Manipulating wetland hydroperiod to improve occupancy rates by an endangered amphibian: modelling management scenarios

Environmental managers have the difficult task of ensuring species persistence despite considerable uncertainty about their response to management. Spatially explicit population models provide one solution for simulating the dynamics of species and evaluating alternative management regimes.
We used a Bayesian model to investigate wetland occupancy dynamics of the endangered growling grass frog Litoria raniformis at a wastewater treatment plant in southern Victoria, Australia. We coupled prior information from earlier research on this species with our survey data to quantify the effects of patch-scale variables and connectivity on the probabilities of occupancy, population extinction and colonization. Hydroperiods of 13 sites were experimentally enhanced to bolster occupancy rates by L. raniformis. We used simulations to assess the extent to which the enhanced hydroperiod regime improved the viability of the focal metapopulation.
Occupancy rate increased by 15% among the enhanced sites...