Distribution, habitat, and conservation status of the Giant Barred Frog Mixophyes iteratus in the Bungawalbin catchment, northeastern New South Wales

Abstract

A distribution and habitat assessment was used to determine the conservation status of the Giant Barred Frog Mixophyes iteratus in the Bungawalbin catchment in northeastern New South Wales. Repeated surveys were used to collect presence absence data at 70 sites between January 1997 and March 1999. Giant Barred Frogs were found at 23 sites (33%) comprising five isolated populations which may have contracted from a single remnant population. Habitat analysis revealed frogs showed a significant preference for sites with pool riffle sequences and the presence of undercuts and overhanging vegetation on the primary stream bank. Principal Components Analysis identified five habitat variables that accounted for 73% of the variability in our bi-variate data. We found the level of disturbance to riparian and instream habitats significantly influenced frog distribution, but this trend was not apparent when adjacent habitats outside the riparian zone were analysed. We propose that sedimentation of waterways may have facilitated this decline due to a reduction in the permanency of surface water flows resulting in reduced recruitment opportunities.