Subsidient: Philip Bijl/Leiden University
Subsidy: S181.61
The Philippine crocodile is a highly endangered crocodile species living in river systems on the Philippines. The present distribution and abundance is not well known as current monitoring methods fall short of providing clear and accurate images. Detection of environmental DNA within the water bodies could provide improved monitoring possibilities but the utility and appropriateness of using eDNA methods on reptile species within river systems is not well known. This research aimed to determine if eDNA methods can provide reliable data to determine the distribution and abundance of the Philippine crocodile so that this method can from then on be used as a better survey method. This was done by combining eDNA sampling with intensive surveys. Philippine crocodile eDNA has been shown detectable within high density areas. Within river systems the used eDNA detection method proved insufficient to determine the distribution and abundance of the Philippine crocodile. This can be attributed to a low DNA concentration in the environment due to low DNA shed of this crocodile species, high flow through in the system and the used sampling method. However, during this research a large contribution was made to the knowledge of present distribution and abundance due to the intensive surveys that were done. This can on itself proof to be of a high value to the conservation of the species.
