Thick forest covers the wet regions, where there are fertile soils, but the drier interior, which has sandy or rocky soils, supports only a thin savanna vegetation. Extensive stands of hardwood, such as ebony, flourish throughout the country. Mozambique has elephants, buffalo, wildebeests, zebras, palapalas, hippopotamuses, lions, crocodiles, nyalas, and other southern African game species, as well as nearly 500 varieties of birds.