DOI: 10.5061/dryad.f83c6
title: Data from: Manipulating wetland hydroperiod to improve occupancy rates by an endangered amphibian: modelling management scenarios

description: 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
 in 2013–2014, whereas the rate of occupancy among unenhanced sites fell by
 11% in that year. Forward simulation using the dynamic occupancy model
 suggested that the minimum occupancy rate across the metapopulation would
 be 18% higher if the enhanced hydroperiod regime was retained over the
 next 20 years. Mean posterior effects of patch-scale variables and
 connectivity on the occupancy dynamics of L. raniformis were consistent
 with the prior effect in all cases, with only small changes to the size of
 these effects. There was no clear effect of water chemistry on occupancy
 dynamics. Synthesis and applications. This work suggests that managing the
 hydroperiod of constructed wetlands can be an effective tool for the
 conservation of amphibians and demonstrates the utility of spatially
 explicit models for assessing metapopulation viability. We encourage
 managers to experimentally test the efficacy of manipulating patch-scale
 variables to improve occupancy rates within amphibian metapopulations.
description: Hamer et
 al_2016_JAPPLE_Habitat&Detection_DataThis file contains data
 on effective wetland area and mean proportion cover of aquatic vegetation
 at 33 sites sampled in each of four years. The water chemistry parameters
 electrical conductivity (EC, log transformed) and turbidity (ntu) are
 provided as a mean over the four years of sampling. A detection matrix is
 provided that contains a '1' whenever Litoria raniformis was
 detected during a survey. 'NA' denotes that a survey was not
 conducted at that time. A distance matrix includes edge-to-edge distances
 (metres) between all 33 sites.Hamer et
 al_2016_JAPPL_base modelThis file contains
 OpenBUGS code for deriving estimates of initial site occupancy, local
 colonisation and extinction, number of occupied sites and metapopulation
 growth rate from a Base model. Parameters included are effective wetland
 area (effarea), mean cover of aquatic vegetation (aqveg) and connectivity
 (conn).Hamer et
 al_2016_JAPPL_water qualityThis file contains
 OpenBUGS code for deriving estimates of initial site occupancy, local
 colonisation and extinction, number of occupied sites and metapopulation
 growth rate from a model of Water Quality. Parameters included are
 effective wetland area (effarea), mean cover of aquatic vegetation
 (aqveg), connectivity (conn), turbidity (turb) and electrical conductivity
 (cond).