An adult African elephant can weigh up to six tonnes - the same as about four cars. Their trunks have around 40,000 muscles and can do incredibly precise things: lift a single blade of grass or pull down a whole tree. Elephants use their trunks to drink, to greet each other, to comfort young calves, and to throw dust over their backs to protect against insects and sunburn.
Elephant families communicate in many ways - through rumbles so low that humans cannot always hear them, through touch, through body language, and through the position of their ears. When an elephant spreads its ears wide, it is saying 'I am big and strong - pay attention.' When ears are relaxed and flopping, the elephant is calm.
In South Sudan, elephants play an important role in shaping the landscape. They knock down trees to eat the leaves and bark, which opens up clearings where smaller animals and birds can feed. Their footprints fill with water and become tiny pools for insects and frogs. Scientists call elephants a 'keystone species' - like the keystone in an arch, everything else depends on them.
Baby elephants are born after a 22-month pregnancy - the longest of any land animal. A newborn calf weighs around 120 kg (heavier than most adult humans) and immediately tries to stand up. The whole family gathers around, touching and rumbling, welcoming the new arrival.