Australia’s Prime Minister Anthony Albanese sought to strengthen security ties with Pacific island nations and counter China’s growing influence during a trip to the region this week. If he walks away with one lesson, it’s that Australia’s climate policy remains a significant sticking point.

The main purpose of Albanese’s visit was to attend annual leaders’ talks known as the Pacific Islands Forum. On the way, Albanese stopped in Vanuatu hoping to sign a security agreement – but he couldn’t ink the deal.

I am in the Solomon Islands this week to observe the talks. I saw firsthand that Australia clearly has its work cut out in its quest to lead regional security – and our climate credibility is key.

Pacific countries say unequivocally that climate change – which is bringing stronger cyclones, coastal inundation and bleached coral reefs – is their single greatest threat. If Australia’s geo-strategic jostling is to work, we must show serious commitment to curbing the dangers of a warming planet.

Australia’s strategy tested in the Solomons

The location of this year’s talks – Solomon Islands’ capital, Honiara – is a stark reminder of Australia’s geopolitical stakes amid rising Chinese influence in the region.

The Solomon Islands signed a security deal with China in 2022, which set alarm bells ringing in Canberra. Penny Wong – then opposition foreign minister – described it as the worst failure of Australian foreign policy in the Pacific since World War II.

Since then, the Albanese government has sought to firm up Australia’s place as security partner for Pacific countries by pursuing bilateral security agreements with island nations. So far, it has completed deals with Tuvalu, Papua New Guinea and Nauru.

On his way to the Solomon Islands, Albanese stopped in Vanuatu hoping to sign a security agreement which reportedly included A$500 million over ten years to address worsening climate impacts. But that deal was postponed. Members of Vanuatu’s coalition government were reportedly concerned about wording that could limit infrastructure funding from other countries, including China.

Albanese had more success in Honiara, where he advanced talks with Fiji’s Prime Minister Sitiveni Rabuka for a new bilateral security pact.

Working with island nations to tackle climate change has become key to Australian strategy in the region. This week Albanese also joined Pacific leaders to ratify a regional fund intended to help island communities access international finance to help adapt to climate impacts. Australia has already pledged $100 million for the project, known as the Pacific Resilience Facility.

Australia is bidding to host the COP31 United Nations climate talks in partnership with Pacific countries in 2026. Pacific leaders formally restated support for Australia’s bid this week.

Palau President Surangel Whipps Jr said an Australia-Pacific COP had broad support from the rest of the world:

We deserve to host COP31, and given the breadth and depth of support, it would be seen as an act of good faith if others would clear the way. We don’t want to let this major international opportunity slip by us.

Whipps also championed an initiative for the Pacific to become the world’s first region to be powered 100% by renewable energy.

Pacific Island countries spend up to 25% of their GDP on importing fossil fuels for power generation and transport. As the costs of renewable energy and battery storage quickly fall, Pacific countries could save billions of dollars by making the clean energy shift.

Albanese this week appeared to acknowledge regional concerns about climate change, saying taking action was “the entry fee, if you like, to credibility in the Pacific”.

But the real test is whether Albanese can follow words with meaningful action.

The work starts at home

Albanese’s Pacific visit comes amid heightened scrutiny of Australia’s efforts to curb emissions.

The government must set Australia’s 2035 emissions reduction target this month. The latest reports suggest the commitment may be less ambitious than Pacific leaders, and many others, would like.

Pacific leaders also expect Albanese to curb fossil fuel production for export. Australia’s biggest contribution to climate change comes from coal and gas exports, which add more than double the climate pollution of Australia’s entire national economy.

However, in coming days the federal government is expected to approve Woodside’s extension of gas production at the Northwest Shelf facility off Western Australia, out to 2070. The decision could lock in more than 4 billion tonnes of climate pollution – equivalent to a decade of Australia’s annual emissions.

All this comes in the wake of a landmark legal ruling in July this year, when the International Court of Justice (ICJ) issued an advisory opinion confirming countries have legal responsibilities for climate harms caused by fossil fuel exports.

Vanuatu led the legal campaign. In Honiara this week, Vanuatu’s climate minister Ralph Regenvanu reiterated that Australia must heed the ruling, saying:

The advisory opinion of the ICJ made it clear that going down the path of fossil fuel production expansion is an internationally wrongful act under international law. The argument Australia has been making that the domestic transition is sufficient under the Paris Agreement is untenable. You’ve got to deal with fossil fuel exports as well.

Albanese may have taken on board some of the Pacific’s concern about climate – and made a little progress at this week’s Pacific Islands Forum. But there is work to do if Australia is to be seen as a credible security partner in the Pacific – and that work starts at home.

Wesley Morgan, Research Associate, Institute for Climate Risk and Response, UNSW Sydney

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

Plastic pollution is everywhere: in rivers and oceans, in the air and the mountains, even in our blood and vital organs. Most of the public attention has focused on the dangers of microplastics. These are fragments smaller than 5 millimetres.

But an even smaller class of fragments, nanoplastics, may pose a greater risk to our health and our environment. With diameters of less than a micrometre (one millionth of a metre), these tiny particles can cross important biological barriers and accumulate in the body. Because they’re so tiny, detecting nanoplastics is extremely difficult and expensive. As a result, determining the extent of their impact has been largely guesswork.

A cheap, easy and reliable way to detect nanoplastics is the first step in addressing their potential impact. In our new study published today in Nature Photonics, my colleagues and I describe a simple, low-cost method that detects, sizes and counts nanoplastics using nothing more than a standard microscope and a basic camera.

Breaking down into ever-smaller pieces

What makes plastics useful is their durability. But that is also what makes them problematic.

Plastics do not disappear. They are not broken down by the ecosystem in the same way as other materials. Instead, sunlight, heat and mechanical stress slowly split the plastic apart into ever-smaller fragments. Larger pieces become microplastics, which eventually become nanoplastics once they are less than a micrometre in size.

At such a small size, they can pass through important biological safeguards such as the blood–brain and placental barriers. They can then start to accumulate in our organs, including our lungs, liver and kidneys. They can also carry other contaminants into our bodies, such as pollutants and heavy metals.

Yet, despite these dangers, real-world data on nanoplastics are scarce.

Today, detecting and sizing particles below a micrometre often relies on complex separation and filtration methods followed by expensive processes, such as electron microscopy. These methods are powerful. But they’re also slow, costly and usually confined to advanced laboratories.

Other optical laboratory techniques, such as dynamic light scattering, work well in “clean” samples. However, they struggle in “messy” real-world samples such as lake water because they cannot easily distinguish plastic from organic material.

An optical sieve

To address these issues, our international team from the University of Melbourne and the University of Stuttgart in Germany set out to make detection simple, affordable and portable.

The result of our collaborative work is an optical sieve: an array of tiny cavities with different diameters etched into the surface of a type of semiconductor material called gallium arsenide. Essentially, a collection of tiny holes, invisible to the naked eye, in a flat piece of a suitable material.

Physicists call these cavities “Mie voids”. Depending on their size, they produce a distinct colour when light is shone on them. When a drop of liquid containing nanoplastics flows over the surface, the nanoparticles will tend to settle into cavities that closely match their size.

Then, with a chemical rinse, mismatched particles wash away while matched ones stay tightly held in place by electromagnetic forces.

That part is simple. But it wouldn’t make the process cheaper or more portable if it still required a large, expensive electron microscope to visualise the trapped particles.

But here’s the key: when a particle is captured inside a cavity, it changes the colour of that cavity. This means filled cavities are easily distinguishable from empty ones under a standard light microscope with an ordinary colour camera, often shifting from bluish to reddish hues.

By observing colour changes, we can see which cavities contain particles. Because only certain-sized particles fill certain-sized cavities, we can also infer their size.

In our experiments, using nothing but our optical sieve, a standard light microscope and a simple camera, we were able to detect individual plastic spheres down to about 200 nanometres in diameter – right in the size range that matters for nanoplastics.

Putting it to the test

To validate the concept, we first used polystyrene beads in a clean solution. We observed clear colour changes for particles with diameters between 200 nanometres and a micrometre.

We then tested a more “real-world” sample, combining unfiltered lake water (including biological material) with clean sand and plastic beads of known sizes: 350 nanometres, 550 nanometres and a micrometre.

After depositing this mixture onto the optical sieve and then giving it a rinse, we were able to see distinct bands of filled cavities with diameters that matched the beads we had added.

This confirmed the optical sieve had successfully detected the nanoplastic particles in the lake water sample and determined their sizes. Importantly, this did not require us to separate the plastics from the biological matter first.

What’s next?

Our new method is a first step in developing a cheap, easy and portable method for routine monitoring of waterways, beaches and wastewater, and for screening biological samples where pre-cleaning is difficult.

From here, we are exploring paths to a portable, commercially available testing device that can be adapted for a range of real-world samples, especially those like blood and tissue that will be crucial in monitoring the impact of nanoplastics on our health.

The author would like to acknowledge the contribution of Lukas Wesemann to this article.

Shaban Sulejman, PhD Candidate, Faculty of Science, The University of Melbourne

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

In a historic move, the New South Wales government has announced a Great Koala National Park will be established on the state’s Mid North Coast, in a bid to protect vital koala habitat and stop the species’ sharp decline.

The reserve will combine existing national parks with newly protected state forest areas, to create 476,000 hectares of protected koala habitat. Logging will be phased out in certain areas, and a transition plan enacted for affected workers and communities.

Conservationists have welcomed the move as a win for biodiversity. However, some industry groups have raised concerns about the economic impact on the region’s timber operations.

The announcement, which follows a long campaign by koala advocates, shows the NSW government recognises the importance of protecting biodiversity. But announcing the national park is just the first step in saving this iconic species.

A worrying decline

Koalas are notoriously hard to count, because they are widely distributed and difficult to spot.

In 2016, a panel of 15 koala experts estimated a decline in koala populations of 24% over the past three generations and the next three generations.

Habitat loss and fragmentation is the number one threat to koalas. Others include climate change, bushfires, disease, vehicle strikes and dog attacks.

The decline gave momentum to calls by conservationists and scientists for the establishment of a Great Koala National Park, taking in important koala habitat on the NSW Mid North Coast.

In 2023, the NSW government pledged A$80 million to create the park. The announcement on Sunday increased the pledge to $140 million.

Announcing the development, NSW Premier Chris Minns said it was “unthinkable” that koalas were at risk of extinction in that state.

The government also proposed the park’s boundary and announced a temporary moratorium on timber harvesting within it – as well as a support package for logging workers, industries and communities.

However, the logging industry remains opposed to the plan.

Not the end of the story

The creation of the park is a welcome move. It will protect not just koalas but many other native species, large and small.

But on its own, it’s not enough to save the NSW koala population. Even within the national park, threats to koalas will remain.

For example, research shows climate change – and associated heat and less rainfall – threatens the trees koalas use for food and shelter. Climate extremes also physically stress koalas. This and other combined stresses can make koalas more prone to disease.

Bushfires, and inappropriate fire management, can degrade koala habitat and injure or kill them outright.

The NSW government says logging must immediately cease in areas to be brought into the park’s boundary. However, logging pressures can remain, even after national parks are declared. Forestry activities must cease completely, and forever, if the park is to truly protect koalas.

What’s more, recreational activities, if allowed in the national park, may negatively impact koalas. For example, cutting tracks or building tourist facilities may fragment koala habitat and disturb shy wildlife.

These threats must be managed to ensure the Great Koala National Park achieves its aims.

Prioritising nature

Of course, the creation of a new national park does not help koalas outside the park’s boundaries. Koala populations are under threat across their range in NSW, Queensland and the ACT.

That’s why the national recovery plan for the koala should be implemented urgently and in full. It includes increasing the area of protected koala habitat, restoring degraded habitat, and actively conserving populations. It also includes ending habitat destruction by embedding koala protections in land-use planning.

As I have previously written, koala protection areas should be replicated throughout the NSW and Queensland hinterlands. My research shows the future climate will remain suitable for koalas in those areas.

And logging must be curbed elsewhere in Australia, such as in Tasmania, where it jeopardises threatened species and ancient forests.

The Great National Koala Park promises be a sanctuary for koalas and other wildlife, and a special place for passive, nature-based recreation and tourism. Yes, the plan has detractors. But saving Australia’s koalas means prioritising nature’s needs over that of people.

And we must not forget: the national park is just one step on a long road to preventing koala extinctions.

Christine Hosking, Conservation Planner/Researcher, The University of Queensland

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

Our planet continues to warm because of greenhouse gas emissions from human activities. The polar regions are especially vulnerable to this warming. Sea ice extent is already declining in both the Arctic and Antarctic. The Greenland and Antarctic ice sheets are melting, and abrupt changes in both polar environments are underway.

These changes have significant implications for society through sea level rise, changes to ocean circulation and climate extremes. They also have substantial consequences for polar ecosystems, including polar bears and emperor penguins, which have become iconic symbols of the impacts of climate change.

The most effective way to mitigate these changes, and lower the risk of widespread impacts, is reducing greenhouse gas emissions. Yet decarbonisation is slow, and current projections suggest temperature increases of roughly 3°C by 2100.

Given the expected change, and the importance of the polar regions for planetary health, some scientists and engineers have proposed technological approaches, known as geoengineering, to soften the blow to the Arctic and Antarctic.

In research published today in Frontiers in Science, my colleagues and I assessed five of the most developed geoengineering concepts being considered for the polar regions. We found none of them should be used in the coming decades. They are extremely unlikely to mitigate the effects of global warming in polar regions, and are likely to have serious adverse and unintended consequences.

What is polar geoengineering?

Geoengineering encompasses a wide range of ideas for deliberate large-scale attempts to modify Earth’s climate. The two broadest classes involve removing carbon dioxide from the atmosphere and increasing the amount of sunlight reflected back into space (known as “solar radiation modification”).

For the polar regions, here are the five most developed concepts.

Stratospheric aerosol injection is a solar radiation modification approach that involves introducing finer particles (such as sulphur dioxide or titanium dioxide) into the stratosphere to reflect sunlight back out to space. In this case, the focus is specifically on the polar regions.

Sea curtains are flexible, buoyant structures anchored to the seafloor at 700 metres to 1,000m depth and rising 150m to 500m. The aim is to prevent warm ocean water from reaching and melting ice shelves (floating extensions of ice that slow the movement of ice from Greenland and Antarctica into the ocean) and the grounding lines of ice sheets (where the land, ice sheet and ocean meet).

Sea ice management includes two concepts. The first is the scattering of glass microbeads over fresh Arctic sea ice to make it more reflective and help it survive longer. The second is pumping seawater onto the sea ice surface, where it will freeze, with the aim of thickening the ice – or into the air to produce snow, to the same general effect, using wind-powered pumps.

Basal water removal targets the ice streams found in the Antarctic and Greenland ice sheets. These streams are fast-moving rivers of ice that flow toward the coast, where they can enter the ocean and raise sea levels. Water at their base acts as a lubricant. This concept proposes to remove water from their base to increase friction and slow the flow. The concept is thought to be especially relevant to Antarctica, which has much less surface melting than Greenland, and therefore melt is more about the base of the ice sheet than its surface.

Ocean fertilisation involves adding nutrients such as iron to polar oceans to promote the growth of phytoplankton. These tiny creatures absorb carbon dioxide from the atmosphere, which gets stored in the deep ocean when they die and sink.

The risk of false hopes

In our research, we assessed each of these concepts against six criteria. These included: scope of implementation; feasibility; financial costs; effectiveness; environmental risks; and governance challenges.

This framework offers an objective way of assessing all such concepts for their merits.

None of the proposed polar geoengineering concepts passed scrutiny as concepts that are workable over the coming decades. The criteria we used show each of the concepts faces multiple difficulties.

For example, to cover 10% of the Arctic Ocean with pumps to deliver seawater to freeze within ten years, one million pumps per year would need to be deployed. The estimated costs of sea curtains (US$1 billion per kilometre) are underestimates of similar-scale projects in easier environments, such as the Thames Barrier near London, by six to 25 times.

One project that planned to spread glass microbeads on ice has also been shut down citing environmental risks. And at their most recent meeting, the majority of Antarctic Treaty Consultative Parties made clear their view that geoengineering should not be conducted in the region.

Polar geoengineering proposals raise false hopes for averting some disastrous consequences of climate change without rapidly cutting greenhouse gas emissions.

They risk encouraging complacency about the urgency of achieving net zero emissions by 2050 or may be used by powerful actors as an excuse to justify continued emissions.

The climate crisis is a crisis. Over the time available, efforts are best focused on decarbonisation. The benefits are rapidly realisable within the near term.

Steven Chown, Director, Securing Antarctica's Environmental Future and Professor of Biological Sciences, Monash University

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

In Far North Queensland, one special winged mammal helps keep rainforests alive. The spectacled flying fox travels vast distances each night, pollinating flowers and spreading seeds far and wide.

But the species is in trouble. It’s now listed as endangered, yet – as my new paper shows – little has been done to protect this vital species.

The spectacled flying fox has a PR problem. It can be seen as a noisy, smelly pest — especially when it roosts in urban areas. But this doesn’t justify inaction.

Local groups and scientists are working to protect the spectacled flying fox, but government support is lacking. Without urgent action, a species that helps hold rainforests together might be gone for good.

A spectacled forest saviour

The spectacled flying-fox (Pteropus conspicillatus) is named for the light-coloured fur around its eyes, which resembles spectacles. It’s found in the Wet Tropics and Cape York in Far North Queensland, and plays a vital role in the region’s rainforests.

Spectacled flying-foxes can fly more than 200 kilometres in a single night – leaving their roosts to find food and returning by morning.

The animals feed on the fruit and nectar of many tree species. They pollinate flowers and move fruits in their guts and mouths. This boosts biodiversity and helps keep trees healthy by preventing inbreeding.

Recovery plans aren’t enough

Global warming and habitat loss are the two biggest threats to the survival of the spectacled flying fox. Persecution by humans is also a threat.

The spectacled flying fox population is in sharp decline. Recent numbers are hard to come by, due to a lack of monitoring. But between 2004 and 2017, the species’ numbers fell by an estimated 75%, and it is listed nationally as endangered.

Authorities draw up “recovery plans” for some endangered species. The plans outline threats to a species, and the action required to prevent its extinction. Species that receive a recovery plan are considered fortunate. Many threatened species never get one.

The federal and Queensland governments jointly published a recovery plan for the spectacled flying fox in 2010, which expired in 2020.

Even a recovery plan does not prevent a species from declining. As I outline in my new paper, most of the 25 recovery actions for the spectacled flying fox haven’t happened.

They include protecting native foraging habitat, increasing knowledge of roosting requirements, and protecting important camps.

The National Flying Fox Monitoring Program did proceed. It provided scientific evidence that the spectacled flying fox population has declined, prompting a change in its status from vulnerable to endangered. However, the program is no longer operating.

Threats are growing

My paper also provides the first update since 2011 of threats to the spectacled flying fox.

Extreme heat is now a lethal reality for the species. For example, in 2018 a major heatwave in Cairns killed 23,000 individuals over several days. This was the first mass death recorded for the species.

Habitat destruction continues, despite the species’ endangered status. Every year, more than 2,000 hectares of forest – which could serve as habitat for the spectacled flying fox – is cleared.

Invasive ants are a new challenge. They can affect roosting behaviour in flying foxes and even kill animals such as skinks.

Introduced grasses are also a threat because they change forest airflows which keep the roosts cool and increase fire risk.

Humans also pose a threat. Spectacled flying foxes have been harassed and deliberately killed. They can also become caught in nets over fruit trees and die.

Some people consider the spectacled flying fox to be a nuisance. This can lead to damaging policies that prioritise public convenience over a species’ decline.

A PR problem

Spectacled flying-foxes can congregate in large numbers and become noisy and smelly. They can also roost in urban areas and drop faeces onto properties and public places. This soils paintwork, swimming pools, roofs and clothes on washing lines.

But these impacts can be minimised – for example, by installing pool covers and shade structures.

Flying foxes carry diseases that can cause illness in people and livestock. Most can be prevented by hygiene measures and avoided by not handling bats. People who regularly handle bats are inoculated to prevent infection.

Sometimes, flying foxes are wrongly accused of carrying certain diseases, as occurred during the COVID-19 pandemic.

Flying foxes also eat fruits in gardens and orchards and can damage fruit trees. However, netting is available to protect fruit.

Looking ahead

Positive, citizen-led action is being taken to prevent the extinction of the spectacled flying-fox. For example, the Tolga Bat Hospital rescues individuals and advocates for the species.

Researchers are monitoring spectacled flying fox colonies using drones, and investigating the species’ heat tolerance. Research and monitoring is also being conducted through federal funding.

But the continued decline in numbers of the spectacled flying fox shows much more action is needed.

Governments are not required to publicly report whether recovery plans are acted on. This must change. And long-term, dedicated funding is needed for conservation and research.

The spectacled flying fox urgently needs our help. The problems they cause can be managed, and their ecological value far outweighs the nuisance.

Noel D. Preece, Adjunct Asssociate Professor, James Cook University

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

For many plants, spring is just a really good time. They have endured a cold, dark, hard winter and in some places, winters can be murderously tough for plants.

It makes sense that when spring comes around, plants are ready to take advantage of warmer temperatures, longer days and more sunshine. They resume growth after their winter dormancies and many rapidly produce flowers.

You’ve probably been spotting the sudden springtime explosion of flowers everywhere on your neighbourhood walks, your commute or in your own garden.

But why exactly do flowers go crazy in spring, and how do they know exactly when to show up for duty? Here’s the science.

Letting loose in a big rush

For many plants, the conditions for growth in spring are close to ideal. Water, warmth and sunlight are suddenly readily available.

Plants don’t have to hold back anymore. They can resume almost unconstrained growth and have the energy and resources to invest in flowering.

Your garden (or a patch of natural bush) is, in fact, a highly competitive environment.

Plants will rush to produce masses of flowers in the hope this will give individual plants an advantage in the reproductive race that ultimately might lead to seed and reproduction. This, after all, is the universal goal of biological success.

There is another factor, however, that also influences spring flowering.

The birds and the bees (and other insects)

Flowering plants (known as angiosperms) are relatively recent arrivals on the evolutionary time line. They first became significant during the Cretaceous Period, about 100 to 120 million years ago.

By then, insects had already been on the scene and evolving for millions of years. Birds had evolved more or less at the same time as these flowering plants, becoming more common during the Cretaceous Period too, but a few million years earlier.

These creatures, the plants noticed, were excellent at dispersing pollen and seeds. Many flowering plants evolved to use their helpful services.

Before the angiosperms, ancient plants used spores for reproduction. Conifers, which had evolved hundreds of millions of years before angiosperms, used wind to disperse their pollen. Seed dispersal was often limited, unreliable and slow.

Flowering plants needed to attract pollinators and seed dispersal vectors, such as insects and birds. Many developed flashy and showy flowers: the epitome of good advertising.

So flowering in spring coincides with the return of migratory birds and the life cycles of insects (insect activity usually declines over winter).

It makes great sense that many plants flower when the insects and birds so vital to their reproductive success are also getting active (and getting busy).

It is a matter of great timing that benefits all involved.

Timing is everything

The way flowering plants time their flowering is superb biology.

Many people assume warmer temperatures trigger spring flowering. But temperature is renowned for its variability and unpredictability. Temperature is not a good indicator of season or time.

So most plants measure day length using a green pigment called phytochrome (literally plant colour). This exists in two forms, one of which is active in triggering plant metabolism.

This phytochrome system enables plants to measure, with remarkable accuracy, both day length (also known as photoperiod) and the night length.

The ratio of the two forms allows plants to measure time like a biological clock.

Photoperiod is a very accurate and reliable measure of time and season and so plants nearly always get their flowering times in spring right.

In some plants there is an extra feature that can affect flowering, where the plants produce an inhibitor (abscisic acid) before winter that keeps them dormant.

Abscisic acid is cold-sensitive. So when spring comes, the inhibitor level is low. This, combined with photoperiod, helps initiate flowering.

The two mechanisms combined are a very reliable and consistent trigger for flowering.

Advantages to being a flower in spring

Flowering in spring means plants can use insects and birds to facilitate pollination and disperse seeds.

The pollen can be spread effectively and in a targeted way to other flowers of the same species. Less valuable pollen is wasted than if you’re relying on wind dispersal.

The seed can spread over much greater distances. The seed for many species will germinate during spring when growth conditions are highly favourable.

It’s not a coincidence flowering plants with this type of reproductive biology spread around the globe very quickly after their emergence during the Cretaceous Period.

They are highly efficient and successful plants.

Not everyone can be a flower in spring

So why don’t all flowering plants bloom in spring?

It is one of the delights of biology that there is nearly always room for contrarians and exceptions.

Some plants flower in autumn or perhaps during winter and some in summer, but there is always advantage in them doing so.

Sometimes it’s to avoid the fierce competition from all those other spring flowers in attracting pollinators.

Sometimes it’s because they are focused on a particular insect or bird vector that another season suits better.

Sometimes it’s because the plants can only survive in a highly competitive environment by not flowering in spring.

In the complex web of plant biology, a one-size-fits all approach never works.

Spring flowering has a lot going for it – as the current profusion of flowers attests – but many plants have made success of being different.

Gregory Moore, Senior Research Associate, School of Agriculture, Food and Ecosystem Sciences, The University of Melbourne

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

You are probably familiar with kangaroos. Wallabies too, and most likely quokkas as well.

Less famous are their small endangered cousins, the bettongs. These little marsupials love to dig and have a thing for mushrooms.

Because of their size and relative scarcity, it has always been hard to work out exactly how many different species of bettongs there are and where they all live.

Scientists have believed there are five living species of bettongs – but our new research, published today in Zootaxa, changes our understanding of the diversity of these creatures. And knowing that might help us understand why many efforts to protect them have failed, and how we can do better in future.

A small hopping engineering crew

A single bettong weighs just a couple of kilos, but can move tonnes of earth each year in an effort to find food. This makes them “ecosystem engineers”, turning the soil over and improving ecosystem health as they forage.

There have long been five acknowledged living species of bettong: the boodie, the woylie, the northern bettong, the rufous rat-kangaroo, and the eastern bettong. There are also a few subspecies that are thought to have gone extinct due to feral cats and foxes.

But our new study changes things.

Bones and teeth

We measured the skulls and teeth of 193 bettongs from museums across Australia, as well as in the Natural History Museum of London and the Oxford University Museum of Natural History. We also looked at their arm and leg bones, to determine how the shape and function of their limbs can be used to tell between species, something that had not been done in detail previously.

The aim of our investigation was to better understand the woylie. It has always been difficult to identify woylie bones in fossil beds, so our work would also help palaeontologists in the field.

Our analysis surprisingly showed that what we have been calling a woylie was actually three separate species.

Meet the family

It was previously believed there were two subspecies of woylie.

The first is what we generally call a woylie: Bettongia penicillata ogilbyi, a living species found in Western Australia. The second is extinct: Bettongia penicillata penicillata (the brush-tailed bettong), once found in South Australia and New South Wales.

However, our study indicates there are enough differences in the teeth and skull to recognise these as two separate species.

We also identified an extinct third species, Bettongia haoucharae or the “little bettong”. Its partially fossilised remains were located in the Great Victoria Desert and Nullarbor Plain, indicating that it was well adapted for the arid outback.

Once we were able to split the woylie (Bettongia ogilbyi) from the brush-tailed bettong (Bettongia penicillata) we could look more closely at the populations within the southwest.

From here we identified that the living woylies of the southwest are made up of two subspecies, both critically endangered. These are Bettongia ogilbyi sylvatica, or the “forest woylie”, and Bettongia ogilbyi ogilbyi, the “scrub woylie”.

The forest woylie is found throughout the cool wet forests southwest of Western Australia, particularly the Jarrah forest, while the scrub woylie is found in more open scrub habitats. Some individuals of scrub woylies were recorded as far as Shark Bay in Western Australia’s arid Gascoyne region. The scrub woylie was better adapted to dry conditions than the forest woylie, but was not a true desert dweller like the extinct little bettong.

So why does this matter?

The woylie is critically endangered, with about 12,000 individuals thought to remain. Conservation efforts have been focused on moving individuals to areas where they were thought to have previously occurred.

At least 4,000 woylies have been moved into different habitats during conservation efforts. However, our new study shows woylies were always restricted to southwest Western Australia and so were unsuited to some of the areas they were moved to. The bettongs that once lived in those other areas were very likely different species, with different adaptations.

Woylies eat fungi, which are known to grow in damp places on the forest floor. The northern bettong is also a fungi specialist, and it faces a threat as temperature increases make mushrooms less available.

When woylies are moved out of the southwest they no longer have access to their fungi food sources. Some previous attempts to move individuals have failed – and researchers have been unsure of why the woylies could not survive where they were thought to have previously lived.

According to our research, the woylie actually was never present in these environments. It was instead another kind of bettong that was better adapted to live in these arid habitats.

Moving individual animals can be a useful tool for both species conservation and ecosystem management. If a species becomes extinct, it may be substituted with a similar species that performs the functions previously carried out by the extinct species.

In the case of bettongs, it’s about finding which species can do that job and thrive in these arid ecosystems. This is worth doing as the ecosystems are suffering in their absence.

With the brush-tailed bettong elevated to full species and the description of the little bettong, our findings add two new extinct species to the ever-growing list of extinct mammal species in Australia.

Our work further highlights the terrible loss of unique marsupial species across Australia that we were not even aware of, and the urgency of protecting what remains.

Jake Newman-Martin, PhD Candidate in Palaeontology, Curtin University; Alison Blyth, Associate Professor, School of Earth and Planetary Sciences, Curtin University; Kenny Travouillon, Curator of Mammals, Western Australian Museum; Milo Barham, Associate Professor, Earth and Planetary Sciences, Curtin University, and Natalie Warburton, Associate Professor in Anatomy, Murdoch University

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

For decades, beekeepers have fought a tiny parasite called Varroa destructor, which has devastated honey-bee colonies around the world. But an even deadlier mite, Tropilaelaps mercedesae – or “tropi” – is on the march. Beekeepers fear it will wreak even greater havoc than varroa – and the ripple effects may be felt by the billions of people around the world who rely on honey bee-pollinated plants.

From Asia to Europe

Tropi’s natural host is the giant honey-bee (Apis dorsata), common across South and Southeast Asia. At some point, the mite jumped to the western honey-bee (Apis mellifera), the species kept by beekeepers around the world. Because this host is widespread, the parasite has steadily moved westwards.

It has now been detected in Ukraine, Georgia and southern Russia, and is suspected to be in Iran and Turkey. From there, it is expected to enter eastern Europe, then spread across the continent. Australia and North America are also at risk.

Why tropi spreads so fast

Like varroa, tropi is a tiny mite that breeds inside capped brood cells, the life stages of the honey-bee when the late larvae and pupae develop inside honeycomb cells that are sealed by a layer of wax. The mite feeds on bee pupae and transmits lethal viruses, such as deformed wing virus – the deadliest of the bee viruses. But there are crucial differences.

Varroa can survive on adult bees for long periods, but tropi cannot. Outside brood cells, it lives only a few days, scurrying across the comb in search of a new larva.

Because tropi spends more time in capped cells, it reproduces quickly. A capped cell that contains a female varroa will result in one or two mated varroa offspring emerging with the adult bee. Tropi offspring develop faster inside a capped cell than varroa offspring, so a tropi “mother” may result in more offspring emerging than a varroa infested cell, more quickly overwhelming the colony.

As a result, colonies infested with tropi can collapse far faster than those plagued by varroa.

Current control methods

In parts of Asia where the parasite is already established, small-scale and commercial beekeepers often manage it by caging the queen for about five weeks.

With no eggs being laid, no brood develops, leaving the mites without a food source. This method is practical where beekeepers manage dozens of hives, but not in places like Europe where commercial operations often involve thousands.

Another option is treating the beehive with formic acid, which penetrates brood cell caps and kills the mite without necessarily harming the developing bee, provided concentrations are kept low. This treatment may offer beekeepers a practical tool.

Why varroa treatments won’t work

Many wonder whether the chemicals used against varroa could also fight tropi. The answer is, mostly no.

Varroa spends much of its life outside of a capped cell clinging to adult bees, where it comes into contact with mite-killing chemicals known as miticides spread through the colony on bee bodies. By contrast, tropi rarely attaches to adults, instead darting across comb surfaces.

Because of this, it is far less exposed to chemical residues. Treatments designed for varroa are often ineffective against the faster-breeding tropi.

Managing both mites together will be particularly difficult. Combining treatments risks harming colonies or contaminating honey. For instance, formic acid for tropi and insecticides such as amitraz for varroa might interact at even low levels, killing the bees as well as the parasites.

There is also the danger of resistance. Over-use of varroa treatments has already produced resistant strains, reducing the effectiveness of several once-reliable chemicals. Introducing more compounds to fight tropi, without careful integrated pest management, could accelerate this process and leave beekeepers with few effective tools.

The wider impact

The spread of tropi will not only devastate beekeepers but also agriculture more broadly. Honey-bees are critical pollinators of many crops. Heavier hive losses will raise costs for both honey production and pollination services, affecting food prices and availability.

Research is underway in countries such as Thailand and China to develop better management strategies. But unless effective and practical treatments are found soon, the spread of this new mite around the world could be catastrophic.

The story of varroa shows how quickly a single parasite can transform global beekeeping. Tropi has the potential to be even worse: it spreads faster, kills colonies more quickly, and is harder to control with existing methods.

The author would like to acknowledge the contribution of Robert Owen, a beekeeper who completed a PhD on the varroa mite at the University of Melbourne in 2022, to this article.

Jean-Pierre Scheerlinck, Honorary Professor Fellow, Melbourne Veterinary School, Faculty of Science, The University of Melbourne

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