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 Endangered
Listing and Conservation Advices Commonwealth Listing Advice on Sinumelon bednalli (Threatened Species Scientific Committee, 2006ab) [Listing Advice].
 
Commonwealth Conservation Advice on Sinumelon bednalli (Threatened Species Scientific Committee, 2008ya) [Conservation Advice].
 
Recovery Plan Decision Recovery Plan not required, included on the Not Commenced List (1/11/2009).
 
Adopted/Made Recovery Plans
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 (43) (14/08/2006) (Commonwealth of Australia, 2006g) [Legislative Instrument].
 
State Government
    Documents and Websites
NT:Bednall's Land Snail, Sinumelon bednalli. Threatened Species of the Northern Territory. (Ward, S., Kessner, V., Braby, M., Woinarski, J., 2006) [Information Sheet].
Non-statutory Listing Status
IUCN: Listed as Vulnerable (Global Status: IUCN Red List of Threatened Species: 2013.1 list)
Scientific name Sinumelon bednalli [79113]
Family Camaenidae:Pulmonata:Gastropoda:Mollusca:Animalia
Species author (Ponsonby, 1904)
Infraspecies author  
Reference Ponsonby, J.H. (1904). Description of a helicoid land-shell (Xanthomelon bednalli) from central Australia. Proc. Malac. Soc. Lond. 6: 182 [182] [Sept. 1904; text figs. 1-2].
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: Sinumelon bednalli

Common name: Bednall's Land Snail

Bednall's Land Snail is a large greenish-yellow camaenid land snail, approximately 20–26 mm in diameter, with a weak reddish spiral colour band. The apex and spire are usually strongly and evenly elevated and there are four to five whorls (Solem 1993 in Ward et al. 2006).

Bednall's Land Snail has been collected at only seven sites in the Macdonnell Ranges of central Australia, from Hugh Gorge 60 km west of Alice Springs to Trephina Gorge, 50 km to the east, and from a location 25 km south of Alice Springs (V. Kessner, pers. comm. in Ward et al. 2006).

It has an extent of occurrence of about 2100 km² (DIPE 2006).

Each of the known locations for Bednall's Land Snail has an estimated area of occupancy of less than 2 km². The total known area of occupancy is thus estimated to be less than 15 km² (DIPE 2006).

The distribution of Bednall's Land Snail is considered to be fragmented. All known locations are widely scattered and the species has almost disappeared from one of its known sites (DIPE 2006).

Seven field trips to central Australia were made to collect land snails, particularly land snails belonging to the camaenids (Solem 1993). Bednall's Land Snail was collected near Alice Springs in 1974 during an initial survey. It was then collected at a second location in 1977. Subsequent surveys aimed to determine the limits of genera distribution (surveying fringe hill systems until no more snails could be located). Unfortunately, sites where no snails were recorded were not listed (Solem 1993).

Surveys for snails in central Australia have been conducted by walking through gorges and raking through the litter of fig trees. Most gorges surveyed have been those easily accessed from roads though a small number of gorges have been accessed by helicopter (V. Kessner undated, pers. comm.). There have been several collecting trips to central Australia undertaken by the Australian Museum and the Chicago Field Museum of Natural History. Many inaccessible areas remain to be surveyed. The species is intrinsically rare and difficult to survey and is likely to occur at other locations in the area (V. Kessner undated, pers. comm.)

As with several other camaenid snail species, Bednall's Land Snail has a very limited range though is likely to be very abundant locally. Further sampling of small patches of figs in central Australia is likely to reveal more undescribed species rather than new populations of Bednall's Land Snail (J. Stanisic undated, pers. comm.).

Surveys for snails are highly dependent on the local weather conditions experienced during the survey. For example, after three days of rain during one survey, many species of snail were collected but despite the favourable conditions, no Bednall's Land Snail were collected (A. Solem undated, pers. comm.).

Bednall's Land Snail is described as being uncommon and having extremely patchy distribution (V. Kessner undated, pers. comm.)

The species may have almost disappeared from one of its known localities near Alice Springs (A. Solem undated, pers. comm.). Trends at other locations are unknown.

Camaenid snails typically mature in their second wet season and are reproductively active by their third wet season. Some may live up to 10–15 years. The generation length of Bednall's Land Snail is likely to be four to five years (J. Stanisic undated, pers. comm.).

The population of Bednall's Land Snail near Alice Springs partially occurs within the Alice Springs Telegraph Station Historical Reserve. It also occurs within the Owen Springs Reserve, Trephina Gorge Nature Park and the West MacDonnell National Park (Ward et al. 2006).

Very little is known about the habitat preferences of Bednall's Land Snail. Adults of this species aestivate (lie dormant) in loose litter under fig trees (V. Kessner, pers. comm. in Ward et al. 2006).

There is no specific information available on the age at sexual maturity or life expectancy of Bednall's Land Snail. The generation length is estimated to be four to five years (J. Stanisic undated, pers. comm.). The generation length is the average age of parents of the current cohort and reflects the turnover rate of breeding individuals in a population. In species that breed more than once the generation length is greater than the age at first breeding and less than the age of the oldest breeding individual.

Bednall's Land Snail is only found at two locations, 41 km apart. It has almost disappeared from one location (near Alice Springs) and is under pressure from urban expansion, fire and weeds such as buffel grass (Cenchrus ciliaris) (DIPE 2006; V. Kessner, pers. comm. in Ward et al. 2006).

Given its close association with fig trees and associated leaf-litter, Bednall's Land Snail would benefit from the protection of figs through fire management and the control of buffel grass (DIPE 2006).

The following research and management priorities have been identified (Ward et al. 2006):

  • conduct further surveys to determine whether populations occur elsewhere;
  • identify specific threats to all of the known populations;
  • protect the habitat from urban expansion; and
  • better safeguard the known populations through encouragement of appropriate fire regimes, and prevention of weed invasion.

A monitoring program should be established for representative populations.

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
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Restricted geographical distribution (area of occupancy and extent of occurrence) Commonwealth Listing Advice on Sinumelon bednalli (Threatened Species Scientific Committee, 2006ab) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation Cenchrus ciliaris (Buffel-grass, Black Buffel-grass) Commonwealth Listing Advice on Sinumelon bednalli (Threatened Species Scientific Committee, 2006ab) [Listing Advice].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Commonwealth Listing Advice on Sinumelon bednalli (Threatened Species Scientific Committee, 2006ab) [Listing Advice].
Residential and Commercial Development:Housing and Urban Areas:Habitat loss, modification and fragmentation due to urban development Commonwealth Listing Advice on Sinumelon bednalli (Threatened Species Scientific Committee, 2006ab) [Listing Advice].

Department of Infrastructure, Planning and Environment (DIPE) (2006). Biodiversity Conservation Section, Northern Territory Government.

Kessner, V. (undated). Personal communication.

Solem, A. (1993). Camaenid land snails from Western and central Australia (Mollusca: Pulmonata: Camaenidae) VI Taxa from the Red Centre. Records of the Western Australian Museum Supplement No 43. Page(s) 983-1459.

Solem, A. (undated). Personal communication.

Stanisic, J. (undated). Personal communication.

Ward, S., Kessner, V., Braby, M., Woinarski, J. (2006). Bednall's Land Snail, Sinumelon bednalli. Threatened Species of the Northern Territory. [Online]. Northern Territory Department of Natural Resources, Environment and the Arts. Available from: http://www.nt.gov.au/nreta/wildlife/animals/threatened/pdf/inverts/Sinumelon_bednalli_CR.pdf.

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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). Sinumelon bednalli in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Tue, 2 Sep 2014 20:04:33 +1000.