UWC Grade 5 (2009-2010)

Three very toxic species of poison dart frogs from Colombia and South America are utilized by Indians to poison the tips of blowgun darts

Today, more than 20% of the Amazon rainforest has been destroyed and is gone forever.

Rainforest cover by biogeographical realm Realm Percent share of world rainforest cover Millionsquare miles Millionhectares Ethiopian/Afrotropical 30.0% 0.72 187.5 Australasian 9.0% 0.22 56.3 Oriental or Indomalayan 16.0% 0.39 100.0 Neotropical 45.0% 1.08 281.2 Total 2.41 625.0

About a metre under the top layer of soil there is ground that is permanently frozen, called permafrost.

by governments, which do not see these forest-dwellers as equal citizens.

 INITIATION

The initiation lasts several days in a hidden place in the depths of the forest. After the boys to be initiated have been undressed, washed, shaved and palm oil is rubbed on their body, they are led into a special hut.

Then, they undergo multiple rituals, some public (such as dances and processions), some secret, for about a week during which they eat, drink and sleep very little.

Poison-arrow frogs are social frogs found in Central and South America. They are known by their bright colors which warn other animals that they are poisonous. Its poison is one of the most powerful known and can cause paralysis or death. It is so potent that one millionth of an ounce can kill a dog and an amount smaller than a grain of salt can kill a human. One frog carries enough poison to kill about 100 people. Native hunters use it on the tips of their arrows which is how the frog got its name. Poison-arrow frogs are about the size of a man's thumbnail (less than one inch). The tiny frogs lay their eggs on leaves. When the tadpole hatches, it is carried on one of the parents' back to a bromeliad where the parents feed it small insects, ants, spiders, crustaceans, and tiny water animals. The mother frog may also lay infertile eggs as food for the tadpoles. Poison-arrow frogs are beautiful to look at. Their colors vary from red to yellow to blue. The enemies they encounter are large animals (including humans) who may step on them. Though poison-arrow frogs carry a deadly poison, they are usually harmless if left alone.

Camel spiders became an Internet sensation during the Iraq war of 2003, when rumors of their bloodthirsty nature began to circulate online. Many tales were accompanied with photos purporting to show spiders half the size of a human. For many years, Middle Eastern rumors have painted camel spiders as large, venomous predators, as fast as a running human, with a voracious appetite for large mammals. The myths are untrue. These creatures do not actually eat camels' stomachs or sleeping soldiers, and they are not so large—but the real camel spider is still an amazing predator. The camel spider's history of misinformation begins with a misidentification. Camel spiders are not even spiders. Like spiders, they are members of the class Arachnida, but they are actually solpugids. Camel spiders, also called wind scorpions and Egyptian giant solpugids (SAHL-pyoo-jids), are only about 6 inches (15 centimeters) long. Photos that purport to show creatures six times that size have misleading perspective—the spider is invariably placed in the foreground where the lens makes it appear much bigger than its actual size. True, they are fast, but only compared to other arachnids. Their top speed is estimated at 10 miles (16 kilometers) per hour. Camel spiders are not deadly to humans (though their bite is painful), but they are vicious predators that can visit death upon insects, rodents, lizards, and small birds. These hardy desert dwellers boast large, powerful jaws, which can be up to one-third of their body length. They use them to seize their victims and turn them to pulp with a chopping or sawing motion. Camel spiders are not venomous, but they do utilize digestive fluids to liquefy their victims' flesh, making it easy to suck the remains into their stomachs.

The World's Lungs? In the past, scientists often referred to tropical rainforests as the "lungs of the world" because of the large amount of oxygen they produce. More recent evidence shows that rainforests don't have much of an effect on the world's oxygen supply. The decomposition of dead plant matter consumes roughly the same amount of oxygen that the living plants produce. But rainforests do play a key role in the global ecosystem. Some experts are now calling them the "air conditioners to the world," because their dark depths absorb heat from the sun. Without the forest cover, these regions would reflect more heat into the atmosphere, warming the rest of the world. Losing the rainforests may also have a profound effect on global wind and rainfall patterns, potentially causing droughts throughout the United States and other areas