Consultation on Species Listing Eligibility and ...€¦ · Web viewTaxonomy. Conventionally accepted as Moggridgea rainbowi Pulleine (1919). Description . The Kangaroo Island (KI)

Consultation on Species Listing Eligibility and Conservation Actions

Moggridgea rainbowi (Kangaroo Island Micro-Trapdoor Spider)

You are invited to provide your views and supporting reasons related to:

1) the eligibility of Moggridgea rainbowi (Kangaroo Island Micro-Trapdoor Spider) for inclusion on the EPBC Act threatened species list in the Endangered category; and

2) the necessary conservation actions for the above species.

The purpose of this consultation document is to elicit additional information to better understand the status of the species and help inform on conservation actions and further planning. As such, the below draft assessment should be considered to be tentative as it may change following responses to this consultation process.

Evidence provided by 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.

Responses are to be provided in writing by email to: [email protected]. Please include species scientific name in Subject field.

or by mail to:

The DirectorBushfire Affected Species Assessments SectionDepartment of Agriculture, Water and the EnvironmentJohn Gorton Building, King Edward TerraceGPO Box 858Canberra ACT 2601

Responses are required to be submitted by 24 June 2021.

Contents of this information package PageGeneral background information about listing threatened species 2Information about this consultation process 3Consultation questions specific to the assessment 3Information about the species and its eligibility for listing 11Conservation actions for the species 23Listing assessment 32References cited 26

Department of Agriculture, Water and the Environment

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Moggridgea rainbowi (Kangaroo Island Micro-trapdoor Spider) Consultation document

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/system/files/pages/d72dfd1a-f0d8-4699-8d43-5d95bbb02428/files/tssc-guidelines-assessing-species-2018.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.

Privacy notice

The Department will collect, use, store and disclose the personal information you provide in a manner consistent with the Department’s obligations under the Privacy Act 1988 (Cth) and the Department’s Privacy Policy.

Any personal information that you provide within, or in addition to, your comments in the threatened species assessment process may be used by the Department for the purposes of its functions relating to threatened species assessments, including contacting you if we have any questions about your comments in the future.

Further, the Commonwealth, State and Territory governments have agreed to share threatened species assessment documentation (including comments) to ensure that all States and Territories have access to the same documentation when making a decision on the status of a potentially threatened species. This is also known as the ‘Common Assessment Method’ (CAM). As a result, any personal information that you have provided in connection with your comments may be shared between Commonwealth, State or Territory government entities to assist with their assessment processes.

Threatened Species Scientific Committee

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The Department’s Privacy Policy contains details about how respondents may access and make corrections to personal information that the Department holds about the respondent, how respondents may make a complaint about a breach of an Australian Privacy Principle, and how the Department will deal with that complaint. A copy of the Department’s Privacy Policy is available at: https://www.awe.gov.au/about/commitment/privacy .

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.

CONSULTATION QUESTIONS FOR MOGGRIDGEA RAINBOWI (KANGAROO ISLAND MICRO-TRAPDOOR SPIDER)

SECTION A - GENERAL

1. Is the information used to assess the nationally threatened status of the species robust? Have all the underlying assumptions been made explicit? Please provide justification for your response.

2. Can you provide additional data or information relevant to this assessment?

3. Have you been involved in previous state, territory or national assessments of this species/subspecies? If so, in what capacity?

PART 1 – INFORMATION TO ASSIST LISTING ASSESSMENT

SECTION B DO YOU HAVE ADDITIONAL INFORMATION ON THE ECOLOGY OR BIOLOGY OF THE SPECIES? (If no, skip to section C)

Biological information

4. Can you provide any additional or alternative references, information or estimates on longevity, average life span and generation length?

5. Do you have any additional information in the ecology or biology of the species not in the current advice/plan?


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SECTION C ARE YOU AWARE OF THE STATUS OF THE TOTAL NATIONAL POPULATION OF THE SPECIES? (If no, skip to section D)

Population size

6. Has the survey effort for this taxon been adequate to determine its national adult population size? If not, please provide justification for your response.

7. Are there any newly discovered subpopulations which have not been identified in the assessment?

8. Do you consider the way the population size has been derived to be appropriate? Are there any assumptions and unquantified biases in the estimates? Did the estimates measure relative or absolute abundance? Do you accept the estimate of the total population size of the species? If not, please provide justification for your response.

9. If not, can you provide a further estimate of the current population size of mature adults of the species (national extent)? Please provide supporting justification or other information.

If, because of uncertainty, you are unable to provide a single number, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of possible subspecies numbers, and also choose the level of confidence you have in this estimate:

Number of mature individuals is estimated to be in the range of:

□ 1 – 2 500 □ 2 500 – 5 000 □ 5 000 – 7 500 □ 7 500 – 10 000 □ >10 000

Level of your confidence in this estimate:

□ 0–30% - low level of certainty/ a bit of a guess/ not much information to go on

□ 31–50% - more than a guess, some level of supporting evidence

□ 51–95% - reasonably certain, information suggests this range

□ 95–100% - high level of certainty, information indicates quantity within this range

□ 99–100% - very high level of certainty, data are accurate within this range

SECTION D ARE YOU AWARE OF TRENDS IN THE OVERALL POPULATION OF THE SPECIES? (If no, skip to section E)

10. Does the current and predicted rate of decline used in the assessment seem reasonable? Do you consider that the way this estimate has been derived is appropriate? If not, please provide justification of your response.

Evidence of total population size change


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11. Are you able to provide an estimate of the total population size during 2008–2010 (at or soon after the start of the most recent three generation period)? Please provide justification for your response.

If, because of uncertainty, you are unable to provide a single number, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of possible subspecies numbers, and also choose the level of confidence you have in this estimate.

Number of mature individuals is estimated to be in the range of:

□ 1 – 2 500 □ 2 500 – 5 000 □ 5 000 – 7 500 □ 7 500 – 10 000 □ >10 000

Level of your confidence in this estimate:



□ 51–95% - reasonably certain, information suggests this range

□ 95–100% - high level of certainty, information indicates quantity within this range


12. Are you able to comment on the extent of decline in the species/subspecies’ total population size over the last approximately 12 years (i.e. three generations)? Please provide justification for your response.

If, because of uncertainty, you are unable to provide an estimate of decline, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of ranges of decline, and also choose the level of confidence you have in this estimated range.

Decline estimated to be in the range of:

□ 1–30% □31–50% □51–80% □81–100% □90–100%Level of your confidence in this estimated decline:



□ 51–95% - reasonably certain, suggests this range of decline


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□ 95–100% - high level of certainty, information indicates a decline within this range


13. Please provide (if known) any additional evidence which shows the population is stable, increasing or declining.

SECTION E ARE YOU AWARE OF INFORMATION ON THE TOTAL RANGE OF THE SPECIES? (If no, skip to section F)

Current Distribution/range/extent of occurrence, area of occupancy

14. Does the assessment consider the entire geographic extent and national extent of the species/subspecies? If not, please provide justification for your response.

15. Has the survey effort for this species/subspecies been adequate to determine its national distribution? If not, please provide justification for your response.

16. Is the distribution described in the assessment accurate? If not, please provide justification for your response and provide alternate information.

17. Do you agree that the way the current extent of occurrence and/or area of occupancy have been estimated is appropriate? Please provide justification for your response.

18. Can you provide estimates (or if you disagree with the estimates provided, alternative estimates) of the extent of occurrence and/or area of occupancy.

If, because of uncertainty, you are unable to provide an estimate of extent of occurrence, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of ranges of extent of occurrence, and also choose the level of confidence you have in this estimated range.

Current extent of occurrence is estimated to be in the range of:

□ <100 km2 □ 100 – 5 000 km2 □ 5 001 – 20 000 km2 □ >20 000 km2

Level of your confidence in this estimated extent of occurrence

□ 0–30% - low level of certainty/ a bit of a guess/ not much data to go on


□ 51–95% - reasonably certain, data suggests this range of decline

□ 95–100% - high level of certainty, data indicates a decline within this range


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□ 99–100% - very high level of certainty, data is accurate within this range

If, because of uncertainty, you are unable to provide an estimate of area of occupancy, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of ranges of area of occupancy, and also choose the level of confidence you have in this estimated range.

Current area of occupancy is estimated to be in the range of:

□ <10 km2 □ 11 – 500 km2 □ 501 – 2000 km2 □ >2000 km2

Level of your confidence in this estimated extent of occurrence:






SECTION F ARE YOU AWARE OF TRENDS IN THE TOTAL RANGE OF THE SPECIES? (If no, skip to section G)

Past Distribution/range/extent of occurrence, area of occupancy

19. Do you consider that the way the historic distribution has been estimated is appropriate? Please provide justification for your response.

20. Can you provide estimates (or if you disagree with the estimates provided, alternative estimates) of the former extent of occurrence and/or area of occupancy.

If, because of uncertainty, you are unable to provide an estimate of past extent of occurrence, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of ranges of past extent of occurrence, and also choose the level of confidence you have in this estimated range.

Past extent of occurrence is estimated to be in the range of:

□ <100 km2 □ 100 – 5 000 km2 □ 5 001 – 20 000 km2 □ >20 000 km2

Level of your confidence in this estimated extent of occurrence


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If, because of uncertainty, you are unable to provide an estimate of past area of occupancy, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of ranges of past area of occupancy, and also choose the level of confidence you have in this estimated range:

Past area of occupancy is estimated to be in the range of:

□ <10 km2 □ 11 – 500 km2 □ 501 – 2000 km2 □ >2000 km2

Level of your confidence in this estimated extent of occurrence:




□ 95–100% -high level of certainty, data indicates a decline within this range


PART 2 – INFORMATION FOR CONSERVATION ADVICE ON THREATS AND CONSERVATION ACTIONS

SECTION G DO YOU HAVE INFORMATION ON THREATS TO THE SURVIVAL OF THE SPECIES? (If no, skip to section H)

21. Do you consider that all major threats have been identified and described adequately?


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22. To what degree are the identified threats likely to impact on the species/subspecies in the future?

23. Are the threats impacting on different populations equally, or do the threats vary across different populations?

24. Can you provide additional or alternative information on past, current or potential threats that may adversely affect the species/subspecies at any stage of its life cycle?

25. Can you provide supporting data/justification or other information for your responses to these questions about threats?

SECTION H DO YOU HAVE INFORMATION ON CURRENT OR FUTURE MANAGEMENT FOR THE RECOVERY OF THE SPECIES? (If no, skip to section I)

26. What planning, management and recovery actions are currently in place supporting protection and recovery of the species/subspecies? To what extent have they been effective?

27. Can you recommend any additional or alternative specific threat abatement or conservation actions that would aid the protection and recovery of the species/subspecies?

28. Would you recommend translocation (outside of the species’ historic range) as a viable option as a conservation actions for this species/subspecies?

SECTION I DO YOU HAVE INFORMATION ON STAKEHOLDERS IN THE RECOVERY OF THE SPECIES?

29. Are you aware of other knowledge (e.g. traditional ecological knowledge) or individuals/groups with knowledge that may help better understand population trends/fluctuations, or critical areas of habitat?

30. Are you aware of any cultural or social importance or use that the species has?

31. What individuals or organisations are currently, or potentially could be, involved in management and recovery of the species/subspecies?

32. How aware of this species are land managers where the species is found?

33. What level of awareness is there with individuals or organisations around the issues affecting the species/subspecies?

a. Where there is awareness, what are these interests of these individuals/organisations?

b. Are there populations or areas of habitat that are particularly important to the community?


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PART 3 – ANY OTHER INFORMATION

34. Do you have comments on any other matters relevant to the assessment of this species?


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Consultation Document on Listing Eligibility and Conservation Actions forMoggridgea rainbowi (Kangaroo Island Micro-trapdoor Spider)This document combines the draft conservation advice and listing assessment for the species. It provides a foundation for conservation action and further planning.

Kangaroo Island Micro-trapdoor Spider © Copyright, Dr. Jessica Marsh

Conservation statusMoggridgea rainbowi (Kangaroo Island Micro-trapdoor Spider) is being assessed by the Threatened Species Scientific Committee to be eligible for listing as Endangered under Criterion 2. The Committee’s assessment is at Attachment A. The Committee assessment of the species’ eligibility against each of the listing criteria is:

Criterion 1: A2ac+4ac: Vulnerable

Criterion 2: B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v): Endangered

Criterion 3: C2a(i): Vulnerable

Criterion 4: Not eligible

Criterion 5: Insufficient data

The main factors that make the species eligible for listing in the Endangered category are severe population reduction and local extinction following the 2019–20 bushfires, restricted distribution, population fragmentation, and continuing decline in habitat and number of mature


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individuals due to weed invasion, increased frequency and intensity of bushfires and creek bank erosion.

Species can also be listed as threatened under state and territory legislation. For information on the current listing status of this species under relevant state or territory legislation, see the Species Profile and Threat Database.

Species informationTaxonomyConventionally accepted as Moggridgea rainbowi Pulleine (1919).

DescriptionThe Kangaroo Island (KI) Micro-trapdoor Spider is a medium-sized spider from the Mygalamorphae suborder, with a broadly uniform dark reddish-brown/black colouration (Harrison et al. 2017). Like all spiders, the body is composed of the abdomen and cephalothorax (fused head and thorax). As with other ‘primitive’ spider clades, mygalomorphs have two pairs of book lungs and downward-pointing chelicerae (mouth appendages), with only two pairs of spinnerets (web-spinning organs) (Wheeler et al. 2017).

Mature males are 9.1 mm in total length, with a rounded 4.1 mm long and 4.0 mm wide reddish-brown dorsal section of the exoskeleton (carapace). The jaws are largely devoid of small hair-like structures (setae), though some are present around the eyes. The legs are stout and without thorns. The abdomen is oval, with rows of blunt setae and a circular indentation on the dorsal side. The abdomen is a dark greyish brown with lighter grey mottling, whilst the sternum and jaws are a lighter golden brown, darkening toward the front margin. This description is drawn from Harrison et al. (2016).

Mature females have a total length of approximately 10–11 mm. The carapace is brown, with a lighter yellowish-brown jaw. The abdomen is a dark greyish brown with lighter grey mottling and a pair of dorsal circular indentations. It is oval from the dorsal view. The carapace is 4.7 mm long and 4.3 mm wide. There are three longitudinal rows of five setae behind the eye region, with more setae sparsely located around the edge of the carapace. The legs are predominately cylindrical with sparse setae, though certain segments are flattened and rotated to form a ‘basket’ over the front of the body. The receptacles for storing sperm (spermathecae) are paired, stout, unbranched and facing inward. This description is drawn from Harrison et al. (2016).

The closest Australian relatives to the species are also part of the family Migidae and occur in Western Australia (WA), Tasmania and Queensland (Harrison et al. 2016, 2017). WA spiders in the Bertmainius genus were previously in Moggridgea, though this was changed in a 2015 taxonomic revision (Harvey et al. 2015). The KI Micro-trapdoor Spider is distinguished from these other Australian migids by the following features: the presence of erect setae composed of thin plates beneath patellae (fourth leg segment) I, III and IV; the absence of spines on tarsi (seventh leg segment) I-IV; and by the shape of the ectal lobe of the pedipalpal tarsus (seventh leg segment on the second appendage of the cephalothorax in front of the first leg), which is pointed towards an apex, and long (Harrison et al. 2016).


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http://www.environment.gov.au/cgi-bin/sprat/public/sprat.pl


DistributionThe KI Micro-trapdoor Spider is the only member of the genus Moggridgea known in Australia. It appears to be a member of the M. quercina-group (otherwise known only from South Africa), and the most similar described species is Moggridgea intermedia from South Africa (Harrison et al. 2016, 2017). Evidence including molecular divergence dating suggests that the ancestor/s of the KI Micro-trapdoor Spider dispersed to KI from southern Africa sometime during the last 2–16 million years (Harrison et al. 2016, 2017). This divergence date significantly post-dates the separation of Africa from Gondwana (95 million years ago), suggesting that long-distance trans-Indian Ocean dispersal is responsible for the colonisation of KI by the species (Harrison et al 2016, 2017).

The KI Micro-trapdoor Spider is a short-range endemic species (Harvey 2002) known only from KI, South Australia (SA), in the Kanmantoo IBRA (Interim Biogeographic Regionalisation for Australia) region (Environment Australia 2000) (Map 1). It is currently only known from five sites, four on the eastern end of the island and one on the western end. The western site (Western River) appears to be genetically distinct from at least one of the eastern sites (American River) (Harrison et al. 2017), with approximately 80 km separating these two sites. Western River and American River were the only known sites for the species, though surveys in recent years have identified a further three subpopulations, all on the eastern side of the island. The other eastern sites are: Baudin Conservation Park (CP) on Dudley Peninsula; Shorty Rd at Chapman River tributary; and a creek line on the outskirts of Penneshaw township. The American River and Baudin CP sites are located very close to the coast, laterally within 10 m of the sea (J Marsh 2020. pers comm 29 October). Baudin CP and Penneshaw may be the same subpopulation, as these sites are c.1 km apart. Individuals from all sites are found along creeklines.

Two of the known sites (Western River and Baudin CP) occur in protected areas. Of the remaining sites, two are on Crown land and Shorty Rd is on private property. The species has not yet been found at other locations with suitable habitat, despite an extensive targeted survey effort from 2018–2020 (Marsh 2020. pers comm 29 October).

Though many apparently suitable sites have already been surveyed, it is likely that other subpopulations remain to be found (J Marsh 2020. pers comm 29 October). Due to the species’ specific habitat requirements, the available sites are necessarily limited to the banks of seasonal watercourses, particularly small creeks near the coast. There are 5700 km of watercourses moving surface water across the island, with many of these terminating in estuaries along the coast (DEWNR 2013). Most of these watercourses are seasonal and flow during the winter months before drying significantly during summer. KI also has some permanently flowing streams, which is unusual for SA (DEWNR 2013). Due to the large network of watercourses across the island, there are potentially many sites that may be inhabited by the KI Micro-trapdoor Spider. However, within the suitable habitat that has been surveyed, only a small proportion have identified subpopulations of the species, suggesting there are other factors influencing its distribution (J Marsh 2020. pers comm November 9). Suitable watercourses are less likely to be in the centre of the island, as this land is flat and is therefore less suitable as habitat (J Marsh 2020. pers comm November 9).


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Almost the entire known range of the Western River subpopulation was burnt during the bushfires which ravaged KI from December 2019 – January 2020. As of December 2020, targeted surveys have detected no surviving individuals in the fire-affected area and four living individuals in two small patches of unburnt creek line (J Marsh 2020. pers comm 29 October; J

Marsh 2020. pers comm 15 December). The unburnt patches were searched thoroughly, and it appears there aren't any other living individuals in or on either side of the sites where they were found. Before the fires, the Western River subpopulation was approximately 30 percent of the total known population, with some of the eastern subpopulations consisting of very small colonies with very low numbers of burrows (J Marsh 2020. pers comm 9 November). The eastern subpopulations were not in the bushfire impacted area and appear to have been unaffected by the bushfires.

Map 1 Modelled distribution of Kangaroo Island Micro-trapdoor Spider.

Source: Base map Geoscience Australia; species distribution data Species of National Environmental Significance database.Caveat: The information presented in this map has been provided by a range of groups and agencies. While every effort has been made to ensure accuracy and completeness, no guarantee is given, nor responsibility taken by the Commonwealth for errors or omissions, and the Commonwealth does not accept responsibility in respect of any information or advice given in relation to, or as a consequence of, anything containing herein. Species distribution mapping: The species distribution mapping categories are indicative only and aim to capture (a) the specific habitat type or geographic feature that represents to recent observed locations of the species (known to occur) or preferred habitat occurring in close proximity to these locations (likely to occur); and (b) the broad environmental envelope or geographic region that encompasses all areas that could provide habitat for the species (may occur). These presence categories are created using an extensive database of species observations records, national and regional-scale environmental data, environmental modelling techniques and documented scientific research.


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http://www.environment.gov.au/science/erin/databases-maps/snes


Cultural and community significance

The cultural significance of the KI Micro-trapdoor Spider is unknown. However, KI has important cultural significance to the Kaurna, Ngarrindjeri, Narungga and Ramindjeri nations, and these groups maintain a spiritual connection to the region (DEH 2006; Ngarrindjeri Nation 2007). The Kaurna, Ngarrindjeri, Narungga and Ramindjeri peoples would like to be involved in the development and implementation of natural resources management in their traditional lands and waters (Ngarrindjeri Nation 2007). Current members of these nations have a strong understanding of Country and feel responsible for lands and waters (Ngarrindjeri Nation 2007; NRKI 2017). Ascertaining the cultural significance of this species is an information/research priority identified in the Conservation and Recovery Actions.

The KI Micro-trapdoor Spider is of high value to the scientific community, due to its restricted distribution and historical trans-oceanic dispersal (J Marsh 2020. pers comm 29 October). The closest relatives of the KI Micro-trapdoor Spider are found only in southern Africa, and the species is believed to have dispersed on oceanic debris between 2 and 16 MYA (Harrison et al. 2016, 2017). It is the only known mygalomorph spider to have achieved long-distance, intercontinental trans-oceanic dispersal, so is of significance to the scientific community.

Relevant biology and ecologyHabitat

KI Micro-trapdoor Spiders construct short, silk-lined burrows approximately 6 cm in length directly into bare vertical clay banks alongside seasonal KI creeks. Many sites, particularly on the western side of the island, occur at the bottom of steep gullies formed by natural topography. Along most of the creek lines, there are large trees and overhanging rocks that provide protection from heat and sunlight to moderate burrow temperature and humidity (J Marsh 2020. pers comm 9 November) (Figure 1). The burrows have a thin hinged lid that fits tightly when closed. Usually, many burrows are clustered within a small area on a creek bank, as juveniles generally construct burrows near their mother’s burrow. At all known sites, burrows are situated within 2.5 km from the coast, with two subpopulations on the edge of the shore, laterally within 10 m of the high tide mark (J Marsh 2020. pers comm 29 October). At American River, the burrows are on vertical clay banks very close to the ocean surface and are soaked by salt spray at high tide (Harrison et al. 2016, 2017). All burrows in all known subpopulations have been found within one metre of the creek bed, or at the base of the clay bank (J Marsh 2020. pers comm 29 October).

Placement of burrows along creek lines is consistent with another trapdoor spider species, Bertmainius colonus (Eastern Stirling Range Pygmy Trapdoor Spider), which was formerly in the genus Moggridgea. It also burrows close to creeks and is distributed along creek lines in the south-west region of Western Australia (Harvey et al. 2015; DPAW 2017a).

In captivity, KI Micro-trapdoor Spider females do not construct a new burrow. Captive males and females stay alive if translocated and left inside their burrow, but quickly die when removed (J Marsh 2020. pers comm 29 October). This suggests that the burrow may provide a stable microhabitat, enabling spiders to regulate temperature and humidity (Harrison et al. 2017). Soil moisture is also important for trapdoor spiders, and was the only environmental variable that predicted spider activity in a study of south-African trapdoor spiders (Engelbrecht 2013). Spiders usually burrow in places where the lower part of their burrows is in humid substrate,


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and moderation of humidity plays an important role in the function of the burrow. Burrows are also designed to protect spiders against harsh environmental conditions, flooding, fire and predation, and provide a place for reproduction and parental care (Decae 1996; Carrel 2008; Uchman et al. 2018).

Figure 2 Vertical clay creek bank bearing Kangaroo Island Micro-trapdoor Spider burrows.

Dispersal

Some spiders can disperse large distances by ‘ballooning’ – floating on air currents using their silk (Weyman 1993: Bell et al. 2005; Harrison et al. 2017). However, the KI Micro-trapdoor Spider is a short-range endemic species and appears not to balloon (Harvey 2002; Harrison et al. 2017). In most mygalomorph spiders, when forming a new burrow, juveniles likely disperse by walking only a few metres from the maternal burrow (Harrison et al. 2017). As such, the dispersal ability of the species is low, likely less than 10 m (DAWE 2020a). The sedentary, burrow-restricted lifestyle of these spiders makes them highly susceptible to certain threatening processes.

Life history and reproductive ecology

The reproductive ecology and life history of the KI Micro-trapdoor Spider is not fully understood, though mygalomorph spiders are usually long-lived, reside in burrows and are highly sedentary (Raven & Wishart 2005). The life expectancy of the KI Micro-trapdoor spider is unknown, though the ecologically and taxonomically similar Bertmainius tingle (Tingle Pygmy Trapdoor Spider) and Eastern Stirling Range Pygmy Trapdoor Spider are considered to live longer than eight years and reach sexual maturity at around or above four years of age (DPAW 2017a, b).

Female KI Micro-trapdoor Spiders are univoltine and are thought to produce 1–10 young per year (DAWE 2020a), which hatch from eggs laid in the maternal burrow. Mature female


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specimens have been collected all year round and were found with eggs during spring, and spiderlings during summer. Of recently collected specimens, only one fifth have been mature and the rest have been juveniles (J Marsh 2020. pers comm 9 November). Once hatched, juvenile spiders are slow growing and appear to stay in the maternal burrow for an unknown period before dispersing, as evidenced by juveniles of different sizes being found in the same maternal burrows (J Marsh 2020. pers comm 29 October).

The generation length of the KI Micro-trapdoor Spider is unknown. However, the related Tingle Pygmy Trapdoor Spider and Eastern Stirling Range Pygmy Trapdoor Spider both have a generation length of approximately four years (DPAW 2017a, b). Until a 2015 taxonomic revision (Harvey et al. 2015), both species were included in the Moggridgea genus. Based on observations of captive KI Micro-trapdoor Spiders and knowledge of the species' breeding in the wild, it is likely the generation length of the KI Micro-trapdoor Spider is four years, similar to the Bertmainius genus (J Marsh 2020. pers comm 29 October).

In the Tingle Pygmy Trapdoor Spider and the Eastern Stirling Range Pygmy Trapdoor Spider, females and juveniles lead sedentary lifestyles, remaining in their burrows for virtually their entire lives (DPAW 2017a, b). Males are also sedentary until they permanently leave their burrows after reaching maturity to wander in search of adult females (DPAW 2017a, b). This search area is very small and may be limited to only few square metres. Once the burrow of a mature female is located, males approach and rely on pheromones to assess her reproductive status (DPAW 2017a, b). If receptive, the male will enter the burrow and mate with the female. After mating with one or more females, the adult male dies. It is likely that the KI Micro-trapdoor Spider employs a similar reproductive strategy to these species. KI Micro-trapdoor Spider males likely wander in search of females during Autumn, as mature male specimens have only been found and collected during Autumn (Harrison et al. 2016).

Diet

The diet of the KI Micro-trapdoor Spider is unknown (J Marsh 2020. pers comm November 9), though most trapdoor spiders are obligate predators of insects and other arthropods. Trapdoor spiders hunt by ambushing prey from their burrow, pouncing as prey moves past (DPAW 2017a). It is then bitten to inject venom and consumed (DPAW 2017b).

Habitat critical to the survivalThe KI Micro-trapdoor Spider inhabits creek banks at five known sites throughout KI, four on the eastern end and one at Western River. It is found within 1 m of the bottom of vertical clay creek banks, usually near the surface of the water during winter. Though it has only been found at five sites, it is likely that the KI Micro-trapdoor Spider persists along other creek lines on KI, (J Marsh 2020. pers comm 29 October). Therefore, all surveyed and unsurveyed seasonal creek banks near the KI coast may be considered critical to the survival of the KI Micro-trapdoor Spider.

No Critical Habitat as defined under section 207A of the EPBC Act has been identified or included in the Register of Critical Habitat.


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Important populationsIn this section, the word population is used to refer to subpopulation, in keeping with the terminology used in the EPBC Act.

There are only five known populations, four on the eastern side of the island and one on the western side. Nearly all individuals from the Western River population were killed in the 2019–20 KI bushfires, with only four individuals found across two small stretches of unburnt creek-line during post-fire surveys (J Marsh 2020. pers comm 15 December). Notably, one of the females found had an egg sac and an empty burrow nearby, suggesting a male was also alive. Due to the relatively low number of individuals and genetic diversity, each subpopulation is vital for the ongoing survival and recovery of the species and should be treated as important populations (J Marsh 2020. pers comm 29 October).

ThreatsThe KI Micro-trapdoor Spider is threatened by bushfires, weed invasion, invasive species, habitat loss, disturbance and modifications, and climate change (Table 1).

Table 1 Threats impacting Kangaroo Island Micro-trapdoor Spider

Threat Status and severity a

Evidence

Habitat loss, changes and modifications

Inappropriate fire regimes

Status: current

Confidence: inferred

Consequence: catastrophic

Trend: increasing

Extent: across the entire range

Bushfires can cause spider mortality directly via heating, smoke inhalation and oxygen depletion. Indirect mortality can also occur via the loss of suitable habitat for shelter. A 2011 study found that the relative abundance of some burrow ambushers and other burrowers was high in recently burnt sites, suggesting that these traits increased resistance to bushfire-related mortality (Langlands et al. 2011). This is likely because the intensity of heat from fires decreases rapidly with increasing soil depth (Whelan 1995) and burrowing spiders can use their burrow microhabitat to shield them from direct disturbance by fire (Langlands et al. 2011). However, a recent study of fires in urban areas in WA found high mortality of burrowing mygalomorph spiders after high-intensity fires (100 percent mortality after a year) (Mason et al. 2019). The study also identified that short-range endemic spiders such as the KI Micro-trapdoor Spider can undergo very severe population reduction after fire, leading to local extinction (Mason et al. 2019). Indeed, initial evidence on the impact of fire on KI Micro-Trapdoor Spider suggests that even low intensity fires can be highly detrimental to the species through the damage it causes to the burrow and surrounding habitat, as well as post-fire effects (J Marsh 2021. pers comm 12 February). If low severity fire has the potential to cause severe population decline, this has important implications for planning of prescribed burns.

Another study identified a significant impact of fire on Moggridgea species in WA. Spiders occupying deeply shaded creek banks with moss-covered loam, silt and clay soils suffered the most severely, as the soil in the wettest places was mineralised by the intense fire, destroying nests and spiders (Main & Gaull 1992). This suggests that inhabiting bare clay banks may offer little protection from bushfire.

Aside from direct mortality, there are significant post-fire threats to surviving spiders. These threats include sediment run-off following rainfall, which in some cases has completely smothered creek lines (J Marsh 2020. pers comm 9 November). After a bushfire, total or partial removal of vegetation and changes to soil properties lead to increases in flow and yield of sediment (Garcia-Comendador et al. 2020). This is an important risk for surviving individuals at the western end of the island


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after the 2019–20 bushfires, as they are found in unburnt patches and occur in creeks at the bottom of steep gullies. Partial smothering of creeks and erosion of clay creek banks across the fire-affected area has been observed (J Marsh 2020. pers comm 9 November). Spiders surviving fires also suffer from high predation pressure, especially where parasitoids (e.g. spider hunting wasps) are dispersive and able to fly in from unburnt areas (J Marsh 2020. pers comm 15 December).

Land clearing and fragmentation

Status: historical


Consequence: moderate

Trend: static

Extent: across parts of the range

KI Micro-trapdoor spiders are short-range endemics that disperse very short distances (<10 m) from their maternal burrow and live along creek lines, therefore they cannot move between fragments or disperse when their habitat is destroyed (J Marsh 2020. pers comm 9 November).

While land clearing has slowed since the introduction of the Native Vegetation Act (1991) in SA, intensive clearing occurred from the 1950s to 1980s (Robinson & Armstrong 1999). Approximately 2300 km2 of land on KI has been cleared and is used for agriculture (Dohle 2007), almost entirely on the eastern side of the island. As the habitat of the KI Micro-trapdoor Spider is clay banks along creek lines, it is unlikely that this land will be targeted for any future development or clearing. However, historical land clearing has likely led to increased and ongoing weed invasion and erosion (J Marsh 2020. pers comm 9 November).

Invasive species

Weed invasion Status: current

Confidence: known

Consequence: major

Trend: increasing


Eight Weeds of National Significance (WoNS) and 27 Declared Weeds of SA (DWoSA) are found on KI, including notable fire-adapted and fast-growing ‘pioneer’ weeds: Bluebell Creeper (Sollya heterophylla), Gorse (Ulex europaeus), Montpellier Broom (Genista monspessulana), Bridal Creeper (Asparagus Asparagoides), Variegated Thistle (Silybum marianum), African Boxthorn (Lycium ferocissimum), Blackberry (Rubus fructicosus) and One-leaf Cape Tulip (Moraea flaccida) (Thorp & Lynch 2000; Landscape South Australia 2020a,b; NRKI 2020). The vast majority of weeds occur on the eastern extent of the Island (DEW 2020b). However, weed invasion has also been identified as a threat to biodiversity in the Cape Forbin area, which includes the Western River Wilderness Protection Area (DEH 2009).

The weed having the most impact on the KI Micro-trapdoor Spider is Bridal Creeper, a highly invasive weed native to southern Africa. It forms a thick mat of underground tubers impeding the root growth and seeding establishment of other plants (DPI 2020a). Bridal creeper is most common close to the coast, especially in alkaline sandy soils and near roads. It is well established throughout the eastern third of KI, especially on Dudley Peninsula (Winkler et al. 2006), and is widespread in four of the five sites that the KI Micro-trapdoor Spider is currently found (J Marsh 2020. pers comm 29 October).

Bridal Creeper is heavily impacting all the eastern subpopulations and is leading to the loss of burrows (J Marsh 2020. pers comm 29 October). The mat of underground tubers formed by the weed appears to prevent the KI Micro-trapdoor Spider from excavating burrows where it is located. There is also evidence of burrow damage (burrows warped and misshapen by Bridal Creeper corms), suggesting that existing burrows are destroyed when Bridal Creeper invades an area (J Marsh 2020. pers comm 29 October). Within each invaded subpopulation, some areas are heavily infested by Bridal Creeper whilst some remain unaffected. In those areas infested by Bridal Creeper, no intact burrows could be located, despite thorough searching (J Marsh 2020. pers comm 9 November). This habitat degradation is potentially leading to declines in the eastern subpopulations (J Marsh 2020. pers comm 29 October). It is estimated that 40% of the known eastern sites inhabited by the KI Micro-trapdoor Spider have been infested by Bridal Creeper since it was introduced. Without appropriate invasive weed management, Bridal Creeper will continue to spread and potentially destroy KI Micro-trapdoor Spider burrows in the eastern sites.

Similar impacts may occur if other matting plants or other vegetation invade the bare vertical creek banks inhabited by the KI Micro-trapdoor


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Spider. Other potentially threatening ground-matting weeds include the ground-matting Bridal Veil Creeper (Asparagus declinatus) and matt-forming grasses such as Kikuyu (Pennisetum clandestinum). Like the Bridal Creeper, the Bridal Veil Creeper threatens the KI Micro-trapdoor Spider by forming underground tubers, destroying burrows (DPI 2020b). Kikuyu does not form tubers but forms dense mats that may also disrupt burrows (Brisbane City Council 2020).

Weeds can also increase fuel load and alter fire regimes (Milberg & Lamont 1995; Setterfield et al. 2013). Grassy weeds invade and establish in native vegetation, particularly following disturbance events, such as bushfires (Hobbs 1991; Hobbs 2002; Brown et al. 2016). These altered fire regimes may create conditions that are detrimental to the maintenance of native species and favourable to the establishment and spread of weeds (D'Antonio & Vitousek 1992; Grigulis et al. 2005).

Erosion of watercourses by livestock

Status: current

Confidence: suspected


Trend: unknown

Extent: across parts of the range

Changes to land use, particularly access to watercourses by grazing stock, have the potential to disturb and erode creek banks. Ungulates walking along creek banks and wading into watercourses cuts and crumbles the soil, destroying the vertical clay banks that the KI Micro-trapdoor Spider relies on for habitat (Fitzpatrick & Peppler 2004). Riparian grazing practices give cattle free access to streams and creeks, accelerating erosion by trampling soil and vegetation. Cattle also often use the banks of streams and creeks for scratching, causing further erosion and loss of vegetation (Fitzpatrick & Peppler 2004). It is unclear if these practices are occurring within the distribution of the KI Micro-trapdoor Spider, though historical ungulate grazing is likely having legacy impacts on the species habitat.

On KI, most of the agricultural land is on the eastern side of the island. Therefore, the eastern subpopulations are most threatened by watercourse erosion caused by agriculture. Given that the Western River subpopulation and Baudin Conservation Estate subpopulations are in protected areas (J Marsh 2020. pers comm 9 November), they are unlikely to be impacted by current or future agricultural activity.

Erosion and habitat degradation by Feral pigs (Sus scrofa)

Status: current



Trend: unknown

Extent: across part of its range

Feral pigs are found in all states and territories of Australia and are listed as a Key Threatening Process (KTP) under the EPBC Act (DoEE 2017). Feral pigs are widespread across the western side of KI, including in the Western River Wilderness Protection Area (DEH 2006, 2009; NRKI 2017).

Like cattle, Feral pigs can destroy native vegetation by trampling plants, compacting soil and facilitating weed invasion (DoEE 2017). As an ungulate, Feral pigs could impact the vertical clay banks (Fitzpatrick & Peppler 2004). Feral pigs pose a similar threat to the KI Micro-trapdoor Spider as cattle grazing, though primarily on the western side of the island. A feral pig control program is currently underway (PIRSA 2021).

Climate Change

Changes to temperature and precipitation patterns

Status: current

Confidence: known


Trend: increasing


KI is projected to undergo increased mean temperatures and decreased median rainfall under both intermediate and high emissions pathways (Resilient Hills and Coasts 2016; Hope et al. 2015). By 2050, annual rainfall is projected to decline by 7.5–8.9% under intermediate and high emissions pathways, respectively.

Droughts may have a substantial effect on water flow through the creeks inhabited by the KI Micro-trapdoor Spider, which are already dry through much of summer (DEWNR 2013; J Marsh 2020. pers comm 9 November). If the water regime changes for a significant portion of the year, particularly if winter rainfall decreases, the KI Micro-trapdoor Spider may be substantially affected. Drought and drying of clay banks may lead to mortality through changes to burrow microclimate, as has been observed in captive individuals without burrows (J Marsh 2020. pers comm 29 October). However, more research is required to determine the impact of winter water flow and rainfall on the species. Drought may also have a substantial impact on the vegetation structure


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of the region, as certain plants are vulnerable to mortality through drought stress and hydraulic failure (Choat et al. 2018). Burrows of KI Micro-trapdoor Spiders require adequate shading and protection from heat and sunlight to moderate temperature and humidity. If the large trees that provide shading to many of the burrows undergo decline due to drought, this may impact the ability of spiders to survive in their burrows (J Marsh 2020. pers comm 9 November).

KI is projected to continue to experience decreased rainfall, increased average temperatures and higher frequency of droughts, leading to bushfires of increased frequency, intensity and scale (Hope et al. 2015; Resilient Hills and Coasts 2016). Accordingly, catastrophic bushfires such as the 2019–20 fires are increasingly likely to occur (DAWE 2020).

Warmer temperatures and changes to precipitation patterns may also favour the spread of weeds (Scott et al. 2014).

Extreme rainfall events and storm surges

Status: future



Trend: increasing


Though mean and median rainfall in the region will decrease in the future, heavy rainfall events are increasingly likely (Resilient Hills and Coasts 2016). Climate change models project an increase in the intensity of extreme rainfall events in the Southern and South-Western Flatlands East Cluster (SSWFE), which includes KI (Hope et al. 2015).

Modelling of climate change scenarios also suggests that KI is also likely to experience higher sea levels and increased storm surges in the future (Resilient Hills and Coasts 2016; Hope et al. 2015). The KI Micro-trapdoor Spider builds its burrows in the top 6 cm of soil along creek banks and near the ocean, and as such is highly vulnerable to erosion and flooding associated with extreme rainfall events and storm surges (J Marsh 2020. pers comm 9 November). Two of the known sites inhabited by the KI Micro-trapdoor Spider are laterally less than 10 m from the coastline (J Marsh 2020. pers comm 29 October) and are particularly vulnerable to extreme storm surges and higher sea.

Status—identify the temporal nature of the threat;

Confidence—identify the extent to which we have confidence about the impact of the threat on the species;

Consequence—identify the severity of the threat;

Trend—identify the extent to which it will continue to operate on the species;

Extent—identify its spatial content in terms of the range of the species.

Each threat has been described in Table 1 in terms of the extent that it is operating on the species. The risk matrix (Table 1) provides a visual depiction of the level of risk being imposed by a threat and supports the prioritisation of subsequent management and conservation actions. In preparing a risk matrix, several factors have been taken into consideration, they are: the life stage they affect; the duration of the impact; and the efficacy of current management regimes, assuming that management will continue to be applied appropriately. The risk matrix and ranking of threats has been developed in consultation with in-house expertise using available literature.

Table 2 Kangaroo Island Micro-trapdoor Spider risk matrix

Likelihood Consequences

Not significant Minor Moderate Major Catastrophic

Almost certain Low risk Moderate risk Very high risk Very high risk

Weed invasion

Very high risk

Changes to temperature and precipitation patterns

Likely Low risk Moderate risk High risk Very high risk Very high risk


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Likelihood Consequences

Not significant Minor Moderate Major Catastrophic

Erosion of watercourses by livestock

Erosion and habitat degradation by feral pigs

Extreme rainfall events and storm surges

Possible Low risk Moderate risk High riskLand clearing and fragmentation

Very high risk Very high riskInappropriate fire regimes

Unlikely Low risk Low risk Moderate risk High risk Very high risk

Unknown Low risk Low risk Moderate risk High risk Very high risk

Priority actions have then been developed to manage the threat particularly where the risk was deemed to be ‘very high’ or ‘high’. For those threats with an unknown or low risk outcome it may be more appropriate to identify further research or maintain a watching brief.


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Conservation and recovery actionsPrimary conservation outcomeThe remaining individuals and subpopulations are protected, and population size increased.

Conservation and management prioritiesHabitat loss, disturbance and modification (including fire)

Inform fire and land managers, in particular the South Australian Country Fire Service, with maps of known locations and specific advice to support decision making in bushfire prevention, preparedness, response and recovery. Where possible, avoid physical damage to the habitat and individuals of the species during and after prescribed burns.

Avoid planned burns in recently burnt habitat.

Protect remaining unburnt subpopulations from planned burns, clearing or other disturbance.

Continue to implement bushfire management area plans for Kangaroo Island, in particular the South Australian Country Fire Service Kangaroo Island Bushfire Management Area Plan. Apply adaptive management to inform future fire management plans and actions.

Undertake active weed control along creek lines to reduce the fuel load in areas inhabited by the KI Micro-trapdoor Spider.

Encourage consideration and protection in relevant planning policies, development decisions and natural resource management.

Investigate and promote opportunities to protect KI Micro-trapdoor Spider habitat on Crown land and private land through voluntary agreements.

Invasive species (including threats from grazing, trampling, predation)

Develop and maintain a coordinated approach to the management of Bridal Creeper across KI.

Regularly survey and map the extent and density of Bridal Creeper infestations across the island, especially in known habitat of the KI Micro-trapdoor Spider.

Implement weed management actions in association with land managers and community groups, especially known sites inhabited by the KI Micro-trapdoor spider. Ensure that processes used for weed removal minimise the likelihood of habitat destruction, using methods that directly target weeds, such as physical removal and spot spraying.

Manage and control other ground-matting weeds with the potential to destroy burrows of the KI Micro-trapdoor Spider.

Implement legislation that requires landowners and land managers to control Bridal Creeper infestations on their land.

Monitor and minimise damage to riparian areas by Feral pigs. Consult with land holders and government bodies to control numbers and fence key sites.

Monitor and minimise damage to riparian areas by livestock, particularly ensuring that seasonal creeks with vertical clay creek banks are not damaged. Collaborate with land


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holders, graziers and government authorities to fence key sites and reduce associated grazing impacts.

Breeding, seed collection, propagation and other ex situ recovery action

Research the applicability and feasibility of establishing a captive breeding and reintroduction program to mitigate the risk of population loss and reduction of genetic diversity.

Stakeholder engagement/community engagement Liaise with the local community and government agencies to ensure that up-to-date

population data and scientific knowledge inform the implementation of conservation actions for this species.

Ensure land managers and property owners where the KI Micro-trapdoor Spider occurs are aware of the species’ presence and provide protection measures against observed and potential threats. Educate land holders and managers on the importance of integrating habitat protection into land management and encourage them to consider this species in their land and waterway management practices.

Engage and consult with traditional owners in conservation actions, including the implementation of traditional fire management actions.

Engage the community in the control of Bridal Creeper infestations by encouraging the public to report invasions and developing a strategy for public assistance with physical weed removal.

Increase public awareness about the conservation and management of KI invertebrates, particularly the conservation of the KI Micro-trapdoor Spider. Produce and disseminate information about projects and achievements being undertaken for KI invertebrates.

Survey and monitoring priorities Continue to undertake targeted surveys for the KI Micro-trapdoor Spider in areas burnt by

the 2019–20 bushfires. Aim to extend these surveys to private land, as ongoing surveys have only been completed in public reserves. Funding for surveys of KI priority invertebrates has been provided under Tranche 2 of the DAWE Bushfire Recovery For Wildlife and Habitat Community Grants Program. Surveys of the fire-affected area are expected to be completed in July 2021.

Undertake targeted surveys for the KI Micro-trapdoor Spider in unburnt areas. This includes surveying of known subpopulations to gauge population trends, as well as surveys of new creek lines to look for previously unknown subpopulations. This project is awaiting funding and is planned to commence in July 2021 (J Marsh 2020. pers comm 29 October).

Implement a monitoring program to assess the species’ ongoing conservation status and population response to conservation actions.

Conduct targeted surveys for the species along creek lines in areas that are proposed for management actions.

Survey and monitor the effectiveness of weed and pest management around known KI Micro-trapdoor Spider subpopulations in reducing encroachment on the habitat of the KI Micro-trapdoor Spider.


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Information and research priorities Conduct research to investigate the life history, demographics and habitat requirements of

the KI Micro-trapdoor Spider. Knowledge gaps exist on the ecology of the species, particularly the dietary ecology and reproductive biology. Determining aspects of the species’ biology such as life span, age of reproductive maturity and breeding period will help to confirm generation length and inform conservation actions.

Investigate the genetic structure of the total population and each subpopulation to determine the level of genetic diversity and minimum viable population size.

Determine the extent of potential habitat for the KI Micro-trapdoor Spider across the island. Prioritise areas for surveying and for informing assessment processes and prioritising certain regions for species management.

Investigate the impact of grazing, weed invasion, pesticide use, fire and tree planting on the KI Micro-trapdoor Spider.

Develop and implement management guidelines to mitigate or remove weeds in the habitat of the KI Micro-trapdoor Spider. Investigate the impact of weed management strategies on the species and ascertain if herbicides are likely to influence the health of KI Micro-trapdoor Spiders.

Identify options for linking and enhancing current subpopulations.

Investigate options for linking, enhancing or establishing additional subpopulations.

Investigate the influence of predicted climate change scenarios on the habitat of the KI Micro-trapdoor Spider, focussing on the outcome of altered temperatures, rainfall patterns and bushfires. Conduct surveys to determine whether some sites are more vulnerable to flooding and erosion than others due to vegetation structure and topography.

Ascertain the cultural significance of the species to Traditional Owners.

Recovery plan decisionNo recovery plan is in place for the KI Micro-trapdoor Spider.

A decision about whether there should be a recovery plan for this species has not yet been determined. The purpose of this consultation document is to elicit additional information to help inform this decision.


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Links to relevant implementation documentsDepartment of Agriculture, Water and the Environment Wildlife and Habitat Bushfire Recovery Program - Tranche 2 Projects (2020)

Reserves of the Dudley Peninsula Fire Management Plan (2020)

Threat abatement plan for Predation, Habitat Degradation, Competition and Disease Transmission by Feral Pigs ( Sus scrofa ) (2017)

Kangaroo Island Natural Resources Management Plan 2017-2027 (2017)

Flinders Chase Fire Management Plan (2009)

Cape Forbin Integrated Fire Management Plan (2009)

Cape Torrens and Western River Wilderness Protection Areas Management Plan (2006)

Conservation Advice and Listing Assessment referencesBell JR, Bohan DA, Shaw EM & Weyman GS (2005) Ballooning dispersal using silk: world fauna,

phylogenies, genetics and models. Bulletin of entomological research 95, 69.

Boulton AJ & Lake PS (2008) Effects of drought on stream insects and its ecological consequences. Aquatic insects: Challenges to populations, 81-102.

Brisbane City Council Weed Identification Tool (2020) Kikuyu. Viewed: 21 October 2020. Available at: https://weeds.brisbane.qld.gov.au/weeds/kikuyu

Brown K, Paczkowska G & Gibson N (2016) Mitigating impacts of weeds and kangaroo grazing following prescribed fire in a Banksia woodland. Ecological Management & Restoration 17, 133-139.

Carrel JE (2008) The effect of season of fire on density of female garden orbweavers (Araneae: Araneidae: Argiope) in Florida scrub. The Florida Entomologist, 91, 332-334.

Choat B, Brodribb TJ, Brodersen CR, Duursma RA, López R & Medlyn BE (2018) Triggers of tree mortality under drought. Nature 558, 531-539.

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DAWE (Department of Agriculture, Water and the Environment) (2020a) Kangaroo Island invertebrates spreadsheet. Viewed: 23 November 2020. Available at:https://www.environment.gov.au/biodiversity/bushfire-recovery/priority-invertebrates

DAWE (Department of Agriculture, Water and the Environment) (2020b) 2019-20 bushfires recovery planning, regional profile Kangaroo Island. Unpublished report for the Department of Agriculture, Water and the Environment (Commonwealth), Canberra.


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https://www.environment.gov.au/biodiversity/bushfire-recovery/priority-invertebrates

https://www.environment.gov.au/biodiversity/bushfire-recovery/priority-invertebrates

https://weeds.brisbane.qld.gov.au/weeds/kikuyu

https://www.environment.sa.gov.au/files/sharedassets/public/park_management/parks_pdfs_capetorrnswpa.pdf

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DEH (Department for Environment and Heritage) (2006) Cape Torrens and Western River Wilderness Protection Areas management plan. Department for Environment and Heritage (SA), Adelaide.

DEH (Department for Environment and Heritage) (2009) Fire management plan: Cape Forbin integrated fire management plan. Department for Environment and Heritage (SA), Adelaide.

DEW (Department for Environment and Water) (2020a) Reserves of the Dudley Peninsula Fire Management Plan. Department for Environment and Water (SA), Adelaide.

DEW (Department for Environment and Water) (2020b) Weeds of National Significance (WoNS) and Buffel Grass - South Australia. Viewed: 5 March 2021 Available at: http://location.sa.gov.au/lms/Reports/ReportMetadata.aspx?p_no=1167+&pa=dewnr

DEWNR (Department of Environment, Water and Natural Resources) (2013) Non-prescribed Surface Water Resources Assessment – Kangaroo Island Natural Resources Management Region. Department of Water and Natural Resources (SA), Adelaide.

DEWNR (Department of Environment, Water and Natural Resources) (2017) South Australian land cover layers 1987-2015: most likely layers. Department of Environment, Water and Natural Resources (SA), Adelaide.

DoEE (Department of the Environment and Energy) (2017) Threat abatement plan for predation, habitat degradation, competition and disease transmission by Feral pigs (Sus scrofa). Department of the Environment and Energy (Commonwealth), Canberra.

Dohle L (2007) Report of condition of agricultural land on Kangaroo Island. Department of Water, Land and Biodiversity Conservation (SA), Adelaide.

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DPI (Department of Primary Industries) (2020a) Bridal creeper (Asparagus asparagoides). Viewed: 22 October 2020. Available at: https://weeds.dpi.nsw.gov.au/Weeds/Details/22

DPI (Department of Primary Industries) (2020b) Bridal veil creeper (Asparagus declinatus). Viewed: 22 October 2020. Available at: https://weeds.dpi.nsw.gov.au/Weeds/BridalVeilCreeper


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https://weeds.dpi.nsw.gov.au/Weeds/BridalVeilCreeper

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DPIPWE (Department of Primary Industries, Parks, Water and Environment) (2019) Managing weed spread after fire. Viewed: 21 October 2020. Available at: https://dpipwe.tas.gov.au/invasive-species/weeds/weed-publications-and-resources/weed-spread-after-fire

Engelbrecht I (2013) Pitfall trapping for surveying trapdoor spiders: the importance of timing, conditions and effort. The Journal of Arachnology 41, 133–142.

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Moggridgea rainbowi (Kangaroo Island Micro-trapdoor Spider) Conservation Advice

Attachment A: Listing Assessment for Moggridgea rainbowiReason for assessmentThis assessment follows prioritisation of a nomination from the public.

Assessment of eligibility for listingThis assessment uses the criteria set out in the EPBC Regulations. The thresholds used correspond with those in the IUCN Red List criteria except where noted in criterion 4, sub-criterion D2. The IUCN criteria are used by Australian jurisdictions to achieve consistent listing assessments through the Common Assessment Method (CAM).

Key assessment parametersTable 3 includes the key assessment parameters used in the assessment of eligibility for listing against the criteria.

Table 1 Key assessment parameters

Metric Estimate used in the assessment

Minimum plausible value

Maximum plausible value

Justification

Number of mature individuals

<10 000 2500 Unknown There are insufficient data available to determine a minimum and maximum value for the number of mature individuals. However, Marsh (2020) states that, according to a population estimate, there is below 10 000 individuals. Given that Marsh (2020) recommended that the species should be listed as Vulnerable under Criterion C1, it is likely there is above 2500 individuals. This was reaffirmed in personal communication (J Marsh 2020. pers comm 9 November).

Trend Declining The population is likely contracting due to loss of suitable habitat and very severe reduction of the Western River subpopulation, resulting from the 2019–20 bushfires. Eastern subpopulations are also declining as a result of weed invasion, particularly from Bridal Creeper.


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https://nc.iucnredlist.org/redlist/content/attachment_files/RedListGuidelines.pdf

http://www.environment.gov.au/system/files/pages/d72dfd1a-f0d8-4699-8d43-5d95bbb02428/files/tssc-guidelines-assessing-species-2018.pdf





Justification

Generation time (years)

4 4 Unknown The related trapdoor spiders Tingle Pygmy Trapdoor Spider and Eastern Stirling Range pygmy trapdoor spider both have a generation length of approximately four years (DPAW 2017a, b). Until a taxonomic revision (Harvey et al. 2015), both species were included in the Moggridgea genus. Based on observation of captive KI Micro-trapdoor spiders and knowledge of the species' breeding in the wild, it is likely the generation length and lifespan of the KI Micro-trapdoor Spider is similar to these species (J Marsh 2020. pers comm 29 October).

Extent of occurrence

896 km2 896 km2 6000 km2 The estimate used in the assessment and the minimum plausible value has been calculated using record data for the five known subpopulations and applying the shortest continuous imaginary boundary which can be drawn to encompass these records, as outlined in the Guidelines for Using the IUCN Red List Categories and Criteria (IUCN 2019).

The maximum plausible value has been inferred based on the assumption that the species could potentially occur on the coast-line around the entirety of KI. Using EOO calculation methods outlined in IUCN (2019), this is approximately 6000 km2.

Trend Contracting EOO is likely contracting due to loss of suitable habitat resulting from the 2019–20 bushfires.

Area of Occupancy

32 km2 20 km2 1200 km2 The estimate used in the assessment (32km) has been calculated using record data for the five known subpopulations and applying 2 x 2 km grid cells, as outlined in the IUCN Guidelines (IUCN 2019).

As the minimum possible size of each site is 4 km2, the minimum total AOO is 20 km2. The maximum plausible value has been inferred based on the assumption that the species may occur across around one quarter of the total land area of KI (4400 km2).


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Justification

Trend Contracting AOO is likely contracting due to direct mortality and loss of suitable habitat resulting from bushfires, Bridal Creeper invasion, creek bank erosion and other threats.

Number of subpopulations

5 5 Unknown There are five known subpopulations: Western River, American River, Baudin Conservation Estate, Chapman River Tributary and Penneshaw Creek. Over the past three years, there have been targeted surveys of other creek lines which have found no other individuals or subpopulations (J Marsh 2020. pers comm 29 October). The Western River subpopulation remains extant after the 2019–20 bushfires, though may not persist due to poor post-fire conditions.

Other subpopulations may occur on unsurveyed creek lines across the island. Targeted surveys of all suitable habitat are expected to be completed by July 2022 (J Marsh 2020. pers comm 29 October). If individuals are found at other sites, the low dispersal ability of the species suggests that sites separated by more than 10 m are likely to be isolated from each other.

Trend Contracting The Wester River subpopulation has likely undergone very severe reduction following the 2019–20 bushfires. Only four living individuals have been found in this subpopulation during post-bushfire surveys (J Marsh 2020. pers comm 15 December), If this subpopulation is extirpated due to post-fire conditions, the total number of subpopulations is contracting.

Basis of assessment of subpopulation number

There are 5 subpopulations already known. Many more may occur across the island, but further surveying is required to appropriately identify them. The limited dispersal ability of the species means that any newly discovered sites are likely to be geographically isolated from known sites.

No. locations 3 2 ≤10 The Western River subpopulation was severely impacted by the 2019–20 bushfires (J Marsh 2020. pers comm 29 October). All eastern subpopulations are severely impacted by the invasion of Bridal Creeper (J Marsh 2020. pers comm 29 October). Other unknown subpopulations likely occur in unsurveyed habitat on the Island. Targeted surveys are expected to be


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Justification

completed by July 2022 (J Marsh 2020. pers comm 29 October).

Unburnt habitat fragments remain within the fire-affected area on the western side of the island, though these have likely been impacted by sediment runoff after the fires (J Marsh 2020. pers comm 9 November). It is likely that one fire event similar to the 2019–20 bushfires can impact all western subpopulations.

The eastern sites are considered to represent two locations, based on the most plausible serious threat (fire). Given that the 2019–20 bushfires covered almost the entire western side of KI, during similar conditions a bushfire could engulf the eastern half as well, extirpating the eastern subpopulations (J Marsh 2020. pers comm 24 November). However, there are lower fuel loads and less contiguous vegetation cover in eastern KI, as well as close proximity to fire-fighting resources. The narrow isthmus between Dudley Peninsula and American River may also assist in fire suppression efforts. Therefore, there are likely two locations on the eastern side of the island (American River and Dudley Peninsula). The total number of currently known locations is therefore estimated at three. The minimum plausible number is estimated at two, as it is still possible, though unlikely, that a single fire impacts all eastern subpopulations.

If surveys of waterways in the centre of the island discover new subpopulations, this will likely increase the number of locations. The extent of the 2020 bushfires was predominately across the west of the Island, and eastern fires will not intersect with sites in the centre of the island. Therefore, many waterways in the centre may not be affected by either of these threats, thus leading to an increase in the number of locations. However, the topography of the centre of the island means that KI Micro-trapdoor Spiders are less likely to occur, and it is considered more likely for unknown sites to be on the east of the island (J Marsh 2020. pers comm


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Justification

Trend Contracting The Western River subpopulation has likely undergone very severe reduction following the 2019–20 bushfires. Four living individuals have been found in this subpopulation during post-bushfire surveys (J Marsh 2020. pers comm 15 December), If this subpopulation has been extirpated, the total number of locations is contracting. The number of locations is also contracting due to increases in the frequency and scale of catastrophic bushfires. As this occurs, the number of locations in which a single bushfire can rapidly affect all individuals will likely decrease.

Basis of assessment of location number

Subpopulations occur across the island (J Marsh 2020. pers comm 29 October), though it is likely that a single bushfire could impact all western subpopulations at once, totalling one location. Eastern sites are also treated as 1 location, as fire conditions similar to those in 2019–20 may potentially impact all eastern sites.

Fragmentation Severely fragmented – The KI Micro-trapdoor Spider is probably severely fragmented due to the species’ specific habitat requirements leading to subpopulations occurring in small, isolated sites. This is coupled with the limited dispersal ability of the species (J Marsh 2020. pers comm 29 October).

Fluctuations There are no known extreme fluctuations in EOO, AOO, number of subpopulations, locations or mature individuals.


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Criterion 1 Population size reduction

Reduction in total numbers (measured over the longer of 10 years or 3 generations) based on any of A1 to A4

– Critically Endangered

Very severe reduction

Endangered

Severe reduction

Vulnerable

Substantial reduction

A1 ≥ 90% ≥ 70% ≥ 50%

A2, A3, A4 ≥ 80% ≥ 50% ≥ 30%

A1 Population reduction observed, estimated, inferred or suspected in the past and the causes of the reduction are clearly reversible AND understood AND ceased.

A2 Population reduction observed, estimated, inferred or suspected in the past where the causes of the reduction may not have ceased OR may not be understood OR may not be reversible.

A3 Population reduction, projected or suspected to be met in the future (up to a maximum of 100 years) [(a) cannot be used for A3]

A4 An observed, estimated, inferred, projected or suspected population reduction where the time period must include both the past and the future (up to a max. of 100 years in future), and where the causes of reduction may not have ceased OR may not be understood OR may not be reversible.

Based on any of the following

(a) direct observation [except A3]

(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

Criterion 1 evidenceEligible under Criterion 1 A2ac+4ac for listing as Vulnerable

Generation length

The related and ecologically similar trapdoor spiders Tingle Pygmy Trapdoor Spider and Eastern Stirling Range pygmy trapdoor spider both have a generation length of approximately four years (DPAW 2017a, b). Based on observation of captive KI Micro-trapdoor spiders and knowledge of the species' breeding in the wild, it is likely the generation length and lifespan of the KI Micro-trapdoor Spider is similar to these species (J Marsh 2020. pers comm 29 October). Three generations gives a timeframe of 12 years for Criterion 1.

Overview

The KI Micro-trapdoor Spider appears to have undergone a substantial population reduction of over 30 percent over the past three generation period (12 years). The direct and indirect impacts of bushfires are primary factors in this decline, in conjunction with weed invasion (J Marsh 2020. pers comm 9 November). The available information, presented below, suggests that 30 percent of the total known population was lost in the 2019–20 bushfires, and an unknown percentage is suspected to be have been lost through weed invasion over the past three generations. The remaining known subpopulations are highly fragmented and are projected to decline further due to climate change, erosion and further weed invasion.


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Nearly 100 percent of spiders in the Western River subpopulation appear to have been killed during the 2019–20 fires. Ongoing targeted post-fire surveys have detected four surviving spiders in the fire-affected area, suggesting the shallow burrows offered limited protection from the direct effects of fire (J Marsh 2020. pers comm 9 November). The eastern KI Micro-trapdoor Spider sites were not impacted by the KI Bushfires. Mapping of the fire extent suggests that 0 percent of the distribution of known eastern subpopulations were in the affected area (DAWE 2020b,c; SAFECOM 2020; Todd & Maurer 2020).

Western subpopulations

In December 2019 and January 2020, the western side of KI was affected by large, severe bushfires. The fire area was estimated using the National Indicative Aggregated Fire Extent Dataset (NIAFED) to be approximately 2232 km2 (51 percent of the total Island area (DAWE 2020c; Todd & Maurer 2020). The fire scar, which included all blackened land surface, was estimated using satellite and aerial photography to be approximately 2012 km2 (46 percent of the total Island area; SAFECOM 2020). The total area burnt was estimated, using NIAFED and Australian Google Earth Engine Burnt Area Map (GEEBAM), to be approximately 1674 km2 (38 percent of the island). Of this, it was estimated that 83 percent was burnt at high or very high severity (DAWE 2020b). The burnt area is predominately on the western side of the island, including Western River, which was affected by severe and fast-moving bushfires (DAWE 2020b, c; SAFECOM 2020; Todd & Maurer 2020).

Based on mortality at a typical severely burnt site, 90 percent of individuals (plausible range: 70–100 percent) in this subpopulation are suspected to have died due to the 2019-20 bushfires (Table 4). However, this now appears to be closer to 100 percent, with targeted surveys at burnt sites recording 0 individuals or colonies since the fires took place (J Marsh 2020. pers comm 29 October 2020). Most unburnt sites also appear to be devoid of living spiders, aside from four surviving individuals in two small patches of unburnt creek line (J Marsh 2020. pers comm 15 December). One female had an egg sac suggesting limited reproduction is occurring. However, post-fire conditions (e.g. predation by spider hunting wasps and sediment runoff) may likely kill all surviving individuals, extirpating the subpopulation (J Marsh 2020. pers comm 15 December). The Western River subpopulation represents approximately 30 percent of the total known KI Micro-trapdoor Spider population (J Marsh. pers comm 9 November). Therefore, the total known population decline as a result of the 2020 bushfires is approximately 30 percent based on direct observation. Post-fire conditions are very unfavourable for the KI Micro-trapdoor Spider due to predation, increased weed invasion, sediment runoff clogging creek lines and erosion by sediment flow and feral pigs (J Marsh 2020. pers comm 9 November).

Other, as yet unrecorded, subpopulations may occur on the western side of KI. If this is the case, it is likely that the 2019-20 fire resulted in nearly 100 percent mortality of individuals within the fire extent (DAWE 2020b, c; SAFECOM 2020; Todd & Maurer 2020; J Marsh 2020. pers comm 9 November). While unburnt habitat fragments remain within the fire-affected area, these have likely been impacted by sediment runoff after the fires (J Marsh 2020. pers comm 9 November). A prescribed burn is also planned for north-west KI in Autumn of 2021. This burn may intersect with a large area of unburnt habitat that may contain unknown KI Micro-trapdoor Spider subpopulations (J Marsh 2021. pers comm 12 February).


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Eastern subpopulations

Although unaffected by the 2019-20 bushfires, the eastern KI Micro-trapdoor Spider sites are imperilled due to weed invasion, particularly by Bridal Creeper. Surveying across the known sites occupied by the KI Micro-trapdoor Spider have found that Bridal Creeper is present at all the eastern sites and covers large sections of creek banks. Since introduction to KI more than 100 years ago, Bridal Creeper invasion is estimated to have invaded 40 percent of the habitat at known eastern sites and may have resulted in loss of 100 percent of spider burrows in affected areas (J Marsh 2020. pers comm 9 November). However, it is unclear if spider burrows were present in all the suitable habitat at known eastern sites. The weed is also widespread in many other creek lines across the eastern side of the island (J Marsh 2020. pers comm 9 November). However, the decline over a three-generation period due to Bridal Creeper is unknown.

Projected threats from climate change will likely impact on the species in the future, however, may not have a significant effect within three generation lengths. Climate projections for KI include reduced mean rainfall, increased median temperatures and more frequent droughts (Hope et al. 2015; Resilient Hills and Coasts 2016). These conditions will increase the frequency, scale and intensity of bushfires in the region. Climate projections also predict more frequent and extreme rainfall events, as well as sea level rise and higher storm surges (Hope et al. 2015; Resilient Hills and Coasts 2016). Such events will lead to erosion and flooding of the vertical clay creek banks that form the habitat of the KI Micro-trapdoor Spider.

Conclusion

A precautionary approach on the extent of the total population reduction has been taken, as on-ground surveys following the 2020 KI bushfires are ongoing and baseline data are missing on population size and pre-fire declines. The species appears to have undergone severe population reduction over three generations, which is equivalent to at least 30 percent. The reduction has not ceased, and the cause has not ceased.

The data presented above appear to demonstrate that the species is eligible for listing as Vulnerable under A2ac and A4ac, as population decline appears to be greater than 30 percent over three generations. However, the purpose of the consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered tentative at this stage, as it may be changed as a result of this consultation process.


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Criterion 2 Geographic distribution as indicators for either extent of occurrence AND/OR area of occupancy


Very restricted

Endangered

Restricted

Vulnerable

Limited

B1. Extent of occurrence (EOO) < 100 km2 < 5,000 km2 < 20,000 km2

B2. Area of occupancy (AOO) < 10 km2 < 500 km2 < 2,000 km2

AND at least 2 of the following 3 conditions:

(a) Severely fragmented OR Number of locations

= 1 ≤ 5 ≤ 10

(b) Continuing decline observed, estimated, inferred or projected in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) area, extent and/or quality of habitat; (iv) number of locations or populations; (v) number of mature individuals

(c) Extreme fluctuations in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) number of locations or populations; (iv) number of mature individuals

Criterion 2 evidenceEligible under Criterion 2 B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) for listing as Endangered

EOO and AOO

The KI Micro-trapdoor Spider has a restricted geographic range and is known only from five sites on KI. The EOO of the known sites (including the western subpopulation) is estimated at 896 km2. Targeted surveys for the species are ongoing and unknown subpopulations may occur in suitable habitat on coastlines all around KI, suggesting a maximum plausible EOO o 6000 km2

. The figures for EOO and Area of Occupancy (AOO) are based on the mapping of point records from 2005–2020, obtained from state governments, museums and the CSIRO. The EOO was calculated using a minimum convex hull, as outlined in the IUCN Guidelines (IUCN 2019).

The estimated AOO of known sites is 32 km2, calculated using the 2x2 km grid cell method as outlined in the IUCN Guidelines (IUCN 2019). If there are other subpopulations found, then the AOO will be larger but is unlikely to be above 500 km2. The AOO of invertebrates is difficult to identify and is influenced by the level of sampling effort across the species range, often leading to significant under-estimation of the actual area. The KI Micro-trapdoor Spider appears to require targeted surveys to identify its presence and other subpopulations likely remain to be found (J Marsh 2020. pers comm 29 October). The species’ specific habitat requirements severely restrict the potential AOO, and previous sites have found subpopulations with very small ranges.

Given that the EOO is less than 5000 km2 and the maximum AOO is likely less than 500 km2, the species meets the threshold for listing as Endangered under sub-criterion B1 and sub-criterion B2.


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The 2019–20 KI bushfires overlapped with almost the entirety of the Western River subpopulation, and ongoing post-fire surveying has identified only four living KI Micro-trapdoor Spiders in the area. If the subpopulation undergoes local extinction due to post-fire conditions, the minimum AOO and EOO may be reduced. The species is identified as a priority for urgent management intervention (DAWE 2020a).

Severely fragmented and number of locations

The KI Micro-trapdoor Spider is probably severely fragmented due to the species’ specific habitat requirements leading to subpopulations occurring in small, isolated sites. This is coupled with the limited dispersal ability of the species (J Marsh 2020. pers comm 29 October).To be considered severely fragmented, over 50 percent of the AOO must be in small and isolated patches (IUCN 2019). There is insufficient information on subpopulation sizes and viable populations for the species, but the isolation of the known subpopulations and limited dispersal suggests the species is likely severely fragmented.

The KI Micro-trapdoor Spider is considered to occur at two or three locations, based on the most plausible serious threat (fire) as per the IUCN Guidelines (IUCN 2019). The 2019-20 bushfires burnt the western half of KI, impacting 38–51 percent of the total Island area (see Threats section above). Subpopulations in the western half of KI, if extant, are therefore considered to comprise one location.

The eastern sites in KI comprise two locations, as there are a few factors preventing a bushfire from engulfing the eastern half of the island during similar weather conditions to 2019–20 (Table 3). Though historical bushfires on the eastern side of the island have never had such a large extent (DEW 2020a), the 2019–20 bushfires were unprecedented and larger than all previous fires on the western side of the island (DAWE 2020a). This suggests that historical fires on the east of the island may not be good indicators of potential fires in the future under climate change scenarios (Hope et al. 2015). Surveys of waterways in the centre of the island may discover new subpopulations, increasing the number of locations as these are unlikely to be affected by fires on the eastern and western sides of the island. However, the topography of the centre of the island decreases the likelihood of finding new KI Micro-trapdoor Spider subpopulations in this area (J Marsh 2020. pers comm 9 November). Any additional subpopulations discovered on KI will most likely be in the east (J Marsh 2020. pers comm 25 November). A large fire could potentially lead to extinction of the species if the eastern side of the island is engulfed completely.

The distribution is severely fragmented with one or two locations; therefore, the species appears to meet the threshold for listing as Endangered under sub-criterion (a).


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Continuing decline

The EOO, AOO, extent and quality of habitat, number of locations or subpopulations, and number of individuals are declining due to ongoing threats from fire, weed invasion and erosion, thereby meeting sub-criterion (b) (i,ii,iii,iv,v). Ongoing surveys have found only four living individuals in the Western River subpopulation, which may undergo extinction due to post-fire conditions (J Marsh 2020. pers comm 15 December). Extinction of the Western River site would lead to a decline in AOO and EOO. Substantial declines to habitat quality have also occurred due to ongoing Bridal Creeper invasion across all the eastern subpopulations.

Climate change is already impacting the population by increasing the risk and severity of bushfires on KI, which will result in continuing decline in the area, extent and quality of habitat, and number of mature individuals (Hope et al. 2015; CSIRO & Bureau of Meteorology 2015). Climate change and will also likely influence the species through increased flooding and erosion.

Fluctuations

There are no known extreme fluctuations in EOO, AOO, number of subpopulations, locations or mature individuals.

Conclusion

The species’ EOO and AOO are restricted, the geographic distribution is severely fragmented with fewer than five locations, and there is a continuing decline in the EOO, AOO, habitat, number of subpopulations and number of mature individuals.

The data presented above appear to demonstrate that the species is eligible for listing as Endangered under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.


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Criterion 3 Population size and decline


Very low

Endangered

Low

Vulnerable

Limited

Estimated number of mature individuals < 250 < 2,500 < 10,000

AND either (C1) or (C2) is true

C1. An observed, estimated or projected continuing decline of at least (up to a max. of 100 years in future)

Very high rate

25% in 3 years or 1 generation

(whichever is longer)

High rate

20% in 5 years or 2 generation


Substantial rate

10% in 10 years or 3 generations


C2. An observed, estimated, projected or inferred continuing decline AND its geographic distribution is precarious for its survival based on at least 1 of the following 3 conditions:

(a)

(i) Number of mature individuals in each population

≤ 50 ≤ 250 ≤ 1,000

(ii) % of mature individuals in one population =

90 – 100% 95 – 100% 100%

(b) Extreme fluctuations in the number of mature individuals

Criterion 3 evidenceEligible under Criterion 3 C2a(i) for listing as Vulnerable

Number of mature individuals

The population size of the KI Micro-trapdoor Spider is not known with certainty. However, according to population estimates gathered using the ratio of presence to absence records during on ground surveys, it can be confidently estimated that the total population of KI Micro-trapdoor Spiders has fewer than 10 000 individuals (J Marsh 2020. pers comm 9 November). It is difficult to give a more accurate estimation of population with any certainty, though there are may be between 1,000 and 4,000 individuals in total. It is unclear how many of these are mature (J Marsh 2021. pers comm 16 March). This is based on targeted surveys that have taken place since 2017, as well as post-fire surveys which have taken place since March 2020. Further population estimates will likely be available after surveys of the bushfire-affected area are completed in July 2021. Surveys of the unburnt eastern sites are also planned from July 2021, though subject to approval and funding (J Marsh 2020. pers comm 29 October).


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Continuing decline

Following the 2019–20 fires, a population reduction of over 30 percent is suspected (as identified under Criterion 1). The impacts of the bushfires and Bridal Creeper invasion are the primary drivers of continuing decline. Evidence suggests that Bridal Creeper is present in 100 percent of eastern sites and has led to 40 percent decline in suitable habitat over the 100 years it has been on the island (J Marsh 2020. pers comm 29 October). However, there does not appear to be sufficient evidence to demonstrate a 10 percent decline over the next three generations (12 years). Though fire, Bridal Creeper and changing climatic conditions are ongoing threats causing continuing decline (Table 1), the level of decline required to exceed the threshold for listing as Vulnerable under sub-criterion C1 has not been met.

Precarious geographic distribution

There is believed to be under 1000 mature individuals present in each known subpopulation. (J Marsh 2020. pers comm 10 December). The largest subpopulation is likely between 200 and 1,000 total individuals, with a best guess estimate of 500 individuals. There is likely 200-300 individuals in each other sub-population. These estimates are very uncertain, and it is not currently possible to determine the number of mature individuals per subpopulation (J Marsh 2021. pers comm 16 March). As the species is undergoing continuing decline, this meets the threshold for listing as Vulnerable under sub-criterion C2.

There are no subpopulations that represent 100 percent of the mature individuals in the total population.

Fluctuations

There have been no known extreme fluctuations in the number of mature individuals.

Conclusion

Based on survey estimates, the number of KI Micro-trapdoor Spider mature individuals is less than 10 000. There is evidence for continuing population decline, but no sufficient evidence to determine if this decline is likely to be above 10 percent in 3 generations. However, the geographic distribution is precarious for its survival, based on each population consisting of fewer than 1000 mature individuals.

The data presented above appear to demonstrate that the species is eligible for listing as Vulnerable under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.


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Criterion 4 Number of mature individuals


Extremely low

Endangered

Very Low

Vulnerable

Low

D. Number of mature individuals < 50 < 250 < 1,000

D2.1 Only applies to the Vulnerable category

Restricted area of occupancy or number of locations with a plausible future threat that could drive the species to critically endangered or Extinct in a very short time

.

- -

D2. Typically: area of occupancy < 20 km2 or number of locations ≤ 5

1 The IUCN Red List Criterion D allows for species to be listed as Vulnerable under Criterion D2. The corresponding Criterion 4 in the EPBC Regulations does not currently include the provision for listing a species under D2. As such, a species cannot currently be listed under the EPBC Act under Criterion D2 only. However, assessments may include information relevant to D2. This information will not be considered by the Committee in making its recommendation of the species’ eligibility for listing under the EPBC Act, but may assist other jurisdictions to adopt the assessment outcome under the common assessment method.

Criterion 4 evidenceNot eligible

The number of mature individuals is difficult to discern, though there estimated to be above 1000 individuals of any age class (J Marsh 2020. pers comm 9 November). Additionally, the KI Micro-trapdoor Spider is not eligible for listing as Vulnerable under sub-criterion D2, as although there are fewer than five known locations there are no plausible future threats that could drive the species to Critically Endangered or Extinct in a very short time.

Conclusion

The data presented above appear to be insufficient to demonstrate if the species is eligible for listing under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.


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http://www.environment.gov.au/biodiversity/threatened/cam

http://www.environment.gov.au/biodiversity/threatened/cam


Criterion 5 Quantitative analysis


Immediate future

Endangered

Near future

Vulnerable

Medium-term future

Indicating the probability of extinction in the wild to be:

≥ 50% in 10 years or 3 generations, whichever is longer (100 years max.)

≥ 20% in 20 years or 5 generations, whichever is longer (100 years max.)

≥ 10% in 100 years

Criterion 5 evidenceInsufficient data to determine eligibility

Population viability analysis has not been undertaken for the KI Micro-trapdoor Spider.

Conclusion

There are insufficient data to demonstrate if the species is eligible for listing under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

Adequacy of surveyThe survey effort has been considered adequate and there is sufficient scientific evidence to support the assessment.

Listing and Recovery Plan RecommendationsNo recovery plan is in place for the Kangaroo Island Micro-trapdoor Spider.

A decision about whether there should be a recovery plan for this species has not yet been determined. The purpose of this consultation document is to elicit additional information to help inform this decision.


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© Commonwealth of Australia 2021

Ownership of intellectual property rights

Unless otherwise noted, copyright (and any other intellectual property rights) in this publication is owned by the Commonwealth of Australia (referred to as the Commonwealth).

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All material in this publication is licensed under a Creative Commons Attribution 4.0 International Licence except content supplied by third parties, logos and the Commonwealth Coat of Arms.

Inquiries about the licence and any use of this document should be emailed to [email protected].

Cataloguing data

This publication (and any material sourced from it) should be attributed as: Department of Agriculture, Water and the Environment 2021, Conservation advice for Moggridgea rainbowi (Kangaroo Island Micro-trapdoor Spider), Canberra.

This publication is available at the SPRAT profile for Moggridgea rainbowi (Kangaroo Island Micro-trapdoor Spider).

Department of Agriculture, Water and the EnvironmentGPO Box 858, Canberra ACT 2601Telephone 1800 900 090Web awe.gov.au

The Australian Government acting through the Department of Agriculture, Water and the Environment has exercised due care and skill in preparing and compiling the information and data in this publication. Notwithstanding, the Department of Agriculture, Water and the Environment, its employees and advisers disclaim all liability, including liability for negligence and for any loss, damage, injury, expense or cost incurred by any person as a result of accessing, using or relying on any of the information or data in this publication to the maximum extent permitted by law.

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Consultation on Species Listing Eligibility and ...€¦ · Web viewTaxonomy. Conventionally accepted as Moggridgea rainbowi Pulleine (1919). Description . The Kangaroo Island (KI)