Ask A Scientist Zoology Archive

name         Liam B.
status       student
age          13

Question -   At the moment I am researching venomous animals and I am
wanting to do my project on a frog from South America. I know there may be
thousands of different types of frogs in South America alone but this one
is special. I do not know the name of it but it is small red and the
Aztecs used their poison on their arrow heads. that about all I have heard
about this frog. Would you possibly give me some more info on this frog
and the name would be great! If you cant find some info on it could you
give me a few links to sites related to this sort of thing? Thanks much.
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This page is pretty technical but it has a good run down of some species:

http://www.asanltr.com/ASANews-99/995frogs.htm

J. Elliott
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Hi Liam!
As you mentioned there are maybe hundreds of poisonous frogs at South America. But I think 
you are referring to the one that
 it is one of the most poisonous animals on earth. For centuries, the called  poison arrow 
 frog has provided South American Indians with poison for the tips of arrows and blowpipe 
 darts. For predators, swallowing a frog means certain death, and even licking one can prove 
 fatal.

Habits: Like all amphibians, poison arrow frogs must stay moist to survive. The red and blue 
species lives in Costa Rican rain forests. The constantly steamy, wet environment reduces the 
frog’s need for streams and pools. It forages through the rain soaked leaves and vegetation 
for small insects such as ants and spiders. The poison arrow frog moves in short hops and 
rarely stays still. Adhesive pads on its toes allow it to climb agilely to search for prey. 
Its vocal sac fully extended, a poison arrow frog croaks a territorial claim.

Breeding: Many frogs lay large quantities of eggs in water and leave them alone. Fish eat the 
newly hatched tadpoles, and few survive to develop into adult frogs. The poison arrow frog 
breeds in a different way that ensures the tadpoles’ survival. After a courtship ritual of 
calling, chasing, and wrestling, the female lays four to six eggs. The male then fertilizes 
the eggs. The newly hatched tadpoles climb onto the female’s back, and she carries them to 
the water. Sticky mucus holds the tadpoles on tight and keeps them moist during the several 
hour journey.

Instead of a pond or stream, the red and blue mother places her tadpoles in tiny condensation 
pools in the centers of tropical plants. The female puts one tadpole in each plant, feeding 
them each week by placing unfertilized eggs in the pools. Feeding on
this nutritious food, the tadpoles grow into adulthood. Males wrestle for mates; their poison 
is for predators.

Defenses: Some frogs protect themselves from larger predators such as snakes and hawks by 
secreting mild poisons from the skin to make themselves taste foul. The poison arrow also 
uses this tactic, but its skin gland secretions are lethal. A predator faces certain death 
if it swallows a poison arrow frog, and even licking one can often prove fatal.

These frog poisons are the most powerful animal poisons known. As little as two micrograms 
of its poison can kill an adult human ­ and each frog contains nearly 200 micrograms. The 
dangerous levels of poison are lower in the red and blue species, but it still is lethal. 
Because the poison arrow frog is too small to be seen by some animals, its brightly colored 
skin makes it more noticeable and acts as a warning to predators that the frog is deadly 
prey. Consequently, fewer frogs are eaten during the day, when predators can recognize them 
as dangerous.

Poison Arrow Frog and Man: The Choco Indians of western Colombia developed the technique of 
using this frog to poison the tips of arrows or blowpipe darts. The Choco use poison from 
three species. With the deadliest frogs, the tribesmen pin a frog to the ground with a stick 
and wipe their arrowheads on its skin. Less poisonous species are warmed over fires on 
skewers to make them excrete large quantities of poison, which is concentrated for use. 
Today the Choco use poison darts or arrows for hunting small game, but in the past they 
were used in wars with other tribes in the forest.

Key Facts:
Sizes:
Length: 1 in. The biggest frog in the family grows to 2 in.

Breeding:
Mating: During the tropical rainy season
No. of eggs: 4-6, laid on land
Tadpole: Develops in flooded leaf joints of plants and feeds on unfertilized eggs

Lifestyle:
Habit: Lives on forest floor and among trees
Diet: Small insects such as ants and spiders
Lifespan: Unknown

Related Species: Of the 116 species in the family, 55 are brightly colored poisonous 
Dendrobates and Phyllobates species: These include the golden poison arrow frog, 
Dendrobates auratus, and the deadly Phyllobates terribilis.
Distribution: The red and blue poison arrow frog lives in the Costa Rican rain forests. 
Other species occur throughout tropical South America from Costa Rica to southern Brazil.
Conservation: Although the poison arrow frog is collected both for its poison and for the 
pet trade, the destruction of its habitat threatens its future.

You can see its picture at the site:
http://ladywildlife.com/animal/redandbluepoisonarrowfrog1.html

There are also many other sites with interesting facts if you ask Google as: " red South 
America poisonous frog"

And thanks for asking NEWTON!
Mabel
(Dr. Mabel Rodrigues)
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