The Urban Sloth Project Recap – Part II | 2022

The Urban Sloth Project Recap – Part II | 2022

The Urban Sloth Project is a research aiming to study how habitat disturbance in urbanized areas of the South Caribbean of Costa Rica is affecting the behavior and ecology of wild sloths. The project is entering its 4th year, and surely, monitoring sloths is never a boring task.

sloth dilemma dog facing sloth
Photo: Suzi Eszterhas


We already made a recap for the first 13 months of the USP, covering from November 2020 to December 2021. We recommend you to give it a look at Part I before reading this one!


January: Falling trees, falling sick, and falling in love with Celeste


The USP got off to a rocky start in January of 2022, beginning with sloth tracker Sarah almost getting squished by a falling tree while out tracking Baguette through Heck Swamp. This was back when Baguette was largely unfindable, and we weren’t sure if it was the equipment or the sloth. Later that month we got a new radio receiver, which at least answered that question (Baguette was just a master of disguise), and we were able to track our other Urban Sloths much more effectively!


Amelia and Dayber at Heck Swamp searching for Baguette.


Covid swept through the Tracking Team in January, laying low our heroic sloth spotters for a few weeks, and unfortunately, they weren’t the only thing that felled: some major deforestation in Luna’s territory the previous December has us really worried, but we and some other conservation organizations came together to fence off the area again, and hopefully prevent it from being used as a parking lot. This will help trees get established, and make it safer for the animals when they have to come down.

For all of the difficulties though, there are always bright spots, and the sickness and danger seemed worth every moment when we spotted Luna with her new baby Celeste! Celeste was only a few days old when Sarah found the duo crawling across the wreckage of trees in their territory, but they eventually made it up to the safety of the canopy to launch 2022 in style.


Luna and her baby Celeste


February: Luiza, the new neighbor for Luna and Celeste


We added Luiza, a three-fingered female sloth, to the USP in February after spotting her on the ground in exactly the same area where we had first found Luna and Sol. Both sloths live at opposite ends of the same stretch of forest.


Luiza and her backpack. Photo Luis André Barroso


Luiza lives next to (and sometimes on) the beautiful Cocles Bluff, Bouncer Of All Radio Signals, which is an oasis of nature just outside of the busy town. You can almost forget you’re a stone’s-throw away from a busy main road.


amelia cocles bluff
Amelia tracking at Cocles Bluff

February also saw Croissant disappear deep into Arse End Swamp, and Mango get over her fear of heights and climb up into the canopy like a proper sloth.


March: Loving tropical fruits and Nachos


Mango has always been a favorite of the USP, partially due to her proximity to SloCo headquarters, so when we got an opportunity to add another nearby sloth we were so excited! Maracuya, a three-fingered sloth, joined the USP in March when the Tracking Team were out looking for Mango. At the base of one of Mango’s favorite trees was a little sloth, nearly identical to Mango, laying under a tangle of vines that had become detached from the trunk. Maracuya and Mango quickly got dubbed the Fruit Twins and were tracked back to back for the duration of Maracuya’s time in the project.


Mango (left) and Maracuya (right)


Nacho, the adventurous two-fingered sloth who was always spotted in bars and restaurants in town, was one of the most interesting sloths we monitored during the months he was part of the project, but after a backpack and a collar were stolen, we decided to remove him from the project.

Nacho was always surprising us with the places we found him in.

April: Baguettes, backpacks, and babies


The highlight of April was the epic Hunt for Baguette, in which the entire SloCo team spent days wading through the stink and dangers of Heck Swamp to find our most mysterious sloth and get her backpack off once and for all.


Arse End Swamp is literally in the middle of Puerto Viejo town.


With the addition of Dayber and Fran, who are usually busy planting trees and connecting canopies, Baguette was finally found, caught, uncollared, and discovered to have given birth to a baby while hiding from us! We were the proudest not-really-godparents ever, and managed to relieve Baguette of her backpack.


Baguette with her baby


The Tracking Team took some volunteers into Mango’s territory in April for a bit of a treat and some sloth education, and besides Mango, they discovered a very angry beehive. Amelia took some stings for the team and most of the volunteers got away without further incident.


May: Tech upgrades for the twins


May saw a change of tech for Mango, upgrading from a collar to a backpack. We felt, when we first found her, that Mango was a little too small for a Daily Diary Logger (otherwise known as a Sloth Backpack) and telemetry tag, but now she’s all decked-out in tech.

Our incredible sloth backpacks have taught us so much about sloth ecology that we barely guessed at before, and quite a few things that we never would have guessed in a million years!


Baguette with a backpack


Mango was very cooperative for her backpacking, and her neighbor Maracuya crossed over to the other side of the road to explore some new territory there. Thankfully for our tracker–and for Maracuya–she quickly returned to the original side of the road, as her new spot featured a guard dog who took his job very seriously. If we’d had a backpack on Maracuya, we might have known exactly how she accomplished this, but alas we only have so many backpacks, and they must be deployed sparingly.

June: Close encounters with snakes and sloths


We got our wish for more sloths in backpacks in June, when we changed out Mango’s backpack AND got one on Maracuya after all!


Dr. Rebecca Cliffe and our volunteer Haley with Mango.


Two months of back-to-back backpacks on Mango was very exciting, and we were thrilled to learn what Maracuya was up to when we weren’t watching.


Maracuya posing for his health check


Luna had some batteries in her collar running low, but cooperated very nicely with us to get her collar changed, and Luiza made a rarely observed descent to the ground. Amelia got a close encounter with a harmless vine snake while watching this, which nonetheless gave her a good reminder as to why we wear snake guards while tracking.


We can’t change the batteries in the collars as the units are completely sealed to make them waterproof. Once batteries have died we have to discard the collar and fit a new one.

July: Welcome, José and Deborah!


The most exciting thing to happen in July wasn’t for once a new sloth, but a new Urban Sloth Project lead! José joined the team in July and has been really showing his colors as he takes the USP to new heights. During his first month on the job he managed to spot the extremely elusive Croissant, thereby seriously impressing the rest of the Tracking Team, who had not had visual confirmation of her in a while.


Meet José Pablo Guzman!


Besides a new sloth tracker, we also got a new sloth in July: Deborah. Like Mango and Maracuya, she is a young sloth that lives near HQ and makes tracking her a dream. Two-fingered sloths are generally more aggressive than their three-fingered counterparts, so Deborah was (unsurprisingly) uncooperative throughout the collaring process.


Sleepy Deborah


Deborah came out of anesthesia more quickly than anticipated and did her best to bite the researchers trying to take her measurements. Happily, she did not succeed in this and was quickly released back into her trees. Alan showed up for a brief cameo after a long absence but did not come down for us to retrieve his collar.


Deborah after her release

August: More tech theft


August was a frustrating month for the USP. Someone removed Maracuya’s collar, necessitating Team Sloth to borrow a metal detector to find it among the weeds bordering the beach near Mango’s territory. We believe that Maracuya was unharmed during this theft, but with no way to track her, we just have to take it on faith that our little fruit sloth came away from her encounter all right!


The precise cut indicates the use of a sharp element like a pair of scissors or another cutting implement.


Luiza got a change of tech in August, which was at least much easier to accomplish than finding Maracuya’s missing collar, as Luiza came low just as the signal from her collar started indicating that it needed a new battery. After a frustrating month, we were very thankful to Luiza for making one task a little easier.


September: Sloth moms


Luiza surprised everyone with a new baby in September, first spotted in photographs taken while tracking, and later confirmed in live sightings! Sloth babies are tiny and hide easily from our eyes up in the canopy, nestled into their mom’s tummy.


Can you spot the baby’s silhouette in this image?


At the end of the month, we also added a two-fingered mom and baby duo who we appropriately named Pumpkin and Pie. Despite Pumpkin being the largest two-fingered sloth in the project by a large margin, collaring her was a breeze. The addition of two two-fingered sloths was welcome, as most of our Urban Sloths are three-fingered.



At this point, four of five of our two-fingered Urban sloths had to be removed from the project for a variety of reasons. Additionally, three-fingered sloths are far easier to collar as they do not need to be anesthetized and the risk of blood-shed is far less, all of which skews the ratio of collared sloths to three-fingereds. September also kept the team busy with a new backpack for Deborah, and more data gathered from Mango.



October got off to a rocky start with the electrocution of a two-fingered sloth in Pumpkin’s territory–initially, we feared it was her, but we can at least report that Pumpkin is fine. We keep a database of all electrocuted animals to report all incidents to the electrical company, ICE.

The rest of the month was super busy with the preparation and execution of the Second International Sloth Festival  and International Sloth Day on October 20th, and the crazy amount of effort that went into pulling off such a major event! It was all worth it though to see how many people turned out in support of our favorite animals, and how much we got to celebrate, learn, and teach.


sloth fest 2022
Our volunteer Faith using the telescope. Photo: Mira Meijer


Jose took many people for a quick jaunt over to Luna and Luiza’s territory to show them firsthand how sloth tracking is done. Luna acted as the ambassador to the event, hanging out in some very visible trees and giving some satisfying visuals to all our would-be sloth trackers!


José explains how the radio receiver we use to track sloths works. Photo: Mira Meijer.

November: The good news and the bad news


If October was busy, November was empty… of sloths, that is. Not all sloths, of course, but Arthur played hard to get, and some extensive tree trimming in Mango’s favorite uva cluster drove her deeper into her territory, though we are happy to say she has since been reclaiming what is left of her tree.

Little Pie heartbreakingly disappeared from Pumpkin, and Deborah nearly went blind from the dust of the road getting into her eyes. She ended up needing emergency treatment to save her sight, which SloCo was able to help her with.


deborah eyes dust
Deborah’s eyes


In better news, Luiza’s baby was happy and active for the month of November, often seen reaching out and taking an interest in the world around her mom. In November we also added Zeus, a two-fingered sloth!


Luiza and her baby. Photo José Guzman.

December: Improvements


December saw José saving some sloths from the road while off duty…though of course, you’re never really off duty when you’re on Team Sloth.

Luiza’s baby continues to thrive, Luna has been moving around her territory a lot, and sometimes she overlaps with her neighbor Luiza. They were once even spotted in the same tree together, though, since sloths are solitary, this probably had more to do with the tree leaves being very tasty this season.

Arthur is still high in the trees and we’re just waiting for him to be reachable so as to remove his collar. We want it back, Arthur!


After many months, José finally got a picture of Arthur!


In better news, Deborah has moved to higher branches in her trees, which is great news as it will likely protect her eyes from further dust attacks.

Finally, we have ordered more data loggers (backpacks), and hope to deploy them for a fresh start in 2023!

2022, what a year!


In conclusion, did we think the Urban Sloth Project would be this eventful? Not really! That’s the difficulty and the wonder of doing something completely new–the things you learn along the way. 2022 was a really eventful and successful year for the Urban Sloth project, and we can’t wait to see how all of our big plans for 2023 turn out!

rebecca cliffe backpack sloth

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2022 | A year in review by Dr. Rebecca Cliffe

2022 | A year in review by Dr. Rebecca Cliffe


For SloCo, December is a time for reflection and review; we write our annual reports, study what went wrong, celebrate what went right, and continuously look for what we can improve. Overall 2022 has been a great year for us: we’ve achieved (and exceeded!) so many goals that our motto for the year has become “Dreams Really Do Come True”!


sloth release
Releasing the sloth named Baguette after fitting her with a data logger backpack. | Photo: Suzi Eszterhas


2022 was a record-breaking year for us and we are thrilled to celebrate the achievement of three of our long-held dreams: the acquisition of land for a protected primary forest reserve, the start of the Great Sloth Census, and the attainment of non-profit status under Costa Rican law.

We also reached some major milestones in our conservation efforts, have continued to oversee the growth of our local sloth-friendly communities, hosted the Second Annual International Sloth Festival to resounding success, and saw our founder and executive director Dr. Rebecca Cliffe honored with the very prestigious Future For Nature Award.

We recognize how important it is to learn from our mistakes and celebrate our achievements, and we are excited to share with you our 2022 recap.


Dreams do come true

Perhaps our most exciting development this year saw us taking our first steps towards creating a primary rainforest reserve where we will hopefully soon have our new SloCo headquarters! We work to protect wildlife at all stages of their interactions with humans, but by far the most satisfying outcome is when they don’t need rescuing at all.


jungle rainforest
A jungle hill with an ocean view in the South Caribbean of Costa Rica | Photo: Suzi Eszterhas


This beautiful plot of land in the South Caribbean will be a safe wild space for sloths and so many other animals and will be an excellent showcase for how to protect and preserve wild spaces.


The Great Sloth Census

This year we launched our most ambitious project yet: the Great Sloth Census. This history-making endeavor will be the first-ever accurate method of counting wild sloth populations and measuring their movements and trends. To achieve this, we are partnering with Working Dogs for Conservation who have helped us to train the first ever sloth detection dog.


Keysha tamara scat dog
Keysha and Tamara working in the rainforest. | Photo: Mira Meijer


This special dog is leading us to the unique places where sloths leave their feces, and we will be able to use this to determine a whole array of fascinating things: including how many sloths live there and how healthy they are!


We are a legal non-profit association in Costa Rica

What’s the difference between an organization and an association? Quite a lot, according to the government of Costa Rica! Now that we have officially received our papers labeling us as an association under Costa Rican law, we are able to expand our services in a lot of exciting ways.


sloco team


We can now fundraise with merchandise and tours, and apply for grants from the government that we previously did not qualify for. This is a huge step for helping integrate SloCo into the local communities!


Winning the Future For Nature Award

In May this year, I became one of the winners of the prestigious 2022 Future for Nature Award! Along with Tiasa Adhya of India, and Gabriel Massocato of Brazil, we proud leaders of the future of conservation work each received €50,000!


Future For Nature Award
Dr. Rebecca Cliffe, Tiasa Adhya, and Gabriel Massocato. | Photo: Future For Nature courtesy.


This funding enabled the beginnings of the Great Sloth Census project, and we are honored to join the ranks of the women and men recognized by the FFN award for their commitment to protecting wildlife.


Sloth Crossing Project

This year the Sloth Crossing Project reached an exciting milestone during the Second International Sloth Festival, held in October, when we put up our 200th sloth crossing bridge!

In April the team drove all the way over to the other side of the country on a five-day excursion to Ojochal and Uvita on the South Pacific Coast, where they installed eight bridges in Marino Ballena National Park.


ojochal marino ballena
We visited this amazing school @lifeprojecteducation and met all the children who go here.


We also worked with ICE long enough to put up 3 wildlife bridges over the main road, and another six over the powerlines in Playa Negra!

This is actually a much bigger undertaking than it sounds like. To install anything over a road in Costa Rica you need legal permission from multiple agencies, including the government and ICE. They have to approve the location and agree that a bridge is necessary.



They have to make sure that the trees being connected are hard-wood and strong enough to support the bridge, that the power lines won’t be affected, and that the design of the bridge is safe and there is no risk of it falling into the road. And finally, they have to turn the power off to an entire region while the bridge is installed! Getting all of this approved is a logistical challenge and SloCo has been working with the relevant agencies for several years for permission to move forward with this project.

Check out this map to see the locations of all our sloth crossings (and tree plantings!) since 2019.


Sloths, Kinkajous, and camera traps

In addition to simply installing the bridges, we also launched the Camera Trap Project to study what other animals use our Sloth Crossings. We will also be studying which crossings get used the most, and why. So far we have installed 13 cameras and are pleased to report some amazing footage of many different species!


camera trap sloth kinkajou
Sloth mother with her baby staring at the kinkajou


Our favorite so far is an interaction between a mother and baby two-fingered sloth (Choloepus hoffmanni) and a kinkjou (Potos flavus). If you’d like to see more of the Sloth Crossing Project, check out this video made by Mongabay!



The Urban Sloth Project

The Urban Sloth Project has seen so much progress since our last yearly update, if you’re not caught up yet, read all about the beginnings of the USP, from 2020 to 2021, here!

We’ve added four new sloths to the USP: Luiza, Maracuya, Pumpkin, and Deborah, and retired two: Baguette and Nacho. Baguette didn’t really want to be tracked anyway, and Nacho, well, he isn’t wearing a collar anymore, but he’s still an honorary Urban Sloth! (If you miss Nacho, don’t worry, he’s still contributing the project and is still up for adoption!


Dr rebecca cliffe with a sloth
Dr. Rebecca Cliffe measuring Baguette | Photo: Suzi Eszterhas

Luna had some changes in her family life and territory, which she has seen through like a total champ, and we are always excited to track her and her neighbor Luiza.

Some great numbers:

  • 19 total sloths monitored
  • 15 adults
  • 4 babies
  • 11 three-fingered sloths
  • 8 two-fingered sloths
  • 37 pieces of jungle-resistant tech
  • 13 backpacks
  • 14 collars
  • 7 antennas used
  • 3 devices lost/stolen
  • 12 sloth trackers
  • +1,300 hours of tracking
  • +21,200 data points manually recorded
  • +3,8 billion data points collected by the backpack data loggers

A large and very exciting change to the USP has been our new sloth researcher, José Guzman, under whose leadership the Urban Sloth Project is poised to grow to new and greater heights. Welcome, José!


The next generation

In March of 2022 we started a collaboration with El Puente to launch the Kukula Kids’ Club, available to local children ages 6 to 12, and is specifically aimed at indigenous kids of the South Caribbean. The club has around 15 members already! Activities for the KKC include many educational activities such as Young Scientist for the Day, Snake identification courses, first aid, and programs about recycling.



The club also visits local bee farms, cacao farms, and wildlife rescue centers, and sometimes takes a day to go to the beach, which many children’s families are often too busy to do despite its close proximity. A particular highlight this year was the photography workshop with Girls Who Click, where each kid received their own camera and was able to showcase their own style and take pictures! Another exciting venture was the KKC participation in the local Wolaba Parade.



Our online Sloth School continues to be a huge hit, reaching out to +6500 students around the world for some virtual sloth education. Our most popular educational booklet, Slocky and Marley the Amazing Sloths, is now available in German! We already have copies in English, Spanish, and Japanese, but here at SloCo there’s no such thing as too many languages.

Last but not least, we also participated in Thinkaton Monge, a Costa Rican event, aimed primarily at young students, organized to promote innovative and creative technological solutions for biodiversity conservation. Such as, for example, an accurate estimate of the sloth population.

Community and responsible tourism

We have continued to work with local businesses to grow our Sloth Friendly Network accreditation and we are now up to 50 businesses this year! The purpose of the Sloth Friendly Network certification is to make human-wildlife coexistence possible by making our streets and properties safer for sloths and wildlife.


sloth on the ground with tourists
Two tourists keeping their distance from the sloth at a beach bar in Puerto Viejo de Talamanca, Costa Rica. | Photo: Suzi Eszterhas.


If you’re planning on visiting the South Caribbean of Costa Rica, check out our Ultimate Guide to Sloth Paradise to learn how to spot sloths in the wild, book the sloth-friendly accommodations, and make your journey responsible!

Welcome to Sloth Town, a visual journey by Suzi Eszterhas

Wildlife photographer and SloCo trustee Suzi Eszterhas did a shocking piece this year on the lives of sloths affected by urbanization. The article and corresponding photography did an amazing job of capturing the essence of what drives the importance of the Urban Sloth Project. Her photograph “Sloth Dilemma” was also on the top 10 Wildlife Photography of the Year.


sloth with dog

Oh My Dog!

Our Oh My Dog project did not have as many events this year as we had hoped for, but we still managed to work with the local pet shelter Puerto Viejo Dogs to spay and neuter 120 dogs this year! Reducing the stray dog population in Puerto Viejo in safe and humane ways continues to be an important goal for us, and dog training lessons have lifelong impacts on the canines that participate in them.

Connected Gardens

It’s hard to believe that a tiny tree nursery in 2018 would become the growing reforestation project that it has, but this year we celebrated the planting of our 5000th tree!



We couldn’t have done it without a wonderful contribution from JetSloth, who partnered with us to plant 1000 trees! This is the sort of epic goal that keeps us, and our brave little saplings, reaching for the sky.

The 2nd International Sloth Festival!

The Second International Sloth Festival, hosted in 2022, was a huge success. No matter how many people we expect, even more always show up. This year we had visitors from Ecuador, Peru, Mexico, Argentina, the United Kingdom, USA, Germany, Italy, and probably even more far-flung countries.



This sloth and conservation-themed festival had booths, vendors, photography exhibits, educational opportunities, real-life sloth tracking for people of all ages, jungle walks, and more. Puppies and trees were adopted, sloths were found, and lots and lots of sloth art were made.

Sloth Community

Also in Slothtober (our name for the 10th month of the year, which is also the month of International Sloth Day!) we launched the Charity Streams Campaign, a collaboration of sloth enthusiasts, gamers, and streamers, where 20 streamers went live to log 300 hours and help fundraise $4000 for sloth education and conservation!

Slothtober always brings together the sloth community from all over the world. From tiny towns in Asia to big cities in Europe (and vice versa), from jungles to mountaintops, and from Central America to Australia, we all celebrate this spectacular sloth community that we have built together. This map here shows exactly how far and wide the reach of this community goes!



What went wrong

On the list of projects that we maintained but didn’t expand, the Oh My Dog project lagged behind our growth estimates this year: we were not able to put together our community spay and neuter clinics or host the dog training lessons we wanted.

Our project to insulate power lines and transformers is still on pause–for reasons beyond our control–as ICE, the power company, is still undergoing an internal overhaul and cannot coordinate with us to safely and legally supervise the insulations. It’s quite frustrating to be kept waiting on bureaucratic matters while sloths continue to be electrocuted.

Team Sloth also had a challenging year in terms of health. Just as we thought the pandemic was slowing down, we were hit with two major covid waves and an outbreak of dengue fever. The entire office had to be closed down for a total of seven weeks out of this year, with nearly the whole team off work either sick or quarantined. Needless to say, this caused a few delays for most of our projects!

On the sloth front, our lovely Deborah suffered some eye trouble and almost went blind from dust exposure on the road, and Maracuya had her equipment taken off her, and a stumbling block that caught Team Sloth completely unprepared this year was the repeated targeting of Nacho for sloth tech theft. We eventually had to retire him from active data collection for his own safety, and we never were able to retrieve his collar or backpack. Happily, this is not the end of Nacho’s story and if you learn more about his journey, read this blog here!

Speaking of staying safe, the Tracking Team was robbed while out looking for Luna and Luiza. This was quite scary, though the team stayed smart and came through this experience unhurt.


2023, we’re waiting for you!

2022 was a great year for us, and 2023 is going to be even better. The Sloth Conservation Foundation is well poised to improve and expand on our current projects!

Most excitingly, we will be continuing the Great Sloth Census, a history-making project that will revolutionize our understanding of wild sloth ecology and give us the tools we need to truly measure sloth conservation and create a future for these amazing animals. There will be new science, and sloth detection dogs, and thermal drones!


Tamara and Diego. | Photo: Suzi Eszterhas


You, our incredible supporters, have been with us this far, and we are so grateful to have you along. You are the fuel that keeps these critical projects alive, and your support is the difference in the lives of so many animals! Without you, there is no sloth science, no reforestation, and no extracurricular education for future generations. Without you, there is no SloCo!

We will have our full 2022 annual report ready soon, and when we do we’ll have our annual report ready–with more details of our projects and finances–so you know exactly how your money is being spent.

Stay with us as we head into 2023. We wish you a happy end of this year, and a new one full of joy, bliss, and sloths!


All the best from the jungle,






Dr. Rebecca Cliffe

Founder and Executive Director


The Urban Sloth Project Recap – Part I (November 2020 to December 2021)

The Urban Sloth Project Recap – Part I (November 2020 to December 2021)


In the South Caribbean of Costa Rica, it is pretty common to find sloths in unusual places: on a restaurant cutlery shelf, a hotel ladder, a fruit stand, clinging to a truck… you name it, sloths have been there. World-renowned wildlife photographer Suzi Eszterhas came to the South Caribbean to take eye-opening photographs of the lives of these sloths in urbanized areas.


sloth between two buildings


The Urban Sloth Project

The Urban Sloth Project aims to study how habitat loss and disturbance in the form of urbanization affect the lives of sloths. How often must they come to the ground to change trees, rather than use canopy branches? How long does it take them to traverse the ground? Are they resting lower down than their counterparts living in optimal rainforest conditions?

If so, is this a behavioral factor, or are they forced lower because the trees are not as tall and mature? Must they change trees more frequently to find suitable leaves? And how much variation is there in their diet?


sloth on a powerline


These are just some of the questions we are aiming to answer through the Urban Sloth Project!

We had our USP timeline mapped out, but unexpected pitfalls, as well as some exciting opportunities, have meant that the old saying has proven itself true, once again – the best-laid plans of sloths and scientists go oft awry.

We would like to share our stories and experiences from the first year of the Urban Sloth Project: the sloths, the trackers, the tears, and the joy.



First came Sharon 

Sharon was a small juvenile two-fingered sloth (Choloepus hoffmanni), and our very first Urban Sloth. We found her while out scouting for our first urban sloth, she was being harassed by dogs while trying to make her way to a Beach Almond tree (Terminalia catappa). Luckily, our team was there to keep her safe.  She helped us as we got our tracking legs underneath us and figured out how the USP was going to work!


sharon urban sloth
Sharon is the first sloth collared for the Urban Sloth Project. She was rescued on the side of a road while being harassed by a dog.



Then came the Bradypus

Next, we collared the first of our three-fingered sloths (Bradypus variegatus): Alan, from the beautifully connected eco-hotel Kukula Lodge, and Croissant, whose original territory covered a road undergoing a huge amount of deforestation and construction.


sloths recap

Backpacks for everyone! 

Our next Urban Sloths were Cacao and Laurel: both Choloepus and both named after the trees they were found in, and made SloCo history as the first subjects for our famous sloths’ backpacks.

(The sloth backpacks, also called Daily Dairies, track millions of data points every minute as sloths move about the canopy; measuring when they climb, descend, stay still, how fast they move while doing so, and many other activities never before measured in wild sloths.)

Cacao’s territory was an aesthetically beautiful, well-manicured garden that unfortunately didn’t have much connectivity between the trees, forcing Cacao to cross on the ground every time he needed to change trees.


cacao sloth
Cacao, found in a cacao tree!


Laurel, meanwhile, took his backpack and disappeared onto private property inaccessible to the Tracking Team, where he stayed for nearly two months. The mature and well-connected property was full of tall Laurel de la India, also called Weeping Fig (Ficus benjamina), with one goliath Sandbox tree (Hura crepitans) in the center. This, as well as the abundance of other sloths in the area, made tracking Laurel difficult.




The Tracking Team was therefore very excited when he returned to his original spot, and with some carefully placed feet on shoulders and a pair of scissors, we retrieved his backpack and un-volunteered him from the USP.


MARCH 2021

The first fatality 

In March we got a call from a local rescue center that Cacao had been admitted after being attacked by dogs. He survived his initial injuries, but did not survive the resulting secondary infections, and passed away in April, a month after the attack.

Luna and Sol 

Although we had lost our beloved Cacao, we were able to collar Luna and her baby Sol, who would go on to become some of our favorite sloths of the USP. A spontaneous addition to the project, Luna was crossing the main road of Puerto Viejo when she was found by Dr. Cliffe.

Sol was our very first baby of the project, and we were privileged enough to watch him grow and eventually gain his independence from Luna!



Houdini the Sloth, aka Sharon

Our first USP mystery – Sharon found her way out of her collar. This was unprecedented in sloth tracking, and we still have many questions that will likely never be answered.



Finding the intact collar on the ground caused great concern that Sharon had been attacked, and the worst-case scenario was that she was nearby, but injured and in pain. Our trackers searched for her, however, five days later she turned up in one of her favorite spots, sans collar, but totally unharmed.


APRIL 2021

Hello to our highest friend

Arthur--a regal adult three-fingered male living between a yoga retreat and some luxury rentals–joins the Urban Sloths as the first three-fingered sloth with a backpack, only to have them disappear high into some dense and well-connected canopy.


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Arthur the handsome.


MAY 2021


Only a few months after relieving Laurel of his backpack, we were informed of a huge amount of deforestation in Laurel’s area. Devastatingly, Laurel’s entire territory, as well as many other trees along the road, had been cut down.


deforestation habitat loss
Dr. Rebecca Cliffe is next to what used to be Laurel’s trees. Photo: Suzi Eszterhas


When Team Sloth went to investigate the damage, there were displaced sloths everywhere we looked. We were able to relocate some to more appropriate areas, and we could only hope that Laurel himself survived the destruction.


man walking a dog next to a sloth
This sloth and her baby were displaced sloths. With no trees, she remained in the hibiscus bush, exposed to dangers, like free-roaming dogs. Photo: Suzi Eszterhas.

These problems are a direct result of the exact issues we aim to address in the USP, and in spite of the heartbreak from witnessing this kind of deforestation, Team Sloth is more determined than ever to gather this important data on sloth behavior and ecology in urban environments-our ability to scientifically document these events is the only way to effect change.

Hello mango! 

Wildlife photographer Suzi Ezsterhas visited SloCo to document the plight of Urban Sloths. While searching for sloths to photograph, Team Sloth stumbled upon a small, wet ball of fur among fallen leaves and coconut husks along the beach path directly opposite SlotHQ. We bought the little three-fingered sloth in from the cold, where she huddled up to Jim, SloCo’s mascot, and promptly fell asleep.


baby sloth cute with teddy bear
Mango became a favorite instantly!

After dining out on some fresh baby guarumo leaves (Cecropia sp.) from our tree nursery, we took the opportunity to fit baby Mango with a tracking collar.

Next to Croissant… Baguette!

We came across a female three-fingered sloth clinging to the top of a fence: she was trying to escape a pack of barking dogs protecting their territory. Team Sloth fought through the pouring rain to rescue the sloth, but before releasing her we fit her with a collar and named her Baguette, since she was found on the same bakery road as little Croissant.


VIP adoption

We’d like the Nachos, please!

Welcome Nacho, one of the most remarkable sloths of the USP! Nacho was first fitted with his collar at a cantina on Cocles beach, and named after Team Sloth’s favorite dish there. Over the next couple of weeks, Nacho made his epic journey all the way from Cocles to downtown Puerto Viejo.



The Tracking Team followed him on his journey to some rather strange places for a sloth to hang out: isolated beach almond trees on the side of the road, the middle of a lively bar, and a restaurant … We soon began to refer to Nacho as out party sloth, for his proximity to human activities.

JUNE 2022

The second fatality

As we were waiting for an opportunity to recollar, we were faced with the second fatality of the USP in June of 2021. Sharon had been electrocuted while using an uninsulated powerline to move between trees.

We were devastated by Sharon’s death and vowed to renew our efforts to understand and help sloths adapt to human-impacted environments.


Farewell, Sharon

The traveler sloth

Nacho surprised us all by traveling over two kilometers in two weeks, a feat we had not previously known was possible for a sloth.

JULY 2021:

We recaught Mango to swap his backpack for a collar. Since he was so young and small when we first fitted him, we knew we’d have to check him often to make sure he didn’t outgrow it. We were pleased to find that he was healthy and growing just as expected.



Croissant’s big move

Throughout late August 2021, we were having a lot of trouble tracking Croissant. The inconsistent signals from her VHF collar were proving difficult for our tracking team to triangulate.



It turns out that she had crossed a lengthy deforested gap by traversing fences and roads to an undeveloped piece of land near the center of town, around 500m away. Since her territory was in the process of undergoing a large amount of deforestation and disturbance, it makes sense that she would seek out greener pastures.

While this area is much more difficult for our team to track her in, it is a much more appropriate sloth habitat, and she has remained there ever since.

Nacho’s intervention

Nacho made it all the way to town this month and took shelter in a restaurant during a rainstorm. While it isn’t too unusual for urban sloths to wander into the local eateries, Nacho decided to climb around under the tables and try to bite the customer’s ankles.



Since this is bad for business, the restaurant owner called the local rescue center, who removed Nacho and called us. After a health check and monitoring period, Nacho was found to be fit and healthy, so we took the opportunity to swap his collar for a backpack!



He was then released into one of the only appropriate habitat spots in his home range; the dreaded swamp which Croissant had also moved to. Over the next few days Nacho crossed the street to one of Puerto Viejo’s liveliest beach bars. There were a few well-connected trees on the property, and Nacho seemed unconcerned by the constant stream of patrons and loud music.


Croissant health check

First collared as a young adult, we had some concerns that Croissant might eventually outgrow her collar. She had been difficult to find in her new home territory, but at the first opportunity, we gave her a health check and tech adjustment. We were pleased to find that although she had grown, her collar had not become too tight and still fit her well. Finding no adverse physiological effects of the tracking equipment was vital to the continuation of the USP!



The case of the missing tracking equipment / Bye. bye Nacho

Underneath Nacho’s favorite trees is the permanent camping spot of a man who is not our biggest fan, and took it upon himself to remove Nacho’s tech. He seemed unaware or uncaring that we knew he had Nacho’s backpack, and when we found and refitted Nacho with a collar, he removed that too.


Behind these palms was Nacho’s tech.

Team Sloth made the difficult decision to not recollar Nacho. We really liked having him in the USP, but we could not risk his well-being by making him a target for people who would handle him and steal our expensive equipment, and so we removed him from the project.



Good luck Sol!

During the month of October, the Tracking Team had noticed baby Sol going through his rebellious teenager phase: he wanted to be further away from his mum and venture out on his own. It started with three limbs rather than four clinging onto Luna’s fur, a set of claws gripping onto a vine instead. Then Sol was seen next to Luna, rather than on her. Then one day, he wasn’t with her at all! Luna gifted Sol a portion of her territory and little Sol was officially all grown up.


Luna without Sol

Always high in the canopy

Baguette remains our most difficult sloth to monitor, and we finally got a chance to retrieve Arthur’s backpack, allowing us to download millions of data points from the backpack (which are still being processed by specialized computers in the Swansea University lab) and confirm that the backpack design works great.


Arthur with his new collar.



The case of the missing collar

One Friday while out tracking, we were receiving no signal at all from little Mango’s collar. While it was possible Mango had decided to move further afield, she would have had to have moved over 10km in less than 24hrs for the VHF signal to not reach the receiver! We know sloths can move faster than most people give them credit for, however this was very much beyond Mango’s capabilities.



We believe that as Mango’s favorite spots were low down, and often in plain sight if you knew where to look, someone walking along the beach saw little Mango and his little collar, and didn’t know what it was. Luckily, the next day some members of Team Sloth were enjoying a weekend at the beach when they noticed Mango sitting low on her favorite guarumo trunk and she was recollared with little fuss! Mango responded to this collar-napping by venturing across the beach path, and she has since doubled the size of her old territory.


Just before Christmas, Luna’s territory was being deforested, leaving a dozen sloths and countless other wildlife homeless. However, the community was not going to stand for this. Community members and local organizations, including SloCo, were able to temporarily halt the work and contact the authorities, who had the power to permanently stop the intended development.



Stay tuned for Part II !



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Tales from the Jungle 15 September | Projects Update Edition

Tales from the Jungle 15 September: Projects Update Edition

Hello, sloth community! This week we have some great news, and we just couldn’t wait until the end of the month to share it with you! What do the numbers 500, 5,000, 200, and 6,000 have in common? Read on and let us tell you.


As you may know, we work with Puerto Viejo Dogs (a local pet shelter) to spay and neuter at least 10 rescued dogs every month, and this month we reached our 500th puppy! That’s 500 dogs that get to live healthier, happier lives, and an uncountable number of puppies that won’t be homeless, add to the stray dog population, pass on zoonotic diseases, or harass wildlife.


500 dogs spay and neuter


Speaking of dogs, have you heard about our latest scientific project to have dogs help us count sloths? Nothing like it has ever been done before, so check out our link to stay abreast of some groundbreaking research!


We started our Connected Gardens Project in the late 2018 with a tiny tree nursery of no more than a few dozen saplings. Our project has grown so much in the last four years that last Friday we celebrated a really epic milestone: we planted our 5,000th tree!


The property that was being reforested used to be a parking lot, but the new owners are committed to making their garden a sloth-friendly place, and worked with us to help plant trees. We are so happy to say that change is possible, and turnabout is only fair play: it was very satisfying to see a parking lot go back to the trees!



200 almost sloth crossing bridge

We are SO CLOSE to this one! We have put up 196 wildlife bridges so far, and we are only four away from reaching number 200 this month. We still need some sponsors though, so if you’d like to be in on this month of milestones, just think of what bridge number 200 would look like with your name on it!

We’re so close, it could happen! Help us connect the canopy!


Perhaps most impressively, our greatest number this month goes to what might be the most important project of all: passing on our love of sloths, science, and conservation to the next generation.

Our sloth school program has now reached 6,000 students–yes, that’s right six THOUSAND young people have had access to enriched education about nature generally, science especially, and sloths specifically! (And if you can say that last sentence three times fast, you automatically graduate.)


school lesson sloth

We work with schools in many countries to get the word out about sloths, though our classes are most popular in Costa Rica, England, and the United States. We have lessons in Spanish and English and are working on adding even more languages!

We like to get out in the forest as much as possible, but when that isn’t feasible, our online classes are available to students all over the world, in any classroom, at any time.

What do sloths have to do with red pandas?


sloth red panda infographic


September 17th is International Red Panda Day and we are excited to celebrate it with our friends from Red Panda Network in our latest edition of Sloths Vs, in the aptly named “Sloth versus Red Pandas”. Can you guess what these two have in common? No? You’ll just have to read on then, because, rather like sloths, red pandas are really cool!


Stay tuned for the upcoming Slothtober, and see you in the next Tales From the Jungle!


-Sloth Team

Sloth Crossings Community update | July 2022

Sloth Crossings Community update | July 2022

Hello Sloth Crossings Community!

We’ve got a lot of exciting news for you this time, involving science, papers, our recent research project, and of course some amazing footage of wildlife using our bridges!

We’re also very excited to announce that we are getting really close to our 200th Sloth Crossing– Only 16 more bridges to go! Stay tuned, we’re almost there!


Where’s my bridge?

We’ve got a map for that! Use the code or coordinates we provided to check it out and see where your bridge is, and while you’re at it, get a view of the network of bridges we’re creating together.


Camera Trap Project update

Thanks to the generous donations of our supporters we are so thrilled to announce we now have 16 camera traps! We are very excited to see the results of our research project on the usage and efficiency of our sloth crossings.


Two-fingered sloth (Choloepus hoffmanni) on the bridge SC-143 at Playa Negra


For a camera trap to be effective on a bridge, it must have a clear line of sight for any animals, with no leaves or branches that would get in the way of the motion sensor triggering the camera.


Variegated Squirrel (Sciurus variegatoides) on Bridge SC-081, Tortuguero. Camera images: ASVO (Asociación de Voluntarios para el servicio de Áreas protegidas)


Additionally, we are currently installing camera traps only on newly built bridges so as to record how long it takes animals to get used to the bridges and begin using them.


Kinkajou (Potos flavus) on bridge SC-143


We have the results for two of our camera traps that recorded footage for three months, and we discovered some really amazing animals using the bridges!


Wooly opposum (Caluromys philander) using bridge SC-081, Tortuguero. Camera: ASVO (Asociación de Voluntarios para el servicio de Áreas protegidas)


If you would like to donate to this project, please consider the camera traps that work best in the Caribbean climate and circumstances (according to our field experience!):

Spider monkey paper and bridge footage

Filippo Aureli from the University Veracruzana in Mexico contacted us asking about our experiences and observations of spider monkeys using our canopy bridges. He was working on a paper: “Do spider monkeys use artificial canopy bridges to cross linear infrastructure?


Spider Monkey (ateles geoffroyi) using bridge SC-081 in Tortuguero Camera ASVO


With the six bridges we installed in the North Caribbean town of Tortuguero last year we do have evidence of spider monkeys using them, and we were proud to collaborate with Aureli for his paper. We also got some very nice footage of spider monkeys using our crossings!


Spider Monkey (ateles geoffroyi) using bridge SC-081 in Tortuguero. Camera ASVO

One of the bridges in Tortuguero that got a lot of use was a connection between two trees on a rather remote property. In fact, one of the trees was in the National Park of Tortuguero. Underneath this bridge was lots of vegetation, smaller trees, and bushes. Observing this, Filippo Aureli and his team concluded that spider monkeys are more willing to use bridges over vegetation in places such as properties and gardens, but they are reluctant to use single-rope bridges above roads.


What a vacation in the South Caribbean might look like

Many of our Sloth Crossings are installed near hotels, house rentals, and accommodation properties. Every now and then visitors can get the chance to see the bridges in action!


Three-fingered sloth using the bridge SC-49, Playa Chiquita | Cederholm photography


This time our friends from UP House Costa Rica, also members of our Sloth Friendly Network Accreditation, shared with us the beautiful footage taken by their guest Ric Cederholm (Cederholm Photography):


Three-fingered sloth using the bridge SC-49, Playa Chiquita | Cederholm photography



Connecting with MOPT to install bridges above the main road

In accordance with our goal of installing differently designed wildlife bridges over roads, we recently had a meeting with MOPT (Ministry of Public Works and Transport). We are happy to say we have had some productive conversations about different bridge designs and places for possible future installations, and we look forward to collaborating with them in the future!



To start this off, we even have a donation of $5,000 from an anonymous donor that will be used to build one of our newer-design bridges over one of the main roads in Limon. Some of the roads in Limon are quite busy and are major contributors to habitat fragmentation in that area.


Bridges in the sky carry sloths to safety in Costa Rica

Need more sloths? Need more jungle wildlife on sloth bridges? We got a visit from a journalist hailing all the way from Mongabay who kindly recorded some of our Sloth Crossing Project footage. Need to learn more about generating safe connectivity for sloths in urban areas? Of course, you do! Check the video below!



Sloths and Monkeys Using Bridges

Last but not least, here is some footage of sloths and monkeys using some of the Sloth Crossing Bridges these past few weeks!



Capuchin monkey using bridge SC-129
Two-fingered sloth using SC-122 bis, above the road


Two-fingered sloth (named Tiki) using SC-122 above Tasty Waves Cantina


Capuchin Monkey on SC-080


Three-fingered sloth using SC-049



We hope you enjoyed this update, thank you so much for your incredible support of this project! Pura Vida!





-Tamara Avila

Sloth Crossings Project

Sloth Crossings Update: January-April

Sloth Crossings Update: January-April

Hello Sloth Crossings Community! In this update, we’ll be covering the highlights of the project from January through April. We’re proud to say that the project continues to expand to new levels and new areas!

January: The Month of Covid

In January approximately 90% of our team either tested positive for COVID or had to quarantine due to close contact with someone who had. It was a bit of a shock for this area, which up until now had seemed to skate by the pandemic in our happy little tropical bubble, isolated from the worst of it by our limited access to the outside world and healthy, fresh outdoor living.

February: Collaboration is Key

In February we finally started working with ICE (the Costa Rican electric company, Instituto Costarricense de Electricidad) to coordinate the installation of bridges above the main road and secondary streets. Installation in these areas requires the powerlines to be deactivated until the bridge is safely anchored on either side of the line.



Since the electric grid in this area is less like a grid and more like a straight line, everyone downstream of this project has no electricity until it’s finished, which can take a few hours. So far we installed three sloth crossings over electrical lines in Playa Chiquita and five in Playa Negra–both of which are important neighborhoods with high levels of urbanization.

Problem Areas

Wildlife crossings help sloths and other animals avoid two of the three biggest sloth killers in the South Caribbean: dog attacks, and powerlines.



The survival rate for animals that have been electrocuted is very low, but insulating power lines requires a lot of time and funds, and as a public company ICE’s budget is limited. The government recognizes this problem and has already invested over $400,000 US in materials to insulate their power lines and transformers! However, this just gets the project started—more funds are needed to see it through to completion.

Since 2019 SloCo has provided over $10,000 to buy the raw materials to insulate power lines and transformers, and we expect to match this number again this year.


March: Record Day!


On March 16th the Bridges Team left the office early in the morning to go to a property in Cahuita, where the plan was to install three or four bridges and plant some trees. Not only did we achieve this, but we also set a new record! The team managed to install five bridges in a single day and planted 30 sloth-friendly trees at the same time! 


Launching the Camera Trap Project

SloCo achieved another big goal this year with the start of our new research program: the Camera Trap Project. Thanks to our Sloth Crossing Community we are very excited to begin research on the usage of our bridges. Special thanks to the Krueger Family who brought the cameras down to Costa Rica in their luggage and made this launch possible!



At the moment we have 13 camera traps covering over 150 bridges. This is an excellent start, but we have even more brides being used by even more animals, and we want pictures of all of them! In the meantime, we are extremely grateful that we are able to make a start with the ones we have. Keep an eye out for our upcoming fundraiser for more camera traps, all and any donations are very much appreciated!


camera trap crossing


The first law of the jungle is that The Jungle Eats All Things. The heat, humidity, and wildlife will make short work of many types of cameras, but our research has shown that the camera traps that work best in the Caribbean climate and circumstances are:


April: Sloth Crossing Team goes to the Pacific!

The Team just got back from a five-day excursion to Ojochal and Uvita on the South Pacific Coast of Costa Rica. We installed eight bridges, including three in Marino Ballena National Park, one of the most ecologically important protected areas of the country.


SloCo Team with the Rangers of Marino Ballena National Park


It is great to be expanding the Sloth Crossing Project to more areas of the country! Special thanks to Oscar from the Reserva Playa Tortuga, Jonathan from SINAC of the National Park Marino Ballena, and Shannon & Micki of Ojochal who contacted us and helped so much with coordinating everything.


We visited this amazing school @lifeprojecteducation and met all the amazing children who go here. This school has bought the plot of land next door as there was so much deforestation and has started to reforest it. 

Expanding Our Borders

Speaking of taking the Sloth Crossing Project even further abroad, we have begun collaboration with an organization in Praia do Forte, in the NorthEast of Brazil, to fund the installation of wildlife bridges adjacent to Sapiranga Reserve.


maned sloth brazil


This is an important habitat for the endangered maned sloths and is the same area where we tagged eight sloths last year as part of a different scientific research project.

Sloths and Monkeys Using Bridges

Last but not least, here is some footage of sloths and monkeys using some of the Sloth Crossing Bridges these past few weeks!

  • Two-Fingered sloth using the Bridge SC-50



  • Howler Monkey using bridge SC-66


  • Howler monkey using the bridge installed in the Maritime Zone SC-93


  • Howler monkey on the bridge  SC-110 / SC-111 at Playa Chiquita


  • Two-fingered sloth using bridge SC-122 at Tasty Waves Cantina



  • Howler monkeys using a bridge over the main road ( SC-122 bis) by Tasty Waves Cantina


  • Three-fingered sloth using SC-058


  • Howler monkey with her baby spotted at Tortuguero, on SC-81


This map shows all of the places where we have installed Sloth Crossing wildlife bridges (blue) and planted trees through our reforestation efforts (green) since March 2019.



We hope you enjoyed this update, and stay tuned for the exciting next steps of this journey. Thank you so much for your incredible support of this project!


Pura Vida!






Tamara Avila

Sloth Crossings Project

The Adventures of Nacho

The Adventures of Nacho

Nacho, a feisty Hoffmann’s two-fingered Sloth, joined the Urban Sloth Project in May 2021. Nacho was one of the most interesting sloths we monitored during the months he was part of the project.



He was always surprising us with the places we found him in, the distance he traveled, or the photos tourists and locals post on social media with him.



Almost as soon as he was collared, Nacho decided he needed a change of scenery, and made the two-week journey from Tasty Waves Cantina into the center of Puerto Viejo de Talamanca, where he has (mostly) remained. In this blog, we’ll recap the adventures of a sloth living in a busy tourist town, and what we learned from it.


Troublesome Sloth

Nacho’s first misadventure was when he was picked up by the local rescue center for relocation in July 2021 (3), after he was caught bothering the patrons of a restaurant (2), trying to bite their ankles like a little dog!



The only upside to this situation was that we were able to conduct a full health check on him and found that his weight in July was almost half a kilogram heavier than in May. This indicates that the collar he was wearing and our research on him had not affected his ability to thrive in his natural habitat.



Sometimes during this period he also gained a large scar between his eyes that he had not had when we first collared him.

We took this opportunity to fit Nacho with a micro-logger Daily Diary, a.k.a. tracking backpack, which would give us an in-depth view of his behavior and movements for 28 days, and provide invaluable data for the USP.


From the swamp in town to the beach bar

After we fitted him with the backpack we released him to a more appropriate spot in his territory near the swamp he had previously spent some time in (4). Nacho must have disagreed with the new spot though, and he decided to move somewhere a little more familiar: another bar (5).



After a nice wild goose chase through the month of May, Nacho found a home at Stanford’s (6). This made him a very enjoyable sloth to track (and made the Tracking Team a familiar sight in town), while we began to recognize his movements and patterns. It was very encouraging to watch Nacho thrive in spite of the ultra-urban environment that most sloths would avoid.



The bar he patronized had chosen to maintain the tree connectivity around their establishment—this is a great policy that makes for a nice atmosphere around the bar, as well as preventing erosion by anchoring the sand with the roots of the sea almond trees…which is important when your bar is located on the beach! Not to mention, it looks nice.


Problematic Humans

Spotting sloths in sea almond trees is easier than in many of the other trees sloths favor, as sea almonds’ branches are not usually cluttered with other plants and vines. They usually hold only almond leaves and the occasional sloth.

So when Nacho’s backpack signal went stationary (indicating that it had not moved in a while), and there was no sloth in the spot where the signal was coming from, we got worried.



The signal was coming from a tarpaulin tent, where a nomadic person had been living for many years.

Concern peaked on day four of the unchanging signal when the Tracking Team spotted a sloth who was around the same size and color as Nacho, snoozing in one of Nacho’s favorite spots, doing an excellent impersonation of Nacho in all ways – except he was missing a backpack. We had to find out if this sloth was really Nacho.

Luckily, we had one very defining future of Nacho’s identity: his scar.

Dr. Cliffe herself scaled the palm tree that potential-Nacho was napping in and was able to confirm that it was indeed Nacho resting in the tree—blissfully unaware of the drama occurring around him. It was very clear that this sloth did not have a backpack on, and the signal was still being emitted from the DIY Settlement.


Moving On Without a Backpack

While there was some relief that Nacho was not in fact being held hostage, we were presented with a new problem—equipment being stolen off the backs of the Urban Sloths.

The very expensive sloth backpack was useless to anyone other than us, held a month’s worth of important scientific data, and was now gone. Unfortunately, trying to communicate with the person who took the equipment proved futile and fruitless.



Team Sloth decided to recollar Nacho and performed a quick health check on him. Despite having an eventful month—visiting the rescue center, being fitted with some new tracking hardware, and apparently having been accosted by a man with scissors who stole his backpack—Nacho was doing as good as ever and had even gained some weight.



For the following months, Nacho remained in the area surrounding the bar and a hostel, finding shelter from the rain in a small lean-to structure. He had a high visibility rate in the months after his ordeal.

In January 2022 we got a case of déjà vu when his tracking signal (this time from a collar and not a backpack) once again was traced to the camp, and once again there was no sign of Nacho.

After a few days of stress and worry on the part of the Tracking Team, Nacho reappeared in exactly the same palm tree as the previous time he had been stolen from. Nacho’s collar was gone.


The End of an Era

It was a difficult decision for Team Sloth to retire Nacho from the USP. While the loss of time, money, and research data from the appropriated equipment was large, the deciding factor was Nacho’s welfare.

In order to fit two-fingered sloths with tracking equipment they must first be sedated, which is not a procedure that should be performed lightly in wild animals, as it can cause the animals a great deal of stress.



Recollaring Nacho would mean a third sedation in less than a year, and the equipment was making Nacho a target for unscrupulous humans. This was not something we could accept for the sake of our research, and we ultimately had to put Nacho’s welfare above all else.

We are happy to say that Nacho has handled his collarings (and de-collarings) with great aplomb and is thriving in his current territory! We are less happy to say that we have not yet gotten our stolen equipment back, but that’s not Nacho’s fault, after all.

We anticipate that without any wearable tech to make him a target for future interference, he will continue to be Puerto Viejo’s unofficial mascot, greeting tourists from his Sea Almonds on the beach, and embodying the spirit of Pura Vida.

What We Learned from Nacho

While there are many questions yet to be answered about Nacho’s lifestyle, and while we gathered valuable data while tracking him, we won’t be able to come to any conclusions about his activities until the end of this long project, when the data from all sloths is collated and analyzed. Not to mention, our treasure trove of data on his movements was never able to be analyzed before being stolen.



We are surprised at how well adapted Nacho is to his urban habitat. However two-fingered sloths are disproportionally likely to be admitted into rescue centers with injuries from dog attacks, car strikes, and electrocutions.

We don’t know what the future holds for a sloth that lives in a busy town, and although we don’t officially monitor him anymore, we still see Nacho as we run errands in town, and the staff at Stanford’s keeps an eye out for him.



-Amelia Symeou & Ames Reeder

The Urban Sloth Project

Luna update: February 2022

Luna update: February 2022

2021, The year of Luna with Sol

We added Luna and Sol to the Urban Sloth Project in March 2021. Once Luna was fitted with a collar in March, we were able to track her and baby Sol every day. We estimated baby Sol to be around three or four months old at this time, but sloths are very difficult to age–we were unable to weigh Sol, which is usually the best way to guess a baby sloth’s age.


sloths on the ground mom and baby


In August we began to see Sol becoming more curious about his surroundings; at first, it was only a limb or two reaching into the liana vines, but one day we came to track them, and we found him sitting next to Luna instead of on her belly!

He wasn’t quite ready to leave Luna entirely, and there was a lot of him going back and forth between his mama and the branches. We felt like proud parents watching little Sol gain his independence.

Becoming independent

By October, we confirmed that baby Sol was all grown up! We had consistently seen him separate from his mother, until one day they were no longer sharing the same tree.

In most mammals, once the parents raise the young to independence, the young are expected to disperse and find their own territory. With sloths, once the baby is ready, the mother leaves them with a portion of her own territory and moves on herself.


Baby Sol

We were able to witness this with Sol, to whom Luna left her very favorite tree, while she moved further south. Luna moved all the way to the other side of the lot they occupied, leaving the tree she raised her baby on to her grown-up boy.  According to our calculations, Sol gained independence at 10 months old.


December: Sol is finally grown up

We still tracked Luna every day, but with no radio collar, it has been hard to find Sol! We have seen him around a few times in his little territory that borders his mother’s, but if he decided to make a big move we probably wouldn’t know about it. Luna has continued to thrive in the new, more southerly portion of her territory, which she shares with a number of other sloths.

One Saturday in mid-December, when the tracking team went out to find Luna, they instead found massive deforestation occurring, with chainsaws and bulldozers cutting down their trees. Happily, the community made a big protest about this, the tree felling was stopped, and has not resumed while the relevant authorities are looking into it.



A new year, a new baby!

We’ve been waiting for it ever since Sol moved on to find his own territory, and the day has finally arrived: Luna has a new baby! Baby Celeste was born in the last week of January (2022), and is sooo tiny!


Luna and her new baby, Celeste. Can you spot the antenna?


Luna probably went into heat and conceived shortly after Sol started independently exploring in August. Although we are not precisely sure of the gestation period of three-fingered sloths, we estimate it is approximately six months. Researchers have not yet had the opportunity to observe a three-fingered sloth during the entirety of her pregnancy, so this gestation period is still being determined.


sloth mom and baby
We think Luna is quite young, but as it is nearly impossible to determine the age of a wild sloth (until we can afford some telomere analysis) we are mostly guessing. She does not have the full complement of green algae on her fur that would indicate a completely mature fur ecosystem, but she does have a nice patchwork of browns and greys that is quite fetching.


Luna’s territory is a good one for sloths

Or it would be if they’d stop cutting down the trees. Several three-fingered mothers are known to inhabit the area. Thus when Sarah stopped by Luna’s territory while covering a shift for Ames (who was quarantined with Covid) she did not immediately recognize the mama sloth with a days-old baby velcroed to her side as our lady Luna.


sloths in guarumo after deforestation
Luna shares her territory with more sloths.


Since the area’s deforestation in December it’s not unusual to find crowds of tourists gathered around the lone guarumo trees, watching and snapping pictures of the half dozen three-fingered sloths that can be seen on any given day. When the crowds are looking up, we know everything is in order and the Sloth Star of the Day is high in the trees and safe. When the crowds are looking down at the ground, we know there is most likely a sloth trying to get somewhere, and it’s time to intervene. The intervention consists of politely explaining to people that the sloths are not here to meet them and asking the tourists to give them a little space so the sloths can get where they are going.

This is what was happening on a Friday when Sarah spotted a crowd and went to see whether the sloth needed an advocate or not. The sloth in question was crawling across an obstacle course of felled trees and organic debris, trying to get from one tree island to the next.



At first, Sarah was quite confident that no, this was not Luna–because look at that tiny baby!–but once she pulled out her own phone camera she was able to zoom in and see the antenna of Luna’s tracking collar. Our favorite mom was a mother all over again.

Sarah got some great footage to use as evidence that reforesting and bridge-building in this part of the maritime zone needs to be made a priority, because who can resist helping out baby sloths?

At least now we know why Luna disappeared on us for a few days; clearly, she just wanted some peace and quiet to deliver her new daughter, currently weighing in at around 300 g. That’s about 10 oz, or about two average-sized smartphones. (For the record, we don’t actually know that the baby is a girl. Right now we’re guessing, and we figured since we called her last baby a boy we needed to even up the gender ratio a bit.)

Though he won’t contribute much to raising little Celeste, we think we know who the father is, as there is only one mature male in Luna’s territory. We don’t have a name for him, but maybe his newest daughter will grow up to look like him!

The babies of Luna

The sex of the babies will remain a mystery for some time as all genitalia are hidden internally in three-fingered sloths. The best and least invasive way to determine male from female is to look out for the brightly colored speculum that develops on all male Bradypus sloths (with the exception of the maned sloths). Unfortunately, the speculum does not develop until sexual maturity (at approximately two years old) which means that it can be difficult to know the sex of sloths before this point.


-SloCo Team

Sloth Crossings Community Update! 2021 Highlights

Sloth Crossings Community Update! 2021 Highlights


What an amazing year we had! When we started this project we had no idea that we’d be installing more than 100 bridges… and in a few weeks, we’ll hit sloth crossing number 150! 

This project was entirely funded by our supporters and donors, so we want to share some of the highlights of this year:


1. Our team is now certified to climb by themselves.

2. The first bridge our team built was on a special trip to Tortuguero.

tortuguero sloth crossing wildlife bridge


3. The Tortuguero bridge was used by spider monkeys just a couple of weeks after we installed it!

monkey using wildlife bridge

4. We installed our 100th sloth crossing bridge in Cocles, in the area where our urban sloths Luna & Sol live!

5. We started installing bridges on the public maritime zone by the beach.


sloth crossing at the beach


6. We’ll be launching the second stage of the project (monitoring the usage of the bridges) next year.

7. One of the camera traps (we currently have 4) captured more than 6000 photos!


camera trap crossing

8. So far, we have installed over 2500 meters (more than 8,000 feet, or 1.5 miles) of rope!

Check out some of the footage of wildlife using the bridges in the following video:



We’ve come a long way

We started this project back at the beginning of 2019, with only two people. Now our team consists of Francisco Rodriguez, who’s also the manager of the Connected Gardens projects and all the reforestation initiatives; Diego Elizondo, who’s also in charge of the forest nursery; Dayber Barker, the main climber and assistant of the Urban Sloth Project; and me, Tamara Avila, who is writing this update.

Meet Dayber:

Meet Diego:



To be honest with you

We tried our best to have your wooden signs ready in time, but unfortunately, the carpenter we hired for this task was unable to meet our deadlines. Thankfully we have since found a small local company helping us with the signs, plus we’re doing many already ourselves.

We’ve come a long way to this point–with some delays, mistakes, disappointments–but also a lot of growth, experiences, and gratitude. Thanks to all of you who had the patience of a sloth and the love to support this idea and help us execute it.

This is just the beginning of this project.

The second stage

Now that we have reached more than 100 bridges we feel confident in taking the next step: We are going to start a deeper study of the usage of these bridges.

So far we have four camera traps, and of course, we can’t just expect to place them on a bridge and get good footage right away. We wish it could be that easy!

The truth is some bridges can take months until wildlife starts to use them. We don’t even know how long it takes for sloths, the true creature of habit, to get used to a new structure in their canopy!


sloth crossings wildlife bridge


Although we did observe one sloth that started using a bridge just a few weeks after installation, we suspect this was the exception rather than the rule.

We did learn that monkeys are faster than sloths (bear with us) in starting to use the wildlife bridges.



The challenge

In order to improve this project, make it more efficient, and start replicating in other locations in Costa Rica (as well as other countries), we need to monitor our bridges. As you can imagine, monitoring over 130 bridges with four camera traps is not going to be easy.

For this reason, we’ll be running a fundraiser for more camera traps. There are three cameras that have the specs we need: they must be jungle resistant, and most importantly, the sensor has to be sensitive enough to actually detect the slow movement of sloths. (Yes, that’s another level of difficulty!)

If you enjoy the updates of this project, and you have already invested in this project, perhaps you would consider helping us in this next stage and donate a camera–which we would of course name after you! You can even donate for a portion of the costs of a camera. Any support will be tremendously appreciated.

See you in 2022!

By the time you receive our next update, we’ll be celebrating the installation of our 150th Sloth Crossing, and hopefully, we can start putting bridges over the main road.

These road spanning bridges cannot be the single rope design we have been using because the canopy gap is much larger, so we need to build more steady, robust structures.

This will be done in collaboration with the Costa Rican Electricity Company (ICE) and with the Ministry of Environment, so coordinating this effort will require time.

I hope you stay with us in the next steps of this journey and continue supporting SloCo. Thank you so much for your great support and help, and I wish you all the best and an amazing 2022!

Pura Vida!







-Tamara Ávila Atagua

Sloth Crossings Project

The Origin of the National Symbol

The Origin of the National Symbol

Team Sloth contacted Jorge Carballo, the man responsible for the idea to declare sloths the national symbol for Costa Rica. Jorge grew surrounded by lush tropical forests and is passionate about nature.

Costa Rica is a paradise in so many respects. The fact that you can find wildlife in your backyard– toucans, monkeys, or sloths feeding or passing through—makes this country a special place. This is exactly how Jorge’s childhood was: a constant contact with nature and animals.

This love for nature eventually grew into the initiative that made sloths the latest national symbol of Costa Rica.

The following transcript has been lightly edited for clarity.


cart costa rica

Jorge, tell us about yourself:

I was born in Limón, but I lived in Guápiles until I was 19 years old. Then I went to study Communication in Buenos Aires, Argentina in 2010. I returned to Costa Rica about 3 – 4 months ago, and now I work for a tech company as a UX Researcher.

Where does your love for nature and sloths come from?

I think it is a product of the environment in which I grew up. From the proximity to the forests that I had for all of my childhood, the contents of my school, and the idiosyncrasy of a country that is entirely loaded with environmentalism. Coexistence with nature is part of the imagination of the Costa Rican. Perhaps this seed does not grow with the same strength in everyone, but the seed is there.

With sloths, this bond is sustained by their characteristics: they are non-aggressive, they are very pretty, they seem to be smiling, and they spend many hours sleeping. They are very noble animals. And their slowness makes them very funny. It is very difficult not to have sympathy for them. Sloths were always there “in the mountains”, and since I was in contact with those spaces, it was not uncommon for me to see them.


national symbol costa rica
Jorge and his brother Christian exploring the Caribbean forest


How did the idea of the sloth as a national symbol come about?

The idea was born from a tweet I read. This person said that the sloth had to be a national symbol, like a joke. Then I shared the tweet with a couple of people. That sparked a conversation, questions, and some research. Little by little the idea became more and more concrete, more solid.

I mentioned this idea to Congresswoman Yorleny León, whom I have known for more than 10 years, and she told me that I could count on her to support it. After a lot of work, the project finally became serious and it ended up national law. It’s amazing, I still can not believe it.

I was surrounded by people who worked with me, who added their effort and desire to make this happen. I definitely wouldn’t have done it alone.

How was the process to write the project?

It was definitely a challenge, but a very cute one. While I had some research and writing experience from my work, I had never done anything legal – legislative. Luckily I was surrounded by people who were able to go where my knowledge could not, and they offered me their full collaboration as if this project were also theirs; as if it belonged to everyone.

It was a project that involved a lot of learning and surprises about the animal. It was also really good learning how much sloths are loved in the world. It is not every day that we have the opportunity to work with something so beautiful and interesting. Maybe that is what made it easier to sit down on the weekends to work on the project: look up information, write, structure, revise, rewrite, look for more information, revise, and so on several times.

I also had Yorleny’s team and that gave me some peace of mind. I was not alone, I did not work alone. I had many advantages, many factors that worked in my favor, but I think what really made the difference was the seriousness with which the project was ultimately taken. That was the key. Going from a wish to a specific job that is now a national law. And that is truly a luxury. I am very happy to have participated in this.


Congresswoman Yorleny León Marchena national symbol
Congresswoman Yorleny León Marchena promoting the project

Why is it important to declare the sloth a national symbol?

Beyond the fact that it is a very beautiful animal, the decision was more strategic than whimsical. The context in which the project was presented was very favorable for its success. Today the sloth enjoys a level of acceptance and good publicity that no other animal in the country has.

That happens both inside and outside the country. The animal is associated with Costa Rica in the imagination of the people, although it also exists in other countries. The memes, the movies, the merchandise, the t-shirts that tourists wear, the comic strips in the newspapers, in short, sloths are everywhere.

So we had to do something. Costa Rica had to take advantage of this opportunity. That’s how this idea began to be conceived: the project had to bring together a number of positive factors to happen simultaneously, to achieve very good things. Good things not only for sloths but also for other animals and the space they inhabit, such as national tourism and environmental education of children in schools, scientists, and the world.

Because we are not only protecting the sloth, we are also creating a precedent to be replicated in other places. This is an experience open to be improved, a seed that can continue to grow.



How do you imagine that this declaration will benefit the conservation of sloths (and wildlife in general)?

I envision two large groups of benefits. The first, more abstract, would be the privileged place that sloths reaffirm in the imagination of the people. Now children are going to learn more about them in schools, older people will see them with more respect. They will never go unnoticed again. I do not remember that any other animal has received so much positive press in the country.

There are still people who do not know sloths exist. There are people who do not know that they exist in Costa Rica. There are people who do not know that what they thought was a leaf or a nest in the tree behind their house is a sloth, but now sloths are being recognized. Today with their faces they tell us “here we are” and now everyone knows it. And that’s good.

The second group would be the most concrete benefits. I am referring to those involving state institutions such as the Ministry of Environment (MINAE), MOPT, ICE and their specific actions such as protecting or expanding habitat areas, placing safe passages for wildlife on highways, and improving public electrical wiring to avoid electrocutions, just to mention a few. In summary, I hope for better living conditions for the sloth and consequently for many other animals.

What is your favorite species of sloth?

That is a difficult question. I have my favorites. Nationally, the three-fingered sloth (Bradypus variegatus) is my favorite. I really like their faces, the shape of their noses, and the black lines in their eyes. Also, I like the hair. Internationally, I love the pygmy sloth (Bradypus pygmaeus) in Panama. They are like a three-fingered mini version. They are endemic to an island and they are small, almost like a character from a legend. Unfortunately, they are endangered. Maybe the next project could be about the pygmy sloth.


What is your favorite fact about sloths?

I am struck by how modest they are when it comes to defecating. I say modest but there may be a more primary reason, more biological and less “cultural” or social, but it is very funny that they take the trouble to go down, make their hole, and after doing their thing, cover it. It is a risky activity because they can die from being exposed to predators that can reach them.

It is almost nonsense. But I think that regardless of how funny this data may be, I also like it because there is still no solid idea why they do it. That mystery seems powerful to me because it reminds us that despite all the advances we have made and all the research there are still things to discover, things to do.