Ancient etchings under threat from La Nina

Mudslides caused by the unpredictable weather pattern La Niña threaten to rub out Peru's enigmatic Nazca lines, and have induced a panic near the heritage site which, to the uninitiated, already resembled a wasteland.

Mudslides caused by the unpredictable weather pattern La Niña threaten to rub out Peru's enigmatic Nazca lines, and have induced a panic near the heritage site which, to the uninitiated, already resembled a wasteland.

Two days of apocalyptic rain in the Peruvian high desert, where it normally drizzles for just half an hour every couple of years, have spurred local civil engineers and labourers into a frenzy of digging drainage ditches along the Pan American Highway. The two-lane road skirts the ancient etchings, and even runs over one sorry lizard figure. The mystery lines were drawn in the sand as long as 2,300 years ago, and it took La Niña to cross them.

Flash floods near the area, 250 miles south-east of Lima, two years ago were shrugged off as an aberration. But this time at least six of the 16 distinctive patterns, which were wrought on the desert floor between 300BC and 900AD, are noticeably smudged. This is inauspicious for tourism, at least, and New Agers and shamans are muttering about mystic portents if the rain erases the images after so long.

The symbols include stylised bird figures - everything from a hummingbird to a heron - which combine spirals, zigzags and geometric shapes on a prodigious scale, some with wingspans of half a mile. There are also outsize renditions of a killer whale, a spider and a nine-fingered monkey cut into the arid plains.

A baffling network of immense straight lines shows up wherever the darker topsoil has been purposefully swept aside. A few lines run in parallel pairs, and all traverse hills and gorges, but never veer off true course. One line runs for eight miles, without a single deviation, then stops dead.

Recent theories suggest that the Nazca lines map out subterranean waterways, herald the start of the seasons or orient toward all the cardinal directions valued by the Nazca culture.It took a German-born mathematician, Maria Reiche, some 40 years to work out the Nazca solar and lunar calendars from these line positions. Ms Reiche, known in Peru as "The Lady of the Lines", died 20 months ago aged 95. "Ancient men must have had instruments of which we know nothing," she wrote. "Together with their knowledge these were hidden. It's the only treasure that we couldn't take away."

When tourists in an allterrain vehicle tracked treadmarks across the forbidding figures after a secret joyride only two years ago, government officials were spitting mad. But by puzzling out the significance of these marks, future anthropologists will be able to determine exactly when the Nazca lines hit the skids.