A combination of the above defenses
Ants protect them
They have thorns
They have toxic chemicals
The savanna gets a fair amount of rain, at least 20 inches a year.
Growing quickly
All of the above
Having deep roots
Developing fire-resistant cover
Antarctica
North America
Asia
Australia
Temperate forest
Grassland
Desert
Tundra
Spring and summer
Winter and fall
Winter and summer
Dry and wet
They avoid each other as much as possible
They all migrate in different directions
They eat different foods
Their territories don't overlap