Golden Poison Frog (Phyllobates terribilis): Facts and Toxin

What does the golden poison frog look like?

The golden poison frog is a stocky little frog with smooth, glossy skin and no pattern at all as an adult. That plain, solid color is unusual among poison dart frogs, most of which have spots, stripes or bands. It is one of the larger members of its family, but it would still sit comfortably on a human thumb.

Despite the name, three main wild color forms are known:

• Golden yellow, from pale lemon to deep gold, the form that gave the species its name. It lives around Quebrada Guangui on the upper Río Saija.
• Orange, metallic orange to yellow-orange, found in the same general area.
• Mint green, which can look pale green, metallic green or almost white. This form, from the La Brea area, is the largest.

Young frogs look completely different. Froglets are mostly black with two golden-yellow stripes down the back, the “primitive” pattern shared by many poison frogs. The black gradually fades and the frogs reach full adult color a few months after leaving the water.

Each foot has slender toes with small, slightly widened discs at the tips, and the long middle toe is often tapped when the frog is excited. Golden poison frogs walk and hop on the ground and are rarely seen climbing.

How big is a golden poison frog?

Adults usually measure 4.7–5.5 cm (1.9–2.2 in) from snout to vent, the standard frog measurement that leaves out the legs. Females are typically a little larger than males. A frog this size weighs only a few grams, about as much as a couple of paper clips, and weights are rarely recorded.

Habitat and range

The golden poison frog lives only on the Pacific side of Colombia, in the Cauca department, inside the Chocó rainforest, one of the wettest places on Earth. Its habitat receives around 5 m (16 ft) of rain a year or more, stays warm, at roughly 26 °C (79 °F) or higher, and is humid almost all the time.

Within that region it is known from a few lowland sites, mainly in the drainage of the upper Río Saija, at elevations below about 200 m (660 ft). Its whole range is estimated at less than 5,000 km² (1,900 sq mi), smaller than the US state of Delaware. The frog depends on undisturbed primary forest, living on the damp forest floor among roots, leaf litter and small streams.

Within its range it can be quite common. Unlike many shy dart frogs, golden poison frogs often sit in the open during the day, which makes sense for an animal that very few predators can eat.

What do golden poison frogs eat?

Golden poison frogs are insectivores. Their main prey are tiny ants, especially of the genera Brachymyrmex and Paratrechina, but they also take termites, small beetles and other little invertebrates. They hunt during the day, stalking prey and snapping it up with a fast, sticky tongue, and they are bold, quick feeders.

The diet matters for more than nutrition. Poison dart frogs do not make their own toxins; they absorb chemical defenses called alkaloids from the arthropods they eat and store them in skin glands. The exact source of the golden poison frog’s batrachotoxin is still not confirmed. The leading idea is a small beetle of the family Melyridae: beetles of this family in New Guinea carry the same toxin. You can read more in why are poison dart frogs poisonous?.

How poisonous is the golden poison frog?

The golden poison frog’s skin contains batrachotoxins, steroid-like alkaloids among the most powerful natural poisons known. Batrachotoxin locks the sodium channels in nerve and muscle cells in the open position, so the cells can no longer send or reset signals. The result can be paralysis, an irregular heartbeat and heart failure, and no antidote is known.

The amount in one frog varies from place to place. A wild adult is commonly estimated to carry somewhere around 1 mg (1,000 micrograms) of toxin, and Myers and colleagues measured up to about 1.9 mg in the frogs they studied. The lethal dose for a human has never been measured directly. It has been estimated from mouse experiments at only a few micrograms to a couple of hundred micrograms, which is why the popular claim that one frog could kill 10 or more people is best treated as a rough estimate.

Only a handful of animals carry batrachotoxin at all: three Colombian Phyllobates frogs (the golden poison frog, the black-legged dart frog and the Kokoe poison frog), a few New Guinea birds such as the hooded pitohui, and some small Melyrid beetles. Of these, the golden poison frog is by far the most toxic. For the full story, see how poisonous is the golden poison frog?, and for other contenders, the most poisonous animals.

Behavior and communication

Golden poison frogs are active by day and live on the ground. Wild frogs are spaced out over the forest floor rather than gathered in groups. In captivity they tolerate each other well and show little of the wrestling and territorial fighting seen in some related species.

Males call to attract females with a long, melodious trill, a train of rapid notes that can last several seconds. The frogs also signal with body language: raising the body suggests dominance and lowering the head signals submission, while excited frogs often tap their long middle toe when hunting or courting.

Their boldness is itself a defense. Bright, solid color and slow, confident movement in the open act as a warning, a strategy known as aposematism. A predator that tastes such a frog, if it survives, learns not to try again.

Reproduction and life cycle

Breeding has been studied mostly in captivity, and the species seems able to breed year-round. Courtship is unusually tactile: partners stroke each other’s head, back and sides before the eggs are laid.

The female lays a small clutch, usually fewer than 20 eggs, on the ground under leaf litter, and the male fertilizes them outside her body. After the tadpoles hatch, about 11–12 days later in captivity, they wriggle onto a parent’s back, usually the father’s, and stick there in a layer of mucus. The adult carries them to small pools of water, where they finish developing. The tadpoles feed on algae, mosquito larvae and other material in the water. Poison frog parenting is covered in more detail in how do poison frogs raise tadpoles?.

The young metamorphose into small black-and-gold froglets and take on adult colors over the following months. Golden poison frogs reach breeding age at around 12–18 months.

Lifespan

How long golden poison frogs live in the wild is not known, because few long-term field studies exist. Their lack of predators suggests that adults may live several years. In captivity they regularly live at least 5 years, and well-kept frogs often live considerably longer.

Predators and threats

Adult golden poison frogs have almost no natural enemies. The only predator known to cope with their toxin is a small South American snake, Erythrolamprus epinephelus, which resists several frog toxins and has been seen eating young golden poison frogs without ill effects.

People are the real threat. The species’ tiny range means that every patch of cleared forest matters, and its habitat has been lost to logging, agriculture, illegal crops and mining, along with the pollution these bring. Collection for the pet trade was once a serious problem. Today most golden poison frogs sold legally are bred in captivity, and the IUCN regards collection from the wild as a smaller threat than habitat loss.

Conservation status

The IUCN Red List classifies the golden poison frog as Endangered, mainly because of its very small range and continuing habitat loss. It is also listed on Appendix II of CITES, which controls international trade. Protecting the remaining primary forest of the Colombian Chocó, much of which lies in Indigenous and Afro-Colombian community territories, is the key to its survival.

Relationship with people

The species was formally described only in 1978, by herpetologists Charles W. Myers and Borys Malkin and chemist John W. Daly, who named it terribilis because of its terrible toxicity. Long before that, Emberá hunters of western Colombia knew the frog well and used it to poison the tips of the darts they fired from blowguns when hunting game. Myers and his colleagues reported that hunters simply wiped the dart tips across the back of a living frog, which shows how much poison the skin holds.

That practice explains the family’s common name, although only three Phyllobates species are known to have been used in this way; see why are they called poison dart frogs?. Batrachotoxin has also become a valuable tool for scientists studying how sodium channels in nerves and muscles work.

Captive-bred golden poison frogs are not toxic, because their food lacks the critical alkaloids, but wild frogs are a different matter. Whether it is ever safe to handle one is explained in can you touch a poison dart frog?.