A brilliant black-and-green dart frog peeks down from a tree limb. One of his buddies gazes up from the forest floor, just 1 inch long and neon green. So tiny, so cute. So toxic.
Dart frogs release a mild toxin through their skin which can make a hands-on human feel sick. The black-and-green, or Dendrobates auratus, is one of 100 different species that have been grouped together as the “poison dart frogs.” Alternately they are known as the “poison arrow frogs” because indigenous tribes, including the Embera people of Panama, traditionally tipped their arrows with poison harvested from these frogs. Dart frogs live throughout Central America and into Northwestern South America, primarily in the lowland rainforests. Dendrobates auratus is one of the more frequently-spotted species on Isla Palenque in Panama, thanks to the unspoiled tropical jungle on the island.
This brilliant, exotic little amphibian is partially arboreal, which means that he spends much of his time in trees, clinging to branches with the delicate suction cups on his feet. If you’re trying to see a black-and-green dart frog in the wild, look in the trees as well as on the forest floor during morning and evening hours when he’s most active. He’s very small – between one and two inches long – but his bright coloration will help you spot him. Despite the “black-and-green” designation, you may spot dart frogs in an array of different colors: yellow, turquoise, bright blue, light brown, bronze, or black, with green or blue stripes, spots, or bands.
Dart frogs evolved their vivid coloring to warn predators of their toxicity, a tactic known as “aposematic coloration.” These little frogs broadcast “don’t eat me!” with bright neon signs, and because of this, most predators know to leave dart frogs alone. The only predator that routinely hunts the poison dart frog is Leimadophis epinephelus, a species of snake that has developed a resistance to the frog’s poison. With so few natural enemies, these frogs often live ten to fifteen years in the wild. Many non-poisonous frog species mimic the poison dart frog’s coloring to capitalize on his “not-good-to-eat” reputation.
The reproductive habits of dart frogs are as colorful and fascinating as the frogs themselves. During mating season, males compete for choice territory on the forest floor where they will station themselves and emit their signature chirping calls to attract attention from female frogs. Females are larger and more aggressive than males; they become extremely territorial, fighting with other females over the resident male population. The male dart frogs who take the best care of the little tadpoles are in high demand with female frogs.
Life begins for a baby Dendrobates auratus amid such wonder and beauty as you can only find in the tropical rainforest. After a female chooses a mate, she deposits her eggs on a leaf. The male frog fertilizes the eggs and protects them for about two weeks until they hatch. Once the tadpoles hatch, they swim onto Dad’s back – he secretes a sticky substance to help them hang on as he carries them up into a tree. Dad releases the newly-hatched tadpoles in a tiny pool of water collected in a bromeliad up in the boughs of the rainforest trees. Here, the tadpoles will spend the next three months transforming into small frogs, growing up surrounded by the fragrance and beauty of an exotic jungle flower.
Highly Adaptable but Still Threatened
Dart frogs aren’t only seen deep in the jungle but are a common species throughout Central America, sometimes spotted on the edges of large urban areas like Panama City. This hardy frog adjusts well to a variety of environments, which is why he’s been adopted as a popular pet; however, this practice is to be discouraged. The black-and-green dart frog is a threatened species of Panama wildlife, and efforts to preserve his natural habitat and sustain populations in the wild aim to keep Dendrobates auratus off the endangered species list.
Interestingly, captive dart frogs do not release the poison for which the species is known. Scientists have determined that dart frogs acquire their poison from a type of ant in the wild frog’s diet and do not produce toxins by any internal process, so cricket-fed captive frogs are safe for handling. However, dart frogs in captivity often become shy and spend much of their time hiding; it’s best to leave them in their natural rainforest homes.
When spending time in the jungles of Panama, keep a sharp eye out for colorful little polka dots on the tree trunks. Move in slowly; it is greatly rewarding to watch these vivid little amphibians darting around the trees. But don’t get too close. Dart frogs flee when they sense the presence of a larger creature, and if you reach out to trap them, the toxicity of their skin could make you very sick. It’s tempting to want to adopt one of these adorable tiny frogs as your own, but with such bright and beautiful colors to delight your eye, looking without touching is enough.