The Coqui Frogs of El Yunque

The coqui is a tiny tree frog native to Puerto Rico, named for the ko-kee call the males make at night. The coqui frog is about one inch long and is a national symbol of the island. About 17 coqui species are endemic to Puerto Rico, and 13 of them live in El Yunque.

The coqui frog's ko-kee call is a two-part message from a male: the co note warns rival males away and marks territory, and the kee note attracts females. Only male coquis call, starting at dusk. A popular local legend says the call means I love you, but that is folklore rather than translation.

A coqui frog's call has been recorded at around 100 decibels from a few feet away, which makes it one of the loudest amphibian calls on earth. That volume comes from a frog barely an inch long. In El Yunque, many males calling together after sunset create a chorus that carries a surprising distance.

Coqui frogs in El Yunque call from dusk through the night, so the chorus is loudest in the evening. During the day you may only hear scattered calls in shaded, humid spots near streams and dense vegetation. For the full chorus, plan to be near the forest as the light fades.

Thirteen of Puerto Rico's roughly 17 coqui species are found in El Yunque National Forest. They range from lowland species near the trails to montane species on the misty peaks. Some of the mountain coqui species have declined in recent decades, partly due to a fungal disease that affects frogs at higher elevations.

Coqui frogs are native only to Puerto Rico, where they have lived for tens of millions of years. The common coqui has been accidentally introduced elsewhere, including Hawaii, where it is considered invasive. Outside those introductions, the coqui remains a Puerto Rican animal, and its call is still the signature night sound of the island.

A coqui frog is a tiny tree frog, barely an inch long, with unwebbed, pad-tipped toes that let it grip leaves and bark. Its genus name, Eleutherodactylus, means free toes for that reason. Because coquis are so small and mostly active after dark, many visitors hear hundreds without ever seeing a single frog.

You can see coqui frogs in El Yunque, but they are far easier to hear than to see. The frogs are most active after dark and cling to leaves and bark. Your best chance of spotting one is after dusk in a shaded, humid spot near a stream, following a single call slowly with a dim light.

Coqui frogs do not have tadpoles; they skip that stage entirely and hatch directly into tiny frogs. That is part of why coquis thrive in the trees rather than in water. Their genus, Eleutherodactylus, means free toes, a nod to the unwebbed, pad-tipped feet that let them grip leaves and bark.

The coqui is a symbol of Puerto Rico because it is native only to the island and its ko-kee call is the signature sound of Puerto Rican nights. Coquis have lived there for tens of millions of years, and their image appears on everything from t-shirts to art across the island.

Some montane coqui species in El Yunque have declined in recent decades, partly because of a fungal disease that affects frogs at higher elevations. The lowland coquis near the trails are still easy to hear at night. If you go looking for coquis, stay on marked trails and leave every frog where you find it.

You can sometimes hear coqui frogs on a daytime guided El Yunque tour, but expect scattered calls in shaded, wet spots, not the full night chorus. Coquis call mostly from dusk onward. The rainforest swimming tour spends the day in humid forest on the south side, at $89 per person or $129 with San Juan hotel pickup.