The 2006 Monts de Cristal Ecosystem elephant survey was conducted using dung counts encountered in recce visits. The dung decay rate was not done on site but it was taken to be 80 days using 14 reviewed studies. Due to the limited information and parameters of the dung decay rate e.g. number of dung piles used, and the use of recce visits instead of systematic transects, the survey was submitted as an informed guess.
Source:Maisels, F., and Strindberg, S. (2012). 'Review of Gabon's elephant status'. Gabon: Wildlife Conservation Society.