The saola, a forest-dwelling bovine, is one of the most rare and mysterious species on the planet. It was first discovered 23 years ago - but is so shy that it was rarely spotted again. Conservationists know they live somewhere in the Annamite Range between Vietnam and Laos - but not exactly where. They are equally in the dark about the number of animals still alive, and fear erosion of natural habitat and use of snares could wipe saolas out altogether. WWF scientists have been using cameras to try and find out more about the elusive saola - so far, to no avail. They are now turning to leeches to help them.
A film by Grit Hofmann