Geography & Wildlife
A large and varied island
Madagascar is the world’s fourth largest island (1600km long and 570km wide). Along with India, it parted from the giant landmass of southern continents (known as Gondwana) around 165 million years ago. Around 65 million years ago, it broke free entirely and now lies separated from Africa by the Mozambique Channel.
A red island
Madagascar is sometimes called the ‘Great Red Island’. This is because the central highlands are dominated by a red soil. Its technical name is ‘laterite’. This red clay-like soil comes from the weathering of underlying rocks in a humid and tropical environment. Rain dissolves and takes away easily soluble elements (such as sodium and silicon) and leaves more insoluble elements such as iron oxide, which gives the soil its red colour.
A chain of mountains runs down the eastern side and their steep escarpments trap the moisture on which the island’s rainforests thrive. This high forested area descends suddenly to meet the narrow east coast strip which lies along the Indian Ocean.
The middle of the island has a central highland plateau (from 800-1800m), which is partly volcanic in origin. Here, there are extinct volcanoes, as well as other distinctive rocky features, such as massive granite outcrops. In the far north, the highest peak, Maromokotro (at 2876m), is part of the Tsaratanana Massif.
To the west, the high areas descend more gradually and there is a wide coastal plain along the Mozambique Channel.
A Noah’s ark for animals and plants
Madagascar is home to the smallest type of chameleon. These are known as Leaf chameleons (Brookesia) and can be just 3cm in length. The island also has the largest, the Parson’s Chameleon, (Calumma parsonii) at up to 40cm. Watch the video and you'll see one of the most colourful of Madagascar's chameleons.
Thanks to its wide variety of habitats, particularly the tropical rainforests, Madagascar is considered a ‘hotspot’ for biodiversity. Although it covers less than 1% of the earth’s surface, the island is home to over half the planet’s plant and animal species.
Because of its separation for millions of years, many of these are unique to Madagascar. Over 70% of its 12,000 plant species are only found here, including a number of palms, ferns and cycads (seed-bearing plants). The ferns and cycads help to give a glimpse of how forests might have looked in pre-historic times. In the dry southwest, there is one whole family of thorny plants – Didiereaceae – which only grow here.
And of course, Madagascar has many insects, fish, amphibians, reptiles, birds and animals which are unique to the island. So for example, 99% of its frogs and over sixty of its mammal species are only found here. Probably the most famous of these mammals is the lemur, a tree-living animal which evolved around 40–50 million years ago. Monkeys evolved around 35 million years ago and it's believed they drove lemurs to extinction elsewhere. But a few lemurs survived and thrived on their island sanctuary of Madagascar. See for more on these amazing creatures.
However, as in many countries, deforestation and loss of habitat threaten precious plant and animal populations – see . To help combat this loss, nearly 50 protection areas and parks have been set up; some of these national parks are shown on the .
There are over 340 species of reptile in Madagascar, which include around half of the world’s species of chameleon. These amazing reptiles can change colour (which they normally do to communicate rather than for camouflage), have eyes which swivel separately and a long suction tongue to catch their insect prey.