Blind shrimps, translucent snails: the 11 mysterious new species we found in potential fracking sites



An ostracod, a small crustacean with more than 70,000 identified species.
Anna33/Wikimedia, CC BY-SA

Jenny Davis, Charles Darwin University; Daryl Nielsen, CSIRO; Gavin Rees, CSIRO, and Stefanie Oberprieler, Charles Darwin University

There aren’t many parts of the world where you can discover a completely new assemblage of living creatures. But after sampling underground water in a remote, arid region of northern Australia, we discovered at least 11, and probably more, new species of stygofauna.

Stygofauna are invertebrates that have evolved exclusively in underground water. A life in complete darkness means these animals are often blind, beautifully translucent and often extremely localised – rarely living anywhere else but the patch they’re found in.

The species we discovered live in a region earmarked for fracking by the Northern Territory and federal government. As with any mining activity, it’s important future gas extraction doesn’t harm groundwater habitats or the water that sustains them.

Our findings, published today, show the importance of conducting comprehensive environmental assessments before extraction projects begin. These assessments are especially critical in Australia’s north, where many plants and animals living in surface and groundwater have not yet been documented.

When the going gets tough, go underground

Stygofauna were first discovered in Western Australia in 1991. Since then, these underground, aquatic organisms have been recorded across the continent. Today, more than 400 Australian species have been formally recognised by scientists.

The subterranean fauna we collected from NT aquifers, including a range of species unknown to science. A–C: Atyid shrimps, including Parisia unguis; D-F: Amphipods in Melitidae family; G: The syncarid species Brevisomabathynella sp.; H-J: members of the Candonidae family of ostracods; K: the harpacticoid species Nitokra lacustris; L: a new species of snail in the Caenogastropoda: M-N: Members of the Cyclopidae family of copepods; O: The worm species Aeolosoma sp.
GISERA, Author provided

Stygofauna are the ultimate climate change refugees. They would have inhabited surface water when inland Australia was much wetter. But as the continent started drying around 14 million years ago, they moved underground to the relatively stable environmental conditions of subterranean aquifers.




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Hidden depths: why groundwater is our most important water source


Today, stygofauna help maintain the integrity of groundwater food webs. They mostly graze on fungal and microbial films created by organic material leaching from the surface.

In 2018, the final report of an independent inquiry called for a critical knowledge gap regarding groundwater to be filled, to ensure fracking could be done safely in the Northern Territory. We wanted to determine where stygofauna and microbial assemblages occurred, and in what numbers.

Our project started in 2019, when we carried out a pilot survey of groundwater wells (bores) in the Beetaloo Sub-basin and Roper River region. The Beetaloo Sub-basin is potentially one of the most important areas for shale gas in Australia.

What we found

The stygofauna we found range in size from centimetres to millimetres and include:

  • two new species of ostracod: small crustaceans enclosed within mussel-like shells

  • a new species of amphipod: this crustacean acts as a natural vacuum cleaner, feeding on decomposing material

  • multiple new species of copepods: tiny crustaceans which form a major component of the zooplankton in marine and freshwater systems

  • a new syncarid: another crustacean entirely restricted to groundwater habitats

  • a new snail and a new worm.

A thriving stygofauna ecosystem lies beneath the surface of northern Australia’s arid outback. We sampled water through bores to measure their presence.
Jenny Davis, Author provided

These species were living in groundwater 400 to 900 kilometres south of Darwin. We found them mostly in limestone karst habitats, which contain many channels and underground caverns.

Perhaps most exciting, we also found a relatively large, colourless, blind shrimp (Parisia unguis) previously known only from the Cutta Cutta caves near Katherine. This shrimp is an “apex” predator, feeding on other stygofauna — a rare find for these kinds of ecosystems.

A microscopic image of Parisia unguis, a freshwater shrimp.
Stefanie Oberprieler, Author provided

Protecting groundwater and the animals that live there

The Beetaloo Sub-basin in located beneath a major freshwater resource, the Cambrian Limestone Aquifer. It supplies water for domestic use, cattle stations and horticulture.

Surface water in this dry region is scarce, and it’s important natural gas development does not harm groundwater.

The stygofauna we found are not the first to potentially be affected by a resource project. Stygofauna have also been found at the Yeelirrie uranium mine in Western Australia, approved by the federal government in 2019. More research will be required to understand risks to the stygofauna we found at the NT site.




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It’s not worth wiping out a species for the Yeelirrie uranium mine


The discovery of these new NT species has implications for all extractive industries affecting groundwater. It shows the importance of thorough assessment and monitoring before work begins, to ensure damage to groundwater and associated ecosystems is detected and mitigated.

Gas infrastructure at Beetaloo Basin
The Beetaloo Basin is part of the federal government’s gas expansion strategy.
Department of Industry, Science, Energy and Resources

Where to from here

Groundwater is vital to inland Australia. Underground ecosystems must be protected – and not considered “out of sight, out of mind”.

Our study provides the direction to reduce risks to stygofauna, ensuring their ecosystems and groundwater quality is maintained.

Comprehensive environmental surveys are needed to properly document the distribution of these underground assemblages. The new stygofauna we found must also be formally recognised as a new species in science, and their DNA sequence established to support monitoring programs.

Different species of copepods from various parts of the world.
Andrei Savitsky/Wikimedia, CC BY-SA

Many new tools and approaches are available to support environmental assessment, monitoring and management of resource extraction projects. These include remote sensing and molecular analyses.

Deploying the necessary tools and methods will help ensure development in northern Australia is sustainable. It will also inform efforts to protect groundwater habitats and stygofauna across the continent.




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The Conversation


Jenny Davis, Professor, Research Institute for Environment & Livelihoods, Charles Darwin University, Charles Darwin University; Daryl Nielsen, Principal Research Scientist, CSIRO; Gavin Rees, Principal Research Scientist, CSIRO, and Stefanie Oberprieler, Research associate, Charles Darwin University

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

COVID has reached Antarctica. Scientists are extremely concerned for its wildlife



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Michelle Power, Macquarie University and Meagan Dewar, Federation University Australia

In December, Antarctica lost its status as the last continent free of COVID-19 when 36 people at the Chilean Bernardo O’Higgins research station tested positive. The station’s isolation from other bases and fewer researchers in the continent means the outbreak is now likely contained.

However, we know all too well how unpredictable — and pervasive — the virus can be. And while there’s currently less risk for humans in Antarctica, the potential for the COVID-19 virus to jump to Antarctica’s unique and already vulnerable wildlife has scientists extremely concerned.

We’re among a global team of 15 scientists who assessed the risks of the COVID-19 virus to Antarctic wildlife, and the pathways the virus could take into the fragile ecosystem. Antarctic wildlife haven’t yet been tested for the COVID-19 virus, and if it does make its way into these charismatic animals, we don’t know how it could affect them or the continent’s ecosystem stability.

A person looking at the red research station in the distance, by the ocean
Bernardo O Higgins Station in Antarctica, where 36 people tested positive to COVID-19.
Stone Monki/Wikimedia, CC BY-SA

Jumping from animals to humans, and back to animals

The COVID-19 virus is one of seven coronaviruses found in people — all have animal origins (dubbed “zoonoses”), and vary in their ability to infect different hosts. The COVID-19 virus is thought to have originated in an animal and spread to people through an unknown intermediate host, while the SARS outbreak of 2002-2004 likely came from raccoon dogs or civets.

Given the general ubiquity of coronaviruses and the rapid saturation of the global environment with the COVID-19 virus, it’s paramount we explore the risk for it to spread from people to other animals, known as “reverse zoonoses”.

The World Organisation for Animal Health is monitoring cases of the COVID-19 virus in animals. To date, only a few species around the globe have been found to be susceptible, including mink, felines (such as lions, tigers and cats), dogs and a ferret.

Whether the animal gets sick and recovers depends on the species. For example, researchers found infected adolescent cats got sick but could fight off the virus, while dogs were much more resistant.




Read more:
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Researchers and tourists

While mink, dogs or cats are not in Antarctica, more than 100 million flying seabirds, 45% of the world’s penguin species, 50% of the world’s seal populations and 17% of the world’s whale and dolphin species inhabit the continent.

A tourist sits near a penguin and takes a photo
Tourists visit penguin roosts in large numbers.
Shutterstock

In a 2020 study, researchers ran computer simulations and found cetaceans — whales, dolphins or porpoises — have a high susceptibility of infection from the virus, based on the makeup of their genetic receptors to the virus. Seals and birds had a lower risk of infection.

We concluded that direct contact with people poses the greatest risk for spreading the virus to wildlife, with researchers more likely vectors than tourists. Researchers have closer contact with wildlife: many Antarctic species are found near research stations, and wildlife studies often require direct handling and close proximity to animals.

Tourists, however, are still a concerning vector, as they visit penguin roosts and seal haul-out sites (where seals rest or breed) in large numbers. For instance, a staggering 73,991 tourists travelled to the continent between October 2019 and April 2020, when COVID-19 was just emerging.

Each visitor to Antarctica carries millions of microbial passengers, such as bacteria, and many of these microbes are left behind when the visitors leave. Most are likely benign and probably die off. But if the pandemic has taught us anything, it takes only one powerful organism to jump hosts to cause a pandemic.

How to protect Antarctic wildlife

There are guidelines for visitors to reduce the risk of introducing infectious microbes. This includes cleaning clothes and equipment before heading to Antarctica and between animal colonies, and keeping at least five metres away from animals.

These rules are no longer enough in COVID times, and more measures must be taken.

The first and most crucial step to protect Antarctic wildlife is controlling human-to-human spread, particularly at research stations. Everyone heading to Antarctica should be tested and quarantined prior to travelling, with regular ongoing tests throughout the season. The fewer people with COVID-19 in Antarctica, the less opportunity the virus has to jump to animal hosts.

A killer whale poking its head out the water near sea ice
Cetaceans, such as orcas, are more susceptible to COVID infections than sea birds and seals.
Shutterstock

Second, close contact with wildlife should be restricted to essential scientific purposes only. All handling procedures should be re-evaluated, given how much we just don’t know about the virus.

We recommend all scientific personnel wear appropriate protective equipment (including masks) at all times when handling, or in close proximity to, Antarctic wildlife. Similar recommendations are in place for those working with wildlife in Australia.

Migrating animals that may have picked up COVID-19 from other parts of the world could also spread it to other wildlife in Antarctica. Skuas, for example, migrate to Antarctica from the South American coast, where there are enormous cases of COVID-19.




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Coronavirus: wastewater can tell us where the next outbreak will be


And then there’s the issue of sewage. Around 37% of bases release untreated sewage directly into the Antarctic ecosystem. Meanwhile, an estimated 57,000 to 114,000 litres of sewage per day is dumped from ships into the Southern Ocean.

Fragments of the COVID virus can be found in wastewater, but these fragments aren’t infectious, so sewage isn’t considered a transmission risk. However, there are other potentially dangerous microbes found in sewage that could be spread to animals, such as antibiotic-resistant bacteria.

A huge cruise ship in icy Antarctic waters
Ships dump 114,000 litres of sewage into the water, each day.
Shutterstock

We can curb the general risk of microbes from sewage if the Antarctic Treaty formally recognises microbes as invasive species and a threat to the Antarctic ecosystem. This would support better biosecurity practices and environmental control of waste.

Taking precautions

In these early stages of the pandemic, scientists are scrambling to understand complexity of COVID-19 and the virus’s characteristics. Meanwhile, the virus continues to evolve.

Until the true risk of cross-species transmission is known, precautions must be taken to reduce the risk of spread to all wildlife. We don’t want to see the human footprint becoming an epidemic among Antarctic wildlife, a scenario that can be mitigated by better processes and behaviours.




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Humans threaten the Antarctic Peninsula’s fragile ecosystem. A marine protected area is long overdue


The Conversation


Michelle Power, Associate Professor in the Department of Biological Sciences, Macquarie University and Meagan Dewar, Lecturer, Federation University Australia

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

Humans force wild animals into tight spots, or send them far from home. We calculated just how big the impact is



Eric Fortin/Flickr, CC BY-NC-ND

Tim Doherty, University of Sydney; Don Driscoll, Deakin University, and Graeme Hays, Deakin University

The COVID pandemic has shown us that disruptions to the way we move around, complete daily activities and interact with each other can shatter our wellbeing.

This doesn’t apply only to humans. Wildlife across the globe find themselves in this situation every day, irrespective of a global pandemic.

Our latest research published today in Nature Ecology and Evolution has, for the first time, quantified the repercussions of logging, pollution, hunting, and other human disturbances, on the movements of a wide range of animal species.

Our findings were eye-opening. We found human disturbances, on average, restricted an animal’s movements by 37%, or increased it by 70%. That’s like needing to travel an extra 11 km to get to work each day (Australia’s average is 16 km).

Disruptions cascade through the ecosystem

The ability to travel is essential to animal survival because it allows animals to find mates, food and shelter, escape predators and competitors, and avoid disturbances and threats.




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And because animal movement is linked to many important ecological processes — such as pollination, seed dispersal and soil turnover — disruptions to movement can cascade through ecosystems.

Our study involved analysing published data on changes in animal movement in response to different types of disturbance or habitat modification by humans. This included agriculture, logging, grazing, recreation, hunting, and pollution, amongst others.

All up, we looked at 719 records of animal movement, spanning 208 studies and 167 species of birds, mammals, reptiles, fish, insects and amphibians. The size of the species we studied ranged from the sleepy orange butterfly to the white shark.

Species included in our study, clockwise from top-left: sleepy orange butterfly, southern leopard frog, tawny owl, white shark, diademed sifaka and red-eared slider turtle.
Photos adapted from Flickr under Creative Commons license CC BY 2.0. Clockwise from top-left: Anne Toal; Trish Hartmann; Les Pickstock; Elias Levy; John Crane; USFWS Midwest Region.

What we found

We found changes in movement are very common, with two-thirds of the 719 cases comprising an increase or decrease in movement of 20% or more. More than one-third of cases changed by 50% or more.

Whether an animal increases or decreases its movement in response to disturbance from humans depends on the situation.

Animals may run away from humans, or move further in search of food and nesting sites. For example, a 2020 study on koalas found their movements were longer and more directed in areas where habitats weren’t well connected, because they had to travel further to reach food patches.

Likewise, the daily movement distances of mountain brushtail possums in central Victoria were 57% higher in remnant bushland along roadsides, compared to large forest areas.

Land clearing can cause animals to move through risky areas in search of suitable habitat.
Tim Doherty, Author provided

Decreases in movement can occur where animals encounter barriers (such as highways), if they need to shelter from a disturbance, or can’t move as efficiently through altered habitats. In the United States, for example, researchers played a recording of humans talking and found it caused a 34% decrease in the speed that mountain lions move.

On the other hand, some decreases in movement occur where an animal actually benefits from habitat changes. A wide range of animals — including storks, vultures, crows, foxes, mongooses, hyenas and monitor lizards — have shorter movements around garbage dumps because they don’t have to move very far to get the food they need.

Huge changes in movement make animals vulnerable

Overall, we found the average increase in animal movement was +70% and the average decrease was -37%, which are substantial changes.

Imagine having to increase the distance you travel to work, the shops and to see family and friends, by 70%. You would spend a lot more time and energy travelling and have less time to rest or do fun things. And if you live in Melbourne, you know what substantial reductions in movement are like due to COVID-related lockdowns.

Examples of what a 70% increase (bottom left) and a 37% decrease (bottom right) in your normal home range (top) might look life if you lived in Melbourne.

In addition to greater energy expenditure, increased movements can mean animals need to move through risky areas where they are more vulnerable to predation.

And decreases in movement can be harmful if animals can’t find adequate food or disperse to find mates, or if ecological processes such as seed dispersal are disrupted.




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For example, flightless rails, birds native to New Zealand, are important for dispersing seeds. But research showed birds in areas of high human activity (campgrounds) moved 35–41% shorter distances than birds away from campgrounds. This could limit the population growth of plants if their seeds are not being dispersed as far.

When disturbances are unpredictable

We compared the effects of different disturbance types on animals by splitting them into two categories: human activities (such as hunting, military procedures and recreation like tourism) and habitat modification (such as agriculture and logging).

Both disturbance types can have severe impacts, ranging from a 90% decrease to 1,800% increase in movement for human activities, and a 97% decrease to a 3,300% increase for habitat modifications.

Changes in animal movement distances in response to different types of disturbance. Positive values mean movement was higher in disturbed compared to undisturbed areas.

But we found human activities caused much stronger increases in animal movement distances (averaging +35%) than habitat modifications (averaging +12%).

This might be because human activities are more episodic in nature. In other words, animals are more likely to run away from these unpredictable disturbances.




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For example, military manoeuvres in Norway led to 84% increase in the home range of moose. And when moose in Sweden were exposed to back-country skiers, their movement speed increased 33-fold.

In contrast, habitat modifications like logging generally represent more persistent changes to the environment, which animals can sometimes adapt to over time.

Moose head behind green bushes
Human activities can lead to huge changes in the movement of animals, such as moose.
Shutterstock

Reducing harms on wildlife

To reduce the harms we inflict on wildlife, we must protect habitats in relatively intact sea and landscapes from getting degraded or transformed. This could include establishing and managing new national parks and marine protected areas.

Where ecosystems are already modified, improving the connections between habitats and the availability of resources (food and water) can help animals move more easily and populations persist.

And with regards to human activities, which generally caused stronger increases in movement, better managing disturbances such as hunting, recreation and tourism can help to minimise or avoid impacts on animal movement. This could include, for example, establishing a no-take zone in a marine protected area, or enforcing restrictions to activities during breeding periods.




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The Conversation


Tim Doherty, ARC DECRA Fellow, University of Sydney; Don Driscoll, Professor in Terrestrial Ecology, Deakin University, and Graeme Hays, Professor of Marine Science, Deakin University

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

It’s bee season. To avoid getting stung, just stay calm and don’t swat



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Caitlyn Forster, University of Sydney and Tanya Latty, University of Sydney

This summer’s wetter conditions have created great conditions for flowering plants. Flowers provide sweet nectar and protein-rich pollen, attracting many insects, including bees.

Commercial honey bees are also thriving: the New South Wales population has reportedly bounced back after the drought and bushfires

While you may have seen a lot of bees around lately, there’s no reason to be afraid. Most bees are only aggressive when provoked, and some don’t sting at all. And some bee-like insects are actually flies.

We are experts on honey bee and other insect behaviour. So let’s look at which bees to watch out for, and how to avoid being stung this summer.

Blue banded bee
Most bees, like this native blue banded bee, are not very interested in people.
Shutterstock

Is it a bee, or a wanna-bee?

Bees in Australia comprise both introduced and native species.

Invasive bees found in Australia, all of which can sting, include the widespread European honeybees, bumble bees in Tasmania, and Asian honey bees in Queensland.




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Australia is also home to about 2,000 native bees, including 11 stingless species.

Stingless bees live in colonies and produce honey. Other native species, such as blue banded bees and leaf cutter bees, are capable of stinging but are rarely aggressive.

Some insects we see around flowers are actually harmless hoverflies. But their yellow and black stripes mean they are often mistaken for bees.

A hoverfly
Hoverflies have similar colouring to honeybees.
Caitlyn Forster

Bees out and about

Bees on flowers are usually more interested in the food they’re collecting than the people around them. However, if you’re concerned about encountering one on your morning walk or in the garden, there are simple ways to mitigate the risk.

Bees sting when they feel threatened. So when you see one, move slowly and keep your distance. If bees fly close to you, avoid sudden movements such as swatting them away.

And wear closed shoes where bees might fly close to the ground, such as around clover or fallen jacaranda flowers.

Bee approaching wattle flower
If you see a bee in the garden, avoid sudden movements.
Shutterstock

What if I see a swarm?

In spring and into summer, healthy honeybee colonies may reproduce by dividing into two. One part of the colony stays at the hive and the other goes looking for a new home.

Worker bees and the queen bee leave the hive in a swarm and find a spot to stay temporarily while scout bees find a new home. That’s when you might see a swarm on a tree, vehicle or building.

Once scout bees find a new home, they return to the swarm and communicate the location via the “waggle dance”. Once a sufficient number of scouts agree on a new nest site, the swarm lifts into the air and flies to its new home.




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Don’t panic if you encounter a stationary swarm of bees. The bees will sting only if threatened. But keep your distance.

Moving swarms can pose a higher sting risk, and should be avoided. If you encounter one, move a safe distance away, or indoors if possible. When moving away, avoid fast movements or swatting.

Swarms are usually present for a few hours or days before they move to a permanent location. If the bees are in a risky location (for example, near a footpath or other busy areas), call a beekeeper to safely remove them.

Stingless native bees swarm for two reasons: mating and fighting.

Mating swarms involve males congregating outside a hive to mate with the queen. Fighting swarms occur when a colony of stingless bees attempts to invade another colony. They do not usually pose a risk to humans.

Native bees capable of stinging are solitary, so don’t swarm. However, male solitary bees are known to group together on branches in the evening.

Bee swarm on a fence during a 2018 cricket match
Bee swarms, such as this on a fence during a 2018 cricket match, usually move on in a few days.
Brendon Thorne

When a bee sting happens

Death and serious injury from bee stings is rare. But in Australia, bees are responsible for more hospital visits than snakes or spiders. European honeybees are also responsible for more allergic reactions than any other insect.

Only female bees can sting. Honeybees can only sting once, and die shortly after. This is because their stinger is barbed – once it stings something, the bee can’t pull the stinger out. Instead the stinger pulls free from the bee’s abdomen and the bee dies.

Other species can sting multiple times because their stingers are not barbed.

When a bee’s stinger enters your skin, it injects venom from a sac on its abdomen. When this happens, you’re likely to experience temporary swelling and redness.

For most people, reactions to bee venom are shortlived. To limit the amount of venom injected by the bee, quickly remove the sting using the edge of your fingernail or credit card.

In some cases, stings can lead to severe allergic reactions, including anaphylaxis. If you think you may have an allergy to bee stings, speak to your doctor.

And seek medical advice if you are stung in the face or neck, if significant swelling occurs or if you develop symptoms such as wheezing, light-headedness or dizziness.

Person squeezing bee sting on arm
Many people develop swelling and redness after a bee sting.
Shutterstock

Learning to like bees

Bees and other insects play an important role in our food production, by moving pollen from one plant to another. They do a similar job in your garden, helping flowers and fruits to flourish.

But worldwide, bees and other pollinators face many threats, including climate change, misuse of pesticides and habitat loss. We must do what we can to keep pollinator populations healthy.

So if you’re out and about and see a bee, or even a swarm, try not to panic. The bees are probably focused on the job at hand, and not interested in you at all.




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‘Jewel of nature’: scientists fight to save a glittering green bee after the summer fires


The Conversation


Caitlyn Forster, PhD Candidate, School of Life and Environmental Sciences, University of Sydney and Tanya Latty, Associate professor, University of Sydney

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

The mystery of the blue flower: nature’s rare colour owes its existence to bee vision



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Adrian Dyer, RMIT University

At a dinner party, or in the schoolyard, the question of favourite colour frequently results in an answer of “blue”. Why is it that humans are so fond of blue? And why does it seem to be so rare in the world of plants and animals?

We studied these questions and concluded blue pigment is rare at least in part because it’s often difficult for plants to produce. They may only have evolved to do so when it brings them a real benefit: specifically, attracting bees or other pollinating insects.

We also discovered that the scarcity of blue flowers is partly due to the limits of our own eyes. From a bee’s perspective, attractive bluish flowers are much more common.

A history of fascination

The gold and blue funerary mask of the ancient Egyptian pharaoh Tutankhamun.
The ancient mask of the pharaoh Tutankhamun is decorated with lapis lazuli and turquoise.
Roland Unger / Wikimedia, CC BY-SA

The ancient Egyptians were fascinated with blue flowers such as the blue lotus, and went to great trouble to decorate objects in blue. They used an entrancing synthetic pigment (now known as Egyptian blue) to colour vases and jewellery, and semi-precious blue gemstones such as lapis lazuli and turquoise to decorate important artefacts including the Mask of Tutankhamun.




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Feeling blue? Get acquainted with the history of a colour


Blue dye for fabric is now common, but its roots lie in ancient Peru, where an indigoid dye was used to colour cotton fabric about 6000 years ago. Indigo blue dyes reached Europe from India in the 16th century, and the dyes and the plants that produced them became important commodities. Their influence on human fashion and culture are still felt today, perhaps most obviously in blue jeans and shirts.

Renaissance painters in Europe used ground lapis lazuli to produce dazzling works that captivated audiences.

A painting of a woman in a vivid blue robe and white hood, with bowed head and clasped hands.
The Virgin in Prayer by the Italian painter Sassoferrato, circa 1650, highlights the vivid blue colour made with ground lapis lazuli.

Today many blues are created with modern synthetic pigments or optical effects. The famous blue/gold dress photograph that went viral in 2015 not only shows that blue can still fascinate — it also highlights that colour is just as much a product of our perception as it is of certain wavelengths of light.

Why do humans like blue so much?

Colour preferences in humans are often influenced by important environmental factors in our lives. An ecological explanation for humans’ common preference for blue is that it is the colour of clear sky and bodies of clean water, which are signs of good conditions. Besides the sky and water, blue is relatively rare in nature.

What about blue flowers?

We used a new online plant database to survey the the relative frequencies of blue flowers compared to other colours.

Among flowers which are pollinated without the intervention of bees or other insects (known as abiotic pollination), none were blue.

But when we looked at flowers that need to attract bees and other insects to move their pollen around, we started to see some blue.

This shows blue flowers evolved for enabling efficient pollination. Even then, blue flowers remain relatively rare, which suggests it is difficult for plants to produce such colours and may be a valuable marker of plant-pollinator fitness in an environment.

Global flower colour frequency for human visual perception (A) shows when considering animal pollinated species less than 10% are blue (B), and for wind pollinated flowers almost none are observed to be blue (C).
Dyer et al., Author provided

We perceive colour due to how our eyes and brain work. Our visual system typically has three types of cone photoreceptors that each capture light of different wavelengths (red, green and blue) from the visible spectrum. Our brains then compare information from these receptors to create a perception of colour.

For the flowers pollinated by insects, especially bees, it is interesting to consider that they have different colour vision to humans.




Read more:
Inside the colourful world of animal vision


Bees have photoreceptors that are sensitive to ultraviolet, blue and green wavelengths, and they also show a preference for “bluish” colours. The reason why bees have a preference for bluish flowers remains an open field of research.

Various blue flowers from our study.

Why understanding blue flowers is important

About one-third of our food depends on insect pollination. However, world populations of bees and other insects are in decline, potentially due to climate change, habitat fragmentation, agricultural practices and other human-caused factors.

The capacity of flowering plants to produce blue colours is linked to land use intensity including human-induced factors like artificial fertilisation, grazing, and mowing that reduce the frequency of blue flowers. In contrast, more stressful environments appear to have relatively more blue floral colours to provide resilience.

For example, despite the apparent rarity of blue flower colours in nature, we observed that in harsh conditions such as in the mountains of the Himalaya, blue flowers were more common than expected. This shows that in tough environments plants may have to invest a lot to attract the few available and essential bee pollinators. Blue flowers thus appear to exist to best advertise to bee pollinators when competition for pollination services is high.

Knowing more about blue flowers helps protect bees

Urban environments are also important habitats for pollinating insects including bees. Having bee friendly gardens with flowers, including blue flowers that both we and bees really appreciate, is a convenient, pleasurable and potentially important contribution to enabling a sustainable future. Basically, plant and maintain a good variety of flowers, and the pollinating insects will come.




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Our ‘bee-eye camera’ helps us support bees, grow food and protect the environment


The Conversation


Adrian Dyer, Associate Professor, RMIT University

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

It’s not too late to save them: 5 ways to improve the government’s plan to protect threatened wildlife



Numbats are among 20 mammals on the federal government’s priority list.
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Euan Ritchie, Deakin University; Ayesha Tulloch, University of Sydney; Don Driscoll, Deakin University; Megan C Evans, UNSW, and Tim Doherty, University of Sydney

Australia’s Threatened Species Strategy — a five-year plan for protecting our imperilled species and ecosystems — fizzled to an end last year. A new 10-year plan is being developed to take its place, likely from March.

It comes as Australia’s list of threatened species continues to grow. Relatively recent extinctions, such as the Christmas Island forest skink, Bramble Cay melomys and smooth handfish, add to an already heavy toll.

Red handfish (Thymichthys politus), cousin of the recently extinct smooth handfish, are critically endangered. They’re small, bottom-dwelling fish that tend to ‘walk’ on their pectoral and pelvic fins rather than swim.
CSIRO Science Image, CC BY-SA

Now, more than ever, Australia’s remarkable species and environments need strong and effective policies to strengthen their protection and boost their recovery.

So as we settle into the new year, let’s reflect on what’s worked and what must urgently be improved upon, to turn around Australia’s extinction crisis.




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How effective was the first Threatened Species Strategy?

The Threatened Species Strategy is a key guiding document for biodiversity conservation at the national level. It identifies 70 priority species for conservation, made up of 20 birds, 20 mammals and 30 plants, such as the plains-wanderer, malleefowl, eastern quoll, greater bilby, black grevillea and Kakadu hibiscus.

These were considered among the most urgent in need of assistance of the more than 1,800 threatened species in Australia.

The strategy also identifies targets such as numbers of feral cats to be culled, and partnerships across industry, academia and government key to making the strategy successful.

The original strategy (2015-20) was eagerly welcomed for putting the national spotlight on threatened species conservation. It has certainly helped raise awareness of its priority species.

However, there’s little evidence the strategy has had a significant impact on threatened species conservation to date.

The midterm report in 2019 found only 35% of the priority species (14 in total) had improving trajectories compared to before the strategy (pre-2015). This number included six species — such as the brush-tailed rabbit-rat and western ringtail possum — that were still declining, but just at a slower rate.

Threatened Species Index trends for mammals (left) and birds (right) from 2000 to 2017. The index and y axes show the average change in populations (not actual population numbers) through time.
The Theatened Species Recovery Hub, Author provided

On average, the trends of threatened mammal and bird populations across Australia are not increasing.

Other targets, such as killing two million feral cats by 2020, were not explicitly linked to measurable conservation outcomes, such as an increase in populations of threatened native animals. Because of this, it’s difficult to judge their success.




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What needs to change?

The previous strategy focused very heavily on feral cats as a threat and less so on other important and potentially compounding threats, particularly habitat destruction and degradation.

Targets from the first Threatened Species Strategy.
Department of Agriculture, Water and the Environment

For instance, land clearing has contributed to a similar number of extinctions in Australia (62 species) as introduced animals such as feral cats (64).

In fact, 2018 research found agricultural activities affect at least 73% of invertebrates, 82% of birds, 69% of amphibians and 73% of mammals listed as threatened in Australia. Urban development and climate change threaten up to 33% and 56% of threatened species, respectively.




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Other important threats to native Australian species include pollution, feral herbivores (such as horses and goats), very frequent or hot bushfires and weeds. Buffel grass was recently identified as a major emerging threat to Australia’s biodiversity, with the risk being as high as the threat posed by cats and foxes.

Five vital improvements

We made a submission to the Morrison government when the Threatened Species Strategy was under review. Below, we detail our key recommendations.

1. A holistic and evidence-based approach encompassing the full range of threats

This includes reducing rates of land clearing — a major and ongoing issue, but largely overlooked in the previous strategy.

A Leadbeater's possum peers out from behind a tree trunk.
Leadbeater’s possums are critically endangered. Their biggest threat is the destruction of hollow-bearing trees.
Shutterstock

2. Formal prioritisation of focal species, threats and actions

The previous strategy focused heavily on a small subset of the more than 1,800 threatened species and ecosystems in Australia. It mostly disregarded frog, reptile, fish and invertebrate species also threatened with extinction.

To reduce bias towards primarily “charismatic” species, the federal government should use an evidence-based prioritisation approach, known as “decision science”, like they do in New South Wales, New Zealand and Canada. This would ensure funds are spent on the most feasible and beneficial recovery efforts.

3. Targets linked to clear and measurable conservation outcomes

Some targets in the first Threatened Species Strategy were difficult to measure, not explicitly linked to conservation outcomes, or weak. Targets need to be more specific.

For example, a target to “improve the trajectory” of threatened species could be achieved if extinction is occurring at a slightly slower rate. Alternatively, a target to “improve the conservation status” of a species is achieved if new assessments rate it as “vulnerable” rather than “endangered”.

The ant plant (Myrmecodia beccarii) is one of the 30 plants on the federal government’s list of priority species. It is an ‘epiphyte’ (grows on other plants), and is threatened by habitat loss, invasive weeds, and removal by plant and butterfly collectors.
Dave Kimble/Wikimedia, CC BY-SA

4. Significant financial investment from government

Investing in conservation reduces biodiversity loss. A 2019 study found Australia’s listed threatened species could be recovered for about A$1.7 billion per year. This money could be raised by removing harmful subsidies that directly threaten biodiversity, such as those to industries emitting large volumes of greenhouse gases.

The first strategy featured a call for co-investment from industry. But this failed to attract much private sector interest, meaning many important projects aimed at conserving species did not proceed.

5. Government leadership, coordination and policy alignment

The Threatened Species Strategy should be aligned with Australia’s international obligations such as the United Nation’s Sustainable Development Goals and the federal Environment Protection and Biodiversity Conservation Act 1999 (which is also currently being reviewed). This will help foster a more coherent and efficient national approach to threatened species conservation.

The biggest threat to the critically endangered swift parrot is the clearing of their foraging and breeding habitat.
Shutterstock

There are also incredible opportunities to better align threatened species conservation with policies and investment in climate change mitigation and sustainable agriculture.

The benefits of investing heavily in wildlife reach beyond preventing extinctions. It would generate many jobs, including in regional and Indigenous communities.

Protecting our natural heritage is an investment, not a cost. Now is the time to seize this opportunity.




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The Conversation


Euan Ritchie, Professor in Wildlife Ecology and Conservation, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University; Ayesha Tulloch, DECRA Research Fellow, University of Sydney; Don Driscoll, Professor in Terrestrial Ecology, Deakin University; Megan C Evans, Lecturer and ARC DECRA Fellow, UNSW, and Tim Doherty, ARC DECRA Fellow, University of Sydney

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