Grizzly Man (15)

Werner Herzog specialises in forces of nature. In fiction films and documentaries, he's taken on the Amazon, assorted mountains and volcanos, the blazing oil wells of Kuwait and, perhaps most recklessly of all, the flamboyantly demented actor Klaus Kinski. Herzog's new documentary looks at grizzly bears and the Alaskan wilderness - but uncharacteristically, does it at one remove. In Grizzly Man, the remarkable footage of wild bears nosing around just a few feet from the camera - and at one point, scant inches from the cameraman - is shot not by Herzog but by his subject Timothy Treadwell, who spent the last 13 summers of his life living close to grizzlies.

In fact, Herzog gets no closer to Treadwell in person than he does to the bears. Treadwell, so enthusiastic about communing with his beloved beasts, was killed by one in 2003, together with his girlfriend Amie Huguenard. Part of Herzog's film - which contains a great deal of Treadwell's extraordinary footage - celebrates his subject's intrepid obsessiveness, as well as his skills as a wildlife film-maker. To say Treadwell gets close to his animals is an understatement: a sort of "bear whisperer", he is seen on camera sweet-talking or schoolmarmishly cautioning his bears, which mostly seem indifferent to, or tentatively curious about, his presence.

But Herzog is also fascinated by the delusion that made Treadwell believe he was safe among bears - even though he was prone to boast about the extreme danger he placed himself in. Treadwell, who took his bear gospel into schools as well as on to Letterman, regarded himself as the bears' only true protector, a self-styled "kind warrior". But he clearly needed the grizzlies more than they needed him, spending 13 summers among them in an Alaskan national park, filming over five of them. But he filmed himself as obsessively as he did the bears, and the film's most riveting footage is actually of Treadwell playing commentator or posing in bandana and fatigues as a sort of rural ninja.

Camp, even girlish, frequently fussing over his Prince Valiant blonde bob, Treadwell coos tenderly at his favoured animals, which have cutesy nicknames like "Mickey" and "Mr Chocolate". His sentimentality about nature is coy, sometimes farcical. He practically weeps over a dead bee, then, as if witnessing a holy miracle, chirrups, "The bee moved!" But he'll suddenly launch into extended rants about his dating troubles, his distrust of humans, his bilious loathing of the US government, with a truly disturbing degree of paranoia and narcissism.

"His rage is almost incandescent, artistic," enthuses Herzog in his voice-over, and adds, "I have seen this madness before on a film set" - and come to think of it, Treadwell's hairdo is not unlike Kinski's in Aguirre, Wrath of God. No less troubling is the fact that Treadwell consistently claimed to be alone in the wilderness, whereas for much of the time he was accompanied: the doomed Amie Huguenard remains a largely unseen absence, her elusiveness fascinating Herzog almost as much as Treadwell's exhibitionism.

The couple's killer was probably not a familiar "Sgt Brown" or "Aunt Melissa", but a more feral outsider, mundanely labelled "Bear 141". And their death is horrific in a way that suits Herzog's fascination with truth and the cinematic image. Treadwell's camera was running when he and Huguenard were mauled, but the lens cap was left on: everything, however, was captured in sound. In an unnerving sequence, Herzog is seen presenting the tape to Treadwell's former girlfriend Jewel Palovak (who is also Grizzly Man's co-executive producer); he tells her she must never listen to it and advises her to destroy it. We never hear the tape, though Herzog does: and while this note of discretion seems rather ostentatiously placed, it gives the tape a chilling status as guarantor of terrible reality, in contrast to Treadwell's fondly cherished fiction of nature.

Treadwell emerges variously as a tragic figure, a monster, a buffoon, sexually confused and with a troubled background. But he is also one of those "holy fools" that have always fascinated Herzog - a sort of Kaspar Hauser in reverse, a product of civilisation who dreams of becoming a wild child, or, indeed, an animal. He is a thoroughgoing contradiction - a man morbidly obsessed with wildness and danger, but whose view of nature was filtered through the most artificial softening optic of romantic sensitivity, New Age philosophy at its most effete.

Herzog himself balks at such views: he declares in his voice-over that for him, nature is not about harmony but about "chaos, hostility and murder". Just imagine if we'd had Herzog's inimitably doleful Bavarian tones doing the commentary on March of the Penguins: "these deluded birds blindly seeking annihilation at the heart of a vast, unforgiving abyss". Grizzly Man is an astonishing film; rest assured, it won't offer much succour to the penguin-hugging intelligent-design lobby.

j.romney@independent.co.uk