Assessment of Seasonal Habitat Characteristics as Predictors of Habitat Suitability for the Threatened Ornamental Snake

The ACARP funded ornamental snake Research Program was undertaken to provide a greater understanding of the habitat usage and ecological requirements of the threatened ornamental snake (Denisonia maculata) within the Bowen Basin mining province.  The ornamental snake was recognised as "signature species" of the Brigalow Belt Bioregion and was listed as vulnerable under the provisions of the Nature Conservation Act 1992 (NC Act) and Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).

The primary aim of the research program was to:

· Collect quantitative data to support the hypothesis that brigalow-gilgai formations support a unique suite of characteristics and microhabitats required to support the ornamental snake as opposed to adjacent habitats within the distribution range of the species; and

· Utilise the improved understanding of this species' habitat and ecological requirements to improve conservation outcomes and long-term management practices within the Bowen Basin mining province and the known distribution range for the species.

The benefits of the proposed research are anticipated to:

· Support a more informed approach by the mining industry in compliance with legislative requirements and responsibilities;

· Improve conservation outcomes and long-term management practices on mine-affected lands within the Bowen Basin mining province; and

· Enhance management decisions in regard to impact assessment of mining proposals, the allocation of non-mined lands as part of end of mine land use plans and the provision of suitable off-site lands as part of a "green offsets" strategy.

Detailed field investigations examining soil, vegetation and fauna habitat variables were undertaken and detailed radio tracking studies were completed to study the biology and ecology of this species and its use of habitats.

Survey sites were selected on the basis that they are known to or are considered likely to support ornamental snake populations.  Seven brigalow-gilgai locations (mound and depression profiles) and six representative eucalypt habitat sites (where the presence of snake populations had not been previously recorded despite extensive survey effort under suitable conditions) were selected.  

Results from the study overall indicated the following:

· Habitat management for ornamental snakes should be focussed on brigalow/gilgai formations, regardless of the presence/absence of actual brigalow shrubs/trees, within the areas identified as part of the predictive modelling assessment;

· The ornamental snake may potentially be susceptible to the impacts of direct cattle access to gilgais during wet periods.  Cattle grazing management plans need to be established for areas suspected of supporting ornamental snakes;

· As snakes appear to reside at shallow depths within the soil profile and the nature of the soils are such that it requires mechanical shrinking and swelling processes to form the cracks within which the snakes reside, any process which disturbs the land form, i.e. clearing, ploughing, erosion, development of access tracks/drill lines etc., has the potential to significantly impact the ornamental snake;

The ornamental snake was susceptible to cane toad toxin and death was highly likely if a cane toad was bitten/consumed.  There was no correlation between the presence of cane toads (and the relative abundance of same) and the relative abundance of ornamental snakes in a particular area of habitat.