The Beast Years of Earth's Life

Once the dinasours departed, what ruled the Earth? The BBC has dramatised the Dark Ages of prehistory, writes FRANCES GRANT.

The big bird is hungry enough to eat a horse. Before the end of this day in the Eocene epoch, 49 million years ago, the giant carnivorous fowl living in the German jungle will satisfy her appetite.

But Polly's dinner will have to wait. First, there's plenty more action in the steaming, volcanic rainforest to check out in this opening episode of Walking With Beasts, the sequel to the BBC's popular simulated natural prehistory series, Walking With Dinosaurs.

A clutch of small hopping mammals called Leptictidium will be happy just to get through the day without becoming supper for the big bird, called Gastornis.

Gastornis has traded weight for flight, unwisely it would seem. The dinosaurs are long gone and while the big birds may be having their ruling moment on the world stage, they cannot nest in trees. Their grounded eggs are vulnerable to hordes of giant ants and other small predators.

Meanwhile, the whale's earliest ancestor, an amphibious predator called Ambulocetus, is lurking in ambush. Ambulocetus (literally, "walking whale") is a crocodile-like beast that snatches thirsty mammals off the lakefront. It's not the sort of creature to inspire whale-watching. .

Like its predecessor, Walking With Beasts is based on well-informed speculation about the behaviour of extinct animals, presented in dramatic style. Each episode follows the fortunes of a handful of species through one day of their enormous struggle for survival on planet Earth.

Using a combination of robotic models and digital animation, the six-part series recreates the bizarre animals that emerged after the dinosaurs' extinction 65 million years ago. It begins with the Eocene period and follows the rise of the mammals from small, hen-pecked forest dwellers to the fiercest predators on land and in the sea. It ends with the emergence of modern humans about 30,000 years ago.

It's a neglected era of evolutionary history, overshadowed by our seemingly endless fascination with dinosaurs. "The period after the dinosaurs is like the Dark Ages of prehistory," series producer Jasper James says in an interview with the Mirror newspaper. "The Earth was populated by weird, wonderful and totally unique animals people just don't know about. We're lifting the lid on a mind-boggling forgotten era.

"Walking With Beasts picks up the story slightly less than 50 million years ago, by which time birds had become giant-sized. Mammals also grew bigger but they were not top dogs," Jasper says.

"I'd heard of mammoths and sabre-toothed tigers, but when I started this series, I didn't know the world was once ruled by giant birds and whales that walked on land."

More than 30 beastly creatures are recreated in this series and close to 500 scientists from around the world were consulted to help the team to make their reconstructions as accurate as possible.

One of the more challenging models to make was that of the Smilodon (pictured on the cover), the friendly-sounding name for the most ferocious of the sabre-toothed cats. The British Radio Times reports that it took four people six weeks to manually blast tiny off-cuts of goat hair on to a model sabre-tooth just to get the fur looking right.

Other hairy moments came during filming. The weight of the Entelodont (a huge, pig-like creature) was such that the film crew had a constant battle to stop it sinking into the mud of the Arizona watering hole where they were on location.

Taking a replica woolly mammoth to Canada for its scenes was no picnic either. "That was quite awkward to say the least," James says in the Radio Times. "We broke his legs and his head came off, so he was cleverly bundled into a crate."

As well as the models, the series' artists created more than 30 hours of computer animation footage, which has been incorporated into 1000 special-effects shots. While the animatronic models were used for the close-ups, landscape shots such as the woolly mammoths lumbering through the snow required computer graphics.

As with Walking With Dinosaurs, the aim was to recreate a long-past era as if the cameras had actually been there. "The whole series is shot as if it were a documentary," James says. "We have times when animals will come along and nudge the camera and put steam on the lens, that sort of thing. Anything to make them real, real, real."

The exotic backdrops for the series are provided by a host of locations around the world, from the Americas to South Africa. Standing in for the German Eocene rainforest of this week's first episode, for example, is Western Java. New Zealand, which played a starring role in Walking With Dinosaurs, does not feature this time.

Meanwhile, back on that day in that lush, hot period, in what will eventually become a much cooler Germany, twilight is approaching. After sashaying through the rainforest, the hungry Gastornis finally gets her horse — or what passed for a horse 49 million years ago.

The equine forerunner, a dog-sized creature called Propalaeotherium, has foolishly been feasting on fermenting grapes and is drunk in charge of a herd. All the better for Gastornis, she likes to take her meal on the hoof.