Now Parsons is aiming to enthral a whole new generation. The tradition of natural history film-making in Bristol, acknowledged worldwide with the success of Life on Earth, is being incorporated into one of the biggest Lottery-backed projects outside London.
Wildscreen@t-Bristol takes the name of the city's biennial Wildscreen film festival which attracts film-makers from nearly 50 countries and awards the natural history equivalent of the Oscars, called Pandas. But the new Wildscreen initiative - part of a pounds 97m dockside redevelopment due to open in the spring - is radically different from mainstream film- making. It weaves the best of wildlife footage into a venture which is neither zoo, nor museum, nor botanical garden, but takes elements of all of them to create a high-tech exhibition of the natural world.
The centre will combine live tiny creatures and botanic houses, where you can walk through rainforest with free-flying birds and butterflies, with the best of wildlife film, interactive technology and a giant-screen IMAX cinema. "This thing, if it's going to work successfully, has got to be perceived as a wonderfully entertaining attraction in the best visitor attraction sense," Parsons says. "We're competing for people when they might otherwise be going to Legoland or Alton Towers."
The purpose is to change people's perceptions of the natural world. Christopher Parsons says that, given BBC impartiality, it would have been wrong for him to have an environmental "mission statement" when he worked for the corporation - which he did until 1982. But working with wildlife convinced him of the importance of the environmental message.
He now sees sustaining biodiversity as central to his work, which means thinking small. "Over 95 per cent of all organisms are less than the size of a hen's egg," he says. "Experts confidently claim that if we eliminated insects, humankind couldn't live on the planet for more than four months." The problem is that beetles aren't sexy; cuddly, brown-eyed pandas are. Wildscreen aims to overcome this.
At the core of the new project is the extraordinary archive of natural history film which has accumulated in Bristol. The city's connection with natural history began with the BBC's regionalisation programme in the 1950s. Bristol became a centre for natural history, not least because Desmond Hawkins, an outstanding producer of such programmes, lived in the region. Sir Peter Scott, founder of the Slimbridge wildfowl centre in Gloucestershire and an early natural history film-maker, was another key player.
The crucial expansion came when Parsons had the idea for Life on Earth in the late 1970s. David Attenborough, trained zoologist, one-time presenter of a series called Zoo Quest and then director of BBC television programmes, was approached to be its front man.
It proved a stunning success, and Parsons was made the first head of the natural history unit which became a fully fledged BBC department. What was happening in Bristol lured other independent wildlife film-makers, notably Partridge Films, to the city. They are all cooperating with the Wildscreen project. The scheme, which is costing about pounds 20m out of the pounds 97m dockside total, cannot afford to have specialist filming in far-flung parts of the globe. Instead, it begs assistance from film crews on location.
Part of Wildscreen includes creating "windows" on the natural world, where visitors can look in on animals at an African waterhole, or butterflies in Mexico. Parsons says: "When we learned that a BBC crew was going to Mexico, we said, `While you're there, could you film a shot in a very special way for us of Monarch butterflies?'"
Similarly, the specialist knowledge accumulated over 40 years is being incorporated into a series of interactive computer games. One depends on deciphering the signals that mating spiders tap out. Another is based on the frogs' chorus.
For Parsons, the initiative is the culmination of a lifetime dedicated to the natural world. He is most proud of Life on Earth, the series which transformed a generation's view of wildlife. But Wildscreen@t-Bristol comes close - "if it works. And the indications are that it will".
Wildscreen@-Bristol (0117 909 2000); previews from 12 August