New information on site occupancy and detection rate of Mixophyes iteratus and implications for management

Abstract

Mixophyes iteratus (giant barred frog) is listed as Endangered in state and federal legislation, but there have been only two previous studies in scientific literature that have focused on habitat preferences of this species. This study aimed to shed light on habitat selection of M. iteratus by conducting surveys during the 2019–2020 breeding season within the Tweed Valley, northern New South Wales, Australia. Detection rate was also quantified, which is a first for the species. A nested survey method was used in conjunction with a conditional survey design. There were 118 detections of M. iteratus over 31 habitat sites, all beside permanent stream pools >10m in length. Occupancy modelling suggested that frogs were more likely found in sites with ≥12m of undercut bank. Over three survey rounds, detection rate was 0.54–0.65. Surveys at historical sites showed that the species can survive severe drought, which was experienced through 2018 and 2019. Findings suggest that at least two surveys for M. iteratus should be conducted at favourable sites or when targeting the species, especially if land management at the site is proposed to change. Riparian management that retains undercut banks and pools is encouraged for the conservation of this species.