Australia’s bushfires could drive more than 700 animal species to extinction. Check the numbers for yourself



Invertebrates out greatly outnumber mammals everywhere, including in bushfire zones.
Michael Lee, CC BY-NC-ND

Mike Lee, Flinders University

The scale and speed of the current bushfire crisis has caught many people off-guard, including biodiversity scientists. People are scrambling to estimate the long-term effects. It is certain that many animal species will be pushed to the brink of extinction, but how many?

One recent article suggested 20 to 100, but this estimate mostly considers large, well-known species (especially mammals and birds).

A far greater number of smaller creatures such as insects, snails and worms will also be imperilled. They make up the bulk of biodiversity and are the little rivets holding ecosystems together.




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A season in hell: bushfires push at least 20 threatened species closer to extinction


But we have scant data on how many species of small creatures have been wiped out in the fires, and detailed surveys comparing populations before and after the fires will not be forthcoming. So how can we come to grips with this silent catastrophe?

This native bee (Amphylaeus morosus) has been devastated by the bushfires across much of its range. It plays important roles in pollinating plants and as part of the food web, but has no common name, and its plight is so far unheralded.
Reiner Richter https://www.ala.org.au/

Using the information that is available, I calculate that at least 700 animal species have had their populations decimated – and that’s only counting the insects.

This may sound like an implausibly large figure, but the calculation is a simple one. I’ll explain it below, and show you how to make your own extinction estimate with only a few clicks of a calculator.

Using insects to estimate true extinction numbers

More than three-quarters of the known animal species on Earth are insects. To get a handle on the true extent of animal extinctions, insects are a good place to start.

My estimate that 700 insect species are at critical risk involves extrapolating from the information we have about the catastrophic effect of the fires on mammals.

We can work this out using only two numbers: A, how many mammal species are being pushed towards extinction, and B, how many insect species there are for each mammal species.

To get a “best case” estimate, I use the most conservative estimates for A and B below, but jot down your own numbers.

How many mammals are critically affected?

A recent Time article lists four mammal species that will be severely impacted: the long-footed potoroo, the greater glider, the Kangaroo Island dunnart, and the black-tailed dusky antechinus. The eventual number could be much greater (e.g the Hastings River mouse, the silver-headed antechinus), but let’s use this most optimistic (lowest) figure (A = 4).

Make your own estimate of this number A. How many mammal species do you think would be pushed close to extinction by these bushfires?

We can expect that for every mammal species that is severely affected there will be a huge number of insect species that suffer a similar fate. To estimate exactly how many, we need an idea of insect biodiversity, relative to mammals.

How many insect species are out there, for each mammal species?

The world has around 1 million named insect species, and around 5,400 species of land mammals.

So there are at least 185 insect species for every single land mammal species (B = 185). If the current bushfires have burnt enough habitat to devastate 4 mammal species, they have probably taken out around 185 × 4 = 740 insect species in total. Along with many species of other invertebrates such as spiders, snails, and worms.

There are hundreds of insect species for every mammal species.
https://imgbin.com/

For your own value for B, use your preferred estimate for the number of insect species on earth and divide it by 5,400 (the number of land mammal species).

One recent study suggests there are at least 5.5 million species of insects, giving a value of B of around 1,000. But there is reason to suspect the real number could be much greater.




Read more:
The Earth’s biodiversity could be much greater than we thought


How do our estimates compare?

My “best case” values of A = 4 and B = 185 indicate at least 740 insect species alone are being imperilled by the bushfires. The total number of animal species impacted is obviously much bigger than insects alone.

Feel free to perform your own calculations. Derive your values for A and B as above. Your estimate for the number of insect species at grave risk of extinction is simply A × B.

Post your estimate and your values for A and B please (and how you got those numbers if you wish) in the Comments section and compare with others. We can then see what the wisdom of the crowd tells us about the likely number of affected species.




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Why simplistic models can still be very useful

The above calculations are a hasty estimate of the magnitude of the current biodiversity crisis, done on the fly (figuratively and literally). Technically speaking, we are using mammals as surrogates or proxies for insects.

To improve these estimates in the near future, we can try to get more exact and realistic estimates of A and B.

Additionally, the model itself is very simplistic and can be refined. For example, if the average insect is more susceptible to fire than the average mammal, our extinction estimates need to be revised upwards.

Also, there might be an unusually high (or low) ratio of insect species compared to mammal species in fire-affected regions. Our model assumes these areas have the global average – whatever that value is!

And most obviously, we need to consider terrestrial life apart from insects – land snails, spiders, worms, and plants too – and add their numbers in our extinction tally.

Nevertheless, even though we know this model gives a huge underestimate, we can still use it to get an absolute lower limit on the magnitude of the unfolding biodiversity crisis.

This “best case” is still very sad. There is a strong argument that these unprecedented bushfires could cause one of biggest extinction events in the modern era. And these infernos will burn for a while longer yet.The Conversation

Mike Lee, Professor in Evolutionary Biology (jointly appointed with South Australian Museum), Flinders University

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

Scientists fear insect populations are shrinking. Here are six ways to help


Scientists need your help to protect Australia’s insects and track their numbers.
Joe Castro/AAP

David Yeates, CSIRO; Katja Hogendoorn, University of Adelaide, and Manu Saunders, University of New England

Are you planning a big garden clean-up this summer, or stocking up on fly spray to keep bugs at bay? Before you do, it’s worth considering the damage you might cause to the insects we share the planet with.

Australia’s insect populations are under pressure. The problem is better known in the Northern Hemisphere, where over the past few years scientific studies have reported alarming declines in insect numbers.

We don’t yet have a true understanding of what is happening in Australia. This week, scientists gathered in Brisbane at the Australian Entomological Society conference to discuss the extent of the problem. Evidence suggests several species and populations are under threat.

Some might see insects as small and insignificant, but they perform functions crucial to sustaining life on Earth. There are several simple steps you can take to address insect decline in your area, or even help scientists keep tabs on the problem.

A gold wasp. Australian insect declines have not been well documented.
Oliver Niehuis/Australian Science Media Centre

We need to know more

In Australia, we know iconic species such as the bogong moth, green carpenter bee and Key’s matchstick grasshopper are in decline. There is documented evidence for the extinction of two Australian insect species, but this is probably just the tip of the iceberg.

A research review published this year suggested more than 40% of insect species globally are threatened with extinction over the next few decades. However, this estimate was based on limited studies of a few iconic insect groups in western Europe and the US.




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Scientists re-counted Australia’s extinct species, and the result is devastating


Such findings should be taken with caution. We do not have enough evidence to extrapolate to the whole planet.

Despite this, factors affecting insect populations overseas – such as habitat loss, climate change and insecticide use – most likely also apply in Australia. Bushfires and drought on this continent can also affect insect populations.

There are no published studies documenting insect decline in Australia, but anecdotal reports from entomologists suggest lower than average populations across a number of species. However, very few of our estimated 250,000 insect species are being formally monitored.

A Pelecorhynchid fly. Studies suggest insect populations are declining, but data in Australia is scarce.
CSIRO Entomology

Why you should care

Insects pollinate plants, dispose of waste and control pests, among other functions. The planet would cease to support life without the services insects provide.

If insect populations are in decline, so are the populations of larger animals such as birds and lizards that feed on them.




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In NSW, bogong moths are a staple food for mountain pygmy possums. A collapse in the moth population would lead to possums going hungry, which affects their breeding success.

Australia’s threatened species strategy prioritises action to protect 20 bird species – 14 of which feed partially or solely on insects.

Mountain pygmy possums feed on bogong moths.
Tim Bawden

Six ways to help insects

Insects are small and can inhabit hidden places, so you may not realise how many exist around you. Here are a few ways to help prevent insect decline in your home and elsewhere:

Household insecticide use can damage local insect populations.
Flickr

1. Entice insects to your garden: Lawn is a virtual desert for insects, so if you don’t really need it, cultivate insect-friendly native plants instead. Plan to have something flowering most of the year and aim for a variety of plant heights and structures, such as tall trees, thick shrubs and ground cover.

2. Put the fly spray away: Insecticides have become very efficient in recent years. They indiscriminately kill all insects, not just the ones you’re trying to get rid of. If you have to use insect spray, do so sparingly.

And whenever you can, choose food produced without lots of pesticides. These products are sold with labels such as organic, biodynamic, or chemical-free.

3. Turn off the lights: If you don’t need that outdoor light on all night, turn it off: the moths in your area will thank you. Many nocturnal insects can’t resist the light, but it disrupts their navigation system. This plays havoc with their ability to feed and reproduce.

4. Build them a home: Think about installing an insect hotel – a small structure of hollows for insects to rest and lay eggs in. Or simply leave dead wood or small areas of bare ground for insects to build nests in. If you don’t have a garden, join a local tree-planting group, or convince your council to plant more natives.

A flower fly. Scientists need help form the public to track insect numbers.
Denis Anderson/CSIRO



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How many species on Earth? Why that’s a simple question but hard to answer


5. Resist the urge to clean up: If there is a section of your garden, local park or nature strip that is unkempt, leave it that way. What looks untidy to you is a great place for insects to live.

6. Track insects on your smart phone: Scientists need help to better understand what is happening to our insects. Citizen science apps such as iNaturalist Australia, Wild Pollinator Count, the Atlas of Living Australia and Butterflies Australia help gather valuable information about insect biodiversity, so solutions can be targeted to problem areas.The Conversation

David Yeates, Director of the Australian National Insect Collection, CSIRO; Katja Hogendoorn, University of Adelaide, and Manu Saunders, Research fellow, University of New England

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

How to get people to eat bugs and drink sewage



Disgust may be an impediment to many of us adopting more sustainable lifestyles, from considering alternative foods to drinking recycled water
http://www.shutterstock.com

Nathan S Consedine, University of Auckland

In wealthy societies we’ve become increasingly picky about what we eat. The “wrong” fruits and vegetables, the “wrong” animal parts, and the “wrong” animals inspire varying degrees of “yuck”.

Our repugnance at fruit and vegetables that fail to meet unblemished ideals means up to half of all produce is thrown away. Our distaste at anything other than certain choice cuts from certain animals means the same thing with cows and other livestock slaughtered for food. As for eating things like insects – perfectly good in some cultures – forget about it.

Disgust has its advantages. Its origins likely lie in the basic survival benefit of avoiding anything that smells or tastes bad. But disgust may also be an impediment to many of us adopting more sustainable lifestyles – from eating alternative sources of protein to drinking recycled water.




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Can anything be done about this? The fact that disgust varies between cultures and across ages implies it can. But how?

We set out to answer this by getting a better grip on how disgust works, focusing on disgust in everyday food choices, rather than aversions to the unknown or unfamiliar.

Our research suggests some disgust responses, once set early in childhood, are hard to shift.
But responses involving culturally conditioned ideas of what is “natural” may be modified over time.

Don’t eat that!

Disgust likely began as a powerful “basic” emotional reaction that evolved to steer us away from (and literally eject) potential contaminants – food that smelled and tasted bad. You can think of it as originally being a “don’t eat that” emotion.

The disgust system tends to be “conservative” – rejecting valid sources of possible nutrition that have characteristics implying they might be risky, and guiding us towards food choices that are ostensibly safer. Research by University of British Columbia psychologist Mark Schaller and colleagues suggests people who live in areas with historically high rates of disease not only have stricter food preparation rules but more “conservative” cultural traditions generally.

Is is unclear exactly how or when individual templates for what is disgusting are set, but generally what is seen as “disgusting” is set relatively early in life. Culture, learning and development all help shape disgust.

It’s just not natural!

In our study, we showed 510 adults pairs of “normal” and “alternative” products via an online survey, and asked them how much they would be willing to pay for the alternatives. We also asked them to rate which product was tastier, healthier, more natural, visually appealing and nutritious. Product pairs included:

  • shiny and typically shaped fruits and vegetables vs knobbly, blotchy, gnarled and multi-limbed examples.
  • plant protein foods vs insect-based foods
  • standard drinks vs drinks with ingredients reclaimed from sewage
  • standard medicines vs medicines with ingredients extracted from sewage.
Out of shape: using common fruits and vegetables meant the study’s results were not muddied by responses affected by fear of the unknown.
http://www.shutterstock.com

Our results show that, even after statistically adjusting for obvious factors like pro-environmental attitudes, those with a greater “disgust propensity” are less willing to consume atypical (weird-looking) products.

This may seem rather obvious but most prior studies have muddled a food’s “novelty” with its possible disgusting properties (by asking people, for example, whether they’d eat bugs). By asking about really common fruits and vegetables, our study shows just how far disgust may reach in influencing what we consume.




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As importantly, our results suggest evaluations of a product’s perceived naturalness, taste, health risk, and visual appeal “explains” about half of the disgust effect.

In particular, lack of perceived “naturalness” was a frequently reason for unwillingness to pay for product alternatives. This result was in line with previous studies that have looked attitudes to eating insects or lab-grown meat. This is a promising area for social marketing.

Therapeutic responses

Given evidence about how much of what we consider disgusting is cultural and learned, marketing campaigns could help shift attitudes about what is “natural”. It has been done before. Consider this advertisement to naturalise sugar consumption.

Thinking differently about emotion-eliciting stimuli is termed “reappraisal”. Reappraisal has been shown to reduce disgust effects among those with obsessive compulsive disorder. Desensitisation (repeated exposures) seems less effective in reducing disgust (versus fear) among people with diagnosed phobias, but it may work better among the general population.




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Of course, such speculations remain untested and their ultimate success remains unclear.

But it wasn’t so long ago that Western consumers turned their noses up at fermented foods, and the notion of “friendly bacteria” made as much sense as “friendly fire”. More than a decade ago the residents of a drought-stricken Australian town voted against recycling sewage for drinking water. Now the residents of an Australian city accept recycled sewage being pumped back into the city’s groundwater.

Given time, circumstance and a little nudging, a future meal at your favourite Thai restaurant may well involve ordering a plate of insects.The Conversation

Nathan S Consedine, Professor of Health Psychology, University of Auckland

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

Sit! Seek! Fly! Scientists train dogs to sniff out endangered insects


Julia Mynott, La Trobe University

Three very good dogs – named Bayar, Judd and Sasha – have sniffed out the endangered Alpine Stonefly, one of the smallest animals a dog has been trained to successfully detect in its natural habitat.

The conservation of threatened species is frequently hampered by the lack of relevant data on their distributions. This is particularly true for insects, where the difficulty of garnering simple information means the threatened status of many species remains unrecognised and unmanaged.




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In alpine areas there is a pressing need for innovative methods to better reveal the distribution and abundance of threatened insects.

Alpine regions rely on cool temperatures, and since climate change will bring warmer weather and lower rainfalls, insects like the Alpine Stonefly, which lives in the alpine freshwater system, will struggle to survive.

And while insects might not be appealing to everyone, they are extremely important for ecosystem function.

Traditional survey detection methods are often labour intensive, and hard-to-find species provide limited information. This is where the labrador, border collie and samoyed came to the rescue.

La Trobe’s Anthrozoology Research Group Dog Lab in Bendigo, Victoria have been training a pool of local community volunteers and their dogs in conservation detection to use with environmental DNA sampling. Using both environmental DNA and detection dogs has the potential to generate a lot of meaningful data on these threatened stoneflies.

For seven weeks in a special program, dogs were trained to memorise the odour of the Alpine Stonefly (Thaumatoperla alpina), a threatened but iconic insect in the high plains.

The dogs have previously been trained to sniff out animal nests or faeces but not an animal itself, so this was a new approach and an Australian first.

Stoneflies are hard to catch

The Alpine Stonefly are brightly coloured aquatic insects and are difficult to find, especially as larvae in water where they live as predators for up to two years in the streams on the Bogong High Plains, Mount Buller-Mount Stirling, Mt Baw Baw and the Yarra Ranges.

They often burrow underneath cobbles, boulders and into the stream bed while the adults only emerge from the water for a few months between January and April to reproduce.

With all this in mind, it’s easy to understand why traditional detection methods can be time consuming and often ineffective.

We predominately focused on the endangered Alpine Stonefly, found across the Bogong High Plains. Their restricted distribution and habitat made them an ideal candidate to trial detection dogs and environmental DNA techniques.




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We need a bank of DNA from dirt and water to protect Australia’s environment


How dogs and environmental DNA help

We collected water samples from across the Bogong High Plains, Mount Buller and Mount Stirling with trace DNA, such as cells shed from the insect. The ability to quickly take these samples from a broad area to indicate the presence of a species is important to understand distribution. But this approach limits the amount of ecological information that is gathered.

Initial training introduced the dogs to the odour of the Alpine Stonefly in a controlled laboratory setting. Then they graduated from the laboratory to small areas of bushland to search for the insect.

Once the dogs successfully completed their training, it was time to trial the dogs in the alpine environment and survey Alpine Stoneflies in their natural environment.

The trial was conducted at Falls Creek with the dogs’ three volunteer handlers. And the surveys were successful, with all three dogs finding Alpine Stoneflies in their natural habitats.

So could this success be transferred to a similar species?

Absolutely. In preliminary trials, Bayar, Judd and Sasha detected the Stirling Stonefly, a related species of Thaumatoperla that lives in Mount Buller and Mount Stirling, suggesting detection dogs can transfer their conservation training from one species to another.

This is a great find as it means this technique can be used to survey yet another species of Thaumatoperla that lives in Mt Baw Baw and the Yarra Ranges.




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Our research is showing that these new sampling techniques supporting conservation are an important part of keeping biodiversity protected in alpine regions.

Now that we’ve successfully trained three dogs, we’re hoping to secure funding to conduct future and more thorough surveys on the Alpine and Stirling Stonefly, and eventually on the third species of stonefly.

By developing creative techniques to detect these species, we boost our ability to document them and, importantly, to protect them.The Conversation

Julia Mynott, Research Officer, Centre for Freshwater Ecosystems, La Trobe University

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

Welcome Asterix, Obelix and Yoda! Finding fun in the serious matter of discovering insects



File 20190307 100781 10wn6hx.jpg?ixlib=rb 1.1
Do these look like Gauls to you? Three of the 103 new weevils identified in Indonesia were named after characters Asterix, Obelix and Idefix.
Alexander Riedel

Nick Porch, Deakin University

Forget the apes, we live on “The Planet of the Beetles”. Welcome.

With an estimated 387,000 formally described species, beetles (Coleoptera) are the most species-rich of the five mega-diverse groups of insects. The others are wasps, ants and bees (Hymenoptera), flies (Diptera), true bugs (Hemiptera), and butterflies and moths (Lepidoptera).




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Today’s publication of 103 new species of weevils from the Indonesian island of Sulawesi is a timely reminder that, after several hundred years of research, we have not even described half of the insect diversity out there. Not even close. Especially in the tropics.

This seems particularly important in light of recent media attention on the global loss of insects (which may or not be an “insectageddon”, depending on how you look at the data).

Knowing what we have

Ideally, before we worry about what we are losing, it would be nice to know what we have.

Guesstimates of the number of beetle species on Earth suggest that only about one quarter of the species out there have been described.

Although most British species were described by the middle of the 19th century, in many parts of the world it is easy to find new species and will be for many decades, providing they hang on that long.




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And it’s probably best to set aside the notion of cracking a bottle of champagne with every new species discovery. As writer Simon Barnes says, referring — in Ten Million Aliens: A Journey Through the Entire Animal Kingdom — to people who discover new species, “they’d be pissed all day”. If you work on weevils, you’d be comatose.

Welcome weevils

Alexander Riedel, a weevil specialist from Germany, and Indonesian museum curator Raden Pramesa Narakusumo are working on the Asia-Pacific weevil genus Trigonopterus.

These small weevils, mostly several millimetres long, are distributed from Samoa in the Pacific through northern Australia to Sumatra. Australian Trigonopterus (32 described species) are mainly restricted to subtropical and tropical rainforests of the east coast, north from around the Queensland/New South Wales border.

The authors’ latest paper describes 103 new species from Sulawesi (Celebes of old) including several they named after Asterix, Obelix and Idefix – principal characters in the French comic series The Adventures of Asterix.

Asterix and Obelix don’t like the Romans much.

Species names are always lower-case and the genus always begins with a capital: for example “Trigonopterus asterix Riedel”, named after Asterix. Italics are used to show that we are talking about a genus and/or species name. The author or authors primarily responsible for describing the species are traditionally appended to the end of the name.

A small greenish forest-dwelling species is named after Yoda of Star Wars fame, and several others after well-known biologists including Charles Darwin, James Watson and Francis Crick (the latter two identified the structure of DNA).

103 new weevil species from Sulawesi: can you pick the differences between them all?
Alexander Riedel

Naming is fun but hard

Naming species in novel ways is more common that you might think. Just this week one of 14 new northern Australian dung beetle species was named Lepanus sauroni Gunter & Weir, after, you guessed it, Sauron of Lord of the Rings fame. Part of the beetle’s abdomen resembles the Eye of Sauron.

Most of the new Trigonopterus (and Lepanus) species are named after the locality where they were discovered, their collector, or distinctive characters they might have.




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Why so many Australian species are yet to be named


You might imagine coming up with 103 new names would be relatively easy, but it’s not that simple. There were already 341 Trigonopterus described (mostly by Riedel and colleagues), and the new names have to be different. The names for new species of this genus described in the future, and there are hundreds more, will have to be different again.

Living in Melbourne, as I do, there are plenty of undescribed invertebrate species including, of course, weevils. If you know what you are doing, many of these are abundant and easy to find. Some may represent charismatic, colourful, fascinating or old evolutionary lineages. Many of these species are known and are preserved in national or international collections awaiting description, but plenty of others are unseen and uncollected.

Who cares? And why?

A widespread lack of enthusiasm for invertebrates translates to a broader lack of knowledge and engagement, and the inevitable “who cares anyway?”.

In Wonderful Life, author Stephen Jay Gould writes:

Classifications are theories about the basis of natural order, not dull catalogues compiled only to avoid chaos.

Describing species, and revealing what is where, fundamentally underlies major fields of biology like ecology, evolution and biogeography, contributing to a deeper understanding of the complexity of life on Earth.

If we’re to prevent the loss of major parts of our biodiversity to extinction, a deeper understanding of the planet’s numerically dominant invertebrate life is critical. Fortunately, there are those like the authors of these papers who follow their passion, and back it up with a lot of highly skilled work.The Conversation

Nick Porch, Senior Lecturer in Environmental Earth Science, Deakin University

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