I am one of the world’s leading experts on sloths and the founder of The Sloth Conservation Foundation, ask me anything!

slothcon profile image Sloth Conservation ・1 min read

Hello - Happy Earth Day! My name is Dr. Rebecca Cliffe and I am considered to be one of the world’s leading experts on sloths. I have spent the last 11 years living in the Costa Rican jungle where I have been researching the behaviour, ecology and physiology of wild sloths. During my years living in the jungle I have been infected with a flesh eating parasite, chased by killer bees and been stranded on a real-life desert island for three days.

Four years ago I founded The Sloth Conservation Foundation; a registered non-profit organisation that is dedicated to saving sloths in the wild through research and conservation initiatives. Through SloCo, we have developed a range of community-based strategies and programs that are providing sustainable ways in which humans and sloths can coexist peacefully. Today I am based full-time in Costa Rica where I manage all of the foundation’s in-field sloth conservation and research programs.

Ask me anything!

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Sloth Conservation


My name is Dr. Rebecca Cliffe and I am the Founder and Executive Director of The Sloth Conservation Foundation.


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Happy Earth Day!

Thanks for doing this AMA - what's the story behind these killer bees?!


Happy Earth day :)

The bees were in Colombia. I was on a field trip to collect some data on sloths over there and we were hacking our way through some pretty dense jungle. Our guide accidentally macheted through a hive of Africanized Killer Bees (major mistake). I had no idea what was happening, but our guide just turned and sprinted back through the jungle in the direction we had come from. With no explanation, and just seeing our 'tough' jungle guide running for his life, we all obviously panicked. We started running after him (all rules about being careful for snakes went out the window) but the bees caught up with us pretty quickly. They were in my hair, inside my clothes, stinging everywhere. The rest is a bit of a blur but I lost both boots, half of our equipment and we didn't stop running until we made it back to the car and locked ourselves inside. Thankfully we were all fine, but we had a LOT of bee stings between us!


Thank you for doing this!

What do Sloths seem to enjoy eating the most? Any special treats?


In captivity hibiscus flowers are an all-round favourite for all sloths! Two-fingered sloths enjoy carrots as well, but wild sloths are quite picky eaters and prefer only certain types of leaves. Young almond leaves are usually a winning choice for wild two-fingered sloths. Three-fingered sloths are big fans of a type of tree called Cecropia. They enjoy the leaves but the absolute favourite is the seed pods!


Just wanted to add a little evidence that sloths love carrots with a video my wife filmed from her phone whilst working with a sloth!


Hi Rebecca, thanks for doing this AMA.

What is your favorite Sloth fact? Any misconceptions about Sloths you'd like to clear up?


This is a hard question - I have so many fun facts about sloths! My favourite is probably that on average it takes a sloth 30 days to digest a single leaf (I discovered this during my PhD by feeding sloths a natural red dye and waiting for red poop to appear). I actually wrote my 10 favorite sloth facts for the BBC recently. You can check them out here:
10 facts about sloths.

And the biggest misconception to clear up is probably the lazy one. When sloths were first discovered they were described in the literature as the "lowest form of existence". They didn’t really get off on a very good foot. People often believe that sloths sleep for 23 hours a day, or that they can spend an entire week and not move. They’ve got stuck with this lazy stigma and everyone believes it because it’s sort of a nice story. What we’re actually finding out is that sloths don’t sleep that much at all. They only sleep for about 10-12 hours a day (I know some humans who sleep more than that!). The rest of the time they are moving, but they’re just doing everything really, really slowly (they move a bit like they are swimming through a lake of Nutella).

Actually, this slowness is an amazing way to survive. When you don’t have the energy or physical capability to run away from a predator then you have to rely on them not seeing you in the first place. Sloths are basically in stealth mode 24/7. If they are able to successfully hide from sharp-eyed predators like jaguars, then they don't have any problems hiding from human observers. This is why they have been so poorly researched, and it is why we know so little about wild sloth behaviour. They have gone completely under the radar for decades. It is only in recent years that we are beginning to see just how fascinating the sloth lifestyle is – and we still have so much to learn.


Hi! Thank you so much for doing this. Why did you get involved with Sloths in particular?


I originally began working with sloths by accident - while I was studying for my undergraduate degree one of my supervisors had set up a research link with a sloth sanctuary in Costa Rica. I needed to complete a 12 month research placement, and I jumped at the chance to spend a year in the Costa Rican jungle. I immediately applied for the position and after several rounds of interviews, I got the job! Two months later I flew out to Costa Rica and the rest is history. During that first year I very quickly discovered that there was very little scientific literature on sloths, and no one was doing any sort of long-term research. Of course baby sloths are unbearably cute, but I find sloths more interesting for their unusual biology. They are so unlike any other mammal on the planet and yet we know so little about them!


So awesome!

What's something particularly interesting and lesser known about sloth behavior? (I'm editing my question here as I realize it overlaps with a few others, haha!)

New question — how are y'all (SloCo) dealing with COVID-19? Can you talk about the impact the virus has had on the org and wildlife conservation in general?


Hi Michael!

Our team at SloCo are all quarantined in Costa Rica and so we have had to put a lot of our sloth conservation programs on hold temporarily (particularly those involving the community). Charitable giving is understandably not very high on anyone’s priority list at the moment and so we are working on developing a strategy to see us through these difficult times. It is of course a very stressful situation for everyone at the moment.

On a more positive note, we are using this time in isolation as an opportunity to diversify our income and get our projects organised behind-the-scenes. We have lots of exciting new ideas that we are working on and I really think our programs are going to benefit from this time in isolation in the long-run.

The virus seems to have had varying degrees of impact on wildlife conservation. Of course, the silver lining to the global lockdowns has been the massive drop in pollution. Mother Nature is bouncing back. It will be interesting to see how life resumes after the global lock-down ends. Hopefully we will all come out of this more caring and compassionate towards the planet! Unfortunately a lot of wildlife conservation efforts (including SloCo) are taking a huge financial hit and programs have had to be suspended. Big funding sources have dried up (e.g. funding through zoos) and fundraising events have all been cancelled. No one can really predict how things are going to play out for the rest of the year, but our team are all grateful that we are safe and healthy here in Costa Rica!


Hello! Stranded on a desert island 😱!? Can you tell us more about that?


We were on an expedition to the isolated and uninhabited island of Isla Escudo de Veraguas in Panama to document the swimming pygmy sloths. We had a successful trip, and just as we were about to make our journey home, a huge tropical storm rolled in and left us trapped without any supplies, food or shelter. We had to ration water, catch lobster and cook it on a fire, and sleep in an open speedboat in the ocean because it wasn’t safe for us to sleep on the beach, as there were deadly snakes and biting flies. We were on the island for three days. We eventually managed to travel back to the mainland in a little boat when the storm lifted and it was safe to make the crossing. It is a notoriously dangerous journey even when the sea is calm, so doing it in the wake of a tropical storm was probably one of the scariest things I have ever done!


Thanks for doing this AMA Dr. Cliffe! These questions come from my daughters who are big sloth fans. In fact they think my job is really cool because our mascot is a sloth. 😉

Here's their questions:

  • Can they visit the Sloth Conservation (assuming post-pandemic 🙃)
  • How old do you have to be to become a volunteer?

They also wanted to let you know that they've visited the Kids Saving the Rain Forest and have also seen quite a few sloths in the wild as well as their bedrooms.

Sloth hot water bottle cover


Hello! So happy to hear that your daughters are big sloth supporters, thanks for sharing the photos! Unfortunately we are not open to the public as we are not a sanctuary or rescue center. SloCo is a non-profit organisation that specializes in the conservation and research of wild sloths - our dream is to prevent sloths from ever needing rescue by tackling the problems that these animals are facing in the wild. We are however aiming to build a sloth education center at the end of the year that will allow us to welcome guests and offer educational opportunities - so perhaps in the future we can show your family around!

We also don't accept volunteers currently as we prefer to provide paid employment for local people in Costa Rica to carry out our conservation programs. We are always looking to have people help out remotely though and we have no age limit on this!!


Thanks for sharing all that info and it's great that you employ local.


Hi Dr. Rebecca :) Your work sounds super interesting, during those 11 years how did you go about researching the behaviour of wild sloths? What are some of the high level things you would do in a week of research?


My work has varied a lot over the years, but my biggest project was something called 'The Sloth Backpack Project'.

You think sloths would actually be quite an easy study subject because they don’t move that much. You’re not chasing a cheetah around the plains of Africa, after all. However, as I started to follow wild sloths around, I soon discovered that once they go up into the trees, you can’t do any observations on them whatsoever. If you’re lucky, you’ll get a glimpse of them every now and again. If you want to know what they’re eating and how much time they’re spending in different behaviors, you can’t see that with your eyes.

The Sloth Backpack Project utilizes the latest in animal-tracking technology to record, for the first time, exactly what wild sloths are doing. The backpacks contain small data loggers called 'Daily Diaries' that record body movement and environmental data up to 40 times per second. When you’re putting a data logger on an animal it is hard to use it in a collar format because the collar can twist around and you never know which direction the animal is facing. That’s where the whole backpack idea came from because it held everything nicely against the animal’s back. Whenever it moved or whenever it did anything we could have the data logger record it. The data loggers are recording GPS points so we know exactly where the sloth is, but they’re also recording every time the animal moves, every time it chews, every time it climbs down the tree or up the tree and we have pressure sensors so we know how high the animal is.

There are also temperature sensors and light sensors so we know whether he’s basking in the sunlight or curled up in the shade. You can really put together exactly what the wild sloths are doing and where they’re doing it. That is key to understanding their ecology. What I wanted to get out of all of this research is to help the conservation of the species. It’s difficult to conserve an animal that you know is suffering in the wild, when you don’t know what the species needs in order to survive.

We are about to expand this project later this year (once the pandemic calms down) because I really want to understand the difference in behaviour between sloths that live in healthy forests, and those that are living in disturbed areas. We are also in the middle of a huge genetics project to look at how habitat loss is affecting the genetic diversity of different sloth populations. This involves climbing a lot of trees to collect hair samples from hundreds of wild sloths!


Do sloths really fart through their mouths 🤔?



Hey Rebecca, great idea to start an AMA for this!

Do Sloths have natural enemies in the wild?


Yes - humans! Unfortunately sloths really don't do very well when faced with a rapid change in the environment, and that is exactly what humans are doing. Aside from people, sloths' main predators are big cats (like jaguars, ocelots) and birds such as harpy eagles!


That's a good point, I think the constant development of land and cities is one of the many aspects how humans are dangerous to Sloths.

Thanks for the answer :)


How smart are sloths?

How do you feel about the portrayal of sloths in Zootopia?


Sloth intelligence is a very poorly studied topic. It is true that sloths have small brains compared to their body size, however scientists are now realizing that this actually doesn't relate to intelligence at all. The brains of sloths might be small but they are very much focused on the specific skills that they need for survival. For example, the section of the brain that controls forelimb movement is well developed for careful climbing, and the sloths spatial memory is particularly impressive. Having a good spatial memory is important for sloths as they are almost completely blind on bright sunny days - they navigate around their home ranges using their memory and sense of smell! However, the sloths social skills and problem solving abilities are somewhat lacking, which often leads to them being labelled as "stupid".

LOVE Zootopia. I think a Flash won the hearts of many people who are now devoted sloth supporters! I particularly liked that they emphasized the sloths being slow, rather than lazy :)


How do conservation organizations think about tech and their websites? Is there a concerted effort to evolve alongside digital changes?


I can only really speak for myself and SloCo here, but we are trying hard to keep up with the rapidly evolving digital world. It's difficult - we are a small team of hard-working people, none of whom have any tech experience. We are also limited by funding, and so it is almost impossible for us to stay on the forefront of technological advances. We are however a relatively young team and I think we are more open to advancements than some of the 'older' organisations. I think there is huge opportunity for people with technological skills to lend their knowledge and expertise to help non-profit organisations that may not have the funding or the staff to dedicate to developing these areas. I know at SloCo we are always super appreciative of anyone wanting to help us out!


Thanks for the reply! I find this very interesting. There is a strong culture of volunteering in the tech community but there is often a disconnect in terms of matching folks with those truly in need.

I don't have an immediate answer because it's a tough problem but your response definitely provides insight.

I absolutely agree! There is probably a market out there somewhere for a platform that matches volunteers with skills to offer with non-profits that are actively seeking someone with those skills...


Another question! For anyone interested in donating to The Sloth Conservation Foundation, where can we go?

p.s. If you want to drop a link to somewhere you just format it like this:

[This is the text folks will see.](Drop the URL you want to link to here.), for example [The Sloth Conservation Foundation](https://slothconservation.com/)


Thanks Michael! As a non-profit organisation, we really do rely on donations to make our work possible - especially during this difficult time! If anyone wants to find out more about our projects, or wants to see how to get involved in helping, all of the information is available on our website.

We have loads of different options available! You can adopt a sloth, or even offset your carbon footprint (we will plant sloth-friendly trees for you in areas where habitat loss is threatening the survival of wild sloths)!


Hi Dr. Cliffe, thanks for doing this fun AMA!

Do you have a favorite sloth you've known? What's the story behind that sloth? Any notable behavior or personality quirks of that sloth?


Without a doubt! His name is Bojangles. I have tracked and followed the movements of this tough little sloth ever since he was born. I fitted him with a miniature baby-sloth sized tracking backpack 8 years ago and I have since watched him grow up to become the fiercest sloth in the rainforest. He once grabbed hold of my finger and didn't let go until he had caused permanent nerve damage. It's a love / hate relationship between me and him (of course I love him, but to him I am just the annoying scientist that follows him around). I am about to have his face tattooed on my arm! He is actually available for adoption through our website., and his full story is included in the adoption packet!


Awesome! Sloths are my favourite animal, as you can see. I even have a sloth tattoo. How are they to interact with close-up? Cuddly or bitey, inquisitive or dismissive? That sort of thing


Good question! A lot of people think that sloths are like living teddy-bears, born to hug. Actually, the opposite is true. As a prey species, sloths are terrified of any human contact and they do not like hands-on contact at all. Even sloths that have been raised by humans in captivity are not particularly fond of people. If you try to cuddle a wild two-fingered sloth then you will regret it very quickly. Sloths have big teeth and they like to use them! I have seen someone get bitten through the hand by a sloth and you could see all the way through the hole in her hand afterwards! Sloths that are subject to a lot of human contact usually tend to internalize the stress. They won't always react aggressively, but science has shown that they experience abnormal blood pressure and heart rate responses when humans approach in a captive setting. This can be a little misleading as people often assume the sloth doesn't mind the interaction, but it is actually causing a lot of internal stress for the animal. This is the reason why we don't support any organisation that offers hands-on sloth interactions for paying guests!


Awesome, thank you. Being bitten through the hand sounds very painful :(.


How is SloCo using public data to further the conservation of sloths? What public data would make a better path to conservation?