Madagascar is a country in the Indian Ocean off the eastern coast of Africa. It is the fourth largest island in the world, and its wildlife is so unique and diverse that it’s nicknamed “the Eighth Continent”.
Geographically, Madagascar split from India approximately 88 million years ago, and as a result of its long isolation it is home to a massive number of unique plant and animal species, with over 90% of its wildlife and 80% of its plants found nowhere else on the planet.
Madagascar is home to nearly 15,000 plant species, with highlights including the massive and ancient baobab trees, the unique spiny forests of the south, over 800 species of orchids, and the dwindling rain forests. Human activity, particularly the fires used for agricultural purposes, have damaged the environment, and since the arrival of humans approximately 90% of the island’s original forest has disappeared.
Animal life on the island is equally impressive, in particular the more than 100 species of lemurs, nearly all of which are rare or threatened. The island is home to over 300 species of birds, approximately 260 species of reptiles, and a massive number of amphibians and insects.
The eastern, or windward side of the island is home to tropical rainforests, while the western and southern sides, which lie in the rain shadow of the central highlands, are home to tropical dry forests, thorn forests, and deserts and xeric shrublands. Madagascar’s dry deciduous rain forest has been preserved generally better than the eastern rainforests or the high central plateau, presumably due to historically low population densities.
The climate is tropical along the coast, temperate inland, and arid in the south. The weather is dominated by the southeastern trade winds that originate in the Indian Ocean anticyclone, a centre of high atmospheric pressure that seasonally changes its position over the ocean. Madagascar has two seasons: a hot, rainy season from November to April; and a cooler, dry season from May to October. There is great variation in climate owing to elevation and position relative to dominant winds.
The east coast has a sub-equatorial climate and, being most directly exposed to the trade winds, has the heaviest rainfall, averaging as much as 3,500 mm (137.8 in) annually. This region is notorious not only for a hot, humid climate in which tropical fevers are endemic but also for the destructive cyclones that occur during the rainy season, coming in principally from the direction of the Mascarene Islands.
Because rain clouds discharge much of their moisture east of the highest elevations on the island, the central highlands are appreciably drier and, owing to the altitude, also cooler. Thunderstorms are common during the rainy season in the central highlands, and lightning is a serious hazard.
Antananarivo receives practically all of its average annual 1,400mm (55.1 in) of rainfall between November and April. The dry season is pleasant and sunny, although somewhat chilly, especially in the mornings. Although frosts are rare in Antananarivo, they are common at higher elevations.