Slothober 2025

Update #50 of The Urban Sloth Project!

That’s more than four uninterrupted years of bringing you updates straight from the field following the sloths we’re monitoring as part of our research on the impacts of urbanization along Costa Rica’s Caribbean coast.

We’re so proud to have kept these updates going, and even prouder of this beautiful community of VIPs. To those who believed in the project from the very beginning, and to those who’ve just joined us:  thank you! None of this would be possible without you! 

What better way to mark the 50th update than by launching our brand-new VIP Portal! Below, you’ll find the latest updates for each sloth in the Urban Sloth Project, plus, we’ll now be sharing updates from our other projects too!

You no longer need to download the PDF to read the news; you can now enjoy it directly here.  But don’t worry: we know many of you love collecting or printing the PDFs, so you’ll still find the file available for download at the bottom.

Now, without further ado… let’s see what the sloths have been up to!

Deborah

After replacing Debbie’s collar, she gave us quite a scare, disappearing for several days even though her signal was strong. The transmitter kept pinging from the same area, raising suspicions that something might have happened, yet the mortality signal never activated.

Jose grew concerned and decided to investigate, taking Diego along after a census day (Diego’s sharp eyes for sloths always come in handy!). That day, the signal suddenly shifted to the other side of the road, an area Debbie had explored before. Within just five minutes, they spotted her, safe and sound, lounging in her usual favorite branches with her new collar still on.

Since then, she’s been her usual self, sticking to her familiar trees and showing no signs of stress.

Pistachio

Pistachio continues to be his laid-back self, spending his days near the Caribeans restaurant and the surrounding trees. On the last day of the month, we even spotted a juvenile two-fingered sloth (Choloepus) in the same jabillo tree where he often rests… perhaps a new neighbor!

On one occasion, while checking on him, it was already getting dark, making it hard to find the usually reliable Pistachio. As Caribeans began to close and people started to leave, the motion-activated lights in the neighboring property, which we had had to go into to get a better angle, flicked on with our movement. That’s when we suddenly spotted him, lying motionless in his favorite spiky tree, perfectly camouflaged and unfazed by all the commotion.

Tender

Tender’s month was peaceful as usual. The only noteworthy change was more vegetation trimming by ICE, the electricity company, similar to what happened near Luiza’s area. Fortunately, the trees weren’t fully cut, though the first tree we ever recorded for Tender was heavily trimmed, almost by half. Despite that, Tender seems unfazed and continues to use the same tree regularly. It appears to be an important part of his home range.

Primary Forest Sloths

Pipa

Pipa remains our most predictable sloth. Even in the dense primary forest, we can locate her in minutes. She favors a tall, vine-covered tree near the road, which is perfect for hiding deep among the leaves. Once we spotted her there the first time, it became easy to find her again, as she rarely strays from that particular perch.

Ponder

Ponder has been especially active this month, roaming far and wide. His collar only activates on Wednesdays, which limits tracking, but mid-month, the signal grew weak and erratic. Jose persevered, eventually isolating the correct frequency and finding Ponder high up in the property: nearly 250 meters from where the car was parked.

It was a new area for him, but by the end of the month, he returned to his usual trees. Maybe next month he’ll wander that way again!

Chill

Of all our sloths, Chill has been the most adventurous lately. She moved from her usual roadside territory deep into the forest, far beyond where we normally track. Jose had to carve a new trail through thick undergrowth, carefully watching for hidden wildlife (including spiders, bees, and even an agouti skull found along the way).

The signal fluctuated, sometimes high, sometimes low, making tracking a challenge. Eventually, he found her: once just three meters up, and another time perched an impressive 35 meters high! It’s wonderful to see her exploring new parts of the forest, healthy and thriving.

Sloth Of The Month: Luiza

This month, Luiza was seen near the main road, close to Sloth City. Unexpectedly, her collar stopped transmitting a VHF signal, even though the battery was supposed to last another year. Luckily, the mortality signal didn’t activate, which told us she was alive and moving.

However, there was a surprise waiting. The area around her home range had recently been heavily trimmed by ICE. Not a light pruning, but a severe cut that removed several of her favorite trees. We feared she might have been injured, relocated, or taken for veterinary care. Thankfully, she was safe, though her habitat had suffered some damage.

Finding Luiza without a signal is no easy task. Anyone familiar with her wandering ways knows this well. But Jose, who has been tracking her for over three years, knows her favorite hangout spots. Within just ten minutes of searching, he found her resting in a beach almond tree, calm and perfectly fine.

When we confirmed it was indeed Luiza, plans began to replace her collar. She was about eight meters high, and as we prepared the equipment, curious onlookers gathered. More than twenty people, drawn in by the sight of not one but two sloths (a male was nearby).

Then Jose noticed something extraordinary: a tiny arm clinging to Luiza’s belly. She had a newborn baby, likely less than two weeks old! Remember, when last month we said we had confirmed she had no baby, after weeks of speculation? Well… we had a reason to be suspicious!

This changed everything. A standard capture and data collection would have stressed both mother and infant, so Jose decided to only replace the collar and minimize handling. Just as we wondered how to safely bring her down, Luiza began climbing lower on her own, perhaps startled by the small crowd. It couldn’t have worked out better. Dayber carefully lifted her down using a ladder, Jose quickly replaced the collar in under ten minutes, and both mother and baby were safely released.

The new collar is working perfectly, and we’ll be able to track Luiza and her little one for at least two more years: barring another battery surprise! 

Since the collar replacement, Luiza has returned to her old haunts, even revisiting a massive tree she used back in 2022. She clearly remembers her favorite spots. On one recent observation, she was perched 40 meters high, too far up for us to see the baby, even with binoculars.

All the best from the jungle,