Indicative distribution
The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas.
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click here to see geographic restrictions).
The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Pommerhelix duralensis
Gazetted date:
09 Apr 2015
Profile last updated:
22 May 2024
Description
Pommerhelix duralensis (the Dural Land Snail), also commonly known as the Dural Woodland Snail, is a medium sized snail with a dark brown to black semi-translucent, subglobose (almost spherical shaped) shell. Adults grow approximately 10–23 mm in height and 14–23 mm in width. The Dural Land Snail superficially resembles the related species Meridolum corneovirens (Cumberland Plain Land Snail), with which the Dural land snail is parapatric (the species' ranges are immediately adjacent to each other but do not significantly overlap).
Unless identified otherwise, referenced material and statements in this description are drawn from the Commonwealth Listing Advice and references therein, and that should be used for further information and referencing purposes.
Distribution
The species is a shale-influenced-habitat specialist, which occurs in low densities along the western and northwest fringes of the Cumberland IBRA subregion on shale-sandstone transitional landscapes.
There is currently a degree of uncertainty about the distribution and identity of the snails in this and related species. Pommerhelix duralensis in the strict sense is found in an area of north-western Sydney between Rouse Hill - Cattai and Wiseman's Ferry, west from Berowra Creek. North of the Hawkesbury and Wiseman's Ferry there is an entity with morphologically similar shells but which have not had the DNA sequenced. The Blue Mountains records have been assigned to Pommerhelix 'Elizabeth', a genetically distinct species which has been sampled at Elizabeth Lookout in Glenbrook, and which extends along the eastern escarpment of the Blue Mountains. In the northern side of Sydney, between Parramatta and Port Jackson and east of Berowra Creek is identified as Meridolum middenense.
The species is definitely found within the Local Government Areas of The Hills Shire, Hawkesbury Shire and Hornsby Shire. Records from the Blue Mountains City, Penrith City and Parramatta City may represent this species. Occurrence in Wollondilly Shire is considered unlikely in light of current knowledge.
Habitat and ecology
- The species has a strong affinity for communities in the interface region between shale-derived and sandstone-derived soils, with forested habitats that have good native cover and woody debris.
- It favours sheltering under rocks or inside curled-up bark. It does not burrow nor climb. The species has also been observed resting in exposed areas, such as on exposed rock or leaf litter, however it will also shelter beneath leaves, rocks and light woody debris.
- Migration and dispersal is limited, with overnight straight-line distances of under 1 metre identified in the literature and studies. The species is active from approximately one hour after dusk until dawn and no confirmed diurnal activity is reported. It exhibits no roost-site behaviour.
- The species is known to aestivate, and secretes an epiphragm to protect against dessication.
- The main food sources are hyphae and fruiting bodies of native fungi. It is possible other detritus may be consumed.
- Reproduction rates are very low, with few eggs (about 32) per season. Mortality is 90% in the first year, and 99.8% within four-five years.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- Research Priorities identified in the Conservation Advice identify that there are many facets of the species population biology, distribution and ecology which remain unclear.
- The species has a limited habitat that is subject to clearing and development pressures.
- The species has low fecundity and high mortality.
- As the species favours combustible materials as hiding sites it will be lost in any burn.
- The populations are small and have low dispersal ability.
- Narrow gaps in groundcover can potentially lead to hostile barriers with the very low dispersal distance exhibited by the species. Examples include walking tracks, bike trails and roads.
- Frequent fire may lead to local loss of the species as it does not exhibit any fire-shelter behaviour.
- Where undertaken for the purposes of asset protection slashing and spraying may produce conditions hostile for the species.
- Predation by common blackbird (Turdus merula) and competition with introduced garden snail (Cornu aspersum)
- Burning of composting material from weed management works has been identified as a threat, with snails attracted to the piles before they are burnt.
- Underscrubbing of vegetation removes the woody debris that the species is dependent upon, and removal of vines and shrub cover (as underscrubbing or as a part of active land management for weed control) can lead to loss of the species.
- Insufficient understanding of distribution.
- Insufficient understanding of taxonomy.
Recovery strategies
A Saving Our Species conservation project is currently being developed for this species and will be available soon. For information on how you can contribute to this species' recovery, see the Activities to assist this species section below.
Activities to assist this species
- Implement an ongoing monitoring program to monitor the progress of recovery, including
the effectiveness of management actions and the need to adapt them if necessary.
- Engage with private landholders and land managers responsible for the land on which populations occur and encourage these key stakeholders to contribute to the implementation of conservation management actions.
- Engage local bushcare groups, such as the Ellerman Park Bushcare Group, to implement recovery actions for the species.
- Undertake appropriate maintenance of habitat in which the species may occur e.g. avoid underscrubbing in areas where the species is known to occur and maintain and/or recover coarse woody debris in habitat for this species.
- Limit use of pile burning (burning composted material) and/or manage pile burning in areas where the species is known to occur.
- Investigate formal conservation arrangements, management agreements and covenants on private land with known occurrences.
- Provide advice to developers, consultants and approval authorities about the existence of the species and its significance.
- Develop and implement a management plan for the control of weeds currently occurring in the region.
- Where necessary and appropriate, restrict access to important sites by installing gates, fencing and educational signs
- Research priorities are identified in the Conservation Advice prepared by the Commonwealth TSSC.
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