The idea of replacing the British monarchy with an elected president always stumbles on the thought of David Beckham, John Birt or (in the near future, once he's retired) Tony Blair applying to be our national figurehead. If - and it's a big if - Sir David Attenborough ever decided to volunteer his services, his opponents would throw in their towels at his mere nomination. Even Alan Bennett and Michael Parkinson, the great British public's second favourite crinklies, would admit it was a shoo-in.
Republicans had better get a move on, however, for Attenborough is now 79. Indeed, in May he became The Oldie magazine's Oldie of the Year. The great man seemed a bit bemused by the honour, and he's certainly not taking it as a cue to hang up his binoculars and swap his passport for a bus pass.
In fact, later this month his new BBC wildlife series Life in the Undergrowth will see Attenborough once more swinging on a harness beneath the canopies of rainforest trees, and clambering on his belly across desert sands as he lifts the lid on the world of the invertebrates - gazing upon scorpions, millipedes and termites with the same awe and respect that he has shown to lions, penguins and blue whales.
The 1979 series Life on Earth established the much imitated, never bettered, Attenborough style - perhaps gently parting some grass to reveal playful tiger cubs, or grooming meerkats, while addressing sotto voce the enthralled TV audiences back home. Wildlife film-making had amazed before, but Attenborough took the genre into a new dimension, and if there is one sequence that cemented his reputation it was his famous encounter with Rwandan mountain gorillas during Life on Earth. Attenborough's easy, intimate style doubles up with an unassuming enthusiasm for the natural world that is infectious, and so much less wearying than David Bellamy's gesticulation.
Life on Earth has been followed by a steady flow of similar series - The Living Planet (1984), The Trials of Life (1990), Life in the Freezer (1993), The Private Life of Plants (1995), The Life of Birds (1995), The Blue Planet (2001) and The Life of Mammals (2002) - that have made him the pre-eminent voice of nature broadcasting. Others - Alan Titchmarsh and Charlotte Uhlenbroek, for example - may have since strayed on to his patch, but Attenborough remains the undisputed big beast of wildlife television.
The younger brother of Lord (Richard) Attenborough (they have another sibling, John, and his parents adopted two German Jewish girls during the Second World War), David Frederick Attenborough never showed the interest in acting that Richard had. Instead, he opted to read Natural Sciences at Cambridge, graduating in 1947. After two years' National Service in the Royal Navy, he joined the BBC in 1952, beginning his famous Zoo Quest series, which combed distant corners of the world in search of rare animals.
But in 1965 he found himself in the least congenial environment for such a creature as himself: behind a desk. Attenborough was the first controller of the fledgling BBC2, overseeing the introduction of colour and a remarkably permissive and lambent regime that coincided with Hugh Carlton Green's enlightened tenure of the director general's post. The first great landmark television series, such as Civilisation and The Ascent of Man, were produced under Attenborough's aegis, while he was also indirectly responsible for a revolution in television comedy when he green-lighted Monty Python's Flying Circus. Perhaps he mistook it for a wildlife programme.
In 1969 Attenborough was appointed director of programmes with editorial responsibility for both the BBC television networks, and it looked like the golden boy of broadcasting was being fast-tracked into the post of director general. Fortunately for us, his natural aversion to management got the better of him, and he resigned in 1973 to return to programme-making. His offerings were unremarkable at first - Eastwards with Attenborough sending him to South-east Asia, while The Tribal Eye considered tribal art. But then, in 1979, he wrote and presented all 13 parts of Life on Earth, a project imbued with Attenborough's experience at overseeing other's people's TV series, and his assault on the national consciousness began in earnest.
With the new millennium, and much to the pleasure of environmental groups long frustrated by his reluctance to speak out on air against man's destruction of nature, Attenborough decided that after 50 years of being the great explainer, he would become the great campaigner. His 2000 series, State of the Planet, focused on the likelihood of a mass extinction even more dramatic than the one that killed off the dinosaurs. "It's about time Sir David came out of the closet," said the then policy director of Friends of the Earth, ignoring the fact that Attenborough helped found the World Wildlife Fund in 1960.
By remaining aloof from campaigning and advocacy Attenborough had been able to retain a particular authority, but in recent years a sense of urgency has seen him lend that authority to various eco-matters: petitioning the UN for the Himalayas to be given special protection status; resisting the construction of a monorail to link the Galapagos Islands; supporting a project to tempt otters back into the River Thames.
But what do we see when we quietly part the long grass and spy on Attenborough himself? When not combing the world for fauna he lives in Richmond, Surrey, watching very little of the medium that has been his making. His wife Jane died in 1997; the loss has not engendered any sudden rush to religious faith. Indeed he has said that if there is a creator then he is a God who has created a Darwinian natural selection.
Attenborough's relationship with animals remains unsenti- mental. He once shot a crocodile, although he has never done anything similar since. He admits to setting mousetraps and eating most meats (but don't even think of serving him whale steak). "I think the shape of our teeth and our guts make it clear we evolved as an omnivore," he has said.
Those that have met him testify to his great dignity, and although national treasure is a horribly overworked phrase, it surely applies in this case. He's unlikely to ever put himself forward as president of any putative republic of Great Britain, however. For, as he showed when he turned down the job of director general of the BBC, there is one beast Attenborough has never been keen to meet: the political animal.
Life in the Undergrowth starts on BBC1 on Wednesday 23 November