There's a reason they call it the loudest amphibian.

You've made it to the Rainforest. You plan to become one with nature and reconnect with yourself. There are giant verdant ferns entwined with tall ancestral trees surrounding you. With every breath, the humid-yet-pure air of mountains is filling your lungs. It feels cool and fresh. Birds are fluttering above you as the mist of the waterfalls you're passing by sprinkle your face. Then, as you are untying all your senses, you hear it: "Co-kee! Co-co-kee!"

As your day in El Yunque National Forest goes by, the sound gets louder and louder. But what is it? Where is it coming from? And most importantly, what does it mean?

You are hearing the sound of the coquí, a tiny tree frog native to Puerto Rico. Its scientific name Eleutherodactylus, which means "free toes," references the frog's shape, while its common name coquí, relates directly to the sound it makes. 

You'll see it all around the Island — from t-shirts and paintings to the actual animal, but you'll find the most significant concentration of these singing amphibians at El Yunque, with 11 out of 13 species present.

It's a singing competition! 

No, there isn't a direct translation for the sound "co-kee," but behavioral patterns have established that when a coquí sings, he announces himself and shows his territory to mate. So, forest biologists like Jessica Isle believe they express something like "here I am" or "hey female, here I am." Female coquís are not generally known to sing; the male does the mating call, and the female listens to identify "which guy sings better."   

There are variations in the syllables, almost like a stutter or incomplete songs, so you might hear "co-kee. Co-co-kee. Co-co. Co-kee-kee," and more. Although you can listen to choruses of male coquís singing from dusk 'till dawn, most species prefer to sing at night. The female coquí acts like a judge in a singing competition: they are looking for energy and pitch. While singing, the male coquí is saying, "I have more territory," "I have more energy," or "I can do it better." So, males spread themselves out to minimize the competition. Studies show that the first "co" part of a call deters other males, while the "kee" part attracts the females.

Coquí all day and night…

Do you remember there are 13 species of coquí? Well, not all of them sing at the same time or in unison. Some species sing in the morning, some in the afternoon, but most sing at night. They all have their niche, and even if they sound the same to the human ear, they are not necessarily making the same noise or the same patterns. 

Some coquís are patient and wait until there isn't much noise around to sing. Because, if you're going to sing, you want to be heard, right? And, the Rainforest gets loud. Choruses of coquís have registered to reach up to 96 decibels. That's as loud as a boom box, a motorcycle, or an ATV!

Did you know? 

You can find coquís in humid places, but all they need to lay their eggs is ¼ cup of water, often found in bromeliads or plants with leaves in shapes that can collect water.  

  • The coquí eats bugs, spiders, and lizards. 
  • They can't bite you, so don't be afraid of them. 
  • They breathe through their skin, so it is not recommended to touch them. 
  • Coquís don't move very far. On average, they don't travel more than a few hundred meters in their life span. 
A coquí frog.

In El Yunque it is easy to have encounters with our beloved little frog, the coquí.

Adopt a Coquí

Puerto Rico is full of natural beauty and unique habitats like mangroves, rainforests, coral reefs, salt flats, bioluminescent bays, and caves from the coast to the mountains.

The heart and soul of the Caribbean has 36 nature reserves, with El Yunque being the most important. The only rainforest in the U.S. National Forest System is home to the coquí, our beloved tiny frog.

In good time, you'll plan a future visit to our forest to enjoy their serenade in person. But, in the meantime, you can virtually adopt a coquí and support on-Island sustainability and conservation programs.


Embrace a Puerto Rican Christmas Tale

Make the most of this holiday season along with your family and learn the Puerto Rican tradition of the Three Kings. The children's book "From Boriquén to Bethlehem: A Coquí and the Three Wise Men" tells the story of a magical coquí who traveled with a young Puerto Rican girl and the Magi to the first Christmas.