throughout the world since 1977.  Visit for more information
  • Anna Nekaris founded the Little Fireface Project in 1993 under the auspices of the Nocturnal Primate Research Group of OxfordBrookesUniversity.  Visit for more information
  • Since 2007, all species of slow lorises have been included on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (Cites), precluding all international trade.
  • Fifteen thousand individual slow lorises have been recorded at illegal animal markets in Indonesia alone.  This toll excludes animals that have died in transit from their wild habitat to the markets.

Loris Fact 6: You can’t chew with somebody else’s teeth

Well that’s a Yiddish proverb, but the loris would agree, and most lorises really love their teeth. Being strepsirrhine primates, lorises have really neat teeth! I think the Albuquerque zoo keeper Howard Kaplan explains it best in his song about the slow loris:

Lower front teeth pointing forward

Form a sharp comb in their arc

They clean the fur where encrusted

And scrape the resin from bark!

The behaviour: You can see in this video how a slow loris uses its toothcomb to groom the beautiful soft fur of its companion – this is called allogrooming and guess what? All this solitary stuff is nonsense! Slow lorises are super social and the toothcomb is essential for grooming and maintaining social bonds!

The anatomy: The toothcomb in the slow loris is made up of four incisors and two canines (the teeth that normally look like fangs). So those two fang-like teeth you can see sticking out in the photos are actually premolars. this means that when traders cut out the lorises’ teeth, they are normally removing 8 teeth. This leaves the loris with only 2 premolars and 3 molars to eat with in the lower jaw.

Conservation implications: This is pretty terrible because the slow loris is specially adapted to eat exudates – gums and saps; in fact this can make up most of their diet, and without their toothcomb they cannot be reintroduced to the wild and can even starve to death in captivity. Also, the shattered roots of these broken teeth most often lead to infection and death in affected animals. Finally, it is very hard to reproduce the exudate diet in zoos. This is why many lorises (who eat too many fruits in zoos) get diabetes, dental cavities, become obese and die. Only with extremely specialised care do lorises without teeth even have a glimmer of hope to lead a happy life. Certainly most people keeping them as pets have no chance.

The Science:

Streicher U, Collins R, Navarro-Montes A, Nekaris KAI.  (2012).Exudates and animal prey characterize slow loris (Nycticebus pygmaeus, N. coucang and N. javanicus) diet in captivity and after release into the wild. In (Masters J, Genin F, Crompton R): Leaping Ahead: Advances in Prosimian Biology, Springer: New York.

Nekaris KAI, Starr C, Collins RL, Navarro-Montes, A. (2010) Comparative ecology of exudate feeding by Asian slow lorises (Nycticebus). In (Burrows A &Nash L, eds) The Evolution of Exudativory in Primates. Springer: New York. Pp: 155-168.

Swapna N, Radhakrishna S, Gupta AK, Kumar A. (2010) Exudativory in the Bengal slow loris (Nycticebus bengalensis) in Trishna Wildlife Sanctuary, Tripura, northeast India. Am J Primatol. 72(2):113-21.

The problem with ‘Slow loris eating rice’

In the last week, a new viral slow loris video has penetrated the internet. An undeniably adorable, wide-eyed slow loris eating a ball of sticky rice, sometimes one grain at a time. Oh my gosh – it is soooo cute!! Or is it?

Well, yes! Slow lorises are beautiful to the eyes of many cultures. They are elegant creatures whose grasping hands are adapted to hold tightly to branches, and snatch important insect prey. Those huge eyes allow them to move in the forest during the darkest nights.

The cruelty of loris pets just begins to unfold. The loris is in a brightly lit room that really hurts its eyes. It goes into super slow mode. Wild lorises can ZOOM 8 km a night on the horizontal (e.g. not counting all the runs they make up and down vines, lianes, trunks and branches). When they are terrified they sit and look wide-eyed in the horrified manner of that cutey in the video. That is why so many of the commentators pick up on his fear and write, “but why does he look so scared?”

Lorises have a fabulously specialised diet, which is why we hardly ever see them in zoos, and why so many die even under specialised care. They eat insects full of secondary compounds, flower nectar, and tree gum. Rice will make them very very ill indeed! A favourite quote of mine about the loris is…’In captivity they will eat fruit, but so will a lion eat rice, or a hungry man his boots, but not with much gusto.”

The video features the Vulnerable CITES Appendix I-listed greater slow loris, Nycticebus coucang, found only in a limited range in Malaysia, Sumatra, Southern Thailand and Singapore. This group probably comprises at least three species or subspecies, meaning their conservation threat will even be greater. This also is one of the rarest types of of lorises found in zoos, meaning the animal in the video is almost without doubt from illegal trade. Even in countries where it is legal to have primate pets, the animal must have come from a legal import, and the parents must also have been legal; otherwise it is ILLEGAL to keep the animal. Even if the animal is bred at a pet shop, the parents must have been legally imported!!  It is almost certain that this little loris is therefore illegal, and YouTube is violating laws by showing illegal activity – the possession of an illegal CITES I listed animal as a pet.

Please don’t ‘like’ or ‘thumbs up’ this video and encourage this cruel trade. The suffering of animals for the trade is many not including:

1. being ripped from the forest, shoved in bags and plastic crates with no food and water

2. babies dying on the mother’s belly in this process

3. pregnant mothers miscarrying

4. most have their teeth cut out to avoid the venomous bite and most die due to secondary infection

5.most cannot stand the terrible market conditions and die before being sold

6. the rest nearly die during illegal transit

7. those that make it as a pet die due to poor diet and ill kept conditions, and live just 1-2 years rather than the 20 years they would live in the wild


The Unusual Suspects!

Radio tracking in Cipaganti has begun in the beautiful  mountains of Garut! Follow @Jolorijo’s blog for all the news, but meet the lorises here…the first two families…

Row 1: One Eye’s family: Mama One Eye, Mr Azka and Baby Hesketh!

Row 2: Ena’s family – Baby Yogi, Mr Guntur and Mama Ena!


Dr Anna Nekaris: Saving the world’s cutest animal

Posted on 19/01/2012

It’s cute.   It’s cuddly.  And it’s the world’s only poisonous primate.  Dr Anna Nekaris on the slow loris.  And how you can help save it.  Peter Moore

Dr Anna Nekaris has dedicated her life to studying the slow loris, a real-life gremlin that is extremely cute but with a venom that can kill.  Now it’s also a YouTube superstar with millions of hits, fueling an illicit trade in the animals as pets.

In the The Jungle Gremlins of Java, a BBC programme, aired on January 25, Dr Anna Nekaris travels to the jungles of Java to solve the riddle of its toxic bite.  She talks to Peter Moore about lorises and the dangers they are facing.

Read more here


Nigel Redman on 25/01/2012 at 21:11 said

I’m an ornithologist and have seen Slow Loris at an easily accessible location in west Java.  Please contact me if you require further information,


Ashley Wheat on 25/01/2012 at 23:22 said

After watching your programme the BBC  on the slow loris I feel truly inspired by your work and passion to help save this most wonderful, interesting and fascinating creature.

Following your comments that he slow loris could soon be extinct because of human exploitation and the illegal pet trade, I would like to ask how I can help in a campaign to save them, and secondly if I could offer advice to you in my area of expertise; multimedia computing, in helping you raise awareness.

Annalisa Fiorentino on 27/01/2012 at 16:04 said

Hey – I’m trying to start an official Facebook page based on your project.  Just wondering whether you already have one?  No point duplicating effort!

From 15 Cute Animals That Could Kill You….

Posted on 02/09/2011

Slow Loris

This animal might look like a harmless, big-eyed baby ewok, but the slow loris is one of the poisonous mammals in the world.  Its subtle nature makes it popular in the illegal pet trade, but unknowing humans should stay clear of its toxin, which is released from the sides of its elbows.  When threatened, the loris takes the toxin into its mouth and mixes it with saliva.  The animal will also lick its hair to deter predators from attack.  The toxin can cause death by anaphylactic shock.

But is it true? Amazing how this myth is all over the net!