Strategic Management Prospects v4.0 Species Forecast Report created on 01 February, 2024
A Species Forecast Report is a summary of currently available information, the predicted 50-year outlook for the species, and potential pathways to recovery through species-specific and landscape-scale actions.
The report collates data from a range of sources including the Victorian Biodiversity Atlas, Strategic Management Prospects (SMP), Specific Needs Assessments, Threatened Species Action Statements, the Genetic Risk Index, and the IUCN Common Assessment Method.
Species Forecast Reports are intended to be used in conjunction with SMP and other spatial outputs in NatureKit, and Action Statements where relevant.
For more information on Species Forecast Reports, SMP and other biodiversity decision support tools, including user guides, visit Choosing actions for nature webpage on the DEECA website.
| Taxon ID | 1679 |
| Scientific name | Engaeus curvisuturus |
| Common name | Curve-tail Burrowing Crayfish |
| Group | Mussels, decapod crustacea |
| FFG status | Endangered |
| EPBC status |
The Curve-tail Burrowing Crayfish is a small terrestrial burrowing crayfish belonging to the southern hemisphere crayfish family Parastacidae. The species is separated from all other taxa in the genus by the combination of tuberculate rostral carinae and a distinctive curve on the transverse suture on the outer ramus of the uropod and has a maximum recorded carapace length of approximately 31 mm (occipital carapace length) (Horwitz 1990). It builds burrow systems, into the soil on the floodplain, females are berried in late spring to early summer (Horwitz 1990), and little else is known about its life history. Burrowing crayfish spend most of their time underground and freshly excavated soil at burrow entrances is the most obvious sign of their presence. Surface activity is suspected to be nocturnal (Richardson and Swain 1980) and is linked to dispersal and foraging (Shaw 1996) and breeding (Van Praagh and Hinkley 1999). Activity is commonly related to seasonal rainfall (Morey and Hollis 1997, Van Praagh and Hinkley 1999). The cryptic behaviour of burrowing crayfish means little is known about their life history and ecology, including the Curve-tail Burrowing Crayfish. Poor dispersal, slow maturation and confinement to discontinuous habitats are common to short-range endemics (Harvey 2002) such as the Curve-tail Burrowing Crayfish. The diet of burrowing crayfish is predominantly plant-based and consists of roots, decomposing leaves and occasionally, small invertebrates (Lake and Newcombe 1975, Suter and Richardson 1977, Growns and Richardson 1988). Males surface during late spring and early summer to search for mates and then enter the burrows of females (Van Praagh and Hinkley 1999). Females incubate egg clusters under the abdomen and the juveniles hatch in late summer (Van Praagh and Hinkley 1999).
The 35 known species of the genus Engaeus are endemic to south-east Australia, with most occurring in Victoria and Tasmania (Horwitz 1994). The distribution of the Curve-tail Burrowing Crayfish is poorly known. It has been recorded from only three sites, one in the upper Yarra catchment at Warburton, and two in the upper La Trobe River near Noojee. There is further Museum record from the Baw Baw area, but this may not be valid because the crays do not occur at that altitude.
The Curve-tail Burrowing Crayfish occurs predominantly in wet sclerophyll forest on private property or within State Forest, however the forest at the Warburton location was partially cleared. All locations are on the floodplain, though sometimes extending further away from the stream. The species constructs burrow systems in grey clay or silty soils, consisting of two to three openings which are each capped with a conical soil chimney and each descending to a depth of 60-70 cm where they converge to a wide, common descending tunnel, which can usually be blocked with silt. In addition, the burrow can also have one or more blind tunnels which ascend but do not open on the surface (Horwitz 1990).
This table contains information on the genetic health of Curve-tail Burrowing Crayfish, informed by recent work conducted by Monash University and cesar Pty Ltd (Kriesner et al. 2019; Kriesner and Weeks 2020). The project undertook genetic risk assessments of ~1,100 species of flora and fauna found in Victoria and generated a large database of available genetic and demographic data for these species. A framework was developed for combining these parameters into a Genetic Risk Index that classified species broadly into ‘Low’, ‘Moderate’, ‘High’, ‘Very High’ and ‘Uncertain’ risk categories. The Genetic Risk Index will continue to undergo refinement and validation to provide further insight into the genetic health of species in Victoria.
| Total Australian population size | Unknown |
| Australian distribution | Only occurs in Victoria |
| Dispersal capacity | Very low: ~320m |
| Reproductive mode | Sexual: species reproduces sexually via male and female gametes |
| Average generation time | One generation every 6 - 10 years |
| Victorian population trend since ~1975 | Population has moderately decreased |
| Inbreeding evidence | Not assessed |
| Genetic diversity | Not assessed |
| Genetic rescue potential | Uncertain |
| Genetic Risk Index | Very high |
The Habitat Distribution Model (HDM) layer shows the modelled distribution of habitat for Curve-tail Burrowing Crayfish in Victoria. Red shading indicates areas of habitat with relatively higher suitability, compared with yellow shaded areas. HDMs are developed by combining Victorian Biodiversity Atlas (VBA) occurrence records for the species with a range of environmental variables to predict where the most suitable habitat for the species is in Victoria. Species may not always occupy areas of suitable habitat. Threatening processes (prior or ongoing) and disturbance regimes (e.g. fire, timber harvesting) may stop species from occupying otherwise suitable habitat for periods of time. Management actions often focus on currently occupied areas, however management of unoccupied areas can also be important to allow populations to re-establish.
No Habitat Distrabution Model is currently available.
No Species Forecast data is available because Curve-tail Burrowing Crayfish is not yet included in our decision-support tools.
A Species Forecast is the estimated likelihood of a species being present in 50 years time. The data for Species Forecasts is drawn from DEECA’s decision support tools, Strategic Management Prospects and Specific Needs Assessments.
Many species benefit from the management of widespread threats, such as weeds and pests, and the benefit of these landscape-scale actions to ~4,200 species is modelled in Strategic Management Prospects. In addition to landscape-scale actions, some species also need actions that improve or protect habitat at certain sites, such as nest boxes or hollow logs, or actions to improve certain populations, such as gene mixing or translocation.
As part of a continuous improvement program for our decision-support tools, we are working to expand the scope of actions modelled in Strategic Management Prospects, and to build the dataset of species benefits from location-specific and population-specific actions.
We can use this data to consider how different actions may benefit a species and examine how different types of on-ground management may contribute to a species’ recovery in 50 years, to develop a Species Forecast.
No Species Forecast data is available because Curve-tail Burrowing Crayfish is not yet included in our decision-support tools.
The benefit data in SMP can be used to consider what the Curve-tail Burrowing Crayfish’s prospects are if the landscape scale management actions in SMP are implemented.
No Species Prospects figure is available becuase Curve-tail Burrowing Crayfish is not yet included in SMP.
For more information on the decision support tools, products and underlying data used in this report, and how the data is collected and developed into products, please visit the following links:
These links include information on how to provide data and feedback into these products.
The Species Forecast Reports will be updated periodically to reflect changes and improvements in the products and tools that inform them (e.g., following updates to SMP).
As the data contained in Species Forecast Reports is drawn from multi-species datasets, it is not currently possible to incorporate species-specific information or feedback directly.
For help or further information get in touch by visiting Choosing actions for nature webpage on the DEECA website.
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Primary Industries, East Melbourne. Retrieved from: https://www.environment.vic.gov.au/__data/assets/pdf_file/0011/33005/Eastern_She-oak_Skink_Cyclodomorphus_michaeli.pdf
* DSE (2013) Advisory List of Threatened Vertebrate Fauna in Victoria
2013. Department of Sustainability and Environment, Melbourne *
Kriesner, P., Weeks, A.R., Razeng, E. and Sunnucks, P. (2019). Assessing
genetic risks to Victorian flora and fauna. A report to the Department
of Environment, Land, Water and Planning, Victoria. cesar Pty Ltd and
Monash University. * Kriesner, P. and Weeks, A.R. (2020). Genetic risks
to Victorian biodiversity following the 2019/20 bush fire emergency. A
report to the Department of Environment, Land, Water and Planning,
Victoria. cesar Pty Ltd. * Robertson, P. and Coventry, A. J. (2019).
Reptiles of Victoria: A Guide to Identification and Ecology.
CSIRO Publishing. Clayton South. * SAC (1996). Flora and Fauna
Guarantee Scientific Advisory Committee: Final Recommendation on a
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