Consultation Document on Listing Eligibility and Conservation
Actions
Zoothera lunulata halmaturina (Bassian thrush (South Australian))
You are invited to provide your views about:
1)
the eligibility of Zoothera lunulata halmaturina (Bassian thrush (South Australian)) for
inclusion on the EPBC Act threatened species list; and
2)
the necessary conservation actions for the above species.
The views of experts, stakeholders and the general public are welcome. Responses can be
provided by any interested person.
Anyone may nominate a native species, ecological community or threatening process for listing
under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) or for a
transfer of an item already on the list to a new listing category. The Threatened Species
Scientific Committee (the Committee) undertakes the assessment of species to determine
eligibility for inclusion in the list of threatened species and provides its recommendation to the
Australian Government Minister for the Environment.
Draft information for your consideration of the eligibility of this species for listing starts at page 3
and information associated with potential conservation actions for this species starts at page 7.
To assist with the Committee’s assessment, the Committee has identified a series of specific
questions on which it seeks your guidance at page 8.
Responses to are to be provided in writing either by email to:
species.consultation@environment.gov.au
or by mail to:
The Director
Marine and Freshwater Species Conservation Section
Wildlife, Heritage and Marine Division
Department of the Environment
PO Box 787
Canberra ACT 2601
Responses are required to be submitted by 21 December 2014.
Contents of this information package
General background information about listing threatened species
Information about this consultation process
Draft information about the Bassian Thrush (South Australian) and its eligibility for listing
Conservation actions for the species
References cited
Collective list of questions – your views
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General background information about listing threatened species
The Australian Government helps protect species at risk of extinction by listing them as
threatened under Part 13 of the EPBC Act. Once listed under the EPBC Act, the species
becomes a Matter of National Environmental Significance (MNES) and must be protected from
significant impacts through the assessment and approval provisions of the EPBC Act. More
information about threatened species is available on the department’s website at:
http://www.environment.gov.au/biodiversity/threatened/index.html.
Public nominations to list threatened species under the EPBC Act are received annually by the
department. In order to determine if a species is eligible for listing as threatened under the
EPBC Act, the Threatened Species Scientific Committee (the Committee) undertakes a rigorous
scientific assessment of its status to determine if the species is eligible for listing against a set of
criteria. These criteria are available on the Department’s website at:
http://www.environment.gov.au/biodiversity/threatened/pubs/guidelines-species.pdf.
As part of the assessment process, the Committee consults with the public and stakeholders to
obtain specific details about the species, as well as advice on what conservation actions might
be appropriate. Information provided through the consultation process is considered by the
Committee in its assessment. The Committee provides its advice on the assessment (together
with comments received) to the Minister regarding the eligibility of the species for listing under a
particular category and what conservation actions might be appropriate. The Minister decides to
add, or not to add, the species to the list of threatened species under the EPBC Act. More
detailed information about the listing process is at:
http://www.environment.gov.au/biodiversity/threatened/nominations.html.
To promote the recovery of listed threatened species and ecological communities, conservation
advices and where required, recovery plans are made or adopted in accordance with Part 13 of
the EPBC Act. Conservation advices provide guidance at the time of listing on known threats
and priority recovery actions that can be undertaken at a local and regional level. Recovery
plans describe key threats and identify specific recovery actions that can be undertaken to
enable recovery activities to occur within a planned and logical national framework. Information
about recovery plans is available on the department’s website at:
http://www.environment.gov.au/biodiversity/threatened/recovery.html.
Information about this consultation process
Responses to this consultation can be provided electronically or in hard copy to the contact
addresses provided on Page 1. All responses received will be provided in full to the Committee
and then to the Australian Government Minister for the Environment.
In providing comments, please provide references to published data where possible. Should the
Committee use the information you provide in formulating its advice, the information will be
attributed to you and referenced as a ‘personal communication’ unless you provide references
or otherwise attribute this information (please specify if your organisation requires that this
information is attributed to your organisation instead of yourself). The final advice by the
Committee will be published on the department’s website following the listing decision by the
Minister.
Information provided through consultation may be subject to freedom of information legislation
and court processes. It is also important to note that under the EPBC Act, the deliberations and
recommendations of the Committee are confidential until the Minister has made a final decision
on the nomination, unless otherwise determined by the Minister.
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Zoothera lunulata halmaturina
Bassian thrush (South Australian)
Taxonomy
Generally accepted as Zoothera lunulata halmaturina (Bassian thrush (South Australian)), A.G.
Campbell, 1906. It is one of three subspecies of Bassian thrush, which is endemic to Australia.
Description
The Bassian thrush is olive-brown to golden brown above, and whitish below. It has mottled
plumage, with scalloped black crescent-shaped bars on its back, rump and head and brownblack scalloping on its underparts. It has a large straight bill with a hooked tip, and a narrow
white eye-ring. In flight a broad dark diagonal bar across the white underside of its wing can be
seen. It is very similar to the Russet-tailed thrush Zoothera heinei but is slightly larger with a
slightly longer tail.
Distribution
The Bassian thrush (South Australian) occurs on Kangaroo Island, the Mt Lofty Ranges as far
north as Tarunda, and in the southern Flinders Ranges from Wirrabara Forest reserve and
Telowie Gorge Conservation Park to Mt Remarkable National Park. Movements of other
subspecies suggest that the mainland and Kangaroo Island birds are likely to constitute a single
subpopulation. It is confined to remnant habitats on the mainland but is widespread on
Kangaroo Island.
Relevant Biology/Ecology
The subspecies mostly inhabits damp eucalypt forest or woodland. Densely forested areas and
gullies are favoured, usually with a thick canopy overhead, a thick understorey of small trees
and tall shrubs, and leaf-litter below. However, it has also been recorded breeding in exotic
Monterey Pine Pinus radiata plantations, and on Kangaroo Island also uses mature mallee
eucalypt woodland. In much of its range, suitable habitat is confined to creek lines or dune
swales. Damp habitats seem particularly important in summer (Garnett et al., 2011; Department
for Environment and Heritage, 2008).
It is mostly sedentary, although there is some evidence for seasonal movements especially
altitudinally. It is shy and secretive with a low flight, its mottled pattern also making it
inconspicuous in leaf-litter. Its diet consists of invertebrates, mainly earthworms and beetles,
and occasionally fruit. It mainly forages on the ground by probing leaf litter, but sometimes takes
fruit from low shrubs. It forages singly, or in small groups (possibly family groups) of two to five.
It is probably territorial (Higgins et al., 2006; Department for Environment and Heritage, 2008).
Breeding occurs from May to November, with 2-3 eggs laid once a year. A large, bowl-shaped
nest is usually placed in a fork of a tree, or occasionally on a thick horizontal branch. Nest sites
are hidden among dense foliage, and may be quite low or up to 15 m above the ground. The
young are altricial and nidicolous, and fed by both sexes (Higgins et al., 2006). The generation
time is estimated at 5.2 years (Garnett et al., 2011; Department for Environment and Heritage,
2008).
Threats
Threats differ between the mainland and Kangaroo Island. On the mainland, much of the best
habitat has been cleared for agriculture in the past. Currently, inappropriate fire regimes are the
major threat and can make habitat unsuitable for the subspecies. Other threats include the
damming of creeks, which results in the desiccation of the litter layer downstream; weed
invasion; grazing by cattle (Bos primigenius), rabbits (Oryctolagus cuniculus) and kangaroos
(Macropus sp.); competition with the introduced common blackbird (Turdus merula); and
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predation by foxes (Vulpes vulpes) and feral and uncontrolled domestic cats (Felis catus)
(Garnett et al., 2011).
On Kangaroo Island much of the decline in the last decade can be attributed to below-average
rainfall. It is unknown whether sites that dried out entirely will be re-occupied. Feral cats (Felis
catus) and inflated populations of the common brushtail possum (Trichosurus vulpecular) on the
island are also likely to take some adults and nestlings. Much habitat has been cleared but
gullies are often undisturbed and rarely burnt (Garnett et al., 2011).
How judged by the Committee in relation to the EPBC Act Criteria and Regulations
Criterion 1: Reduction in numbers (based on any of A1 – A4)
A1. An observed, estimated, inferred or suspected population very severe 90%, severe 70%
or substantial 50% size reduction over the last 10 years or three generations, whichever is
the longer, where the causes of the reduction are clearly reversible AND understood AND
ceased, based on (and specifying) any of the following:
(a) direct observation
(b) an index of abundance appropriate to the taxon
(c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
(d) actual or potential levels of exploitation
(e) the effects of introduced taxa, hybridization, pathogens, pollutants, competitors or
parasites.
A2. An observed, estimated, inferred or suspected population very severe 80%, severe 50%
or substantial 30% size reduction over the last 10 years or three generations, whichever is
the longer, where the reduction or its causes may not have ceased OR may not be
understood OR may not be reversible, based on (and specifying) any of (a) to (e) under A1.
A3. A population size reduction very severe 80%, severe 50% or substantial 30%, projected
or suspected to be met within the next 10 years or three generations (up to a maximum of
100 years), whichever is the longer, based on (and specifying) any of (b) to (e) under A1.
A4. An observed, estimated, inferred, projected or suspected population size reduction very
severe 80%, severe 50% or substantial 30% over any 10 year or three generation
period (up to a maximum of 100 years into the future), whichever is longer, where the time
period must include both the past and the future, and where the reduction or its causes may
not have ceased OR may not be understood OR may not be reversible, based on (and
specifying) any of (a) to (e) under A1.
Evidence
As at 2010, the population is estimated to be 4200 mature individuals and declining (Garnett
et al., 2011). There are probably about 4000 mature individuals on Kangaroo Island.
Anecdotal reports suggest a decline in calls heard on Kangaroo Island in the last decade, but
no other reports of decline. The subspecies is very rare in the Mt Lofty Ranges, where there
are probably < 100 birds and where it is thought to have declined by 30%. There may also be
about 100 birds in the southern Flinders Ranges, based on the area of suitable habitat
(Garnett et al., 2011).
The information presented above appears to demonstrate that the subspecies is not eligible
for listing under this criterion. However, the purpose of this consultation draft advice is to
elicit additional information to better understand the subspecies status. This conclusion
should therefore be considered tentative at this stage, as it may change as a result of
responses to this consultation process.
Criterion 2: Geographic distribution (based on either of B1 or B2)
B1. Extent of occurrence estimated to be very restricted <100 km2, restricted <5000 km2 or
limited <20 000 km2
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B2. Area of occupancy estimated to be very restricted <10 km2, restricted <500 km2 or
limited <2000 km2
AND
Geographic distribution is precarious for the survival of the species,
(based on at least two of a–c)
a. Severely fragmented or known to exist at a limited location.
b. Continuing decline, observed, inferred or projected, in any of the following:
(i)
extent of occurrence
(ii) area of occupancy
(iii) area, extent and/or quality of habitat
(iv) number of locations or subpopulations
(v) number of mature individuals.
c. Extreme fluctuations in any of the following:
(i)
extent of occurrence
(ii) area of occupancy
(iii) number of locations or subpopulations
(iv) number of mature individuals.
Evidence
As at 2010, the extent of occurrence is estimated to be 7900 km2 and the area of occupancy
estimated to be 1000 km2 (Garnett et al., 2011). The subspecies exists at more than 10
locations and is not considered limited. The population appears to be declining, but has not
exhibited extreme fluctuations (Garnett et al., 2011).
The information presented above appears to demonstrate that the subspecies is not eligible
for listing under this criterion, as although the extent of occurrence and area of occupancy are
limited, the population does not exist at a limited location, is not severely fragmented, and has
not exhibited extreme fluctuations. However, the purpose of this consultation draft advice is to
elicit additional information to better understand the subspecies status. This conclusion should
therefore be considered tentative at this stage, as it may change as a result of responses to
this consultation process.
Criterion 3: The estimated total number of mature individuals is very low <250, low <2500 or
limited <10 000; and either of (A) or (B) is true
(A)
evidence suggests that the number will continue to decline at a very high (25% in 3 years
or 1 generation (up to 100 years), whichever is longer), high (20% in 5 years or 2
generations (up to 100 years), whichever is longer) or substantial (10% in 10 years or 3
generations (up to 100), whichever is longer) rate; or
(B)
the number is likely to continue to decline and its geographic distribution is precarious for
its survival (based on at least two of a – c):
a. Severely fragmented or known to exist at a limited location.
b. Continuing decline, observed, inferred or projected, in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii) area, extent and/or quality of habitat
(iv) number of locations or subpopulations
(v) number of mature individuals.
c. Extreme fluctuations in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii) number of locations or subpopulations
(iv) number of mature individuals.
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Evidence
As at 2010, the total number of individuals is estimated at 4200 (Garnett et al., 2011) and there
is an inferred ongoing decline in numbers. However, there is no evidence to suggest that the
number will continue to decline at a substantial or higher rate, or that the geographic
distribution is precarious for survival (Garnett et al., 2011).
The information presented above appears to demonstrate that the subspecies is not eligible
for listing under this criterion, as although the total number of individuals is limited and
declining, there is no evidence to suggest that the number will continue to decline at a
substantial or higher rate or that its geographic distribution is precarious for its survival.
However, the purpose of this consultation draft advice is to elicit additional information to better
understand the subspecies status. This conclusion should therefore be considered tentative at
this stage, as it may change as a result of responses to this consultation process.
Criterion 4: Estimated total number of mature individuals:
(a) Extremely low <50
(b) Very low <250
(c) Low <1000
Evidence
As at 2010, the total number of individuals is estimated at 4200 (Garnett et al., 2011).
The data presented above appear to demonstrate that the subspecies is not eligible for
listing under this criterion, as the number of mature individuals is low. However, the purpose
of this consultation draft advice is to elicit additional information to better understand the
subspecies status. This conclusion should therefore be considered tentative at this stage, as it
may change as a result of responses to this consultation process.
Criterion 5: Probability of extinction in the wild based on quantitative analysis is at least:
(a) 50% in the immediate future, 10 years or three generations (whichever is longer); or
(b) 20% in the near future, 20 years or five generations (whichever is longer); or
(c) 10% in the medium-term future, within 100 years.
Evidence
Population viability analysis has not been undertaken for this species, therefore there is
insufficient information to assess against this criterion.
Recovery Plan
There should not be a recovery plan for Zoothera lunuata halmaturina as conservation advice
for the subspecies would provide sufficient direction to implement priority actions and mitigate
against the key threats.
Recovery and Impact avoidance guidance
Primary Conservation Objectives
1.
Populations retained in the Mt Lofty and southern Flinders Ranges.
Important populations
The single subpopulation is of high conservation value.
Important habitat for the survival of the subspecies
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Damp eucalypt forest or woodland, and mature mallee eucalypt woodland on Kangaroo Island,
are important habitat for this subspecies.
Information required, research and monitoring priorities
1. Trends in numbers at Mt Lofty Ranges, southern Flinders Ranges, and Kangaroo Island
2. Monitor numbers on the mainland
3. Survey Kangaroo Island to determine density and abundance
Management actions required
1. Maintain the subspecies’ habitat values in all mainland reserves.
2. Protect remnant habitats from wild fire.
References cited in the advice
Department for Environment and Heritage (2008). Adelaide and Mount Lofty Ranges South
Australia Threatened Species Profile Zoothera lunulata halmaturina. Retrieved 8 July
2014 from www.environment.sa.gov.au/.
Department for Environment and Heritage (2001). Biodiversity plan for Kangaroo Island, South
Australia 2001. Retrieved 28 July 2014 from http://nrmonline.nrm.gov.au/catalog/mql:16
Department of Environment, Water and Natural Resources (2013). Biodiversity in the Flinders
Ranges National Park – Discussion Paper. Retrieved 28 July 2014 from
http://www.environment.sa.gov.au/haveyoursay/flindersranges-mgtplan.
Garnett ST, Szabo JK and Dutson G (2011). The Action Plan for Australian Birds 2010. Birds
Australia, CSIRO Publishing, Melbourne.
Higgins PJ, Peter JM, Cowling SJ, eds. (2006) Handbook of Australian, New Zealand and
Antarctic Birds. Volume 7 Boatbill to Starlings, Part B Dunnock to Starlings. Oxford
University Press, Melbourne.
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Collective list of questions – your views
1. Do you agree with the current taxonomic position of the Australian Faunal Directory and
Birdlife Australia for this species (as identified in the draft conservation advice)
2. Can you provide any additional references, information or estimates on longevity, age of
maturity, average life span and generation length?
3. Has the survey effort for this species been adequate to determine its national distribution
and adult population size?
4. Do you accept the estimate provided in the nomination for the current population size of the
species?
5. For any population with which you are familiar, do you agree with the population estimate
provided? If not, are you able to provide a plausible estimate based on your own
knowledge? If so, please provide in the form:
Lower bound (estimated minimum):
Upper bound (estimated maximum):
Best Estimate:
Estimated level of Confidence: %
6. Can you provide any additional data, not contained in the current nomination, on declines in
population numbers over the past or next 10 years or 3 generations, whichever is the
longer?
7. Is the distribution as described in the nomination valid? Can you provide an estimate of the
current geographic distribution (extent of occurrence or area of occupancy in km2) of this
species?
8. Has this geographic distribution declined and if so by how much and over what period of
time?
9. Do you agree that the species is eligible for inclusion on the threatened species list, in the
category listed in the nomination?
10. Do you agree that the threats listed are correct and that their effects on the species are
significant?
11. To what degree are the identified threats likely to impact on the species in the future?
12. Can you provide additional or alternative information on threats, past, current or potential
that may adversely affect this species at any stage of its life cycle?
13. In seeking to facilitate the recovery of this species, can you provide management advice for
the following:



What individuals or organisations are currently, or need to be, involved in planning to
abate threats and any other relevant planning issues?
What threats are impacting on different populations, how variable are the threats and
what is the relative importance of the different populations?
What recovery actions are currently in place, and can you suggest other actions that
would help recover the species? Please provide evidence and background information.
14. Can you provide additional data or information relevant to this assessment?
15. Can you advise as to whether this species is of cultural significance to Indigenous
Australians?
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