Even in its south-western corner, where there are some bare sand dunes, the vegetation is more characteristic of dry steppe than desert. The savanna ranges from Acacia shrub savanna in the south-west through acacia thorn bush and tree savanna 'parkland' into denser woodland and eventually forest as one moves north and east. Mopane woodland covers much of the northern and eastern third of the country, with the exception of the open grasslands immediately surrounding the Okavango delta and Makgadikgadi pans. Plant life in the acacia shrub savanna includes tsamma melons, an invaluable source of liquid for humans and animals in the thirstland. See Veld Products Research .
Animal life is extremely varied in a thirstland environment.
About 150 species of mammal are found in Botswana. These range from 30 species of bats and 27 of rodents to over 30 species of large mammal. Many large and small antelope, and scavengers such as jackals and hyaenas, can be found across the savanna, though rarely near centres of population or main roads. Botswana suffers less poaching than countries to the north, and there are active wildlife conservation groups. Bird life is prolific, with more than 460 species including ostrich and bustard on the plains, cormorant and herons in aquatic areas, vulture and eagle or kite near hills, and woodland species such as goshawk and warbler.