Prasophyllum milfordense (Milford Leek-orchid)

Advice to the Minister for the Environment and Heritage from the Threatened Species Scientific Committee (TSSC) on Amendments to the list of Threatened Species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)

1. Scientific name, common name (where appropriate), major taxon group

Prasophyllum milfordense (Milford Leek-orchid)

2. National Context

The species is endemic to Tasmania. The species is currently listed as endangered under the EPBC Act and the Tasmanian Threatened Species Protection Act 1995.

3. How judged by TSSC in relation to the EPBC Act criteria.

TSSC judges the species to be eligible for listing as critically endangered under the EPBC Act. The justification against the criteria is as follows:

Criterion 1 - Decline in numbers

There is no quantitative data available against this criterion.

Criterion 2 - Geographic distribution

The species is known from a single population. The area of occupancy is 5ha and extent of occurrence is 0.25km2. Continuing decline in the area, extent and quality of habitat, and the number of mature individuals is projected due to ongoing habitat clearance.

Therefore, the species is eligible for listing as critically endangered under this criterion.

Criterion 3 - Population size and decline in numbers or distribution

A total of 200 mature individuals from a single population have been recorded in dedicated field surveys with the upper limit estimated to be less than 250. Continuing decline in the area, extent and quality of habitat, and the number of mature individuals is projected due to ongoing habitat clearance.

Therefore, the species is eligible for listing as critically endangered under this criterion.

Criterion 4 - Population size

The number of mature individuals is very low with the population recorded to number 200 and estimated to be less than 250.

Therefore, the species is eligible for listing as endangered under this criterion.

Criterion 5 - Probability of extinction in the wild

There is no quantitative data available against this criterion.

4. Conclusion

The number of mature individuals (200) that has been recorded in dedicated field surverys is very low and all known specimens exist in a single population. The geographic distribution of the species is very restricted and precarious for the survival of the species, it having an area of occupancy of 5ha and there being an ongoing threat of habitat clearance. The species is eligible for listing as critically endangered under criteria 2 and 3.

5. Recommendation

TSSC recommends that the list referred to in section 178 of the EPBC Act be amended by
transferring from the endangered category to the critically endangered category:

Prasophyllum milfordense (Milford Leek-orchid)