A savanna is a grassland that is greatly lacking in moisture.  Often, there are only a few trees throughout the grassy areas.

Many conditions in the environment must be right for savannas to form.  There must be high temperatures, relatively low rainfall, frequent fires (for some savannas), proper soil conditions, and the needed plant life.

Savannas are usually 10-25% covered with trees.  The main covering of savannas is grass, both in permanent form and in perennial grasses that reappear each year.  Savannas also have under 20 inches (50 centimeters) of annual rainfall.

A variety of ecosystems fall under the category of savanna.  Anything from pure grasslands to deciduous forests can be classified as savannas.

Savannas are present on every continent except Antarctica.  They are often home to many animals, including mammals, birds, insects, and reptiles.

In Africa, animals on savannas include giraffes, zebras, impalas, lions, cheetahs, jackals and more.  In North America, bison and wolves were once common on savannas.  In Asia, tigers live on savannas, and in Australia, savannas are home to emus.

As humans have moved into new environments, they have destroyed savannas.  In the last 200 years, many animals that once lived on savannas have lost their habitats and become extinct.

The plant life that inhabits savannas has had to adapt to be able to survive.  Bushes and trees have developed small, leathery leaves that can resist drought and intense heat.  Because there is a great deal of sunshine, the plants must be sure to have sufficient moisture to survive.