The aim of this work was to gather data on the abundance and densities of the three giant reptile species of South East Asia which are playing a mayor role in the international trade of reptile skin, viz. the Water Monitor (Varanus salvator), the Blood Python (Python curtus), and the Reticulated Python (Python reticulatus) and primarily reflects the author's PhD. thesis. Nothing was known about the actual densities of these three species and Mark Auliya spent a year in the interior of West Kalimantan, Indonesia. His task was extremely difficult: he had to solve innumerable logistic problems, design traps for the unusually large study objects, and finally, establish good contacts with the networks of reptile skin dealers in order to gather sufficient data on numbers, size classes etc. of the harvested monitor lizards and pythons. But this was not all. With admirable energy, he surveyed the biodiversity that existed in the habitats of the pythons and monitors. Not only was the remaining herpetofauna surveyed - including fascinating new discoveries - but also mammals, birds, even some arthropod groups and part of the vegetation. In summary, the book is a masterpiece of biodiversity and conservation research since it reveals the first reliable data as to what amount of exploitation the populations of the three giant reptile species in their Bornean habitats may or maynot withstand.