Referral guideline for the vulnerable water mouse Xeromys myoides

About the guidelines

The primary intent of this guideline is to help proponents proposing actions within the distribution of the water mouse to avoid significant impacts. This guideline has been developed in consultation with species experts, ecological consultants and state government representatives and the general public. It was first released as a draft in 2009 and now finalised it includes improved structure and clarity, including an upfront summary, new research findings and a reference list and updated survey guidance and distribution mapping. It is recommended that proponents consider this guideline when proposing actions within the modelled distribution of the water mouse. Generally speaking, conformance with this guideline will ensure that proponents are best placed for a streamlined assessment of their action, and for achieving the assessment decision and outcomes they are seeking if they choose to refer their action. Conformance with the principles within this guideline will also help minimise offset obligations under the EPBC Act if assessment is required.

Guideline summary

The water mouse is listed as Vulnerable on the threatened species list under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). It is a nocturnal rodent that inhabits mangrove communities and associated saltmarsh, sedgelands and clay pans, as well as coastal heathlands and freshwater wetlands. Where these habitats have intact hydrology, active nest sites and prey resources, they are habitat critical to the survival of the water mouse. This habitat is threatened by urban and industrial development and by unsympathetic agricultural practices where it continues to be cleared or degraded by changes in hydrology. Of parallel concern is the growing evidence of foxes predating on water mice and habitat degradation by feral pigs. Cats are also considered likely predators. Modelling under global sea level rise scenarios has predicted water mouse extirpation in c.50 years assuming ongoing predation and habitat loss from urbanisation.

The national recovery objective for the water mouse is to improve its conservation status and habitat through habitat protection, reduction of threats, research and increasing public participation in recovery activities. Actions interfering with water mouse recovery are highly likely to have a significant impact and will require referral to the Department prior to any commencement of the action.

This guideline contains ecological information important for decision-making, advice about undertaking surveys and mitigation standards.

The following points summarise this guideline:

• The water mouse is one single nationally important population
• Fundamental to avoiding significant impacts on the nationally important water mouse population are:
  • protecting habitat critical to the survival of the water mouse
  • avoiding any adverse effects to habitat critical to the survival of the water mouse and
  • retaining dispersal opportunities for the water mouse
• Proponents proposing actions in suitable water mouse habitat are encouraged to undertake targeted surveys for the water mouse, applying the primary survey techniques outlined in this guideline
• Proponents proposing actions in habitat that is already known to be critical to the survival of the water mouse should adopt less invasive survey approaches and instead focus on mitigation measures and field studies verifying habitat, hydrology and connectivity to improve effectiveness of the mitigation measures
• Referral to the Department is likely to be required when habitat critical to the survival of the water mouse is adversely affected
• Adopting the standards in section 6 of this guideline will assist in avoiding adverse effects on habitat critical to the survival of the water mouse.
• Referral to the Department is unlikely to be required if the standards in section 6 are met.

Further information

• EPBC Act policy statements