Phyllobates terribilis

Phyllobates terribilis is found in the Amazonian rainforest along the Pacific coast of Colombia. Other members of the Family Dendrobatidae have been found in close proximity along the coast of South America into the southern part of Central America. Phyllobates terribilis population is concentrated along the upper Rio Saija drainage in the vicinity of Quebrada Guangui’ and at La Brea in Colombia. Geographically isolated populations exist along the east and west banks along this river, dividing the population. Overall P. terribilis has a limited range, but is abundant within that area. (Bolívar and Lötters, 2004; Maxson and Myers, 1985; Stewart, 2010)

Golden poison frogs thrive in lowland Amazonian rainforests. This an extremely humid region that receives up to 5 m of rain per year and a minimum of 1.25 m. The region they inhabit is characterized by a hilly landscape, elevations varying from 100 to 200 m, and is covered by areas of wet gravel and small saplings and relatively little leafy debris. They are terrestrial animals that live on the forest floor, but they rely on freshwater to support their young. (Bolívar and Lötters, 2004; Stewart, 2010)

Golden poison frogs have a variety of bright vibrant colors that cover their entire bodies, from mint green to yellow to orange and sometimes white. Yellow or deep yellow, is the most common color seen, giving them their common name. Phyllobates terribilis is the most toxic species of frog. Unlike most other members of the Family Dendrobatidae, Phyllobates terribilis has uniform body coloration, rather than dark spots and stripes, as in their relatives Phyllobates aurotaenia , Phyllobates lugubris and Phyllobates vittatus. Adults are more brightly colored than young, which have the same primitive pattern of most other members of the family Dendrobatidae. They have dorsolateral stripes on dark bodies until they mature. By the time they reach adulthood, their coloration has changed to a single bright color. (Duellman and Trueb, 1994; Maxson and Myers, 1985; Stewart, 2010)

An easy way to identify these frogs is by the odd protrusion from their mouth. This gives the false illusion that these frogs have teeth. Instead, they have an extra bone plate in their jaw that projects outwards and gives the appearance of teeth. These frogs have three toes on each foot. Each outside toe is almost equal in length but the middle toe is longer than the other two. (Duellman and Trueb, 1994; Maxson and Myers, 1985; Stewart, 2010)

Bright skin coloration in P. terribilis is thought to be a warning to predators that they are poisonous. Their skin is saturated in an alkaloid poison that contains batrachotoxins. These toxins prevent nerves from transmitting nerve impulses and ultimately result in muscle paralysis. About 1900 micrograms of batrachotoxins can be found in these frogs. Only 2 to 200 micrograms is thought to be lethal to humans. (Duellman and Trueb, 1994; Maxson and Myers, 1985; Stewart, 2010)

Adult females are typically larger than males. The average body length reaches 47 mm but females can reach 50 to 55 mm. Compared to the 175 species of dendrobatids, P. terribilis does not have a wide range of sizes. Other species can be as small as a human fingernail. (Duellman and Trueb, 1994; Maxson and Myers, 1985; Stewart, 2010)

Like most frogs, golden poison frogs go through complete metamorphosis. Eggs are laid in small clutches of less than 20 and carried on the backs of males to small pools of water, where they develop and metamorphose into froglets. (Myers, et al., 1978; Stewart, 2010)

Phyllobates terribilis is polygynandrous; both males and females have multiple mates. Courtship and egg laying have only been observed in captivity, with limited specimens. Each breeding involved two or more male frogs and one female. Males attract females by using a variety of high pitched calls. Mating could be described as a frantic frenzy where individuals move quickly around each other during egg laying. This is hard to observe because the movement is so fast and done under cover of vegetation. Specifics on mode of reproduction are unconfirmed but it is believed that there is some vent to vent contact between frogs during copulation. However, golden poison frog mating rituals have not been observed in their natural habitat. Golden poison frogs are thought to mate year round. (Myers, et al., 1978; Stewart, 2010)

Golden poison frog eggs have not been found in the wild. In captivity, clutches of eggs usually do not exceed 20. In captivity, once eggs are laid and fertilized in water (by captive carers) they hatch 11 to 12 days later, typically taking 2 to 4 days for all the eggs to be completely hatched. Not even 10 days after leaving the water, they begin to feed on Drosophila flies. (Myers, et al., 1978; Stewart, 2010)

In the wild, once the female lays the eggs, the male fertilizes them and attaches them to its back. Only three male frogs have been captured with clutches of eggs on their backs. It seems that this period of carrying tadpoles on their backs is brief. It is a method of getting the eggs from their laying and fertilization site to the water to hatch. After fertilization and transfer to a small area of water for development, there is no further parental care. (Myers, et al., 1978; Stewart, 2010)

In the wild golden poison frogs are believed to live up to 5 years or more. Due to their high toxicity levels, these frogs have few predators, contributing to their long lifespan. Lifespan in the wild has not been confirmed because these frogs have only been observed in captivity, where they have lived up to 5 years old. (Myers, et al., 1978)

Golden poison frogs are diurnal and strictly terrestrial. Both in captivity and when observed in the wild, golden poison frogs have not been seen climbing on any surfaces. They have only been observed sitting on the ground or sitting a few centimeters above the ground on a tree root or pieces of vegetation. Most species of dendrobatids are secretive and quick to hide, however the behavior in P. terribilis is quite different. It is thought to be because of their extremely toxic nature that they are not afraid of predation. These frogs are also not often found in dense aggregations. Captive golden poison frogs thrive in crowded conditions with little aggressive behavior. This differs from other closely related species which have been observed to be highly aggressive and territorial in nature. Most aggression takes place between the same sex, where calling, chasing and wrestling can occur.

These frogs in captivity exhibit strong learning ability. They are quick to associate the opening of the terrarium with feeding and swiftly snap at anything presenting movement. Even the slightest movement in front of the terrarium is enough to excite the frogs as they expect to be fed. (Myers, et al., 1978)

The size of the home range for P. terribilis is unknown.

Golden poison frog males engage females in courtship by singing a long, melodious trill. This trill lasts 6 to 7 seconds followed by a 2 to 3 second version. The trill is usually a uniform train of notes uttered at a rate of 13 beats per second. The frequency for this tune is 1800Hz. This is a lower frequency when compared to related species of the family Dendrobatidae. They also communicate through gestures. A push up movement of the body represents dominance while the lowering of the head implies submission. A sign of excitement usually seen during hunting and courting includes the tapping of their long middle toe. (Duellman and Trueb, 1994; Stewart, 2010)

Golden poison frogs are insectivores and prey primarily on species of Brachymyrmex and Paratrechina ants. They also consume small invertebrates such as termites and beetles. Golden poison frogs use their long, sticky tongues to capture prey. They stalk and attack prey in one quick movement; this movement is so fast it's hard to see the mechanics of it with the naked eye. An adhesive tongue enables the prey to stick to its mouth to aid in capturing. Typically, they will not attack an insect bigger than a full grown cricket, approximately 1 inch. It has recently been discovered that feeding on a small Choresine beetle (Family Melyridae) may be the main source of toxicity for P. terribilis. (Duellman and Trueb, 1994; Stewart, 2010)

Golden poison frogs are best known for their extremely potent poison. The toxins they produces are twenty times more powerful than any other poison dart frog toxin. Their brightly colored bodies warn predators of their extreme toxicity. This serves as the frog’s main anti-predator adaptation. The toxins produced are steroidal alkaloids batrachotoxin, homobatrachotoxin, and batrachotoxinin A. These compounds are extremely potent modulators of voltage-gated sodium channels. They keep the channels open and depolarize nerve and muscle cells irreversibly. This damaging action may lead to arrhythmias, fibrillation, and eventually cardiac failure. When accidentally transferred onto human facial skin, these toxins have been reported to cause a burning sensation lasting several hours.

There is only one known predator of P. terribilis: Liophis epinephelus. This is a small snake that feeds on young frogs. The snake is immune to the toxins produced by golden poison frogs but since it is so small, it can only feed on juvenile frogs. (Daly, et al., 1980; Myers, et al., 1978; Stewart, 2010)

Golden poison frogs have only one natural predator. They usually sit out in the open. When approached they do not try to hide, but rather further their distance from the thing that approaches it. They are generalist feeders, preying on all types of fruit flies, crickets, beetles, and termites. Recent research shows that these frogs may obtain some of their poison by eating a beetle that belongs to the family, Melyridae. (Gratwicke, 2011; Myers, et al., 1978)

Golden poison frogs are the most highly toxic of all frogs. Colombian tribes, such as the Embre and Choco Indians, use poison secreted from the frogs’ skin to poison their blowgun darts. After heating darts over a fire, they are wiped over the frogs’ backs. Heat causes the back of the frog to moisten with poison which makes it easily accessible. Poisoned darts can stay lethal for up to two years. The toxin enables these tribes to catch small animals for food. These frogs are also being captured, bred, and sold as pets. This is possible because of their decrease in toxicity once held in captivity for a certain period of time. Medical research is also being done to see if these poisons can be developed into muscle relaxants, anesthetics, and heart stimulants. It is thought that it could even become a better anesthetic than morphine. (Gratwicke, 2011; Stewart, 2010)

Golden poison frogs do not display aggressive behavior towards humans. However, contact with their skin can prove fatal because of their extreme toxicity. This is not true of captive individuals, which tend to lose their toxicity in the absence of the wild prey that are the source of that toxin. (Myers, et al., 1978; Stewart, 2010)

Golden poison frog populations have been decreasing due to deforestation for agricultural purposes. They can be found in fewer than five areas. This species is listed as endangered according to the IUCN Red List of Threatened Species. (Bolívar and Lötters, 2004)