I’m searching firegrounds for surviving Kangaroo Island Micro-trapdoor spiders. 6 months on, I’m yet to find any



Jess Marsh, Author provided

Jess Marsh, Murdoch University

This article is part of Flora, Fauna, Fire, a special project by The Conversation that tracks the recovery of Australia’s native plants and animals after last summer’s bushfire tragedy. Explore the project here and read more articles here.


I’m standing on a hill in Kangaroo Island’s Western River Wilderness Protection Area, looking over steep gullies and sweeping hillsides. As far as I can see, the landscape is burnt: bright patches of regrowth contrast with skeletal, blackened trunks. It’s stark, yet strangely beautiful.

It’s late May, five months after the catastrophic summer fires burned 90% of the park. I’m here to assess the damage to some of our tiniest Australians.

Much attention has been given to the plight of Kangaroo Island’s iconic birds and mammals – the Glossy Black Cockatoo and the Kangaroo Island Dunnart, for example. However, the invertebrates – spiders, insects and myriad other groups – have largely been overlooked. These groups contain some of Australia’s most threatened species.

Among the invertebrates listed by the federal government as a priority for intervention is an unassuming, brownish-black spider with squat legs and a body about the size of a A$2 coin. Its name: the Kangaroo Island Micro-trapdoor spider (Moggridgea rainbowi).

The trials it now faces offer an insight into the enormous challenges ahead for invertebrates – the tiny engines of Australia’s biodiversity – in the wake of last summer’s cataclysmic fires.

A female Kangaroo Island Micro-trapdoor spider (Moggridgea rainbowi)
Jess Marsh, Author provided



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The sea-faring spider

The Kangaroo Island Micro-trapdoor spider has an interesting history. It is the only member of its genus found in Australia, its closest relative being in Africa. Studies show it arrived here between 2 and 16 million years ago, likely rafting across the ocean on vegetation! A true voyager.

Kangaroo Island Micro-trapdoor spiders exist only on Kangaroo Island. They live in short, 6cm burrows, built neatly into creek banks. They are slow, calm spiders, spending most of their time in their burrow, determinedly holding the door shut with their fangs.

The females care for their young; I have opened a trapdoor to find 20 tiny spiders living together with their mother. When ready, the young disperse short distances to build burrows of their own, tiny versions of the adult’s.

When ready, young Kangaroo Island Micro-trapdoor spiders build their own burrows not far from their mothers’.
Jess Marsh, Author provided

Assessing the damage

My colleagues and I are in this conservation park today to locate patches of less fiercely burnt land in which to look for survivors. Sadly, all the known western populations of this enigmatic spider were destroyed. I am yet to find any survivors in the fire ground, but it is early days.

We will be out here for the next year or so, walking hundreds of kilometres of creek lines, searching for signs of life. There is a lot of land out there. Around 210,000 hectares was burnt, almost half of Kangaroo Island. I remain hopeful that some colonies have survived.

If we find some Kangaroo Island Micro-trapdoor spiders – what then?

Surviving the initial blaze is the first step in the struggle for survival. The post-fire environment has many threats – habitat loss, exposure to hungry predators, weeds. Today, I noticed areas where soil, loosened by fire, has washed into creeks, completely burying them.

If we find some surviving individuals, we’ll protect them by installing sediment control, removing weeds and monitoring them in future.

Why should we care?

Not everyone loves spiders. I get that. But the functions invertebrates perform are vital. Our ecosystem relies on them; humans rely on them. Yet collectively our understanding of invertebrates – their importance and their value – is dangerously low.

The Kangaroo Island Micro-trapdoor Spider plays its own role the ecosystem. It is a predator, but we don’t really know what it eats. It’s a food source for birds, mammals or reptiles, but we don’t know what eats it. So, why should we care?

Firstly, I firmly believe every species has its own intrinsic value; every extinction, although a natural part of life, is a loss.

Secondly, the ecosystem is so complicated we don’t know exactly how the loss of one species will impact its prey, the parasites that live on it or its predators. And when we’re facing multiple extinctions, these effects could be devastating.

The Kelly Hill Conservation Park in Kangaroo Island was badly burnt in last summer’s fires.
Jess Marsh, Author provided

The Kangaroo Island Micro-trapdoor spider, the Kangaroo Island Assassin Spider, the Green Carpenter Bee – we only know these species are threatened because scientists like me have spent years or decades studying them.

But the majority of Australia’s invertebrate species are yet to be discovered. Many will be similarly at risk, but we have no way of measuring the scale of risk or the repercussions. That’s a fact we should all find scary.

There is hope, though. It’s not yet over for these species. Work such as ours is a step towards understanding how worsening bushfires will affect these vital, but often forgotten, members of our ecosystem.




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The Conversation

Jess Marsh, Research fellow at the Harry Butler Institute, Murdoch University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Trapdoor spider species that stay local put themselves at risk



File 20190405 123397 omwexr.jpg?ixlib=rb 1.1
A palisade trapdoor spider of the new species E. turrificus walks across the rainforest floor near Maleny, Queensland.
Jeremy Wilson, Author provided

Jeremy Dean Wilson, Griffith University

Several new species of trapdoor spiders found in Queensland are finally described in an article published this month in Invertebrate Systematics.

But each of the new species occurs in only its own single, isolated patch of rainforest in southeastern Queensland, and nowhere else.

Because these species have such tiny natural distributions, they are especially vulnerable to extinction.




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Unique spider burrows

These newly described spiders have been given the common name palisade trapdoor spiders because of the strange and unique burrows they construct. The entrance to the burrow projects out from the surrounding soil like a miniature turret.

The remarkable palisade burrows constructed by two different species of palisade trapdoor spider. The burrow entrances project from the surrounding soil.
Jeremy Wilson (left), Michael Rix (right)

Not only that, but each of the four new palisade trapdoor spider species constructs its own unique type of burrow.

One species, found in national parkland near Gympie and known scientifically as Euoplos crenatus, constructs a particularly elaborate burrow. The hinged door that covers the burrow entrance is adorned with several rounded lobes which project from the door’s circumference.

This marvel of natural architecture is constructed by the spider using silk and soil. No other spider species in the world constructs something similar.

This species was originally discovered by local naturalists Kelvin and Amelia Nielsen in 1999, who then guided researchers back to the discovery location in 2016 to collect specimens so the species could be formally named.

The burrow entrance of Euoplos crenatus, with its peculiar ‘crenate’ burrow door.
Michael Rix

Another species, Euoplos thynnearum, constructs a burrow entrance with a thick lip within which the burrow door sits. It’s found in the Mary Cairncross Scenic Reserve, a 55-hectare patch of subtropical rainforest popular with visitors to the Sunshine Coast hinterland.

This species is named after Elizabeth, Mabel and Mary Thynne, who originally donated the reserve land to the local council in 1941 to honour their mother Mary Thynne (née Cairncross). Currently, this species is known to occur only within the reserve and in other rainforest patches in the immediate vicinity.

Burrow entrances of the new palisade trapdoor spider species Euoplos thynnearum. This species is largely restricted to a single rainforest patch, occurring within Mary Cairncross Scenic Reserve near Maleny.
Michael Rix

Short-range species at risk

Species that only only occur in a very small area, like these new palisade trapdoor spider species, are known as short-range endemic species.

Although scientists are naming new species at a faster rate than ever before, estimates of the total number of species on Earth still suggest that most animal species have not been formally named. With so much work still to do, some scientists have chosen to prioritise work on particular types of animals that are especially vulnerable to extinction.

In 2002, Mark Harvey, an arachnologist from the Western Australian Museum, proposed that scientists should prioritise the discovery and description of short-range endemic species.

He reasoned that the small ranges of these species make them inherently vulnerable to extinction, and that identifying, naming and studying them is the first step to protecting them.

The strange burrows of the trapdoor spider species Euoplos crenatus project out from between the roots and leaf-litter on the bank of a creek in a rainforest patch near Gympie, Queensland.
Jeremy Wilson

Staying local

For trapdoor spiders, short-range endemism is the rule, not the exception. These spiders live their entire lives in a burrow. Juvenile spiders walk only short distances from their mother’s burrow, before constructing a burrow of their own.

Usually, these spiders will then remain in the same burrow for the remainder of their lives, enlarging it as they grow.

Examples of different trapdoor spider species from eastern Australia. Top left, Arbanitis longipes; top right, Heteromigas sp.; bottom left, Cataxia sp.; bottom right, Namea sp.
Jeremy Wilson

Adult male trapdoor spiders will also leave their burrow to breed, but will only travel relatively short distances. Over time, this extremely limited dispersal ability has led to the evolution of many different trapdoor spider species, each of which occurs in only a very small area.

Since 2012, a research team, led by Queensland Museum researcher Michael Rix, has been trying to discover and name all species of spiny trapdoor spider – this group includes the palisade trapdoor spiders, as well as other strange trapdoor spider species such as the shield-backed trapdoor spiders of Western Australia.

A shield-backed trapdoor spider from Western Australia, showing the distinctive hardened disk on its abdomen which the spider uses to ‘plug’ its burrow as a protection from predators.
Mark Harvey

So far, this project has led to the description of more than 100 new species from throughout Australia, some of which are already classified as threatened by federal and state governments.




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The most iconic of these is Idiosoma nigrum (also a shield-backed trapdoor spider), which is a listed threatened species.

The discovery of all these weird and wonderful spider species should remind us that Australia has some of the most remarkable invertebrate species in the world, and new species are waiting to be discovered in the national parks and reserves which occur around, and even within, our towns and cities – under our noses.

Next time you visit a national park, or drive past a patch of forest while commuting along Australia’s east coast, think to yourself, what might be living in there? Do those species occur anywhere else? And above all, if we lose that forest remnant, what unique species might disappear along with it?The Conversation

Jeremy Dean Wilson, Ph.D candidate, Department of Environment & Science, Griffith University, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.