Uncovering a Secret World on the South Coast

Page header?? UNCOVERING A SECRET WORLD ON THE SOUTH COAST Hiding beneath leaf litter and under rocks on the south coast lies a hidden world of spineless animals. Thanks to the tireless work of the South Coast Threatened Invertebrate Group we are getting a better picture of these amazing animals and how best to protect them. by Sarah Comer, Melinda Moir, Mark Harvey and Deon Utber LANDSCOPE 47 he south-west of Western published scientific literature each year Previous page Australia is recognised as one of 34 due to the many species requiring names Main Mark Harvey collecting invertebrates global biodiversity hotspots, and and the few taxonomists available to do at Middle Island off the south coast. T Photo – Sarah Comer/Parks and Wildlife while the flora and vertebrate fauna are the job. The term ‘Linnaean Shortfall’ Bottom The WA pill millipede (Cynotelopus relatively well described, the challenge of describes this bottleneck situation, but notabilis). documenting invertebrate diversity is one doesn’t help to identify which species that has kept the South Coast Threatened might require conservation. This is partly Above A female Zephyrarchaea mainae found Invertebrate Group (SCTIG) members achieved by conducting surveys and at Torndirrup National Park. Photos – Michael Rix/WA Museum busy for nearly 15 years. examining records to determine how restricted species actually are, where UNDERSTANDING THE they occur and, just as importantly, SPINELESS MAJORITY where they do not occur. This lack of To fully comprehend the challenges of knowledge on a species biogeography is Australia and Parks and Wildlife sought to invertebrate conservation it is important referred to as the ‘Wallacean Shortfall’. address the initial challenge of identifying a to understand some of the concepts So, while the importance of taxonomy is particular subset of potentially threatened that describe how little we know and unquestionable, conservation managers invertebrate fauna in the South Coast what is being done. Invertebrates are also need to have some idea of which Region to improve conservation outcomes ‘hyperdiverse’ – a term used to describe species are likely to need special attention for these species. The expertise of those organisms containing extremely high for management. specialists from the WA Museum, and numbers of species – and of those that Addressing this issue has been the the universities of Western Australia and have been found, many are new to science focus of the SCTIG, which first gathered Melbourne have provided the backbone and yet to be named. There is a bottleneck in 2001. A strong collaboration between for these efforts, with help from a in describing these species, with only a staff from the Western Australian number of Parks and Wildlife staff who very small percentage formally named in Museum, The University of Western have assisted not only with collecting 48 LANDSCOPE Above left Samichus sp. millipedes found at Two Peoples Bay Nature Reserve. Photo – Melinda Moir/UWA Above An idiopid trapdoor spider burrow entrance found during SRE surveys of Fitzgerald River National Park. Photo – Alan Danks/Parks and Wildlife Far left South Coast Threatened Invertebrate Recovery Team meeting. Photo – Melinda Moir/UWA Left The idiopid trapdoor spider from the burrow above. Photo – Alan Danks/Parks and Wildlife “The challenge of documenting invertebrate diversity is one that has kept the SCTIG members busy for nearly 15 years.” invertebrates but also with taking up the These particular habitats had already to disperse and are restricted to isolated challenge of incorporating invertebrate been identified as refuges for a number pockets of specialised habitats. SREs conservation into broader biodiversity of species, including the Stirling Range are only found within areas of less than management programs. Moggridgea spiders that had been studied 10,000km2 and many of these are restricted by Barbara York Main, one of the founding to much smaller areas. This makes them IDENTIFICATION OF REFUGES members of the SCTIG. Barbara’s early more vulnerable to the processes that Given the observed increase in 1990s work on the detrimental effects impact directly on the refugial habitat, and bushfires and the drying climate through of fire on the shallow burrows of these so they require special management to climate change in south-western WA, miniscule trapdoor spiders provided some avoid the risk of extinction. SCTIG initially decided to target the insights into fire and refugial habitat One of the early inspirations groups of invertebrates that were for park managers. More broadly, the illustrating the concept of SREs for dependent on relictual Gondwanan specialised habitats of Moggridgea – south- Parks and Wildlife’s South Coast Region habitats, or those long unburnt pockets east facing moist gullies – were recognised staff was a pin-board in the office of of vegetation likely to remain moist and as essential refuges for a number of species WA Museum mollusc curator Shirley damp throughout the year. ‘Relictual’ with naturally small ranges, known as Slack-Smith. Shirley had placed different habitats provide the moist conditions that short-range endemics (SREs). Examples of coloured pins on a large map of the many specialised invertebrate species invertebrates that are predominantly SREs south-west, with each colour representing prefer, and were deemed a good place to include Gastropoda (snails), Onychophora what she thought were distinct species of start looking for invertebrates that might (velvet worms), Araneae (especially the land snail genus Bothriembryon. The have specialised habitat requirements with mygalomorph spiders) and Diplopoda myriad of localised patches of vivid colours a limited ability to disperse. A modelling (millipedes). clearly illustrated the restricted range of exercise carried out in 2002 provided a The ecological and life history many species. This group was difficult to rough idea of where these habitats might characteristics of these groups are similar; study, but in recent years the work has occur across the south coast. many are hampered by their poor ability been taken up by Corey Whisson from the LANDSCOPE 49 “As a result of the recent surveys, some 26 species have been recognised as threatened, including 17 millipedes, five spiders and four insects.” WA Museum, and he is collaborating with these was the eastern massif assassin Above left Frances Leng hunting for Dr Bram Breuer from the Netherlands spider (Zephyrarchaea robinsi), which is invertebrates in the Stirling Range National Park. to examine diversity of the group using known only from the eastern peaks of the molecular sequence data. Stirling Range. The habitat of this species Above right Acacia weevils (Melanterius is highly vulnerable to fire, and it is one servalus) on Acacia veronica in Stirling Range INVENTORY – PRIORITIES of five assassin spiders in the region now National Park. FOR SURVEY listed as threatened. Photos – Melinda Moir/UWA Other examples of ‘opportunistic’ Above Mark Harvey and Mike Rix from the WA Many collections of animals of collections were invertebrates collected interest had inadvertently already been Museum photographing trapdoor spiders at from vertebrate sampling across the West Cape Howe National Park. made when the SCTIG formed, for region. One collection, made from a pit Photo – Sarah Comer/Parks and Wildlife example, through the broadscale leaf litter trap in a deep gully on Mt Arid during a invertebrate collections conducted to LANDSCOPE Expeditions trip to Cape assess the habitat of the insectivorous and Arid National Park in 2006, was of an endangered noisy scrub-bird (Atrichornis unusual pill millipede. Sarah suspected it clamosus). One of the first actions of the was different and WA Museum Senior Coast NRM which recognised the need SCTIG was to have Parks and Wildlife Curator Mark Harvey and his colleagues to improve our understanding of poorly staff and volunteers extract potential SRE identified that it was the first record surveyed groups and provided funds to invertebrates from jars storing the noisy of the Epicyliosoma genus (now called support some more targeted surveys. The scrub-bird food samples for museum staff Cyliosoma) in WA. Further surveys mapped refugia from the 2002 model was to identify. Many trapdoor spiders and by researcher Melinda Moir found this an excellent starting point and in 2006 millipedes were extracted from leaf litter species, later to be named Epicyliosoma Melinda, with a number of assistants samples collected between Mt Manypeaks sarahae by Melinda and Mark, in several from the museum, surveyed many of the and the Walpole Wilderness. other refugial habitats, but to date it has spots for SRE invertebrates. This work Mountain-top surveys conducted still only been collected from Cape Arid was supported by other targeted work by by Sarah Barrett in the 1990s provided and Cape Le Grand national parks. WA Museum staff and collaborators, and invaluable invertebrate samples that Further documentation of SRE opportunistic collecting by staff from the identified species that appeared to be invertebrates across the region was then Department of Conservation and restricted to summit habitats. One of made possible by support from the South Land Management. Finally, in 2008, the 50 LANDSCOPE Above left Melinda Moir and threatened flora officer Sarah Barrett at Banksia montana translocation site. Photo – Frances Leng Above The clouds that cloak Stirling Range National Park create microclimates

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