Botswana is home to about a third of Africa’s remaining savanna elephants, over 130,000. But it is a burden as well as a blessing. It puts pressure on local communities, and the cost of conservation is huge. Climate change means elephants are moving into new areas in their search for water and in some parts of this sparsely populated country there are more elephants than people. Jo Dwyer travels to northern Botswana, where safari-based tourism helps drive the economy. Elephants bring in the tourists, but conservation is a balancing act.