Common savanna species cover most of the drier inland areas— amounting to about one-third of the country—between altitudes of 300 and 1,200 m (1,000 and 4,000 ft). Two main types of closed-forest trees—low-level hardwoods and mountain softwoods—are found in high-rainfall areas on the main mountain masses and in parts of the Lake Victoria Basin. Wooded grasslands are widely scattered throughout the country.
The drier central areas include bushlands and thickets. Grasslands and heath are common in the highlands, while the coast has mangrove forest.
The 4 million wild mammals include representatives of 316 species and subspecies, notably antelope, zebra, elephant, hippopotamus, rhinoceros, giraffe, and lion. Various types of monkeys are plentiful.
There are about 827 species of breeding birds, ranging in size from ostrich to warbler. Insect life, consisting of more than 60,000 species, includes injurious species and disease carriers. There are at least 25 species of reptiles and amphibians and 25 poisonous varieties among the 100 species of snakes. Fish are plentiful.
The flora and fauna of Zanzibar and Pemba are varied. Mammals common to both are galagos, fruit-eating and insectivorous bats, genets, mongooses, small shrews, rats, and mice. Zanzibar has the leopard, Syke's monkey, civet, and giant rat. Unique species of tree coney are found on Pemba and Tumbatu Islands. There are also five unique mammals—Kirk's colobus (monkey), two elephant shrews, duiker antelope, and squirrel.