Nairobi’s National Park is the only safari park within a capital city anywhere in the world.

A conservationist leads a safari tour – with a ranger on standby in order to protect us from the animals. But, as Reinhard Bonke points out, in amongst the dozing crocodiles and yawning lions lies an even greater threat – Parthenium.

Reinhard is driven by his Christian faith, from which he has been taught to be a 'custodian of the Earth'. He explains how human development has brought this invasive plant species into a park and how, combined with losing land to property developers, the future remains uncertain for Nairobi's National Park.

Producer: Sophia Smith Galer