The influence of landscape features on the distribution of the Vulnerable <i>Mixophyes iteratus</i> within the Tweed Valley, northern New South Wales

Gregory Lollback; Michele Lockwood; David Hannah

Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

The influence of landscape features on the distribution of the Vulnerable Mixophyes iteratus within the Tweed Valley, northern New South Wales

Gregory Lollback , Michele Lockwood , David Hannah

Abstract

Context. There is a lack of information about frog distribution at the landscape scale in Australia, especially for the Vulnerable Mixophyes iteratus. Knowing the influence of landscape features on occurrence or abundance may aid conservation management. Aims. Our aim was to understand how Mixophyes iteratus is influenced by landscape features and fill in the knowledge gap on species distribution within the Tweed Valley landscape. Methods. The species was sampled at 40 stream-based transects during three breeding seasons, from 2019 to 2022. Occupancy analysis and general additive models were used to investigate the relationship between landscape features and frog occurrence and maximum frog count, respectively. Variables included elevation, proportion of vegetation cover, stream morphology and distance to conservation reserves. Key results. Mixophyes iteratus distribution was concentrated in the western half of the Tweed Valley, over a range of landscape features. Landscape features did not strongly affect distribution at specific scales or in general. There was some spatial clustering of maximum frog count, especially in large, forested areas in the south and southwest of the Tweed Valley. Detection rate was higher in this study compared to a previous study with shorter transects. Conclusions. Modelling suggests that Mixophyes iteratus occurred over a broad distribution within the western half of the Tweed Valley before broad scale clearing occurred. Species occurrence is wider than previously thought, however, population strongholds appear to be within large tracts of forest. Implications. Species conservation informed by small scale habitat selection would be enhanced by knowledge of landscape scale distribution.

PC24079 Accepted 21 May 2025