Amphibians
Strawberry Poison-dart Frog
Oophaga pumilio · also called strawberry poison frog, blue jeans frog, flaming poison frog
The strawberry poison-dart frog is a thumbnail-sized jewel of the Central American rainforest floor — usually bright red with blue legs, though it comes in dozens of colour schemes. Behind the colour is a toxic skin built from its ant diet, and a mother that hauls each of her tadpoles up a tree and then feeds it eggs by hand for two months.
Overview
Strawberry poison frogs live on the Caribbean slope of Central America, from Nicaragua to Panama, in lowland and foothill rainforest and adjacent plantations. They are active by day, moving over the leaf litter hunting ants and mites, and males call persistently from low perches to hold small territories.
Toxic, but from its food
The frog’s skin contains pumiliotoxin alkaloids — bitter, irritating, and dangerous in quantity. Crucially, the frog does not make them: it sequesters them from the ants and mites it eats. A strawberry poison frog raised on other insects in captivity becomes non-toxic. The bright colour is a warning to predators that have learned the connection.
Many colours, one species
It is among the most colour-variable vertebrates known, with 15–30 local forms — the red-body-blue-legs “blue jeans” type, plus green, orange, white-and-black, and near-black variants, several confined to individual islands in Panama’s Bocas del Toro. The colours can flip within a few kilometres, and why is still debated.
The dedicated mother
Care of the young is extraordinary. The female lays eggs on a leaf; the male keeps them damp. When they hatch, she lets one tadpole climb onto her back and carries it into the canopy to a water pocket in a bromeliad or tree hole, leaving it there alone — repeating this for each tadpole, in separate pools. Then, for six to eight weeks, she visits every tadpole every few days and lays unfertilised eggs into its pool as food. The tadpoles have no other food source and cannot survive without her.
Status
The strawberry poison frog is Least Concern but declining locally with rainforest clearance and collection for the pet trade, where its colour forms are prized. Several island morphs have tiny ranges and are more vulnerable than the species as a whole.
Strawberry Poison-dart Frog: common questions
How poisonous is the strawberry poison-dart frog?
It is genuinely toxic, but nowhere near the level of the golden poison frog. Its skin holds a cocktail of alkaloids, mainly pumiliotoxins, that taste foul and can cause pain, numbness, swelling, and — at high enough doses — muscle weakness or cardiac effects. For a predator, biting one is a memorable mistake; for a human, the risk from casual contact is low, though the toxins can irritate broken skin, eyes, and mouth, so the frogs should not be handled and hands should be washed. Indigenous groups did not typically use this species to poison darts — that was a few larger Phyllobates species.
Why does it come in so many colours?
The strawberry poison frog is one of the most colour-variable vertebrates known, with roughly 15 to 30 distinct local forms, several of them on small islands in the Bocas del Toro archipelago of Panama. The classic mainland form is a bright red or orange body with dark blue lower legs, which gives it the nickname "blue jeans." Others are solid green, orange, yellow, white with black spots, or so dark they look black. The colours are warning signals (aposematism), and why they diverge so sharply over short distances — sometimes within a few kilometres — is an active research question involving predator learning, mate choice, and island isolation.
How does the mother frog raise her tadpoles?
With unusually intensive care. The female lays a small clutch of eggs on a leaf on the forest floor, and the male keeps them moist. When the tadpoles hatch, the female backs into the clutch, lets one tadpole wriggle onto her back, and carries it — climbing high into the canopy — to a tiny pool of water held in a bromeliad leaf or a tree hole, depositing it there alone. She does this for each tadpole, placing them in separate nurseries. Then, every few days for the next six to eight weeks, she returns to each tadpole and lays a clutch of unfertilised "nurse eggs" directly into its pool for it to eat, since these tree-hole pools contain almost no other food. The tadpoles cannot survive without her.
Are these the frogs used to poison blowgun darts?
Only loosely, and not this species. The name "poison dart frog" or "poison arrow frog" applies to the whole family Dendrobatidae, but only three species — all in the genus Phyllobates, including the golden poison frog — are known to have been used by the Emberá and Noanamá people of Colombia to coat blowgun darts. The strawberry poison frog and most other members of the family are toxic enough to deter predators but were not used this way. The name has simply spread to the entire colourful family.