Dir: Alastair Fothergill/Mark Linfield. UK/Germany 2007. 98 mins.
Probably the most ambitious nature documentary ever produced, Earth is a feature-length condensation of the eleven-part BBC series Planet Earth, broadcast in the UK in 2006 and on Discovery Channel in the US in spring 2007. Better than a trip to the zoo, and a lot less pungent, Earth is like an updated, people-free version of one of those exotic round-the-world travelogues from the early days of cinema.

Seeing the breathtaking footage on the big screen (preferably with digital projection, as during the film's San Sebastian gala showing) does full justice to the crystal-clear photography, most of it filmed using HD cameras.

Already sold to a raft of territories, Earth looks certain to outdo Deep Blue, the previous high-budget nature documentary from Alastair Fothergill (who co-directed the present film with Mark Linfield) and production partners Alix Tidmarsh and Sophokles Tasioulis, which grossed around $30 million internationally.

But the refreshing decision not to Disney-fy the material too much by pretending that animals are people too will lose the film some of the younger viewers that waddled along to see March of the Penguins or the recent Arctic Tale with their parents; in this ravishing but by no means airbrushed film, when a big bad wolf chases a cuddly caribou, there's no happy ending.

Though it would be crime not to watch this on as large a screen as possible, DVD sales will no doubt be buoyant.

The main challenge of a nature feature like this is how to give the miles of footage a dramatic structure and storyline. True to its title, Earth sets out to chart the infinite variety of the natural world all over the planet, so this was always going to be a multi-linear narrative.

Opening in the snowy wastes of the Arctic with a family of polar bears emerging from their snow-den, the film does at first seem to be straying into 'nature fiction' (aka 'wildlife adventure') territory.

But the patient, unhurried photography and editing, and Patrick Stewart's restrained commentary, doesn't curry favour with its audience by turning life in the wilds into a bittersweet Capra comedy.

We soon leave the bears behind and move on to other climes and other creatures: a lynx in the Siberian taiga, caribou migrating across the Candian tundra, filmed from such a height that they become a grey-brown river, improbable birds of paradise doing courtship dances in New Guinea (this is one of the few times when the narration allows itself a few moments of anthropomorphic comedy in the style of the redubbed US version of March of the Penguins), elephants trekking across the Kalahari in search of water, demoiselle cranes crossing the highest peaks of the Himalayas on their northward migration, and - in one of the most astonishing sequences from a technical point of view - close-up footage of a hunchback whale mother swimming alongside her calf. Less space is given in the film version to the plant kingdom, or to creepie-crawlies (there appears to be nothing here at all from the TV episode on cave life).

Structurally, the film is probably closest to Jacques Tournier's bird epic Winged Migration: here too the passing of the seasons (in this case a whole calendar year, month by month) gives unity to the disparate stories; here too certain animal groups (the polar bears, the elephants, the humpback whales) get more screen time and character development. The major difference is that whereas Winged Migration showed scenes of birds in contact with the human world, Earth manages to paint homo sapiens entirely out of the picture. The intention is presumably to make the audience look afresh at their own planet, and such is the sheer majesty of the widescreen images that it works.

George Fenton's soaring, Elgar-like orchestral soundtrack, recorded with the Berliner Philharmoniker, would sound bombastic in any other context.

There are times when the commentary feels a little cliched ('this is the never-ending cycle of life'), and the ecological subtext (more prominent here than in the TV series) occasionally comes on like a Greenpeace promo-doc. But it's what's going on on the screen that really matters here. Slow-mo footage of a cheetah hunting down a gazelle or a great white shark leaping clean out of the water (filmed using super high-speed cameras developed for use in car crash testing) is riveting - as is most of the aerial photography and time-lapse sequences (according to the filmmakers, no CGI was used).

One day, Earth may be looked on as a repertoire of fabulous, semi-legendary creatures and landscapes: for now, though, it's a stirring celebration of what we still have.

Alastair Fothergill
Mark Linfield

Production companies
BBC Worldwide (UK)
Greenlight Media (Ger)

International sales
Greenlight Media

Alix Tidmarsh
Sophokles Tasioulis

Executive producers
Andre Sikojev
Nikolaus Weil
Stefan Beiten
Mike Phillips
Wayne Garvie

Narration written by
Leslie Megahey
Alastair Fothergill
Mark Linfield

Andrew Anderson and 29 others

Martin Elsbury

George Fenton

Narrated by
Patrick Stewart