La Selva Sloths | Downloading the data wirelessly

La Selva Sloths | Downloading the data wirelessly


Our team of researchers spent three days at La Selva Biological Station and Reserve at the end of August. There, they tried downloading the data from the GPS collar we fitted on Misty, George, and Selvina.



Day 1: The first sloth we found

Our journey began at the crack of dawn on Tuesday 29th August, as we aimed to reach La Selva in time for breakfast. Back in June, we deployed our first GPS collars onto three wild sloths living at the 1500 acres of secondary rainforest biological research station. La Selva borders the Braulio Carilo National Park, which is over 100,000 acres, and gives the area a unique level of protection against development. 



Upon our arrival, we wasted no time and quickly fueled up with breakfast before going in search of brand new equipment waiting for us in one of the labs. On our way, we were scanning the trees – which just becomes a habit after a while of doing this work, whether we’re on the clock or not – and spotted a three-fingered sloth.


Misty the sloth, has a cloudy eye.


As this was the tree where Misty was first spotted, we immediately broke out the binoculars. However, after some comparison between the sloth in our binoculars and the photographs we have of Misty’s unique face, we concluded that this was definitely not Misty.

This was actually somewhat of a relief, as this sloth definitely did not have a collar, and sloths losing their tracking equipment is not something we came prepared to fix. (Literally – we needed to pack light and did not include extra collars.)

New Equipment and Wireless Wonder

Following this, we were shown around the lab by Danilo, who has worked at La Selva for almost 40 years. We couldn’t resist picking his brain about what he’s seen over the decades: two-meter (six ft) long bushmasters (Lachesis stenophrys) and Jaguars crossing the bridge at 7 a.m. while everyone ate breakfast were certainly highlights.



Among the goodies waiting for us was a state-of-the-art antenna and a PinPoint Commander, which allows us to wirelessly download the GPS points from the collars. To do this, we simply have to be in the range of the sloth, who we locate manually using our usual VHF telemetry methods.

We no longer need to capture the sloths; we just need to get close enough to them – a true game changer! 



These GPS collars are set to run for over six months, which is only possible because they are programmed to emit VHF signals for only two hours daily between 8 a.m. and 10 a.m. 

Unfortunately, when we tuned into Misty’s frequency at the tree we had first spotted her in, we were greeted with silence rather than the steady beep we were expecting. It was disheartening, but it’s all part of the scientific journey. In a bid to conserve battery power, we’ve set a schedule for signal transmission and data download, strictly from 8 AM to 10 AM. With the signal gone after 10 AM, we dedicated the rest of the day to computer work and mastering the intricacies of our new equipment. 

The team sat in a humidity and temperature-controlled library for the rest of the day, which was the highlight of the trip for everyone. 



Day 2| Early Rise and Rainy Quest

Knowing our strict start time of 8 a.m., we began hiking to our furthest sloth at 7:30, planning to work our way back to the camp where Misty was first located. Our aim today was to locate the sloths and complete figuring out our new GPS equipment for use tomorrow.



Encouragingly, we received strong and directional signals for George and Selvina. We followed Selvina’s signal, passed her release tree and into some dense forest when the rain started. We looked at our new equipment and at the number of fallen trees around us and decided to call it a day instead of risk a storm. Misty is still Missing In Action, but we were able to set everything up for the GPS downloads tomorrow.


Day 3 | The Great Download

Another early start, today we utilized both of our antennas and split up, half of the team looking for George and the other looking for Selvina. We followed our paths from yesterday, which led us deeper into the jungle. 

While we could not visually spot either of them, we successfully downloaded both of their GPS datasets onto a memory card. The great thing about this technology is that it makes spotting the sloths a great bonus, but not vital to the data collection. As we’re sure you already know if you’ve chosen to read this, the difficulty of spotting sloths in the thick jungle is part of the reason that there is such a large deficit in sloth research, so this new technology is truly groundbreaking. 

As we left the forest we tuned into Misty’s frequency, which was dishearteningly silent. The absolute silence rather than a very faint beep indicated that Misty’s collar was either not turned on or had malfunctioned (i.e. It did not indicate that she was just very far away). This was proven when Jose decided to try his luck with the PinPoint Commander and was able to download Misty’s GPS data! 

This confirmed to us that there is an issue with her collar, but she is still close to where she had been released, which is a huge relief. The issue with her collar can hopefully be sorted with help from our Brown University colleagues, who are collaborating with us on this research project.  


Amelia Symeou

Ecology Coordinator

The Urban Sloth Project


This website uses cookies.

We use cookies to personalise content and ads, to provide social media features, to track access and usage for security purposes and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners who may combine it with other information that you've provided to them or that they've collected from your use of their services. You consent to our cookies by continuing to use our site and online resources. Click here for our full privacy policy.