Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Critically Endangered
Listing and Conservation Advices Commonwealth Conservation Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee, 2008aei) [Conservation Advice].
 
Commonwealth Listing Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee (TSSC), 2008aen) [Listing Advice].
 
Recovery Plan Decision Recovery Plan not required, the Lord Howe Island Biodiversity Management Plan has been adopted as a recovery plan under the EPBC Act and Lord Howe Island is a current World Heritage Area. Therefore the approved conservation advice for this species provides sufficient direction to implement priority actions and manage key threats (19/12/2008).
 
Adopted/Made Recovery Plans
Other EPBC Act Plans Threat abatement plan to reduce the impacts of exotic rodents on biodiversity on Australian offshore islands of less than 100 000 hectares 2009 (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2009u) [Threat Abatement Plan].
 
Federal Register of
    Legislative Instruments
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (64) (19/12/2008) (Commonwealth of Australia, 2008f) [Legislative Instrument].
 
Scientific name Pseudocharopa whiteleggei [81249]
Family Charopidae:Pulmonata:Gastropoda:Mollusca:Animalia
Species author Brazier, 1889
Infraspecies author  
Reference  
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images

Scientific Name: Pseudocharopa whiteleggei

Common Name: Whitelegge's Land Snail

This species is conventionally accepted as Pseudocharopa whiteleggei.

Whitelegge's Land Snail has a loosely coiled shell of few whorls which is 13 to 16 mm in diameter and 6 mm in height. The shell is relatively flat with a depressed spire and a unicolour appearance of dark red-brown (Iredale 1944).

The geographic distribution of Whitelegge's Land Snail previously included both Mount Gower and Mount Lidgbird, on Lord Howe Island. However recent survey work suggests the species' geographic distribution has declined so that it is now confined only to Mount Gower. The area of the summit of Mount Gower is estimated to be 27 ha, and represents a very restricted geographic distribution, given that the species is located on a single mountain on one small island (TSSC 2008aen).

A total of 34 specimens, including dead and living specimens, of Whitelegge's Land Snail have been collected from Lord Howe Island and lodged at the Australian Museum. This is a very small percentage of the total number of snail specimens in the Museum's collection from Lord Howe Island (0.15%). This suggests that Whitelegge's Land Snail may persist at a low abundance, relative to the abundance of other species of snail on the island. There is evidence to suggest a decline in abundance over time of Whitelegge's Land Snail (TSSC 2008aen).

Collection records indicate that the number of specimens collected has declined from 32 prior to 1920 to just two since 1971, with no specimens having been recorded between 1920 and 1971. Given that there has been an increase in overall snail collecting activity from 1925 onwards, predominantly dead specimens, the decline in the numbers of Whitelegge's Land Snail collected suggests that the species has undergone a decline in numbers. The most recent survey, in 2002, found only one specimen (living) on Mount Gower (TSSC 2008aen).

There are insufficient quantitative data available to judge that the species has undergone a reduction in numbers. However, as evidenced by the decline in specimens collected since 1920, Whitelegge's Land Snail is suspected to have undergone a reduction in numbers (TSSC 2008aen).

Although the generation length of Whitelegge's Land Snail is not known, Placostylus species from New Zealand reach maturity at three to five years and may live for 20 years or more (Parrish et al. 1995). Despite differences in size, the long generation length of Placostylus species and the similarity in habitats suggest that Whitelegge's Land Snail is also likely to be long-lived (TSSC 2008aen).

As the species is severely restricted and it has a limited dispersal capability, all populations of Whitelegge's Land Snail are important.

The Lord Howe Island Group is listed as a World Heritage Area (DEWHA undated). Whilst the Whitelegge's Land Snail is found within the reserved area in the southern half of the island, their very limited numbers and very restricted distributions make them highly vulnerable to extinction from threats or catostrophic events.

Little is known about the biology and ecology of this species. It has been recorded living under and inside logs and in moss (TSSC 2008aen).

Habitat degradation and modification

The Lord Howe Island Group was listed as a World Heritage Area in 1982 (DEWHA undated). Much of the island is covered in rainforest, with about 10% of land area cleared for urban development and agriculture, with a further 20% disturbed by introduced animals and exotic weeds (WWF 2001). The southern half of the island is reserved, and whilst this is where Whitelegge's Land Snail occurs, the restricted distribution of the species makes it highly vulnerable to extinction from on-going threats or catastrophic events.

Feral animals

The key threat to Whitelegge's Land Snail is predation by introduced rats. The Ship Rat (Rattus rattus),also known as the Black Rat, arrived on the island from a wrecked ship in 1918 and has since become well established on Lord Howe Island (NSW Scientific Committee 2000a). Ship Rats prey on snail species, and are thought to have been responsible for the significant decline in, and possible extinction of, a subspecies of Placostylus (Placostylus bivaricosus etheridgei) on Lord Howe Island (NSW NPWS 2001a; Ponder 1997b). Ship Rats are likely to prey on Whitelegge's Land Snail, though the program of baiting of rats currently undertaken on the island is likely to benefit the species if it persists on Mount Gower. However, this baiting program is unlikely to completely mitigate the effect of predation by Ship Rats on the Whitelegge's Land Snail as it is not undertaken across the species' entire range. Two large species of land snails, Epiglypta howinsulae and Placostylus bivaricosus etheridgei that were restricted to the southern mountains are apparently now extinct, almost certainly due to the activity of the Ship Rat (Ponder 1997b). The NSW Scientific Committee has declared predation by the Ship Rat on Lord Howe Island as a key threatening process (NSW Scientific Committee 2000a).

Pigs and goats that were introduced to Lord Howe Island by settlers for food later became feral pests (DEWHA undated). Both species caused damage to the surface litter and ground cover in areas where Whitelegge's Land Snail occurred, most notably near the trail to Mt Gower (Smithers et al. 1977). It is likely that this resulted in a decline in the species' numbers. However, these pest species are no longer likely to be directly impacting on the species, as pigs have now been eliminated from the island, and goats virtually eliminated (DEWHA undated).

Another potential threat to Whitelegge's Land Snail is predation and habitat disturbance by invasive ant species. The African Big Headed Ant (Pheidole megacephala) is present in the northern settlement area of Lord Howe Island and may affect the Whitelegge's Land Snail should it invade the Mount Gower area.

Further potential threats include introduced birds, particularly the Song Thrush (Turdus philomelas) and Common Blackbird (Turdus merula), which prey upon Placostylus species on Lord Howe Island and may prey on the Whitelegge's Land Snail. Although the habitat of the Whitelegge's Land Snail is protected in the reserved southern area of Lord Howe Island, the species is potentially threatened by trampling, disturbance and collection by visitors, habitat damage by weeds and wildfire.

Global warming

The cloud forest on top of Mount Gower is threatened by global warming (UNESCO 2002).

A Conservation Advice for Whitelegge's Land Snail identifies research priorities and actions that will assist in the recovery of the species. These include:

  • Research into the biology and ecology of the species
  • Investigate the impacts of rodent eradication methods on non-target species and other environmental impacts.
  • Implement the draft Biodiversity Management Plan of Lord Howe Island.
  • Raise awareness of the species within the local community.
  • Investigate and if appropriate, undertake a captive breeding program that could potentially lead to the establishment of additional populations of the species in the wild.

The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

Threat Class Threatening Species References
Biological Resource Use:Hunting and Collecting Terrestrial Animals:Illegal hunting/harvesting and collection Commonwealth Listing Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee (TSSC), 2008aen) [Listing Advice].
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Restricted geographical distribution (area of occupancy and extent of occurrence) Commonwealth Conservation Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee, 2008aei) [Conservation Advice].
Human Intrusions and Disturbance:Recreational Activities:Soil disturbance and/or trampling due to bushwalking Commonwealth Listing Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee (TSSC), 2008aen) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Rattus rattus (Black Rat, Ship Rat) Commonwealth Listing Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee (TSSC), 2008aen) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation by birds Commonwealth Conservation Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee, 2008aei) [Conservation Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation by rats Commonwealth Conservation Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee, 2008aei) [Conservation Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition, predation and/or habitat degradation Turdus merula (Common Blackbird, Eurasian Blackbird) Commonwealth Listing Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee (TSSC), 2008aen) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition, predation and/or habitat degradation Turdus philomelos (Song Thrush) Commonwealth Listing Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee (TSSC), 2008aen) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition, predation and/or habitat degradation Pheidole megacephala (Big-headed Ant, Coastal Brown Ant, Brown House Ant, Lion Ant) Commonwealth Listing Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee (TSSC), 2008aen) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Grazing, tramping, competition and/or habitat degradation Capra hircus (Goat) Commonwealth Listing Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee (TSSC), 2008aen) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Grazing, tramping, competition and/or habitat degradation Sus scrofa (Pig) Commonwealth Listing Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee (TSSC), 2008aen) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Negative impacts caused by insects Commonwealth Conservation Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee, 2008aei) [Conservation Advice].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Commonwealth Listing Advice on Pseudocharopa whiteleggei (Threatened Species Scientific Committee (TSSC), 2008aen) [Listing Advice].

Department of Environment, Water, Heritage and the Arts (DEWHA) (undated). Heritage Places: Lord Howe Island Group. [Online]. Available from: http://www.environment.gov.au/cgi-bin/ahdb/search.pl?mode=place_detailplace_id=105085.

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2009u). Threat abatement plan to reduce the impacts of exotic rodents on biodiversity on Australian offshore islands of less than 100 000 hectares 2009. [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/tap/exotic-rodents.html.

Iredale, T. (1944). The Land Mollusca of Lord Howe Island. Australian Zoologist. 10(3):299-330.

New South Wales National Parks and Wildlife Service (NSW NPWS) (2001a). Lord Howe Placostylus Placostylus bivaricosus (Gaskoin 1855) Recovery Plan. Hurstville, New South Wales: New South Wales National Parks and Wildlife Service.

NSW Department of Environment and Climate Change (NSW DECC) (2007f). Lord Howe Island Biodiversity Management Plan. [Online]. Sydney, NSW: NSW Department of Environment and Climate Change. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/lord-howe/index.html.

NSW Scientific Committee (2000a). Predation by the ship rat on Lord Howe Island - key threatening process declaration (final determination). Predation by the ship rat on Lord Howe Island - key threatening process declaration. [Online]. Available from: http://www.threatenedspecies.environment.nsw.gov.au/tsprofile/profile.aspx?id=20019.

Parrish, R., G. Sherley & M. Aviss (1995). Giant Land Snail Recovery Plan Placostylus spp., Paraphanta sp. Threatened Species Recovery Plan Series No. 13. New Zealand: Threatened Species Unit, Department of Conservation.

Ponder, W.F. (1997b). Conservation status, threats and habitat requirements of Australian terrestrial and freshwater mollusca. Memoirs of the Museum of Victoria. 56:421-430.

Smithers, C., D. McAlpine, P. Colman & M. Gray (1977). Lord Howe Island. Special Issue of Australian Natural History. Page(s) 23-26. Sydney: The Australian Museum.

Threatened Species Scientific Committee (2008aei). Commonwealth Conservation Advice on Pseudocharopa whiteleggei. [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/81249-conservation-advice.pdf.

Threatened Species Scientific Committee (TSSC) (2008aen). Commonwealth Listing Advice on Pseudocharopa whiteleggei. [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/81249-listing-advice.pdf.

UNESCO (2002). Australian National Periodic Report. Section II. Report on the state of conservation of Lord Howe Island. UNESCO Periodic Report 2002 (section II Lord Howe Id). 1-28. Page(s) 1-28.

World Wildlife Fund (WWF) (2001). Lord Howe Island subtropical forests (AA0109). Wildworld WWF Full Report. [Online]. World Wildlife Fund. Available from: http://www.worldwildlife.org/wildworld/profiles/terrestrial/aa/aa0109_full.html.

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Pseudocharopa whiteleggei in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Sun, 20 Apr 2014 05:51:04 +1000.