The deadly H5N1 strain of bird flu has now spread from migratory birds to infect resident Australian birds. Clusters of dead birds have been found in several locations. The virus will inevitably infect other wildlife, most notably mammals.

Death rates range from 75-100% in poultry and some wild bird species. There’s great uncertainty about how big the death toll will be over both the short and long-term. Native species such as the black swan are highly vulnerable, while others may prove more resilient.

Based on overseas experience, we can expect many thousands, if not millions, of Australian birds, and large numbers of mammals, to perish. Poultry will likely become infected, while some beloved pets may die.

Overall, the populations of many Australian species will likely plummet. Some threatened species will move closer to extinction, and relatively safe species could become threatened. As the virus spreads through widespread species such as silver gulls, white ibis, pigeons, ducks and crows, many of us will be confronted by wildlife deaths close to home.

Facing a threat like this can make us feel powerless. But there are actions we can take.

Blow after blow for wildlife

Over the 2019-20 summer, megafires incinerated forests and wildlife. In 2025, the lethal South Australian algal bloom denuded large marine areas.

The prospect of yet another hammer blow to wildlife is haunting and emotionally triggering for conservationists, wildlife carers and people who love nature.

To date, the official messaging asks us to watch for, report and record sick birds and mammals. This is important, but it risks leaving the community feeling disempowered witnesses to catastrophe. The situation is far from hopeless. Now is the time to act.

What can be done?

Following overseas work on ways to reduce the toll, we have come up with eight actions.

1. Tackle other threats to give species a fighting chance

While federal, state and territory response plans are not public, what we do know suggests a focus on controlling threats other than bird flu, especially for species that are threatened.

For example, locally eradicating predators such as cats and foxes could give more individuals a chance to get through the first wave of bird flu. Banning duck hunting could also reduce one threat to wildlife.

2. Secure insurance populations

Threatened birds and mammals with populations in captivity provide some security. We can boost these insurance populations by increasing their genetic diversity and the number of individuals kept.

For at-risk species without these populations, we may have to collect wild animals before infection reaches them (where practical). Zoos may offer the most protection, but there’s scope to translocate species (such as northern quolls) to safer wild places.

3. Vaccinate species at risk

New Zealand authorities are already giving vaccines to birds at risk. To date, Australia is not doing so, though policymakers are exploring the option. Limited trials in mammals have been undertaken in the United States.

Wild animals have to be caught, given the vaccine, and recaptured for a booster 4-6 weeks later. This is challenging but often feasible. In the US, authorities captured and vaccinated endangered Californian condors, then released them back to the wild.

We need to explore new vaccines, especially for mammals.

4. Widen monitoring

We need good monitoring to track the spread, understand whether our efforts have helped and plan future actions. Monitoring will show what the virus has done to species, track viral mutations and assess survival rates.

For many seabirds and waterbirds, existing programs give us good estimates of current population size. This will let us estimate declines and any recoveries. But we don’t have robust estimates for other at-risk bird and mammal species. This gap needs to be rapidly filled with funding for targeted monitoring. Citizen scientists can also help.

5. Expand research

Much Australian fauna is very distinct from species overseas, meaning lessons learned elsewhere won’t necessarily apply. We need to know which species are most vulnerable, which species spread the virus most effectively, whether survivors have compromised immune systems and how much genetic diversity has been lost.

6. Slow the spread

The virus spreads rapidly in contaminated water and through the movements of infected birds and mammals. Even so, we can slow the spread. In some situations, authorities can remove sick or dead animals to reduce the chance of scavenging birds and animals eating them and contracting then spreading the virus.

Some areas may need to be closed to the public to reduce infection risks through disturbance or contamination. It may be necessary to shut down some water sources or make them less attractive to waterfowl, who are often good carriers of the virus. Poultry farmers will need to control water sources too, to avoid attracting infected birds.

7. Involve interested groups

Authorities must ensure community members, land-owners, First Nations groups and conservationists are involved in creating response plans. Bird flu is a shared problem. Governments cannot respond alone.

8. Look for some silver linings

This virus will likely have dire consequences for many species. But it could also kill introduced predators and scavengers such as feral pigs, cats, foxes and common mynahs.

Time to act

The damage this virus will do isn’t set. We can shape some outcomes. We believe this package of actions could help avert the worst future for Australian birds and mammals – and encourage their recovery.

Acknowledgements: Ecologist Tanya Loos provided helpful feedback.

John Woinarski, Professor of Conservation Biology, Charles Darwin University; Euan Ritchie, Professor in Wildlife Ecology and Conservation, School of Life & Environmental Sciences, Deakin University, and Stephen Garnett, Professor of Conservation and Sustainable Livelihoods, Charles Darwin University

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

Australia has confirmed deadly H5N1 bird flu has been found in 102 wild seabirds across five states at the time of writing, including the country’s first mass death of birds.

The question is no longer if this virus can harm Australian wildlife, but whether we should use every available tool to protect species most at risk.

Vaccination cannot stop H5N1 spreading through wildlife. But it could prevent an outbreak from killing all of the at-risk species in an area – a tragic local extinction.

Australia should begin targeted vaccination of threatened birds. It should also urgently develop a strategy for seals and sea lions, rather than waiting until thousands are dead.

A policy exists, but action remains too cautious

Australia has a national policy that allows emergency vaccination of rare, protected and valuable birds, including animals in zoos, sanctuaries, breeding programs and some managed wild populations.

The government has also purchased an inactivated H5 vaccine – containing no live virus – and is running pilot studies in captive non-poultry birds.

This is important groundwork, but not yet a public program comparable with New Zealand’s ambitious and proactive approach to vaccinate five of the country’s rarest birds before the arrival of H5N1.

Australian zoos and sanctuaries have received funding to strengthen biosecurity and captive “insurance populations”. Pilot vaccinations are underway, but the government has not announced which threatened species will receive wider vaccination, where, or when.

More importantly, the policy excludes non-avian (bird) species, meaning marine mammals are not considered despite their known vulnerability to H5N1. No plans have been announced to the public for Australian vaccination trials for seals or sea lions.

What overseas programs show

New Zealand prepared before H5N1 arrived. After species-specific trials, it began vaccinating about 300 core breeding birds of rare species, including kākāpō, takahē and black stilts. These are captive or closely managed populations whose individuals can be found, vaccinated twice and monitored.

The United States acted after H5N1 killed 21 critically endangered California condors. By October 2024, 207 captive and free-flying condors had been vaccinated. The vaccine was judged safe, although two birds had treatable adverse reactions.

France has conducted a vaccine trial in wild king penguin chicks on the French sub-Antarctic island of Crozet. The vaccine produced strong, virus-neutralising antibodies without detected adverse effects.

These programs do not prove vaccination will prevent every infection. But it could lessen severe disease and reduce the number of animals that die in threatened populations.

Which species should Australia vaccinate?

Broadscale vaccination of free-ranging wildlife is unrealistic. Most H5 vaccines require two doses, and most wildlife is difficult to capture once, let alone being recaptured for a booster and blood test.

The best candidates are small populations of at-risk species that are either easily accessible or already under management. For example, threatened birds in zoos or breeding centres, or small, known colonies with tracking or regular handling.

On Tuesday, the Australian government released a list of at-risk species, that showed almost one-in-five Australian bird and mammal species is at high, very high or extreme risk from the virus.

Five bird species are at extreme risk – the Christmas Island frigate bird, Houtman albatross, Herald petrel, imperial shag on Heard Island and imperial shag on Macquarie Island. The marine mammals most at risk are the sea lion, fur seal and elephant seal, while the Tasmanian devil and eastern quoll are the highest risk species on land.

Decisions must balance extinction risk, exposure to the virus, cost, vaccine performance, whether enough animals can be reached, and whether capture would cause unacceptable stress. Vaccination must sit alongside existing biosecurity, surveillance and conservation measures – not replace them.

Australia needs a seal plan

H5N1 has decimated seal and sea lion populations across South America and the Southern Ocean. More than 17,000 southern elephant seal pups were killed in Argentina in 2023. An estimated 13,359 pups died at the Australian sub-Antarctic Heard Island in 2025, believed to be from the virus. Southern elephant seals were listed as vulnerable on the IUCN Red List in April, in part because of the catastrophic mortality caused by bird flu. It will take decades for these populations to recover.

Australia’s most vulnerable seals include the endangered Australian sea lion, Australian and long-nosed fur seals, and southern elephant seals. H5N1-positive terns have already been found at Seal Bay on Kangaroo Island, home to a major Australian sea lion breeding colony. Southern elephant seals have a large breeding colony on Australia’s sub-Antarctic Macquarie Island, which remains free of H5N1 at this time.

There is currently no bird flu vaccine designed specifically for marine mammals. A United States trial aimed at protecting endangered Hawaiian monk seals found a vaccine developed for cattle was safe in northern elephant seals and produced measurable antibodies.

This was the closest comparable species for which a safe, conditionally licensed vaccine was available. Developing and approving a separate vaccine for every wildlife species is costly and time-consuming, so conservation programs commonly adapt vaccines already approved for domestic animals.

Now is the time to act

Australia should identify priority seal colonies now, trial candidate vaccines in a suitable surrogate species and plan how vaccination could be deployed. We should not wait to learn how susceptible these animals are by watching more mass deaths unfold.

Vaccination is not a silver bullet. But when a disease can erase years of conservation work in weeks, we should not wait for perfect certainty. It’s time to act before catastrophe.

Jane Younger, Senior Lecturer in Southern Ocean Vertebrate Ecology, Institute for Marine and Antarctic Studies, University of Tasmania

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

Australia had years to prepare for the arrival of bird flu. The deadly, highly transmissible H5N1 strain emerged in late 2020 in Asia, before spreading to every other continent bar Australia.

After the first case was confirmed in Western Australia on June 19, federal Environment Minister Murray Watt claimed the nation was well prepared. Preparations include A$47 million of on-ground action such as improving habitat and controlling introduced species, as well as boosting surveillance. The virus is now spreading domestically, with mass mortality events being detected.

What the arrival of bird flu shows is how reliant conservation in Australia is on volunteers. Early on, the first people responding to sick birds were often volunteers and wildlife carers – even though authorities have consistently asked the public to “avoid, record and report” any sick or dead animals. Wildlife carers in Western Australia called for help and protective gear after finding themselves on the frontline. The WA government is now distributing PPE.

As the virus spreads, nursing sick birds and animals is no longer possible for volunteers. We will need these volunteers to report sightings and support injured wildlife. They will need support.

Why is Australia so reliant on volunteers?

Australia is wealthy and has a huge variety of species. Almost half the economy has a moderate to very high reliance on nature. But spending on conservation is very low.

There is no doubt that conservation is financially stretched in Australia. The Biodiversity Council estimates spending for on-ground programs is just 0.06% of the federal budget.

Because conservation has been underfunded for many years, much of the work has fallen to volunteers.

In 2019, researchers estimated Australia had over 20,000 volunteer wildlife carers, each of whom spend an average of $5,300 of their own money on food and equipment annually (about $100 million in total). On average, each volunteer put in 32 hours a week. If we were to pay minimum wage for their time, it would cost over $1 billion.

It was no surprise that volunteers would form a critical part of Australia’s response to bird flu, alongside official preparation.

In South Australia, not-for-profits and volunteers partnered with the state government to create a distributed surveillance network.

Australia’s largest wildlife carer organisation, WIRES, has mobilised its network of 4,000 volunteers nationally to focus on surveillance of sick animals.

What role do volunteers have?

Much of our wildlife care is conducted by volunteers, not-for-profit groups, or vets working pro bono, who are already “operating in crisis mode”.

There’s a clear gap between the official advice to avoid contact with any sick animal and Australia’s long reliance on volunteers to care for wildlife.

In July, volunteers spoke out over concerns this advice could mean many animals go untreated out of caution – even those who have injuries or other illness.

In New South Wales, the official advice is that injured birds or animals should still be reported to wildlife carers – but sick birds or animals should be recorded and reported.

Bird flu can infect humans in rare circumstances, but it doesn’t jump from person to person.

Regardless of the small risk, volunteers should not have to risk their health to care for animals.

Authorities must provide the life jacket

The bird flu crisis is yet another reason a big increase in conservation funding would make sense.

But that doesn’t mean turning away from the work done by thousands of passionate volunteers and wildlife carers. They provide scale which can’t be achieved by professionals alone.

It would make sense to be more strategic in supporting volunteers. Directing a small amount of funding to support coordination of volunteers is incredibly efficient compared to paying professionals.

The key is to match requirements with volunteer capability. Replacing professionals with citizen scientists is clearly the wrong approach. But volunteers can do many tasks that give vital, useful data in the fight against bird flu. When partnered with professional scientists, their effect can be much larger.

To use a metaphor, we wouldn’t have “citizen pilots”. But we do ask passengers to put on their own life jacket because it’s easy and the pilot can’t do it for everyone. Likewise, non-professionals can do specific tasks with the right support (we provide the life jacket, they put it on).

This article’s author is involved in the Great Reef Census, which relies on volunteers to collect an enormous amount of data from the Great Barrier Reef through a simple photo survey. It’s not a replacement for professional monitoring. But it gets results because scientists deliver the technical components, while the volunteers provide the scale scientists can’t.

Which way forward?

As the virus tightens its grip, experts are calling for an urgent funding boost to give wildlife a better chance of survival.

Boosting the official response is important. But we also need to ensure Australia’s volunteer workforce of citizen scientists and wildlife carers are supported.

Volunteers don’t have to keep showing up. They give their time to causes they care about. As our recent study found, keeping volunteer citizen scientists engaged needs recognition and ownership of the project.

Realistically, Australia’s sheer size means any bird flu surveillance program will rely on a distributed workforce of volunteers reporting sightings, while scientists focus on technical aspects such as genetic testing or biosecurity measures.

It makes clear sense to support these vital volunteers as a way to strengthen both wildlife conservation and national biosecurity.

Wildlife Health Australia has detailed advice on what to do if you see sick, dying or dead wildlife. You can report sick or dead animals via the official Emergency Animal Disease Hotline on 1800 675 888.

Christopher Lawson, Research Fellow in Marine Ecology, The University of Queensland

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

Australia is now confronting an outbreak of a deadly bird flu strain.

As of Monday, the highly pathogenic H5N1 virus had been detected in 78 wild birds across mainland Australia. Until now, there had been no evidence of a large-scale outbreak.

But authorities have confirmed the first instance of mass death caused by H5N1 among dozens of greater crested terns off South Australia’s south-east coast. They are also conducting further testing on a cluster of sick and dead terns in south-west Victoria.

As H5N1 spreads across the country, researchers, wildlife managers and the broader public are increasingly concerned about the risks it may pose beyond birds.

Recent outbreaks have threatened aquatic mammals, including southern otters, dolphins and porpoises. H5N1 has also decimated pinniped populations around the globe, including in South America. Pinnipeds are marine mammals that live in the sea and form colonies but spend extended periods on land, such as sea lions, fur seals and elephant seals.

As the risk of a broader outbreak rises, Australia must protect its wildlife by drawing on lessons from other continents already battling bird flu.

Looking to South America

H5N1 poses an urgent threat to wildlife worldwide. Since 2021, this fatal strain of bird flu has spread to every continent and infected poultry flocks, dairy cattle, wild birds and a growing range of wild mammals. In June, it finally reached Australia, first detected in a sick brown skua.

This strain has been particularly devastating in South America. In late 2022, H5N1 spread rapidly from infected seabirds into pinniped colonies. At least 30,000 South American sea lions died in Peru, Chile, Argentina, Uruguay and Brazil during the subsequent outbreak. In some areas, major breeding colonies lost up to one third of their population within a single breeding season.

Current evidence suggests H5N1 also caused mass deaths in southern elephant seals – the same species as Neil the seal – with more than 17,000 pups dying at Península Valdés in Argentina. Scientists still don’t know how many adults died.

Our team of researchers – from the Universidad Nacional del Comahue in Argentina and Deakin University in Australia – documented a dramatic decline in the number of seals in northern Patagonia following the 2022-23 outbreak.

Subsequent studies across South America show infected pinnipeds developed severe neurological and respiratory disease. Symptoms include lethargy, tremors, impaired coordination and laboured breathing, among others. Affected animals showed severe respiratory disease and neurological signs, and post-mortem examinations revealed marked lung lesions. Many animals died within a short period after clinical signs appeared.

Australian mammals at risk

Though confronting, the South American outbreak gives us crucial insight into how H5N1 spreads, which species may be most vulnerable and what strategies could reduce its impacts.

Each time H5N1 infects and replicates in a mammal, the virus becomes better at adapting to mammalian hosts. Monitoring how efficiently it spreads between mammals is therefore essential for protecting wildlife. It also allows us to assess the risk of human infection — which currently remains low — and the potential for a broader pandemic.

For now, H5N1 has not yet reached Australia’s pinniped colonies, which are already under pressure from fishery nets and hooks, pollution, habitat destruction and climate change.

So we still have time to protect them from H5N1. Authorities should start with Kangaroo Island, where infected seabirds have been found near the breeding habitat of the endangered Australian sea lion.

Other threatened marine mammals may also be vulnerable. This includes the rare Burrunan dolphin, of which there are less than 200 individual animals swimming around Victoria’s Port Phillip Bay and Gippsland regions.

So, how can we protect them?

As Australia’s number of confirmed H5N1 cases rises, urgent action is needed to protect our vulnerable marine mammals.

Australian authorities can learn from the South American outbreak by:

• frequently conducting population censuses, to detect unusual deaths and sudden changes in the size of seal and sea lion colonies

• closely monitoring live animals and taking samples of any dead animals, to track how the virus is circulating before any mass deaths happen

• removing all carcasses, particularly near tourist areas, to stop scavenging birds, dogs and animals from being exposed to infected animals

• ensuring researchers, wildlife managers and tourism operators stick to strict biosecurity protocols, such as wearing appropriate personal protective equipment when handling sick or dead wildlife and disinfecting boots and equipment between sites

• tightening biosecurity measures around food production, particularly intensive poultry farms where commercial poultry may be exposed to infected wild birds.

The public can also help protect our vulnerable pinnipeds by:

• not approaching any sick wildlife

• keeping pets away from wildlife

• reporting any sightings of sick or dead birds, seals, sea lions or other animals to the 24-hour Emergency Animal Disease Hotline by ringing 1800 675 888, noting details about the date, location, type and number of animals.

As the number of infected seabirds rises, so does the threat of a H5N1 outbreak among Australia’s marine mammal colonies. South America reveals how devastating this virus can be for entire ecosystems. Australia should heed that warning while there is still time to protect our precious pinnipeds.

Correction: This article originally stated post-mortem examinations of infected pinnipeds revealed the virus directly affected animals’ brains and lungs, and could lead to death within a short period. This has been corrected to say post-mortem examinations of infected pinnipeds revealed marked lung lesions, and many of them died within a short period after clinical signs appeared. Full necropsies were not carried out on the Argentinian seals due to biosecurity concerns, meaning the cause of death cannot be definitively attributed to the virus.

Saia Nahir Bartes, PhD Student and Research Teaching Fellow, School of Life and Environmental Sciences, Deakin University

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

Lethal bird flu is now spreading in Australia. This is bad news for many native species.

New federal government analysis suggests close to one in five Australian bird and mammal species is at high, very high or extreme risk. But this risk assessment omits something vital – how genetically well-equipped the species is to fight the virus.

While species such as black swans are likely to be very hard-hit, others such as wild ducks are expected to be less affected. One reason for this is different immune systems – some are more or less able to fight the virus. But there’s a more significant factor – how much variation there is in key immune system genes across populations.

Right now, we don’t have an overview of which threatened species are at highest risk based on this. If we urgently create a national immune-risk map for species at risk, we can act to protect those in most danger.

Why immune gene variations matter

When a virus enters an animal’s body, its immune system must first detect it, then respond. Key immune genes help determine if an animal fights off infection, becomes seriously ill or dies.

Different individuals will have slightly different immune responses based on variations at different immune genes. Some variants will allow an individual to survive the virus, and others won’t. This is why diversity in these genes is critical across the species.

Large wildlife populations often have a wide array of variants at each immune gene. This acts as biological insurance – when a new disease arrives, some individuals will be more able to survive. But if a species becomes threatened and its population falls, it’s likely to lose much of this protective diversity.

If the remaining individuals share similar vulnerabilities, a lethal disease such as H5N1 bird flu could be enough to push the species closer to extinction.

Threatened species are often immunologically fragile

Australia’s wildlife faces threats such as habitat loss, climate change, invasive species, pollution and disease. These threats not only reduce population size – they erode genetic diversity.

Small, fragmented populations may have enough genetic diversity to look viable in the short term. But when a new disease arrives, they may lack the breadth of variation at the immune genes needed to survive the new disease. This is a large, hidden vulnerability.

The orange-bellied parrot is a species that worries us deeply. The small, migratory parrot is one of Australia’s most endangered birds. Just 86 birds are left in the wild, with a few hundred more in captive breeding populations.

Our previous research found the parrot has suffered a dramatic loss of genome-wide diversity over the past century – including variation in immune genes.

If H5N1 infects these parrots, they may lack the immune gene variants needed to buffer the species against severe disease.

Tasmanian devils are similarly at risk. These iconic marsupials have critically low immune gene diversity due to population bottlenecks over the past 5,000 years. This left them vulnerable to the contagious devil facial tumour disease, which saw populations plummet with local declines of 95%, and an estimated 80% decline across Tasmania since the disease arose in the 1990s. Our preprint research shows facial tumour disease is still eroding immune gene diversity.

These scavengers are likely to be exposed to bird flu by eating carcasses, and we know which devil populations eat seabirds. The question will be whether devils have enough immune variation to respond to H5N1.

How a national immune-risk map could help

While we know how some species are likely to respond to the virus, the picture is far from complete.

We could fill in the blanks quickly, using DNA samples held in museums or from animals in zoos to generate genomic data on many more species.

We could then analyse immune gene variation across different populations of each species to measure how diverse they are. This approach could reveal populations that have lost important immune variants and may be particularly vulnerable to bird flu.

The Threatened Species Initiative, has collected this data for more than 125 threatened species. But there are hundreds more threatened animal species for which we have no data and no samples.

If we worked quickly to create a national immune-risk map, wildlife managers could focus surveillance, vaccination and protection efforts on the populations likely to be at most risk.

Importantly, they could establish new captive populations before the virus arrives, using breeding programs to maximise immune fitness and keep inbreeding to a minimum.

This is not science fiction. We led immune-guided conservation work in Tasmanian devils, where data on immune genes shape decisions around breeding. The end result: devil joeys with stronger immune systems.

If we use this approach for more at-risk species, we could better protect wildlife from bird flu and future diseases.

No time to waste

Responses to wildlife diseases are often reactive. Animals start dying in large numbers and then we investigate. This approach will be much too slow to respond to the fast-moving H5N1 strain.

Australia has world-leading wildlife genomics expertise, valuable museum and zoo collections, threatened species recovery programs and growing genome resources.

What’s missing is a coordinated way to translate immune gene data into practical action.

It’s not too late. But we have to act fast to identify species and populations with low immune diversity and roll out measures before irreversible losses occur.

Katherine Belov, Professor of Comparative Genomics, University of Sydney and Carolyn Hogg, Professor of Biodiversity & Conservation and Co-Lead, Australasian Wildlife Genomics Group, University of Sydney

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

The spread of H5N1 birdflu is worsening.

At the time of writing, Australia has 53 confirmed detections in wild seabirds across five states. In South Australia there are 39 confirmed cases, including a silver gull at Robe and 19 greater crested terns found along the Limestone Coast and Seal Bay on Kangaroo Island.

South Australian authorities are also investigating 49 dead and 35 sick greater crested terns found by aerial surveillance teams at an offshore location south of Cape Jaffa.

Samples are still being tested, but if confirmed, this would represent the first mass mortality of Australian animals associated with the virus.

Until recently, Australia’s detections were mostly isolated migratory seabirds arriving from the Southern Ocean. But these detections show this has changed, with local transmission among wildlife that live in Australia.

Which species are most at risk?

Animals that gather densely in breeding colonies face the greatest danger. Terns, gulls, gannets and albatrosses can transmit the virus rapidly through close contact and contaminated environments, with these groups experiencing devastating mortality in other parts of the world.

The silver gull infections are particularly concerning because they move between beaches, towns, rubbish tips, wetlands and inland waterways. A suspected case at Monarto, SA, does not prove H5N1 is yet established inland, but it shows infected seabirds cannot be “coastally contained”.

Seals and sea lions also require urgent surveillance. H5N1 killed more than 17,000 southern elephant seals in Argentina in 2023, with 95% pup mortality at one monitored colony. Around 13,000 elephant seal pups later died on Heard Island. While it was not possible to carry out postmortem examinations on all individuals at this remote location, H5N1 was confirmed as present and recorded as the most likely cause of death.

Five infected terns have now been confirmed at Seal Bay, a critical breeding site for the endangered Australian sea lion. Australian sea lions and fur seals breed in dense colonies where disease could spread quickly.

Can we predict how far it will spread?

We cannot reliably predict the spread of H5N1 in Australia. The 53 confirmed detections are not the true number of infections – they are the birds found, reported and tested. Many infected animals will never be detected.

Cases from the rest of the world show this strain of H5N1 is capable of spreading huge distances, carried by migratory wildlife. Every other continent, including Antarctica, has been infected by this strain of H5N1 over the past five years, with deaths in the millions.

Hundreds of species of birds have been infected, and the virus has evolved to spread more efficiently between mammals. This pattern makes it very difficult to confidently predict how the virus will spread in Australia, but we must be prepared for a widespread and devastating outbreak.

What about poultry farms and backyard chooks?

There are still no detections of H5N1 in Australian poultry or other livestock, but the risk has increased as confirmed infections rise among resident wild birds.

Wild birds can introduce influenza to poultry through direct contact or by contaminating water, feed, footwear and equipment.

Backyard owners should prevent contact with wild birds, cover feed and water, avoid untreated surface water, and clean footwear and equipment. Sudden illness or deaths should be reported immediately.

Australia’s response now needs to evolve

Sadly, the impacts of bird flu on species and ecosystems will play out for decades to come.

Australia’s pre-outbreak preparation and coordination has been strong. Federal and state governments established response plans, increased surveillance and prepared the poultry industry before H5N1 arrived.

As wild bird infections increase, the poultry industry needs to be supported in implementing biosecurity procedures, and strategic surveillance is needed for both farms and wildlife.

Reliable mortality estimates are essential to understand the long-term impacts, and support species to recover. Australia should also assess whether vaccination could protect vulnerable marine mammals before mass deaths begin.

We cannot stop wild birds from flying. But we can decide whether this becomes an unmanaged wildlife catastrophe or a closely tracked outbreak, with farms and vulnerable species given timely protection.

Please do not touch sick or dead birds or marine mammals. Record the location, take photographs from a safe distance, keep pets away, and report the sighting to the Emergency Animal Disease Hotline on 1800 675 888.

Jane Younger, Senior Lecturer in Southern Ocean Vertebrate Ecology, Institute for Marine and Antarctic Studies, University of Tasmania

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

Australia’s unique animal species are in sharp decline, with more than 40 mammal extinctions over the past 238 years. This atrocious mammal conservation record is the worst in the world.

Unfortunately, this is not simply a historic problem – almost 700 animals are currently at risk of future extinction. At least 200 of these are directly threatened by feral cats, as well as other pressures such as land-clearing, disease and invasive species.

Feral, domestic and stray cats now occupy almost the entire continent and are estimated to kill more than 1.5 billion native animals each year. These estimates are based on more than 100 cat diet studies, which identified prey animals using the traditional scientific methods of examining stomach contents and scats (droppings).

However, our new research – the first in Australia to use DNA for cat stomach analysis – shows traditional methods may greatly underestimate the true number of native animals killed by feral cats.

Stomachs, scat or DNA?

Scientists traditionally study the diet of predators such as feral cats by manually looking through their stomach contents or scat samples. Searching for hair, bones, feathers or other partial remains is an unpleasant task that can help identify a cat’s prey.

However, the bodies of animals rapidly degrade within a cat’s digestive system, and it can be difficult to identify small prey fragments. In fact, more than 50% of prey can be unidentifiable, and this only includes the remnants still visible to the naked eye.

We were curious to find out whether small or soft-bodied species, such as microbats and birds, were being missed by these traditional methods. Other research has shown soft-bodied New Zealand frogs were detected more often when DNA analysis was used on the contents of mammal stomachs. So we decided to analyse stomach contents, rather than scats, to increase the likelihood of detecting smaller or soft species.

We used both manual and DNA metabarcoding, a forensic method that allows scientists to detect even tiny remains of animals that have been eaten by predators. All organisms have a unique genetic “barcode” that can be identified from certain regions of their DNA.

These two methods were used to analyse the stomach contents of cats that had been culled around Wild Deserts, a fenced conservation reserve in New South Wales. This is the first time DNA methods have been applied to cat diet studies in Australia, and one of few globally.

The results were sobering: DNA detection identified twice as many mammal species and three times as many bird species as traditional manual detection. But it was less effective for certain reptiles.

In summary, more species were detected, and were found within more cats. This means they are being consumed at a higher rate than traditional methods estimated.

Interestingly, we did not detect any microbats, in line with previous research at these sites. This might be because cats generally eat rodents and other small mammals, and eating bats is likely a sporadic event. But we know cats are a threat to bats in other regions.

DNA findings emphasise cat threat

Building predator-free fenced reserves known as safe havens, is one way conservationists have tried to slow the extinction and severe declines of many Australian wildlife species. These reserves allow us to remove species such as cats, foxes and rabbits, enabling native species to thrive in pre-colonial conditions.

Projects such as Arid Recovery, Wild Deserts, Secret Rocks, and several others managed by conservation organisations such as Australian Wildlife Conservancy and NSW National Parks, have successfully returned species that were locally extinct to their former homes.

However, we cannot fence the whole of Australia. Therefore, we need to know which species are most at risk from cats so resources can be directed to protect them. Unfortunately, it is often the rarest and most threatened species that are of greatest risk from cats, such as small mammals. Due to their scarcity, they are difficult to detect.

Ironically, scientists have relied on cat diet analysis to confirm if very rare species are persisting (or not) in an area, and DNA methods could increase the confidence of these results.

Exciting next steps

More recently, these projects have begun releasing native animals beyond the fences into areas where cats have been suppressed to low numbers. As we move into this exciting next stage of rewilding Australia, it is vital we know how many of these pioneer animals are eaten by cats. Yet traditional methods may not detect them.

Our research complements decades of work by individuals and organisations that have monitored the effects of invasive predators, including cats, on Australian ecosystems. It is important to incorporate this local expert knowledge with DNA analyses.

Traditional manual methods remain a practical, cost-effective approach to routine dietary analysis. However, using DNA methods alongside these techniques will help us better understand and estimate the impacts of cats and other invasive predators.

Oliver Aylen, PhD candidate, UNSW ; Katherine Moseby, Professor of Conservation Biology, UNSW ; Kylie M. Cairns, Research Fellow in Canid and Wildlife Genomics, UNSW , and Rebecca West, Principal Ecologist Wild Deserts, UNSW

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

Nature is not doing well in Australia. Many unique mammals, birds and insects are struggling. Entire ecosystems are collapsing.

In response, the federal government signed a global pledge in 2022 to protect and restore nature. The global goal is to restore 30% of degraded ecosystems. But Australia only proposes to have “priority degraded areas […] under effective restoration by 2030”. The terms are not defined, no 30% target is included, and there is no method proposed to measure success.

With 2030 less than four years away, it’s time to ask hard questions. What does it actually mean to restore nature? What would success look like? And what would it cost?

What does it mean to restore nature?

If we walk through protected forests with abundant wildlife, we might think the end goal is simple: more of this.

The problem is, many current ecosystems – communities of species – look very different to those before European colonisation began in 1788. Some ecosystems no longer exist.

The tireless burrowing of millions of bandicoots and bettongs once shaped the grassy woodlands of southeast Australia. But foxes and cats, coupled with logging, farming and mining, have largely put an end to their work as ecosystem engineers.

Regent honeyeaters were once seen in “immense flocks” in eucalypt forests. There are now less than 300 birds left – so few they are losing their song.

Oyster reefs once carpeted southern seas so densely colonial ships struggled to navigate them. But the reefs were quickly dredged to near-extinction and now exist only in fragments.

It’s hard to judge the health of nature when so much has been lost. This is known as shifting baseline syndrome – each new generation will see nature’s current level of degradation as normal.

Remembering what was lost

Gone from living memory doesn’t mean gone for good. The historic record is richer than most people realise.

For tens of thousands of years, Aboriginal and Torres Strait Islanders managed Country using fire and selective harvesting, based on an intimate knowledge of seasonal cycles and species behaviour that Western science is only beginning to appreciate.

Much of this stewardship has been encoded in language, ceremony and oral tradition and passed down. This is how we know millions of bogong moths once gathered in alpine areas to cluster on cave walls and enter a low-energy state over the hot summer. Their migration once supported the gathering of many nations for ceremony.

Early colonial journals, field guides, fisheries ledgers and ship logs describe a different continent. In the upper Murray River, diaries from explorers Hume and Hovell describe abundant Murray cod, and lagoons “literally crowded with wild ducks”.

Fossils such as bone fragments left by owls over thousands of years also help us envisage earlier ecosystems.

It’s useful to reconstruct what Australian ecosystems once looked like. But this work offers reference points for nature restoration, not goals.

In some cases, we cannot recreate the lost ecosystems of 1788. Today’s climate is already very different to that of 238 years ago and climatic change is intensifying. Introduced species have also altered many ecosystems irrevocably.

It’s also false to assume ecosystems are static – they never were. Australia’s ecosystems have been managed by people for tens of thousands of years.

A better goal would be to strive for biodiverse, functional ecosystems, informed by past conditions and practices. We should focus on what we value most about landscapes, rather than solely focusing on recreating the past.

Restoration must be about whole ecosystems

Restoring biodiversity requires working at landscape scale to reintroduce cultural burning, manage invasive species, replant and reseed vegetation, give rivers more water, keep livestock numbers sustainable, connect remaining areas of habitat and bring back species once found in an area.

The high profile Gondwana Link in Western Australia shows how restoration requires linking fragments of habitat so animals and plants can better move through the landscape as well as invasive species control and returning traditional fire regimes.

Hard choices are necessary

Over the last 12 years, the amount of protected land has almost doubled. The problem is, this growth has largely not been in areas where it matters most.

There’s been less growth in important areas closer to population centres, which are home to threatened and culturally important species. Unfortunately, the most threatened places are often sought after for farming or development.

We need to honestly acknowledge this tension, rather than pretending we can restore Australia’s ecosystems using marginal or abandoned land.

Policymakers will need to make difficult choices. If an ecosystem is almost gone, those last precious remnants need protection – even if they could be turned into farms or suburbs.

How much is enough?

The global target is to restore 30% of degraded ecosystems. But Australia hasn’t announced a numerical target.

The nation has 418 million hectares of land modified enough to be considered “degraded”, according to a new CSIRO dataset. If Australia aimed to restore 30%, that would mean 125 million hectares. This is a concrete target – the kind that means we will know if we meet it or not.

If policymakers set this as a target, they would need to carefully decide which areas are chosen. The good news: we know how to prioritise restoration.

Is it possible?

Restoring nature faces real obstacles. But it is possible.

Aiming to restore 30% of degraded land would mean working across private lands, public reserves and the Indigenous estate. It would likely take decades and come with a substantial price tag. Our ballpark figure is a little over A$7 billion a year over 30 years.

That’s less than a third of what the federal government spends subsidising activities which damage nature annually.

The shifting baseline means it’s hard to see what has been lost. But most of Australia’s native species still exist. The knowledge is there. And we know restoration at scale is possible.

Michelle Ward, Lecturer, School of Environment and Science, Griffith University; Brendan Wintle, Professor in Conservation Science, School of Ecosystem and Forest Science, The University of Melbourne; Jack Pascoe, Senior Lecturer, School of Geography, Earth and Atmospheric Sciences, The University of Melbourne; James Watson, Professor in Conservation Science, School of the Environment, The University of Queensland, and Martine Maron, Professor of Environmental Management, The University of Queensland

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

Mangroves are perplexing plants.

They breathe through their roots, appear to stand on stilts and grow best in hot, salty seawater drawn in and out by the tide.

Historically, mangrove forests have been dismissed as inhospitable places to avoid and have been extensively cleared. But these fascinating trees are now gaining attention for how they support biodiversity, store carbon and buffer the effects of storms, cyclones and tsunamis.

Since 1984, scientists have been monitoring the growth and geographical reach of mangrove forests using satellites. And for the first time, these unique ecosystems are expanding at a faster rate than they are declining.

So what’s driving this? And could it help curb climate change?

Why mangroves matter

Mangrove forests were long viewed as largely expendable places. Research shows people were quick to convert them into rice paddies, oil palm plantations and aquaculture operations. Some were even used as rubbish tips.

However, mangrove forests are now recognised as a vital part of our coastal environments. They provide habitat for a wealth of plants and animals including fish such as barramundi and giant shovelnose rays, reptiles such as seasnakes and even mammals such as the proboscis monkey and water mouse. They are crucial carbon stores, locking up roughly four times more carbon than other land-based forests. Mangroves can also shelter coastal communities and ecosystems from natural disasters by reducing the risk of flooding and erosion.

From an economic perspective, mangrove forests allow millions of fishers to earn a living as well as supporting commercial fisheries. These forests are also of immense cultural value to First Nations communities, many of which associate mangroves with certain religious gods or cultural practices.

Mangroves are bouncing back

For decades, mangrove forests have been systematically cleared and destroyed. Between the 1980s and 2010, we lost more than 12,000 square kilometres – an area the size of Jamaica – of mangroves worldwide. That means there are far fewer mangroves that can trap harmful greenhouse gas emissions and slow the effects of climate change.

However, this trend may be reversing. A recent study analysed four decades of global data documenting the reach and growth of mangroves. It had three key – and somewhat surprising – findings.

Mangroves are rebounding despite climate change

Human-induced climate change is putting immense pressure on our mangrove forests. It is driving more severe and frequent droughts and storms that can damage or kill mangroves. It is also accelerating sea level rise, potentially drowning mangroves.

This study shows the world’s mangrove forests are rebounding, even as our planet rapidly warms. Since 2010, they have expanded by more than 2,000 square kilometres.

Importantly, the reasons for this vary between regions. Before 2010, Myanmar and Indonesia were hot-spots of mangrove loss. But this trend has now stabilised, with policymakers strengthening the laws around mangrove protection following the catastrophic 2004 Indian Ocean tsunami and 2008 cyclone Nargis.

Australia’s mangrove forests are also expanding. However, research suggests this is because mangroves are increasingly growing on floodplains. Rising sea levels allow tides to reach further inland, creating the salty conditions in which mangroves thrive.

In some places – such as where mangroves regenerate in unused aquaculture ponds – this shift inland is positive. In northern Australia, however, it threatens to degrade freshwater ecosystems and is an urgent concern for Traditional Owners.

Mangroves are shifting closer to the sea

This new study suggests mangroves are increasingly growing on newly formed mud flats.

This is counter intuitive because rising sea levels should, in theory, restrict mangrove growth. It may be happening because rivers are carrying soil and sand from deforested areas to the coast, creating new habitat for mangroves.

This demonstrates the resilience of mangrove ecosystems. However, it seems mangroves aren’t regenerating rapidly in the coastal regions where they once thrived – an indicator of successful restoration.

Mangroves are expanding and retreating at the same time

The authors of this study also examined trends in mangrove degradation.

Degradation occurs when mangrove canopies become less dense – a sign they are not as healthy as before. The researchers point to human activities, such as harvesting or pollution, and extreme weather as the main factors driving mangrove degradation.

However, exact causes will differ between regions.

More work needed

The expansion of the world’s mangrove forests is promising – and perhaps unexpected – news. However, we can’t be complacent. Current evidence suggests mangrove forests are still thinning overall, putting coastal ecosystems and climate action efforts at risk.

To combat this trend of mangrove degradation, we should support policies that strengthen mangrove protection and restoration.

Organisations such as the Global Mangrove Alliance and Mangrove Breakthrough are also raising the profile of these fascinating ecosystems.

Further research is needed to monitor the varying impacts of climate change on mangroves.

Catherine Lovelock, Professor of Biology, The University of Queensland

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

During the most recent ice age, much of North America disappeared beneath ice sheets several kilometres thick. These frozen giants covered most of present-day Canada and parts of the northern United States, while smaller ones spread across northern Europe.

They dominated the landscape for thousands of years, storing so much water that global sea levels fell dramatically.

Scientists have long known these enormous ice sheets transformed the climate of the northern hemisphere. They shifted North Atlantic storms southward and influenced rainfall across Europe.

But what if these mountains of ice influenced climate much farther away than anyone realised? Could they have altered climate on the other side of the world?

In our new study, published in Climate of the Past, we show they could, despite the ice never reaching Australia. The discovery reveals just how interconnected Earth’s climate really is. It also reminds us that understanding Australia’s past and future climate requires looking far beyond our shores.

A world that looked different

Our study focuses on a climate about 49,000 years ago during the last ice age when the world looked very different from today.

The giant ice sheets in North America were not yet as large as when they reached their peak around 21,000 years ago, but they were already large enough to influence climate far beyond their edges.

At the same time, atmospheric carbon dioxide levels were very low, and changes in Earth’s orbit altered how sunlight was distributed across the planet compared with today.

Building ice sheets of this size required enormous amounts of water. As more water from the oceans became locked away as ice on land, sea levels fell by around 60 metres, exposing underwater landscapes.

Coastlines stretched much farther out than they do today. Australia and New Guinea were joined into a single landmass called Sahul, while many islands across Southeast Asia merged into another large landmass called Sunda.

But the ice sheets did much more than reshape coastlines.

Their bright surfaces reflected more sunlight back into space, cooling the planet. They also stood several kilometres high, forming gigantic walls of ice that disrupted the normal paths of winds moving around the globe.

Imagine placing a mountain range thousands of kilometres wide in the path of the atmosphere. Air cannot simply flow straight through it. Instead, it is forced around the obstacle, creating ripple effects that spread far beyond it. The North American ice sheets behaved much like a continent-sized mountain range.

Looking beyond the North Atlantic

While the regional effects of the northern hemisphere ice sheets across Europe and the North Atlantic are now well established, much less was known about whether the influence of the ice sheets extended far beyond the North Atlantic.

Could ice sheets in North America also influence rainfall in Australia?

To answer this question, we used a series of climate model experiments. Instead of changing everything at once, we sequentially altered atmospheric greenhouse gas concentrations, Earth’s orbital configuration (the position and orientation of Earth relative to the Sun), ice-sheet albedo (how much sunlight they reflected), and ice-sheet elevation.

This approach allowed us to identify which factor was responsible for different climate changes.

The height of the ice sheets reshaped global winds

While orbital conditions helped create a wetter Australian climate, one result stood out. The bright white ice helped cool the climate by reflecting sunlight back into space.

But it was the height of the North American ice sheets that produced the biggest changes in atmospheric circulation.

Their towering walls of ice redirected winds across the globe. Those changes rippled through the atmosphere into the tropics, shifting the tropical rainfall belt southward and strengthening the circulation that drives Australia’s summer monsoon.

This southward shift also reduced rainfall in parts of Indonesia and Papua New Guinea, while increasing summer rainfall across much of Australia.

A connected system

The past provides one of the best natural experiments available for understanding how Earth’s climate system works. These results show that changes in one part of the world can trigger responses thousands of kilometres away through the atmosphere.

As atmospheric greenhouse gases continue to rise and major changes are projected to occur at high northern latitudes, understanding how these changes influence the southern hemisphere will become increasingly important.

The giant ice sheets that once covered North America never reached Australia. Yet their influence did. They altered Australia’s rainfall, helped shape the landscapes inhabited by the continent’s earliest people some 60,000 years ago, and reminded us that Earth’s climate has always worked as one connected system. What happens in one part of the world can echo far beyond its borders.

Himadri Saini, Postdoctoral Research Fellow, Climate Dynamics, The University of Melbourne; UNSW and Laurie Menviel, Associate Professor, Climate Change Research Centre, UNSW

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

Imagine spotting a butterfly species in your garden you have never seen before. You might take a photo and upload it to a citizen science app, or tell a local nature group about your new encounter. It feels like a small moment of joy.

But if that butterfly has appeared in your backyard because its old home is becoming too hot, too dry or too damaged, the sighting is more worrying.

Around the world, ongoing environmental changes are prompting many butterfly species to relocate and search for new homes, a process referred to as species range shifts or species redistribution. As temperatures, rainfall and habitats change, butterflies can relocate over long distances, or even move vertically up and down mountain ranges.

Our new global study found one in ten known butterfly species has already shifted in range. So, where are they going – and why?

How do we know butterflies are on the move?

The data used in our global study was comprehensive: more than 6,180 reports of butterfly range shift from 565 studies and 68 expert assessments, which covered 1,758 species across 105 countries.

These showed 80% of the documented butterfly species had expanded their ranges latitudinally, meaning north to south, or longitudinally, meaning east to west. We found 27% had reduced their range and 22% had shifted up or down slopes on hills or mountains. Many species showed a combination of these range changes.

The public narrative is often simplistic: as the world warms, species are shifting towards cooler temperatures at higher latitudes, or moving upwards in mountains. This is happening, but it is only one piece of the puzzle.

In fact, butterflies need more than to find new homes at the right temperature. Caterpillars often depend on specific host plants; adults need nectar, shelter and safe places to breed; and populations also require connected habitats so individuals can move easily through the landscape, meet, reproduce and breed.

Change can come quickly

Some species show how fast changes can happen. The tawny coster (Acraea terpsicore) native to the Indian subcontinent, has expanded through Southeast Asia and into Australia. In Brazil, (Godartiana byses) has expanded from Rio de Janeiro and Bahia into São Paulo, a shift linked to climate warming.

Other species show the opposite pattern. The small blue (Cupido minimus) has lost 40% of its habitat in the United Kingdom over the past 150 years. In Germany, the cranberry fritillary (Boloria aquilonaris) has lost much of its original habitat because of bog drainage. In Romania, an increase in farming has been linked to a severe range contraction of the danube clouded yellow (Colias myrmidone).

Even range shifts along mountain slopes are not always straightforward. In Mexico, the painted lady (Vanessa cardui) shifted upslope at a rate of about 83 metres per year between 1988 and 2011. Over the same period, the queen butterfly (Danaus gilippus) shifted downslope at a rate of about 32m per year.

Together, these examples show butterfly species range shifts are not simply a story of animals moving towards the poles.

What’s causing this change?

In our study, climate change and extreme weather events were the most common reasons why butterflies shifted their range. But climate change is not the only factor. Agriculture, forestry, urban development and habitat destruction are also reshaping where butterflies can live and reproduce. These disturbances destroy host plants and breeding sites, and fragment large habitats into patches too small to sustain a healthy population.

Europe and North America have many long-term butterfly monitoring programs, run by expert volunteers and citizen scientists. We found that in some European countries, range shifts have been documented for more than half the national butterfly species. But in most countries, records exist for fewer than 10% of known butterfly species.

We know the least about butterflies in Central Africa, Southeast Asia, New Guinea and the Amazon Basin, some of the richest places on Earth for biodiversity. They are also places where many species may already live close to their upper thermal limits. Even small increases in temperature can make parts of their habitat unsuitable.

Supporting experts and volunteers to develop citizen science monitoring programs would better protect butterflies in these megadiverse countries.

Why this matters

Why should people care? Butterflies are part of the living fabric around us. Adult butterflies contribute to pollination. Caterpillars feed birds, spiders and other insects. When butterflies disappear, it can signal the plants, grasslands or woodlands once visited by butterflies are also changing.

This matters for conservation. Many protected areas are based on maps of where species lived in the past. But if butterflies and other species are moving, those maps quickly become outdated.

The message is simple. Conservation cannot only protect habitats where species once lived – it must include the places where they will relocate, and the wildlife corridors they will use to get there. If not, we may keep protecting yesterday’s nature while tomorrow’s nature has nowhere left to go.

Shawan Chowdhury, Head of Global Change Ecology Lab, Monash University; Aletta Bonn, Head of Department Biodiversity and People, Professor of Ecosystem Services, Helmholtz Centre for Environmental Research-UFZ; German Centre for Integrative Biodiversity Research; Friedrich-Schiller-Universität Jena, and Jonathan Lenoir, Senior Researcher in Ecology & Biostatistics (CNRS), Université de Picardie Jules Verne (UPJV)

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

Being diagnosed with amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, can be devastating.

ALS is the most common form of motor neurone disease, a neurodegenerative condition that affects people’s ability to speak, eat, breathe and swallow. It is debilitating and progresses rapidly: on average, people survive just 2–3 years after a diagnosis. Most people are diagnosed between the ages of 40 and 70.

A new study, published today, has found that being exposed to pesticide at work can increase the risk of developing ALS by 61–71%. The study brings together the findings of eight other studies – but not all of them assess risk in the same way. Here’s why we need to interpret the findings with caution.

What we know about ALS causes

Men are around 20% more likely to develop ALS than women.

The disease occurs sporadically in over 90% of patients, meaning the large majority have no known family history or identified genetic cause. The remaining 10% of cases are familial, meaning the person has a known genetic variant or family history of ALS.

However, it’s not well understood exactly what triggers both the sporadic and familial forms of the disease, although an interaction between genes and environment is likely.

Over the last few decades, researchers have been investigating exposure to pesticides as a possible trigger.

Several studies have found associations between being exposed to pesticides and a higher risk of developing ALS. However, a causal relationship has not been established.

What the new study did and what it found

This new study pooled data from eight separate studies, five from the United States, one spanning Canada and France, one from Italy, and one from Australia.

It asked a simple but important question: does having ever being exposed to pesticides at work raise someone’s risk of developing ALS?

The answer, based on this combined analysis, was yes.

Overall, people who had ever had any exposure to pesticides (including fungicides, herbicides and insecticides) at work were 61% more likely to develop ALS, compared to those who hadn’t.

Pesticide exposure appears more strongly linked to ALS risk in men than in women in this analysis. But the evidence is too limited to know whether this reflects a true biological difference, or gaps in how exposure was measured for women.

The risk was slightly higher with exposure to herbicides (a type of pesticide), which was associated with a 71% heightened risk of developing ALS.

ALS affects an estimated 8 in every 100,000 Australians. So a 61–71% increase would mean a small number of new cases.

But these numbers don’t reflect how devastating and debilitating this disease is for families and communities affected by ALS. There is currently no cure.

But here’s why we should be cautious

This review was able to assess the link between pesticide and ALS in a large sample, by combining 1,734 ALS cases across the eight studies. This is more than any single study could provide alone.

But combining studies in this way inevitably introduces some inconsistencies, as each one has been conducted independently, using different methods. So it’s hard to control for the differences.

Several of the studies in the review found a link between developing ALS and other separate risk factors, such as head trauma or being exposed to other kinds of toxins. But the analysis couldn’t fully disentangle these risk factors from pesticide exposure. This means we can’t tell how much someone’s exposure to pesticide contributed to them later developing ALS, or whether it was due to the other contributing factors too.

One study also assessed military veterans exposed to Agent Orange, a herbicide the US used as a weapon during the Vietnam war. This kind of exposure is likely quite different to typical occupational pesticide exposure today. But the new review didn’t assess this separately.

Most of the included studies also relied on self-reported exposure, meaning participants had to recall and estimate how much pesticide they’d likely been exposed to. These studies tended to show a stronger link between pesticides and ALS than studies that independently measured exposure.

As the authors of the new study noted, this means recall bias may have played a role. People who already have ALS, or who already suspect a link between pesticides and the disease, may be more likely to remember and report being exposed to pesticides.

So, what does this all mean?

Overall, the study supports the case that being exposed to pesticide at work increases your risk of developing ALS.

These findings highlight the need for more rigorous research into the specific details. We need to understand which chemicals or pesticide ingredients may be responsible, and whether the risk is related to dose. This means understanding whether being exposed to pesticides over a longer time, or at a higher dose, might further increase your risk.

Someone’s risk of developing ALS is likely influenced by a combination of factors, including genetics and environment.

The way multiple exposures to risk factors accumulate and interact over a person’s lifetime may also play a role; for example, if you work with pesticides every day and have also been exposed to other toxins, had a severe head injury and/or a have genetic predisposition.

This is known as a “multistep” model of disease development and it isn’t currently possible to determine someone’s personal risk profile with precision.

The picture is still evolving. More evidence will help regulators and employers make better decisions about safe exposure levels and potential risk mitigation strategies.

Rachel Tan, Associate Professor in Neuroscience, The Brain and Mind Centre, University of Sydney

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

Snakes are seemingly simple in structure, a head attached to a long unremarkable noodle. They do have some pretty cool features at the front end, with venomous fangs and the capability to stretch their mouths and swallow large prey whole, but their bodies are not just the simple tubes we once thought.

My new research, published today in the Journal of Morphology, reveals their body structure to be surprisingly complex – far more than we once thought. In fact, it shows snakes have among the most complex spines in reptiles.

Let’s talk about vertebrae

Let’s first talk about vertebral columns. Within our own spines, we have three main regions.

First is the cervical region, or neck, which supports our heads and gives us mobility to look around. Next is the thoracic region, with ribbed vertebrae to protect our internal organs. Finally, we have the lumbar region in the lower region, whose main function is to support our upper bodies.

Within each region, the vertebrae have distinct shapes based on the functions they serve, and we can see this in a host of different animals.

When it comes to snakes, however, the story becomes a bit more complicated. Snake vertebrae similarly change shape throughout the column, but the boundaries between these regions aren’t as clear-cut.

This led to a lot of early research concluding that snakes just had one big long body, with a uniform gradient of change throughout.

But this was not the consensus, and debates raged until a seminal paper in Nature came out in 2015.

It found snakes do in fact have regions – four, in fact: the cervical, anterior thoracic, posterior thoracic and lumbar regions.

However, a decade on, my findings change a few things.

Snakes have short necks

Colleagues and I took three Australian snake species: the eastern brown snake, copperhead and tiger snake.

We measured the shape of every single body vertebra in 13 snake specimens. By quantifying each vertebra’s shape, we can study how it changes along the body.

What we found is not a uniform gradient of change, but rather some areas of rapid change and some areas without. This corroborates that snakes do in fact have regions within their bodies, where there are sections of vertebrae that have a similar regional shape, then a rapid transition zone into the shape of another region.

By looking at this much detail, we found five regions within a snake’s body – not four. We also found that snake necks are shorter than once thought. While previous research thought of the neck as long, up to 15% of the body, we show it’s more likely to be around 5% of body length.

This means snake necks are around 7 to 12 vertebrae long, similar to their lizard cousins. This suggests that while snakes elongated other parts of their body, their necks retained a more ancestral form, remaining short throughout evolution.

Changes reflect ecology

We also found a previously undescribed region, which we are calling the middle thoracic region, as it’s nestled in between the anterior and posterior and thoracic regions.

This finding contributes to an emerging theory, where limbless animals have undergone shifts in their vertebral columns. Basically, if you don’t have any limbs, the only way for you to adapt to your environment is by changing your entire body.

Overall, we see how snakes retain ancestral regions within their vertebral columns despite limb loss and elongation. But they have also gone further, repatterning their vertebral columns to be even more complex than their limbed counterparts.

Ammresh, PhD Candidate, School of Biological Sciences, Monash University

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Every summer, communities across northern Australia brace for the tropical cyclone season. Tropical cyclones draw their power from the warm seas, extracting heat and moisture from ocean water.

To improve cyclone forecasting – and better protect lives and property – we enlisted an unlikely ally: deep-diving sea turtles equipped with oceanographic sensors on their shells.

At times these turtles have encountered powerful tropical cyclones, allowing their sensors to gather and can gather critical information on how the temperature in the water changes as the storm passes overhead.

How oceans affect cyclones

Tropical cyclones are fuelled by warm tropical seas. Higher sea surface temperatures usually generate more powerful storms.

As a cyclone passes over the ocean, its powerful winds and waves churn the water around like a blender. This action mixes warm surface water with cooler water from deeper down, leaving behind a “cool wake” – colder ocean water left behind on the sea surface. This cooling reduces the heat available to the storm, which can in turn can limit its strength.

Traditionally, cyclone forecasters have focused on sea surface temperatures, but the ocean depths also matter. If cooler water sits just below the surface, a storm can rapidly cool the sea surface by mixing it upwards. But if warm water extends deeper down, the mixing does not have the same cooling effect. This means forecast accuracy is highly dependent on the ocean temperatures below the waves.

Observing northern seas

Despite the key role northern Australian seas play in shaping tropical cyclones, we have surprisingly few observations below the surface. The region, which includes the Timor and Arafura seas between Australia and Indonesia, is vast, remote, and shallow.

This makes it difficult or expensive to use traditional ocean observation methods. Ships and underwater ocean gliders can only sample small areas, and nobody wants to collect measurements in the middle of a cyclone.

Australia needs an ocean observing system that can work in all weathers in this region. Following a collaboration between the Australian Institute of Marine Science, the Integrated Marine Observing System, CSIRO and Macquarie University, the University of Western Australia, UNSW and traditional owners, we think we’ve found one.

Turtle power: how it works

To address the data desert to Australia’s north, we have enlisted the help of deep-diving olive ridley and flatback sea turtles, which lay their eggs on beaches around tropical Australia.

Biologists have tracked sea turtles for decades using miniaturised GPS tags. Building on experience from overseas, we paired a GPS tracker with an oceanographic probe that measures temperature when the turtle dives, sometimes as deep as 80 metres.

The temperature data is transmitted almost immediately by satellite, making it available to forecasters in near real time. Over several deployments on 46 animals between 2014 to 2024, the turtles took more than 8,000 ocean temperature snapshots across northern Australia, from the Pilbara to the Gulf of Carpentaria.

Into the maelstrom

In April 2023, a tropical storm formed off the Kimberley coast. This storm, named Ilsa, would go on to become a Category 5 cyclone and register the Bureau of Meteorology’s fastest-ever recorded sustained winds: 219 kilometres an hour. Tragically, two fishing vessels were caught in the storm, and eight people died.

As Ilsa was drawing energy from the warm Timor Sea, it passed directly over one of our turtles carrying ocean instruments. This reptile, seemingly unbothered by the maelstrom above, collected sub-surface observations within the eye of the storm – before, during, after the storm’s passage.

From the turtle observations, we found Ilsa’s cold wake cooled the ocean surface by about 2°C. Had the storm stayed still, this cooling would have potentially reduced Ilsa’s strength from category five to category 4.

Excited by this result, we matched turtle observations with the Bureau of Meteorology’s historical storm database. Our turtles had taken real time observations within the core of five tropical cyclones, including the category four Cyclone Rusty. In all but one case, turtles observed strong cooling of the ocean as the storm passed overhead.

When we compared the turtle data with a state-of-the-art ocean model, we found a potential weakness in Australia’s weather forecasts. Our turtle observations indicated the ocean model did not capture the mixing of deeper, cool water with the warm surface, the very process that causes the cold wake. This can lead to overestimates of cyclone intensity.

Sentinel turtles

To improve tropical cyclone forecasts, we need reliable sub-surface ocean observations.

But ocean observation is expensive and developing an all-weather observing system is beyond the capabilities of many of the nations most vulnerable to tropical storms.

The instruments we used can be deployed on land with minimal equipment, and the Olive Ridley turtle lives in tropical seas. Sea turtles could become a key part of observing cyclone weather systems, protecting lives and livelihoods across the tropics.

Christopher Chapman, Senior lecturer in oceanography, UNSW ; Clive McMahon, IMOS Animal Tagging, Sydney Institute of Marine Science, and Rob Harcourt, Emeritus Professor of Marine Ecology, Macquarie University

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

At first glance it looks exactly like a seahorse. It has the same horse-shaped head tilted down from the body, the same curled and grasping tail, and in the males a fully enclosed pouch for brooding the young.

But this little fish, no longer than your thumb, is not a seahorse, as we report in our new study published in the Journal of Lost Species. This is Australyichthys aegis, a newly described fish from the deep reefs off southern Australia. We have given it the common name helmethead sea muppet, after the domed, helmet-like crest on its head.

Its scientific name follows the same idea: in Greek mythology the aegis was a protective shield. Together with its two relatives, the bullneck sea muppet (A. minotaur) and the paradoxical sea muppet (A. paradoxus), it makes up a small group we nickname the sea muppets.

All three, we have now shown, belong on their own branch of the family tree. The seahorse look has arisen more than once, and these fish are a case of it evolving well away from the true seahorses. That evidence had been sitting in museum drawers, misfiled, for decades.

Bycatch from the deep

You will not find these fish while scuba diving.

Every known specimen was brought up by accident, caught in trawl nets or dredges working the seafloor between about 50 and 125 metres down. The single specimen of A. aegis came up in 2006 near the Gambier Islands, at the mouth of South Australia’s Spencer Gulf.

The dredge that caught it was sampling for small shelled animals known as brachiopods during a natural history expedition. Because that expedition was after invertebrates, the fish was mistakenly catalogued into the invertebrate collection of the South Australian Museum, where it sat unrecognised for years.

After each chance capture the fish were preserved, then largely forgotten. The rest are held in Australian museum collections, among them the Australian Museum, Museums Victoria and CSIRO.

The whole genus is known from just seven specimens gathered over about 65 years, scattered across more than 2,500 kilometres of coastline, and nothing has been collected in nearly two decades.

Irreplaceable specimens

The specimens are irreplaceable, so we could not dissect them. Instead we used micro-CT scanning, the same X-ray technology used in hospitals but fine enough to resolve tiny bones.

That let us build three-dimensional models of each fish’s skeleton and compare them bone by bone with true seahorses (Hippocampus).

Every earlier assessment had rested on external appearance, and the skeletons did not support it. Seahorses have a particular internal architecture, including a rigid cage of fused bony plates supporting the belly and a bony crown, called a coronet, on the head.

Our scans showed that Australyichthys has neither. In their place is a different arrangement of bones supporting the belly, one that appears in no seahorse.

Only one specimen could give us DNA.

A. aegis had been fixed in ethanol rather than formalin, the only member of the genus stored that way, and ethanol leaves genetic material intact. Sequencing it placed the fish well outside the seahorses, on the branch that is their closest relative. The genes said what the bones had already said.

All three species had been placed in the seahorse genus on the strength of how they look, and on that evidence they were seahorses. They are not, and they needed a genus of their own. We named it Australyichthys, from the Latin for southern and the Greek for fish.

A shared way of life

When separate lineages evolve to look alike, biologists call it convergent evolution, and it usually reflects a shared way of life rather than shared ancestry.

The whole seahorse body, with its bent head, gripping tail and brood pouch, has been built at least twice within a single fish family, the Syngnathidae, which includes seahorses, pipefishes, pipehorses and seadragons.

Working out how that happened may reveal why evolution keeps arriving at the same solution.

All this happened along the Great Southern Reef, the connected system of kelp forests and rocky reefs that rings southern Australia. Many of its species are found nowhere else, and its deeper zones are barely explored.

In fact, an entire genus of vertebrate hid there, misidentified, until a CT scanner settled the question.

No one has ever seen one of these fish alive; they have turned up only by chance in a passing net or dredge. On that record they now qualify as lost species, known from a handful of preserved animals and never from a living one.

Calling them lost is not a prediction of extinction. It marks them as a priority for targeted surveys that go looking rather than waiting for the next accidental catch. They are most likely still down there, in a part of the sea we hardly ever visit.

Graham Short, Research Associate in Ichthyology, Australian Museum and David Harasti, Adjunct Assistant Professor, Faculty of Science and Engineering, Southern Cross University

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

I love my garden mulch and I love the way birds forage in it.

I love the mess this causes, and I love periodically using my broom and rake to return some order to things. To me, this meditative, cyclical interaction with nature is at the heart of gardening.

However, some of us want a very neat, formal garden and feel untidy mulch out of place will not do. For some, those pesky birds that turn over the mulch are more curse than blessing.

There’s a product on the market to meet such needs: mulch glue, sometimes also known as landscape glue. This is essentially a glue you can spray onto mulch to keep it in place.

So, what do you need to know before using it?

The magic of mulch

Good mulch works wonders. It can:

• improve soil and facilitate plant growth
• aerate soil and keep it moist
• deliver vital organic matter and nutrients to soil, benefiting microbiota.

There are many different types of organic mulch, including, pea straw, sugarcane, pine bark, softwood chips, hardwood chips and various mixtures. Inorganic mulches, such as pebbles, can help reduce weeds, slow down soil surface water evaporation and even provide habitat for a few small invertebrates.

Whatever you use, mulch works best when air, water, fungi, bacteria and insects can work their way through it. Your garden, after all, is a living thing.

Mulch glue is a non-toxic water based adhesive made from either acrylic or urethane polymers. It is sprayed over mulch to keep it in place.

The glue allows water and air to penetrate into the soil. But – depending on how much you use – it might limit birds turning over and foraging in mulch.

This is a shame because bird foraging helps aerate soils and gardens, which is a boon for soil micro-oroganisms and insects. Birds help by adding manure to gardens, which gets worked in among other organic matter when birds forage.

Landscape glues are UV-light stable so persist for a long time; some people have flagged concerns that as they degrade, plastic particles can enter waterways and drains.

While studies on mulch glue are scarce, there are concerns it might affect worms and other small soil organisms indirectly by slowing mulch decomposition.

Embracing the chaos

Overall, there’s very little peer-reviewed research on mulch glue.

It can be useful in some contexts. In some cases, an initial application on sloped sites may be beneficial, allowing mulch to settle. And it might be helpful for older people or those with limited mobility who can’t always be returning mulch to its original spot.

That said, there’s a chance it could reduce the ability of birds to turn over mulch, and act as environmental engineers. It may inhibit the activities of worms, fungi and insects that contribute to soil structure and fertility. The movement of material around your garden – whether that’s via birds, rain or wind – is part of a natural and positive process.

It’s also worth thinking about the fact that mulch glues (and related products such as mulch dyes) come at an environmental cost. Their manufacture, packaging and transport takes energy and resources, so their use must be justified.

In the longer term, I reckon it’s best just to let the birds forage in your mulch – and embrace a little bit of chaos in the garden.

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.