Poison -arrow frogs: Their fatal attraction!

There may be many among you who love and admire the most popular frog in the entertainment world - Kermit the Frog, who plays a key role in Sesame Street. Today, we are going to feature some of Kermit's cousins. However, they (or at least a few of them) are not as harmless as Kermit and other members of his family.

The frog species we feature today are found only in the rainforests of South and Central America. They live mostly on damp leaf litter. Even though these particular species of frogs are called poison-arrow frogs, arrow-poison frogs or poison dart frogs, not all are actually harmful. In fact, out of around 170-200 species so far identified, only a small number of frogs are harmful to animals and humans.

One of the deadliest is the Golden Arrow-poison Frog which belongs to the Dendrobatids family. The skin secretions of the poison-arrow frogs are believed to be one of the most powerful animal venom discovered. Even a small amount of this poison is considered fatal. It is this poison, which for centuries the South American Indians have been using on arrow tips, that have earned the entire family of frogs the deadly name, even though most are actually non-toxic.

The venom from certain species of poison arrow frogs can easily result in muscular paralysis and has been of particular value to the American Indians hunting small mammals high in the forest canopy. The poison from one Golden Arrow-poison Frog, the most deadly of all amphibians, is enough to be used on about 40 arrows.

Appearance

Poison-arrow frogs, although very small are beautifully coloured and attractive in appearance. Most are not more than one to one and a half inches in length. Many of the frogs have contrasting colours such as, yellow and black, iridescent green and black, bright orange and even blue.

They either have spotted patterns or striped patterns, and display flash colours when they jump about. These vibrant colours generally warn predators that the animal is not fit to be eaten. If a predator were to even lick one of the arrow-poison frogs, the secretions produced from their skin would make them sick. But, most humans and even animals too could be fatally attracted by these very colours!

The Blue Arrow-poison Frogs are considered to be the most striking of the lot. They come in a variety of blue-ranging from a powder blue to cobalt or sapphire blue, with either black spots or stripes. These Blue Arrow-poison Frogs are also only found in tropical rainforests.

The male frogs can be distinguished from the female arrow-poison frogs by their larger front toe pads which also have a nail-like plate.

Food and habits

Like all amphibians, the arrow-poison frogs too are terrestrial (live on land), but go back to the water to breed. They do not migrate or hibernate. They enjoy moist and shady places in the rainforests. They are diurnal (day time) creatures and are active in the mornings and evenings.

These frogs thrive on various small arthropods (animals with jointed limbs and segmented bodies) such as spiders and other insects. They eat termites and insects by catching them with their long tongues which are generally sticky.

Frog babies

The poison-arrow frogs lay their eggs on the forest floor, mostly on leaves. They are said to have remarkable breeding habits.

Once the six or more eggs are laid by the female, it is generally the male who cares for them. Males are therefore considered to be good fathers because they care for the clutch until they are hatched and even carry the tadpoles to water on their backs.

As the tadpoles are attached to the father's back by a mucus secretion from the skin, which is soluble only in water, there is no danger of the tadpoles falling off, when being transported to water. The tadpoles are sometimes placed in bromeliad pools, for better protection. Bromeliads are a type of plant that grow attached to trees, shaped like bowls to hold water in them.

Perhaps, some frog papas believe that their offspring are much safer in these bromeliad pools than in small ponds, tree holes, coconut shells and such places, which could be easily trampled and disturbed by other animals. The tadpoles are allowed to climb one at a time on to the father's back and then wriggle off into whatever 'pool' the father has chosen for them to grow up in.

The baby frogs or tadpoles live on moss and insect eggs, growing limbs and becoming adult frogs...

More facts on these deadly frogs

* A Cuban frog, Sminthillus limbatus which is closely related to the Golden Arrow-poison frog, is considered to be the smallest frog in the world, measuring only 8-12 mm, that is less than 0.5 inches!

* It has been discovered recently that an extract from the skin of arrow-poison frogs could block pain 200 times more effectively than morphin.

* It takes about 12 weeks for a Blue arrow poison tadpole to turn into a frog.

* The Marbled milk frog and Thai tree frog are also relatives of the arrow-poison frogs.

* One frog carries enough poison to kill about 100 people.

* Called the champion poisoners, the tiny kokoi frogs, as little as one gram, are lethal.

* The young frogs are defenceless because they do not have any poison. They are brownish black in colour.

* Very few frogs look after their young, once hatched, and among those who do, are the red and blue arrow-poison frogs who even produce infertile eggs to feed the tadpoles.

* Because of their lethal defence system, these frogs are able to live trouble free lives. Their existence is threatened purely by deforestation of rainforests.

* These frogs are social frogs.

* They are so bold because of the defence system, that they even sing out in the open.

* The eggs are laid on a jelly-like mass that is guarded by a parent or visited and regularly moistened.

We'll bring you more information on different types of frogs in our future issues.