Amphibians
Coqui
Eleutherodactylus coqui · also called common coqui, Puerto Rican coqui, coqui frog
For a frog you can perch on a coin, the coqui makes an enormous amount of noise — and an enormous cultural impression. Its two-note call, co-QUI, is the sound Puerto Rico goes to sleep to, and the frog is one of the island’s defining symbols.
Overview
Eleutherodactylus coqui is native to Puerto Rico, where it lives everywhere from coastal gardens to the tops of the mountains. It is 2.5–5 cm long, brown and variable, with big eyes and large round toe discs for climbing. Only males call; the first note stakes a territory, the second draws females.
Life without a pond
The coqui lays its eggs on land, in leaf litter and bromeliads, and they undergo direct development — hatching after two to three weeks as fully formed froglets, with no tadpole stage. The male guards the clutch throughout.
A frog that travels
Because it needs no water body to breed, a clutch hidden in the soil of a potted plant can found a new population anywhere warm and damp. That is how it reached Hawaii around 1988, where it now occurs at far higher densities than at home and is treated as a serious pest for its noise and its impact on island insect life.
Status
The common coqui is Least Concern and abundant. But several of its 17 Puerto Rican relatives are endangered, and at least three are extinct.
Coqui: common questions
Why is the coqui so important to Puerto Rico?
It is woven through the island's culture in a way few animals are anywhere. The sound of coquis calling at night is the background noise of life in Puerto Rico, from the rainforest to city gardens, and for many Puerto Ricans, especially those living away from the island, hearing it is the sound of home. The frog appears in the pre-Columbian carvings of the Taino people, in folk songs and poetry, on souvenirs, and as a mascot. The common saying "de aqui como el coqui" uses the frog as shorthand for being authentically, unmistakably Puerto Rican.
How does skipping the tadpole stage help the coqui spread?
A frog that needs ponds or streams to breed can only colonise places with the right water. The coqui does not. It lays its eggs in damp vegetation and leaf litter, the male keeps them moist, and they hatch straight into tiny froglets. That means a few frogs or even a single clutch hidden in the soil of a potted plant can start a new population anywhere warm and humid enough, with no water body required. This is exactly how it reached Hawaii, in shipments of ornamental plants, and why it has been so hard to stop once established.
Why are coquis considered a problem in Hawaii?
Several reasons. The chorus is extremely loud; in dense infestations the night-long noise has affected sleep, property values, and the nursery and tourism industries. The frogs reach far higher densities in Hawaii than in Puerto Rico, in some areas tens of thousands per hectare, and collectively eat vast numbers of insects, which raises concern about competition with native birds and insects and about disrupting island food webs. Hawaii has no native amphibians, so the coqui slots into an ecosystem with no history of frogs. Control uses citric acid or hot-water treatment of plants and habitat.
Are all coqui species doing well?
No. The common coqui, Eleutherodactylus coqui, is abundant and even invasive, but it is one of about 17 coqui species in the genus that are native to Puerto Rico, and several of those are in serious trouble. At least three are considered extinct, including the web-footed coqui and the golden coqui, and others such as the mottled coqui are critically endangered, hit by habitat loss, climate change, and the amphibian chytrid fungus. The familiar backyard coqui masks a group with real conservation problems.