IT SEEMS hard to believe, but the noiseless sport of paragliding can lead to avalanches and landslides. Swiss researchers found paragliders scare mountain goats into the forests downhill. The hungry goats can do a lot of damage to these forests, the main protection against avalanches and landslides in many areas, says Reinhard Schnidrig-Petrig from the University of Berne (BBC Wildlife, Vol 11, No 11). But what is it about the paraglider that spooks the goats, which graze nonchalantly at the approach of a helicopter? Noiselessness, which adds an element of surprise, says Schnidrig-Petrig. Aerial predators, after all, do not sound like helicopters and almost any animal instinctively shudders at a sudden, arc-shaped shadow, he adds.