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The third episode of Seven Worlds, One Planet focuses on the most species-rich continent on Earth - South America.

The episode shows how some of the continent’s wildlife have developed unique traits to survive amongst so much competition. Find out more about some of South America’s wildlife and some of the continent’s natural wonders below.

Abundance of wildlife in the Amazon

Most of us have heard of the Amazon Rainforest and with good reason. It is the largest tropical rainforest in the world and is important for the role it plays in absorbing carbon dioxide and producing oxygen.

The huge rainforest, which is over 24 times the size of the UK, is home to thousands of plants and wildlife species. According to the World Wildlife Fund (WWF), the total known number of species in the rainforest includes: 427 mammals, 1300 birds, 378 reptiles, over 400 amphibians and between 2,500 - 3,000 freshwater fish. These numbers are nothing compared to the number of smaller life forms. In Brazil alone, more than 100,000 invertebrate species have been described by scientists. This abundance of wildlife is largely due to its warm, but liveable temperatures, plentiful of prey, and various ecosystems for wildlife to live in.

Running through the rainforest in the northern portion of South America is the Amazon river. Although it’s disputed if the Amazon is the longest river in the world, it does carry more water than the world’s next seven biggest rivers combined. Scientists think the river originates in the Andes Mountains of Peru. It travels from west to east through Ecuador, Colombia, Venezuela, Bolivia and Brazil before emptying in the Atlantic Ocean. Although it’s very hard to say precisely where the Amazon starts and ends, scientists believe it is at least 6,400 km (4,000 mi) long.

Paperclip-sized frog with lethal poison

If you thought all dangerous animals had sharp teeth or big claws then you would be wrong. Poison dart frogs can be very dangerous, and they are only about the size of a paper clip.

Golden poison dart frogs have enough poison to kill ten grown men - they are among the most poisonous animals we know. The source of their toxicity is unknown, but scientists assume that it may be from plant poisons carried by their prey. Strangely, poison dart frogs raised in captivity and eating insects away from their natural habitat never develop poison.

The bright, colourful patterns on their skins are designed to ward off potential predators.

South America’s huge waterfalls

As well as the Amazon rainforest and the high mountains of the Andes, South America is home to some spectacular waterfalls. Angel Falls in Venezuela is the highest waterfall in the world, measuring almost 1 km (0.6 mi) from top to bottom.

South America is also home to the Iguazu falls, where around 12 million litres of water tumble over every second, the same as 150,000 full bathtubs. The falls, which are also called Iguaçu Falls, sit on the Argentina-Brazil border. At 2.7 km (1.7 mi) wide, they are not one whole waterfall - rocky and wooded islands on the edge of the cliffs divide them into 275 separate falls.

The brightly-coloured scarlet macaw

Known for their bright colours and loud screeches, scarlet macaws are iconic animals in the tropical forests of Central and South America. The macaws are the largest parrots in the world and some can live up to 50 years in the wild.

Scarlet macaws are highly social animals and are rarely alone. They live in family groups or in pairs, forming lifelong bonds with their mates. Unlike other parrots who only stay together during breeding season, scarlet macaw pairs will stay together year-round.

This colourful bird has some handy features to help them survive. They have a high capacity for learning, excellent vision and their powerful beaks can be used to crush nuts and seeds, while serving as an ‘extra grip’ when climbing. Macaws can often be found munching on clay walls along riverbanks. The clay neutralise any toxins they have built up from their diet, whilst providing them with essential sodium and calcium.

The world's largest snake

Native to the tropical waters east of the Andes Mountains is the green anaconda, the largest snake in the world. The long oval-spotted snake is around 5 m (16 ft) long but some have been reported to measure over 10 m (33 ft).

The huge anacondas lie in water (usually at night) and ambush some large animals that come to drink. By seizing prey by the neck and wrapping their body around, they are effective at killing by constriction. They then stretch their jaws to swallow large mammals whole. After a big meal, they can go weeks or months without any food.