Living with nature: Kampala's conundrum, river accidentally rerouted to the Amazon and the world's biggest baobab

We hear how human activity transformed the mighty Araguari River in Brazil. We also visit Uganda's capital, which has been designated as a 'Tree City of the World', but also deals with extreme air pollution — are trees enough to clean its air? And speaking of trees... in South Africa, there's one so big, it's home to hundreds of birds and bats, and it even houses a cave within it!