Dyeing Poison Dart Frog


ORDER: Anura

FAMILY: Dendrobatidae

GENUS: Dendrobates

SPECIES: tinctorius

DESCRIPTION:
Smooth skinned, slender frog. Horizontal pupils in black eyes. Fingers and toes are unwebbed. Mainly terrestrial, but still they have small discs on fingers and toes to climb through vegetation. Two inches long. Basic color is black with a pattern of golden stripes and the legs and feet are blue with black spots. Also may be white and black, white and blue, or blue and black. The name is probably because Spaniards reportedly thought natives in South America used the skin of the frog to dye the parrot feathers used in their rituals.

GEOGRAPHICAL RANGE AND HABITAT:
Amazonia, especially the three Guyanas.

DIET:
Mainly ants and termites, from which the frog derives the chemicals necessary to synthesize its poisonous skin secretion. When kept in captivity and denied their natural diet of toxic insects, they eventually lose their potency.

LIFE CYCLE/SOCIAL STRUCTURE:
Diurnal and terrestrial. Both sexes engage in posturing, chasing and bouts of wrestling on the forest floor. Breeding occurs throughout the year. Most poison-dart frogs do not indulge in amplexus. Males may deposit sperm followed by the females laying the eggs or vice versa. Females usually lay small clutches of eggs (2-10) on a leaf or carefully cleared patch of ground. Tadpoles upon hatching wriggle carefully onto the back of an attending parent, where they are attached by a sticky mucus and carried to a small pool. Metamorphosis takes 8 to 12 weeks. Several clutches are laid during the year.

SPECIAL ADAPTATIONS:
These frogs evolved to be able to roam freely in daytime when they could take advantage of the vast food source of day-active ants. Mucous-producing skin glands on the back of the frog have been modified to produce toxic compounds called alkaloids. These compounds cause varying effects from a distasteful numbness on the palate to heart failure. Their coloration is a warning to predators that they are toxic. The bright colors warn the color-vision predators, such as birds. Placing the colors in a pattern on a dark background warns the mammal predators that see in black and white.

INTERPRETIVE INFORMATION:
Members of at least four genera in this family are known as "poison dart frogs" or "poison arrow frogs". Skin secretions from some of the most poisonous are used by native Indians to tip the darts of their blowpipes for hunting. If the toxins enter the blood stream, they act on the nervous system, blocking transmission and causing rapid paralysis. Scientists are currently studying these secretions, hoping to develop local anesthetics, muscle relaxants and heart stimulants for medical use.

OUR ANIMALS:

STATUS IN WILD:
Many of the genera Dendrobates are listed on the IUCN Red List as Vulnerable, but this species is not listed as vulnerable or endangered.

BIBLIOGRAPHY:

  1. Internet: IUCN Red List.
  2. Bartlett, R.D. Frogs, Toads, and Treefrogs. 1996. Barron's Educational Series, Hauppauge, NY.
  3. Davies, Robert and Valerie. The Reptile and Amphibian Problem Solver. 1997. Tetra Press, Blacksburg, VA.
  4. Hiller, Ian. "Into the Light" The Institute. Spring, 1992. Publication of the Audubon Institute.
  5. Hutchins, Michael. Grzimek's Animal Life Encyclopedia. Vol. 6 Amphibians. 2003. The Gale Group, Farmington Hills, MI.
  6. Preston-Mafham, Ken.Frogs and Toads. 1999. Chartwell Books, Edison, NJ.
  7. Showler, Dave. Frogs and Toads. 2004. St.Martin's Press, New York, NY. CL:05, 06

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