Dendrobates tinctorius

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Geographic Range

Dendrobates tinctorius inhabits small isolated pockets in French Guinea and northeastern Brazil. (Obst, 1988)

Habitat

Dendrobates tinctorius are creatures of humid, usually wet habitats, and their skins are not waxy enough to prevent evaporation in dry air. Often it is found in heavy vines one to two meters above the ground where its bright yellow stripes stand out in the darkness of the forest. (Walls, 1994)

Physical Description

This is a large poison frog, commonly 40 to 50 mm with some females reaching 60 mm. This is a bright blue frog with two broad yellow stripes on the back, these stripes are connected by cross bands to produce 2 to 3 oval blue islands down the middle of the back. The arms and legs are black or deep blue with many bright yellow or black spots. Sometimes the yellow is replaced with white or the two yellow stripes fuse across the back to produce a frog with a solid yellow back on a bright blue or black background--they are truly striking animals. It has a typical erect posture and a distinct tympanum about half the diameter of the eye. In theory males can be distinguished from females by having larger finger discs that are cut straighter across the tips. Additionally, males are somewhat territorial and may wrestle, but so do females on occasion. Of course only males call. (Walls, 1994)

Development

Reproduction

Amplexus occurs always on land, never in water. Eight to ten eggs are laid and the male ejaculates the sperm directly over the eggs. The male will carry the nearly hatched tadpoles on his back to water. There tends to be considerable sibling aggression among the larvae. (Obst, 1988) Dozens of tadpoles may be placed in one large water hole by several males. Tadpoles reach transformation size in about ten weeks and feed on almost anything. (Walls, 1994)

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)

Behavior

All Dendrobatids are diurnal and live on or close to the ground. Males have two vocal slits and an unpaired jugular vocal sac. They give off humming, trilling or chirping sounds. Their territory is optically and vocally defended, usually from an exposed location such as a rock or tree stump. There can be intra specific ritualistic fighting (shoving, jumping, pushing, biting). (Obst, 1988) The bright color obviously advertises its poisonous nature, and it has few predators. (Walls, 1994)

Food Habits

All Dendrobatids are insectivores. The diet consists mainly of ants, termites, and other small insects and small spiders. Adults tend to actively search and hunt down prey. (Obst, 1988 and Walls, 1994)

Economic Importance for Humans: Positive

Though this species is not the one native people use for darts, they are highly prized in the pet trade. They are also insectivores eating ants and other small pests.

Conservation Status

Because of the unusual nature of forests in Guianas, with relatively dry savannahs and high mountain plateaus, no two populations of D. tinctorius are exactly alike(Walls,1994. One or two cases of overcollecting could wipe out a whole population. A violent storm or clear cutting could also have negative effects.

Other Comments

Both the common and scientific names of this frog come from an old story introduced to Europe along with the first preserved specimens of the frog. For over two centuries there have been legends that Amerindians of various tribes in Guianas and the Amazon use animal concoctions of various types to change the plain green feathers of parrots into red feathers. Dendrobates tinctorius was pinpointed in these legends as the frog used in the Guianas to produce the color change, a technique called tapirage. Supposedly the living frog or a tincture of frog skin and blood was rubbed on the selected area of the parrot where a color change was wanted. The parrot had to be young, and its original green feathers had to be plucked. When the new feathers grew in, they would magically be bright red or perhaps yellow. In effect, they would have been dyed. (Walls, 1994)

Contributors

Matt Jolman (author), Michigan State University, James Harding (editor), Michigan State University.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

References

Obst, F. 1988. The completely illustrated atlas of reptiles and amphibians for the terrarium. Neptune City, NJ: T. F. H..

Walls, J. 1994. Jewels of the rainforest. NJ: THF.