The flora and fauna of Madagascar have developed in isolation from those of Africa, and the flora is highly specialized.
Scientists hold that Madagascar was originally covered with evergreen forests in the wetter areas of the east and north, which gave place to savanna on the plateau and semiarid vegetation in the south. Much of the original vegetation was destroyed by burning, so that the evergreen forest is now found only in a narrow strip along the steep eastern edge of the plateau, from north to south. Where the forest was destroyed, it was replaced by bush known as savoka, especially in the narrow east coast plain. There are a few small patches of deciduous forest in the northwest and west and mangrove swamps are general along the northwest and west coasts. Most of Madagascar is covered with a rather bare savanna-steppe, green in the wet season but brown and red in the summer. The greater part of the plateau has a covering of laterite and fertility is low. The extreme south is free of laterite, but lack of rainfall prevents the greater fertility from being of much practical use.
The fauna is remarkable chiefly because of the presence of 28 species of lemur, a lower primate largely confined to Madagascar. The island has 32 species of chameleon. Among the 202 species of birds, 105 are found nowhere else in the world. The same is true for 80% of the island's flowering plants and more than 95% of its reptiles. Madagascar is also unusual in its lack of poisonous snakes and, except for recent introductions, useful mammals.