The most extraordinary thing about Timothy Treadwell - who died three years ago, at the age of 46, in a tent in the Alaskan wilderness - was that he managed to live to be so old. For 13 consecutive summers, the former addict and self-described environmental warrior set up camp in Alaska's Katmai national park, in an area heaving with bears, and sought to survive among them on little more than the belief that he could.
"If I show weakness, if I retreat, I may be hurt, I may be killed," he explains breathlessly at one point in the 100 hours of videotape he shot there. "They may chop me up into bits and pieces." An average Alaskan grizzly can run at up to 40mph, and smell meat from nine miles away. But in Treadwell's case, they bided their time, and he became a minor celebrity, touring American schools and appearing on the Letterman show. Then inevitability asserted itself: in October 2003, park officials found the remains of Treadwell and his girlfriend, Amie Huguenard, their bodies partially devoured by a hungry bear.
The breathtaking footage Treadwell left behind - of bears in the wild, and of his own psychological descent - forms the heart of Werner Herzog's new film, Grizzly Man, a nature documentary that is to March of the Penguins what The Exorcist is to Rentaghost. Treadwell's fatal error, Herzog makes clear, was to believe in a Disneyfied version of nature: for all his talk of being killed, he saw the bears as fundamentally cute. On camera, he strokes their noses, gives them nicknames like Rowdy and Mr Chocolate, chides them like children for snarling at him, and tells them, over and over, that he loves them. At night in his tent, he cuddles a teddy; during the day, he rants about the evil poachers and government agencies from whom he must protect the real bears. In fact, they appear to have been in little peril, except perhaps from Treadwell himself, who was arguably endangering them by acclimatising them to human contact.
"Timothy Treadwell crossed a boundary that we have lived with for 7,000 years," says a native Alaskan museum curator in Herzog's mesmerising film. "It's an unspoken boundary. But when we cross it, we pay the price." Treadwell's environmental charity was called Grizzly People, and the name seems apt. More than anything, it seems, this high-school dropout from Long Island with the bleached-blond hair and a string of failed human relationships behind him wanted to become a bear.
The story is classic Herzog: the celebrated German director practically has copyright on the concept of the half-crazed, obsessive outsider picking a fight with the forces of nature. But he came across the Treadwell footage in almost absurdly accidental circumstances, while hunting for his car keys in the offices of a television producer named Erik Nelson.
"I have the impression that characters like Timothy Treadwell come across me," Herzog says in his precise but heavily accented English. "I was standing there and poking in my pockets, and I looked intently at [Nelson's] messy desk - his half-eaten lunch, his video cassettes. And he thought I was spotting something specific, and he shoved an article across the table and said: 'Read this.'"
Herzog read it the same evening, and hurried back the next day. "I asked, 'Who is directing it?' And Erik said, 'I'm kind of directing it.' I looked him in the eye, and I said, in my accent, 'I will direct it.'" Nelson evidently decided not to resist this particular implacable force of nature. "I stuck out my hand," Herzog recalls, "and he took it, and we were happy ever since."
Watching Grizzly Man, though, you sometimes get the feeling that Herzog wasn't quite prepared for what he was getting involved in. By chance, Treadwell recorded his and Huguenard's deaths - the lens cap was still on the camera, but the audio was running - and there is an extraordinary scene in which Herzog, wearing headphones, listens in horror to the maulings. In the room at the same time is Jewel Palovak, Treadwell's former girlfriend and an executive producer on Grizzly Man. To this day she has never heard the tape, and we don't get to, either. "I didn't waste five seconds to know: this will not be in my film," Herzog says. "My instant decision was, one, we are not going to do a snuff movie. And, two, there is such a thing as privacy, and the dignity of your own death ... Sometimes it is better to have a question with no answer." That seems a fair way of summarising Treadwell's life, as well as his death. His motivations remain mysterious to the end, even to his parents, whom Herzog interviews.
Laughter is the only possible response to much of Treadwell's behaviour. When lack of rainfall depletes the rivers where the bears feed on salmon, he performs a manic religious rite, calling for the intervention of God, Jesus, Allah, and "the Hindu floaty thing"; at another excruciating point, while he blathers to the camera about wilderness and death, one of the objects of his devotion lumbers towards him from the background. The temptation to shout "Behind you!" is almost too much to resist.
But it's the sadness of Treadwell's situation, not its humour, that lingers after the film has finished. His attempt to find a home in the society of bears was doomed to fail - and yet it removed him sufficiently from the society of humans to leave him stranded between the two. Days before his death, he had tried to make the annual transition back to civilisation, arriving at an Alaskan airport to catch a plane back home. But an altercation with an obese airport staff member, enigmatically recorded in the last pages of his diary, sent him straight back off to the wilderness in a fury, with Huguenard in tow. By then it was late in the season: the bears Treadwell knew, and who were accustomed to his presence, had moved on. The grizzly that killed the couple was probably a straggling latecomer, down from higher ground in search of a meal.
Timothy Treadwell's problem was that he saw wild nature as essentially friendly; Herzog sees it as essentially hostile. Where Treadwell saw the signs of personality in the eyes of the bears, Herzog sees "only the overwhelming blank stare ... [and] a half-bored interest in food." It's a bleak vision, pitting Treadwell's American optimism against Herzog's Germanic pessimism, and sometimes during Grizzly Man you catch yourself wanting to believe in the former: those bears can seem awfully cute. But then you remember how fast they can run, and how they can smell their next meal from nine miles away, and at this point British pragmatism kicks in. Go camping if you must. But what's wrong with the Lake District?
· Grizzly Man is released next Friday
