Poison Arrow Frogs
Genus/species: Dendrobates auratus (green poison arrow frog)
Dendrobates tinctorius (dyeing poison frog)
D. auratus frogs reach sizes of about one to 1.5 inches (3 to 4 cm). Frogs in some populations may reach 2.5 inches (6 cm). There are many color variants based on geographic area. Most are black and either green or light blue with the black in bands or spots. The stripes or spots can range from blue, blue-green, green, yellow-green, or white.
D. tinctorius is a very large poison frog. They reach lengths of about two inches (4 to 5 cm). There is quite a bit of variation in size and color. Some can reach 2.5 inches (6 cm).
Poison arrow frogs are known for their beautiful colors. These colors are used as warnings to predators that they are poisonous (their poisonous defense evolved to ward off predators.) Some scientists think that the reticulated pattern of the frogs also act as camouflage among the forest shadows. This idea is not the norm.
Distribution and Habitat
Poison frogs live in the rainforests of Central and South America. D. auratus is found on the Pacific coast from southern Costa Rica to northern Columbia and on the Caribbean coast of southern Nicaragua to Columbia and the island of Tobago. There is also a stable population on Oahu, Hawaii, after they were introduced in 1932. D. tinctorius is found in Suriname, French-Guiana, and Guyana. They can also be found in a small area of Brazil, near Suriname.
D. auratus’s natural habitat is the wet tropical rainforest below 2,600 feet (800 m) near a pool or stream. They are also found in secondary forests and cultivated land. D. tinctorius live in primary rainforests to elevations of 1,300 feet (400 m). They spend most of their time on the rainforest floor near little streams.
Diet in the Wild
Both feed mostly on spiders and small insects such as ants and termites, which they find on the forest floor using their excellent vision. They capture their prey by using their sticky, retractable tongues.
They are fed small crickets daily.
The mating season for D. auratus occurs throughout the entire rainy season from mid-July through mid-September.
Male frogs go through an elaborate ritual to attract mates. The males vocalize, a trill sound, to attract females. Once the courtship ritual is complete the females deposit up to 40 eggs on leaves. The eggs are encased in a gelatinous substance for protection against desiccation.
During the two-week development period, the male returns to the eggs periodically to check on them. Once the tadpoles hatch, they swim onto the male’s back and he carries them to a place suitable for further development, such as wet holes in broken trees and branches, little ponds, wet coconut-shells, and even in tin cans and car tires.
Bromeliads are also used but not as much as in other species. The tadpoles are attached to the male’s back by a mucus secretion, which is soluble only in water so there is no chance for them to fall off. Once at their final destination, the tadpoles are on their own. They need an additional three months to metamorphose into small frogs.
They may live more than ten years in captivity.
These frogs are not currently listed as endangered and are bred in captivity for the pet trade. However, the destruction of their habitat is causing numbers to decline.
Currently the possibility of new medications from these frog’s
secretions is being explored.
Poison arrow frogs are also called poison-dart frogs because some of the Amerindian tribes use their secretions to poison their darts. Not all arrow frogs are deadly, only three species are very dangerous to humans. The most deadly species to humans is the Phylobates terriblis. Its poison, batrachotoxin, can kill many small animals or humans. These frogs are found in Columbia along the western slopes of the Andes. Arrow frogs are not poisonous in captivity. Scientists believe that these frogs gain their poison from a specific arthropod and other insects that they eat in the wild. These insects most likely acquire the poison from their plant diet.
In 1999 a Zoo pathologist published his discovery of a then- mysterious infection that was afflicting and eventually killing poison arrow frogs and White’s tree frogs. Through his effort, cutaneous chytridiomycosis was documented for the first time as a vertebrate parasite. The veterinarians along with keepers and pathologists also developed a treatment for the chytrids. The same antifungal that is used to kill athletes’ foot in humans can be used with the frogs and toads.
Source of Information
All or part of this information was provided by the Animal Diversity Web and Museum of Zoology of the University of Michigan.
It appears here with their permission. The original author of this information was Rachel Schafer.
For more information, including references, see the Animal Diversity Web account for this species, here:
http://animaldiversity.ummz.umich.edu/ site/ accounts/ information/ Dendrobates_auratus.html.