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LIFE IN THE DARK Paolo Agnelli, Stefano Vanni Zoologists are an unusual bunch, forever prepared to put themselves on the line by setting off to explore the most unusual of environments, in search of the natural mechanisms that govern those places and the creatures that populate them. When coming across bona fide explorers, who push themselves even harder, to the very limits of research, and who invite them to participate in a biospeleology expedition to one of the most beautiful caves in the world, the zoologists are not likely to demur. This is what happened to us when we accepted the invitation to share a new Philippine adventure with the speleologists of the La Venta Association, to study the extraordinary biological environment of the Puerto Princesa Underground River (PPUR) Cave on the island of Palawan. The limited knowledge of the fauna in this cave came from a pair of expeditions organised between 1990 and 2000. The urgent need to learn more about the fauna that populates the cave – recently recognised by UNESCO as a World Heritage Site – was due to the fact that the number of tourists visiting it has now reached the
Gallery of the Gaia Branch
very substantial level of 1000 people a day! It was therefore important to evaluate the impact on the fauna of such an imposing anthropic presence before it was too late. Based on the results of the previous biological missions and on an examination of the photographs taken during the geological and speleological surveys, we knew that the place held many surprises in store. We had to wrestle with an enormous cave, playing host to an array of ecosystems that are very diverse because not only is there a large underground river, but also extensive, isolated fossil branches, as well as a second upstream entrance that puts the cave in contact with a beautiful rainforest. We could, then, envisage the presence of a plethora of different types of fauna. The task we set ourselves was to discover which species live in the cave, what ecological relationships bind them together, and which species are most under threat from the use of the environment by tourists. With a view to providing advice on appropriate tourist management, it was last but not least important for us to identify, out of
