Jessica’s Nature Field Note: Ni Oso, Ni Perezoso

Ni Oso, Ni Perezoso

Abstract: Sloths are known to the world as the slowest creatures alive. Even the Spanish word for sloth is “oso perezoso” but does this name suit the sloth?

I’m sure you have noticed, I have developed a sloth obsession during my time in Costa Rica. Sloths are quite popular in popular culture right now, but I was never really interested in them – not until I saw one in real life. It was just so cute! The first one that I saw was in Monteverde. (Do you remember the night walk I went on and the sloth I saw, hanging in the tree with her baby?) Since then, I have seen two more in the wild and five more at a wildlife rescue.

So naturally for my Nature Field Note article, I decided to focus on sloths. I have learned so much about sloths recently! My first impression of sloths before coming to Costa Rica was that they were slow and lazy. I thought that they didn’t need to sleep because they never used any energy, they never moved and they lived up in trees like koala bears. I have learned that only one of those three impressions proved to be true. Can you guess which two were incorrect?

What does this creature or plant look like?

A sloth, or in Spanish, an oso perezoso, looks very unique. You cannot really compare a sloth to another animal very well. It is interesting because its name in Spanish directly translates as “lazy bear.” I have come to find out through observation and a tour at a wildlife rescue, that sloths are neither lazy, nor bears. (I was wrong. They do move!) Our guide even said that there is a campaign called “Ni Oso, Ni Perezoso” that is trying to change sloths’ reputation.

While I was at the wildlife rescue, I saw both types of sloths, the two-toed and the three-toed sloths. They actually look pretty different from each other. A two-toed sloth had lighter colored hair whereas the three-toed sloth had darker colored hair. The three-toed sloth also always appears to be smiling!

How did I feel when I saw it?

I actually got the opportunity to hold a baby sloth named Natalie who is two months old. She is a two-toed sloth. When they are babies, they are darker colored. Then, their hair lightens as they grow up. It takes about four years for a sloth to mature. Because Natalie is so young, she was wrapped in a blanket. Our guide told me not to try to pet her because she wasn’t sure if she would bite me. They are calm creatures, but when they are young, like any animal, they don’t like sudden movements and they don’t like people that they don’t recognize touching them.

Our guide told us also that her sloths recognize her and respond to their names. This took a while for them to learn though. While we were at the wildlife rescue, it began to rain. We waited under an overhang while she went to get one of the sloths. The sloth was not happy about having to get wet so she hissed at our guide. Our guide told us that she has never had her hiss at her before so she must really hate the rain, but she was never afraid that Millie, the sloth, would hurt her. That made me feel at ease because I had always wanted to hold a sloth and this happened before I got to hold the baby.

Where does it live?

Sloths can be found in the rainforest, which means they enjoy a tropical environment. They are mostly concentrated in Central America because it has a tropical environment that houses the tropical rainforests. These are rainforests that are found near the equator.
Sloths tend to live within the branches of trees. (I was right!) Three toed sloths have darker hair to blend in to darker colored trees more easily. Two toed sloths have lighter hair or light brown hair and usually spend their time in trees that have lighter colored leaves. This is how they camouflage, or blend in to their surroundings.

How does it use its environment to survive?

As I said, sloths are equipped with natural coloring in their fur that allows for them to blend into the trees in which they live. This protects them from predators, animals who might want to harm the sloth.

Sloths also are nocturnal, which means they are more active at night than during the day. I thought originally that sloths didn’t need to sleep, but really, they just use less energy during the day by moving more slowly in order to save their energy for the night time. They nap off and on during the day as they avoid the heat according to my tour guide. (I was incorrect. They do need to sleep.) The sloths that I saw at the wildlife rescue were still active during the day, but only to crawl up a branch for a leaf snack. The one that I saw in Monteverde on our night walk was VERY active. This makes sense since I learned that they are nocturnal.

What can harm this creature? Are we worried about it?

I learned that the sloth’s main predators are the jaguar and the human. Our guide told us a particularly sad truth about what happens in Costa Rica very often. People think sloths are cute, so they want them as pets even though it is illegal to have exotic pets. They will find them as babies at a park or on the side of the road and take them home, without knowing how to care for them. They will not intentionally mistreat them, but they do not know how to care for a sloth and are afraid to ask a veterinarian because they might be turned in.

The rescue that we went to was originally only for toucans. After a few months, our guide, who also manages the rescue, received a sloth that was suffering from malnutrition; it had not been receiving the correct diet to get all of the nutrients its body needed. She took in the sloth and nursed it back to health, but since she had received him as a baby, he could not return to the wild because he would not know how to survive. Now, he lives at the rescue with her in a large area and is well taken care of.

The biggest threat to sloths is humans who try to take them in as pets or to sell them. Sloths are worth a lot of money on the exotic black market (where they sell illegal animals) so people steal sloths from their homes to sell them.

All of the information about sloths came from the tour that I had at the wildlife rescue. This is their website if you’d like more information.

This is the sloth I saw on the side of the road. Look how well he camoflages.

This is the sloth I saw on the side of the road. Look how well it camouflages.


My first sloth encounter in Monteverde.

My first sloth encounter in Monteverde


This is a picture of a three toed sloth that I had to take a picture with.

Me and a picture with a three-toed sloth

A two toed sloth at the rescue eating a leaf.

A two toed sloth at the rescue eating a leaf.

Millie the sloth at the wildlife rescue

Millie the sloth at the wildlife rescue

Millie the sloth at the wildlife rescue

Millie the sloth at the wildlife rescue


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