If you've ever been to Puerto Rico and gone out to the rainforest or anywhere beyond the urban sprawl of the city, you'll soon be serenaded by Puerto Rico's unofficial mascot. You won't be able to see the source of this melody, but you can certainly hear it: a two-note orchestra which sounds like this: Co-qui.
And that's how a tiny tree frog species that are endemic to Puerto Rico got its name. The coquí is, for me at least, one of the natural wonders of Puerto Rico.
This endemic species live in the island's forests (although it has been introduced to the U.S. and other islands) and is truly petite: it reaches 1 to 2 inches in length and weighs between 2 and 4 ounces. Ironically, that makes them one of the largest frogs in Puerto Rico. And it also makes it even more impressive that the sound they produce is so loud! The call of the coquí is clear, high-pitched and unmistakable. And if you ever get to spend a night or two in El Yunque, you'll hear their song all night long without interruption. This symphony will either drive you nuts or lull you to sleep.
These little guys aren't just amazing because of their music. The coquí (scientific name Eleutherodactylus coqui, which means "free toes")) is different from many frogs in that it doesn't have webbed feet; instead, their toes have special pads that let them climb and stick to trees and leaves. The song of the coquí is produced by the males of the species to attract females and ward off competitors during mating season.
(Given how frequently you hear this sound pretty much throughout the year, that's a whole lot of flirting or posturing!). And unlike most frogs, coquís don't have a tadpole stage: they emerge from their eggs as tiny frogs with tails, which the male watches over (male coquís are quite the industrious lot, aren't they).
Coquís have passed into the lore of Puerto Rico, and form part of island's culture. You'll find coquí toys, books and t-shirts at any souvenir store in San Juan. Many establishments bear the name "Coquí," and the Puerto Rican version of egg nog is called the coquito (it's a mix of rum, cinnamon, cloves, coconut and egg, if you ever want to try it; you can also buy bottles of it on the island). There's a common story (corroborated by the USDA Forest Service, by the way) that it even "rains frogs" in El Yunque. Apparently, the little guys often find themselves on the canopy of the forest, where they're more exposed to their natural predators. Rather than making the cumbersome and time-consuming scramble back down the bark for a place to hide, the irrepressible coquís merely launch into the air and literally float back down to the ground.