Using dark data to track down Kiwis...

The kiwi is the national symbol of New Zealand. It's about the same size as a chicken, with a long curved beak, and it can't fly! But unlike chickens, the kiwi is an endangered species, which means keeping tabs on the population is critically important so scientists can monitor the effects of conservation efforts. Ed Abraham, of Dragonfly Science, is a computer scientist who began life as a theoretical physicist working with Stephen Hawking in Cambridge. He's developed a neat way of measuring kiwi populations using what he dubs dark data, as he explains to Chris Smith and Simon Morton...