SEE THE WORLD IN ANIMAL VISION
David Attenborough shows astonishing findings in his new series about how animals see colour – with Martin Stevens’ stunning snaps
To the human eye, a single glimpse of a Bengal tiger is unmistakable. The one pictured on this page has been hunting in the forests of central India, slipping through the long grass with grazing chital deer in her sights. The deer seem oblivious. How is it they fail to see such a large, luridly coated predator? And why has the tiger, which relies on stealth, evolved with flame-coloured fur?
The importance of colour across the animal kingdom has been a source of fascination to David Attenborough for 70 years, ever since his first programme. Now it’s the subject of his new two-part BBC1 series, Life In Colour, ranging from spectacular birds of paradise to the minute hues – invisible to our eyes – that are essential to insects.
In one of his breathy voiceovers, he explains, ‘The tiger’s orange and black coat is crucial to her success. Chital deer have only two types of colour receptors in their eyes, compared to our three. They are effectively blind to red and orange. To the deer, the tiger is a muted shade of green nearly impossible to register.
‘The first programme I wrote and produced was about exactly this,’ David, 94, tells me over the phone. ‘It was called The Pattern Of Animals because, of course, we didn’t have colour TV then. The presenter described the colours of the fur and feathers that viewers saw only as shades of grey.’
As he ventured around the world, his pictures were aired in black-andwhite – though much of the material was shot on colour film and has been restored. In 1957, he set out for Papua New Guinea. ‘I desperately wanted to be the first person to film the courtship displays of birds of paradise in the wild.’ He travelled to the Wahgi Valley and his guide spotted a Count Raggi’s Bird, which has an orange body and wings, a green-and-yellow head and a luminous cream tail. ‘I remember it so clearly,’ he says. ‘This species only displayed at early dawn, so we set out at 3.45am and found the bird in a tree, silhouetted against the light. We filmed in black-and-white and the results could hardly have been more boring.’
He’s returned many times, with progressively better equipment, and has now seen the displays of more than 20 species. ‘You have to be an expert to tell some apart. But one is allowed these foolish little quirks.’
One of the most fascinating aspects of these displays, he says, is the proof they give that birds perceive colour and beauty as humans do.
‘Charles Darwin pointed out that birds have an aesthetic sense and are aware of beauty. We think a male peacock’s tail is lovely for exactly
the same reason that a female is impressed.’
Some animals, David points out, do not need colour. ‘There’s no advantage to an elephant in having beautiful plumage – it has invested in sheer size.’ But at the other end of the scale, Costa Rica’s hummingbirds have dazzling displays. In California’s Mojave desert, the male signals to a potential mate by flaring iridescent purple feathers around its throat. The birds weigh just 2-3g and to avoid being seen by predators, they manoeuvre in flight to catch the light and direct scintillating flashes to the female. ‘Like a wink across a crowded room, meant for one person,’ says David.
Some animals use colours invisible to us. Male blue moon butterflies have wing patches only seen in the ultraviolet spectrum. In the show, state-of-the-art cameras let us switch between visible and ultraviolet light, or human and butterfly vision.
Since ultraviolet vision is so useful, it might seem strange that humans have not evolved to have it. This deficiency goes all the way back to our ancestors in the age of the dinosaurs. ‘Mammals don’t have good colour vision, though primates like us are better than most,’ says David. ‘Back in the Cretaceous era mammals were nocturnal – little things that scuttled around at night. They didn’t need colour vision in the dark, and different groups evolved it separately later on.’
Some primitive animals can see colour in ways unimaginable for us. ‘Polarised light’, where light waves vibrate in a single plane rather than multiple planes, highlights shapes and patterns and helps, for example, fiddler crabs see predatory birds from a distance. Innovative camera lenses used for the first time here simulate polarised light. It’s like black-and-white TV with the contrast turned up to maximum.
Colour has played a prominent part in David’s career. He was controller of BBC2 in the 1960s, and oversaw the introduction of colour TV. ‘The pictures we had then were extraordinarily crude compared to what we have today. But content matters most. Even in black-and-white, you can tell a good story. That’s what people tune in for.’
Attenborough’s Life In Colour, February 28 and March 7, BBC1. Pictures (except those of David and the Bengal tiger) taken from Life In Colour: How Animals See The World by Dr Martin Stevens, published by BBC Books on Thursday, about €23. © Humble Bee Pictures Ltd and SeaLight Pictures Pty Ltd 2021