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All animals need to eat to survive, grow and reproduce. To do so, they also need to avoid being eaten. This is a big challenge for many of Australia’s native mammals, because when they search for food, they must also escape the attention of introduced predators, namely, feral cats and red foxes.

Tragically, many have been unable to overcome this test of survival, becoming one of the 40 native mammal species driven to extinction since European colonisation.

But what happens if we reduce the numbers of introduced predators? Do our surviving native species think there is less risk of being the next meal for a cat or fox? How do they respond? And how might we tell? With peanut butter balls, of course!

A deadly game of hide and seek

Natural environments contain predators and prey engaged in a deadly game of hide and seek, and – from the prey’s perspective – a landscape of fear. The extent to which the two groups are aware of each other and able to respond (hunting vs hiding and escape) varies across time and space. Prey might perceive some areas as a riskier proposition, such as more open habitats or times when predators are most active. They therefore reduce their activity to minimise the likelihood of being eaten.

But avoiding being eaten comes at an energetic cost. It may mean preferred areas or times to feed are reduced, which in turn limits rates of growth, reproduction and survival of prey species. Prey animals are constantly weighing up this tradeoff of risk vs reward as they go about their lives.

Tasty treats can assess risk appetite

We can’t know for sure how much animals fear being eaten, but we can assess it indirectly, through their willingness to eat. In our recently published study, we measured how much food animals don’t eat as a indicator of their fear of being eaten. The more food they give up, the greater the risk of predation those animals are assumed to perceive. These experiments are made easier by the fact many mammals are mad about gobbling up peanut butter.

French Island has long been fox free, but had thousands of feral cats. In 2010, authorities began a feral cat eradication, which made it a perfect place for our research.

Importantly, we were able to start our experiment prior to an eradication program of feral cats, which began in 2010 on French Island, Victoria. This means we were able to measure changes in long-nosed potoroos and eastern barred bandicoots habitat use and foraging as cat numbers and activity fell.

So, on fox-free French Island, we placed balls of peanut butter, rolled oats and golden syrup into trays with soil and dug them into the ground, ensuring they were below the soil surface. We did this in more open grassland areas (likely riskier habitat, with less cover and protection from feral cats) and more densely vegetated areas (less risky habitat, due to increased cover).

We used camera traps to measure how often potoroos and bandicoots visited these feeding trays to dig up the tasty treats, and how much of the peanut butter balls they left behind in different habitats and at different periods throughout the ongoing feral cat eradication program.

When feral cats are away, native animals play (more)

As the number of feral cats on French Island was reduced, potoroos and bandicoots used both open and closed habitat types more frequently, and they increased their activity, giving up less food over time. This suggests bandicoots and potoroos do recognise feral cats as a threat, and are able to fairly rapidly change their habitat use and foraging accordingly.

Aside from the obvious benefits of fewer feral cats killing and eating potoroos and bandicoots on French Island, our study suggests there may be substantial benefits for native wildlife — namely increased access to habitats and foraging opportunities — even before the ultimate longer-term goal of cat eradication can be achieved.

Our study’s results are encouraging. Outside the safe havens of invasive predator-free islands and fenced sanctuaries, feral cats are notoriously hard to eradicate from large areas, and there is a constant threat of their return.

To change this, new and more effective ways to control and eradicate feral cats are needed. But until then, reducing and keeping feral cat numbers lower, while also carefully managing habitats to benefit wildlife, can still give native animals the helping hand they need to survive.

We would like to acknowledge that this work was led by former Deakin University Honours student, Te Ao Marama Eketone, and it occurred on the unceded Country of the Bunurong/Boonwurrung peoples.

Euan Ritchie, Professor in Wildlife Ecology and Conservation, School of Life & Environmental Sciences, Deakin University; Amy Coetsee, Threatened Species Biologist, The University of Melbourne; Anthony Rendall, Lecturer in Conservation Biology, School of Life and Environmental Sciences, Deakin University, and Duncan Sutherland, Deputy Director of Research, Phillip Island Nature Parks; Research Fellow, The University of Melbourne

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

If you stand beside Seven Creeks in Victoria or Spring Creek in Queensland, they might seem small and unremarkable. But these creeks flow into the mighty Goulburn and Condamine Rivers, and punch far above their weight.

Small headwater creeks, at the beginning of a river network, act as the first source of water for bigger rivers. Headwaters deliver the first cool winter flows and the large seasonal pulses of water that trigger fish migration, setting the river’s rhythm. But they’re also the first to suffer from drought, heatwaves and water captured by thousands of small farm dams.

As the rivers of Australia’s largest system, the Murray-Darling Basin, experience a hotter and more variable climate, their headwaters are at the forefront of change.

This year, the Murray-Darling Basin Authority is reviewing the basin plan. The plan sets sustainable, legally enforceable limits on water usage, and rightly identifies climate change as a central challenge. Yet its new discussion paper pays surprisingly little attention to the vast network of smaller tributaries that feed the basin’s larger rivers.

We need attention on these “forgotten” rivers and streams, which are increasingly central to the survival of the Murray-Darling Basin as a whole.

The Basin’s blind spot under climate change

The discussion paper focuses on the big-name river systems in the basin, such as the Darling (Baaka) River in the north and heavily regulated rivers in the south such as the Murray, where big dams, barrages and diversions shape almost every drop of water.

This omission reflects how the original plan was conceived, and then in released 2012. Environmental priorities were defined around “priority assets”, such as major river reaches, internationally protected wetlands and refuges for wildlife where environmental flows were expected to deliver measurable ecological benefits.

This made sense when pressure from agricultural water extraction was the major threat. But this leaves out a huge part of the basin’s story.

Threading through the Basin are thousands of kilometres of small, so-called “unregulated” rivers and headwater streams. Historically, they were assumed to be relatively healthy because big dams were absent. But climate change is overturning that assumption. With declining rainfall and hotter temperatures, even small reductions in runoff can dramatically affect their flow.

Worse still, thousands of small farm dams scattered across the landscape are reducing how much water flows through these waterways. More of these streams are now ceasing to flow for the first time, or remaining dry for longer. Climate change is amplifying every existing stress on smaller rivers.

If we are serious about preparing the basin for climate change, we can no longer overlook the springs and creeks which feed the system. These rivers are not peripheral – they’re central to its resilience.

How the warming climate is changing streams

Headwater streams may be small, but they form the ecological backbone of the basin’s rivers. These upper tributaries are biodiversity hotspots, supporting insects, frogs, fish and riverbank species dependent on regular flushes of water and cool, shaded habitats.

When these streams dry out, warm up or fragment into pools, these delicate ecological processes are disrupted. The effects stretch far downstream. Climate change is pushing these streams into more extreme boom–bust cycles, with longer, hotter dry periods punctuated by short bursts of intense rainfall. In small catchments, these shifts affect the entire flow regime: low flows become lower, and flooding becomes less reliable or arrives at the wrong time of year.

Headwater streams are known to be highly sensitive to changes in flow. Under a drier climate these disruptions will intensify.

Can these changes be managed?

We can adapt to some degree. Rules limiting pumping from rivers during low flow periods, and better oversight of farm dams, can help keep water moving during crucial dry periods.

But when rivers are high, it’s a different picture. When river are full or even break their banks, it’s great for aquatic life. Fish move and breed, habitat is refreshed, nutrients moved downstream and wetlands rejoin the system.

Unregulated rivers lack the infrastructure, such as dams or barrages, to create or shape the big replenishing flows that ecosystems rely on, and climate change means these may simply happen less often.

If smaller rivers stop sending these floods downstream, larger rivers lose an essential part of their ecological rhythm.

Why this matters for the whole basin

What happens in the smaller creeks and rivers has a big impact. These small streams set the baseline conditions for the entire Murray–Darling system – from water quality and temperature to the timing of flows. When they falter, the effects are felt downstream.

The 2026 Basin Plan Review offers us a chance to revisit its original assumptions. Focusing on major rivers once addressed the dominant sources of environmental decline, but under climate change, risk is no longer confined to those places.

If the basin loses its headwaters, no amount of downstream engineering can compensate. Bringing these “forgotten rivers” into climate planning isn’t optional — it underpins our environmental, cultural and economic future.

Avril Horne, Research Fellow, Department of Infrastructure Engineering, The University of Melbourne; Nick Bond, Professor of Freshwater Ecology and Director of the Centre for Freshwater Ecosystems, La Trobe University, and Robert Morden, Researcher in Hydrology and Ecology, The University of Melbourne

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

A growing number of new housing developments feature a little known but powerful bit of tech: smart rainwater tanks.

That’s where the rainwater tank next to each house is fitted with a little computer to open and close a valve that releases water. Software can tell the valve to open to let some water out when, for instance, a storm is coming and you don’t want the tank to overflow. Or, it can keep it closed when you want to capture rainfall to boost household water supplies.

Our research is investigating new ways to network smart tanks together. When the tanks are part of a network, a computer program can keep track of what every tank is doing, and which ones need to release water and where.

Our project is implementing this smart rainwater tank technology to protect and restore stream habitats for platypus in Monbulk Creek, east of Melbourne.

We aim to scale up this ecologically-informed approach so it can be used anywhere, regardless of what species needs to be protected.

Tanks for platypus

Our project, known as Tanks for Platypus, focuses on using a network of smart water tanks in Monbulk Creek to support local platypus populations.

Once widespread across Melbourne and surrounds, the iconic platypus is now listed as vulnerable in Victoria.

Reasons for this decline include urbanisation, changes to stream flows and habitat fragmentation and loss.

Platypus require water flow conditions that support waterbugs (their main food source). They also need space to swim and hide from predators.

The Tanks for Platypus project involves offering eligible residents in the Monbulk Creek catchment a free smart rainwater tank.

We aim to use these networked rainwater tanks and three urban lakes to provide more natural flow conditions for platypus. When finished, this smart rain grid will be distributed across both private and public land with the cooperation of local residents, schools and businesses.

What we did

We have developed a new algorithm that manages how water is released from tanks into waterways, to improve the habitat for platypus and other aquatic life in Monbulk Creek.

We surveyed the creek in detail and simulated flow to map creek habitat. We mapped how much habitat is underwater and where water is deep enough for a platypus to be fully submerged under different flow conditions.

We can now use this information to guide our stormwater release and storage algorithms. For example, when water is not deep enough for platypus to feed and hide, our algorithm requests releases from the rainwater tanks.

During dry periods, supplementing creek flow with water releases from these tanks could significantly improve habitat conditions for platypus.

At times, just 1 megalitre per day (less than half an Olympic swimming pool) can increase available habitat by more than 10%.

This makes the water available when it’s needed and reduces the risk of flooding due to tanks overflowing during rain.

In fact, our algorithms can calculate how much water the tank should release before a storm. This means the tank ends up almost full after a storm, keeping rainwater available for residents.

Where to from here?

We are now investigating how our designs and findings in Monbulk Creek can be applied more broadly, including in high-density housing and new urban developments.

One ecological objective might be, for instance, to reduce incidents where water gushes from overflowing tanks into waterways, eroding streambeds and banks, and potentially disturbing native species. Another might be to boost water levels in local creeks or lakes during dry periods.

Algorithms could be programmed to meet these needs, as well as others such as providing water from the tank to the household water for toilet flushing and garden watering.

And those lucky enough to live near a waterway with platypus will also know they are doing their bit to look after a unique part of our Australian wildlife.

Kathryn Russell, Research Fellow, Urban Stream Geomorphology, The University of Melbourne; Alison Miller, Visiting Fellow, School of Agriculture, Food and Ecosystem Sciences, The University of Melbourne; Darren Bos, Senior Research Fellow (Knowledge Broker) School of Agriculture, Food and Ecosystem Sciences, The University of Melbourne; Rhys Coleman, Honorary Researcher, School of Agriculture, Food and Ecosystem Sciences, The University of Melbourne, and Tim D Fletcher, Professor of Urban Ecohydrology, The University of Melbourne

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

Where are you at most risk when a flood or bushfire strikes? You might think it’s at home. But in reality, the most dangerous time is when you leave and jump in your car. Many flood and bushfire deaths are linked to vehicles, often driven by people evacuating late.

One of the clearest examples comes from the 2009 Black Saturday bushfires in Victoria, in which 173 people lost their lives; 35 of those deaths occurred during evacuation, with many on the road.

What is going through people’s minds as they try to escape? We don’t have to guess – many self-recorded evacuation videos are publicly posted on social media. We analysed hundreds of these videos from around the globe to get a better understanding of how people end up in these dangerous situations.

We found many people either evacuated late after realising the situation was more dangerous than they first thought, or drove back to defend their property. They thought they were doing the right thing in trying to flee to safety – only to find the roads were far more dangerous than they expected.

How risky are roads during bushfires?

When disasters escalate rapidly, the decision to leave can become one of the most crucial moments people face.

Between 2010 and 2020, bushfire deaths in Australia often occurred on the road rather than at the fire front. An analysis found 33 of 65 bushfire deaths during this period were vehicle-related, many during late evacuations.

More recently, an ABC program documented survivor accounts from Black Saturday, including firefighters, people who defended their properties and those who took to the road in the final minutes.

One firefighter’s account, in particular, captures how quickly conditions can change on the road. At first, nothing about the drive appeared unusual.

when I drove up over the top of the hill down into Kinglake, there was nothing untoward. It was just a normal hot day […] a bit of smoke around.

But within minutes, the road environment changed completely.

so I do a U-turn, and there was a wall of smoke. I’m thinking, where did that come from? All of a sudden, […] You can’t see. It was pitch black. As we’re driving, the sides of the roads were igniting.

The risk of conditions changing is not confined to a single event or location. It is a recurring and ongoing feature of bushfire emergencies in Australia.

How dangerous are roads during floods?

Floods present a different kind of threat, but the risks on the road can be just as severe.

In Australia, nearly half of all flood fatalities are associated with vehicles, most commonly when people attempt to drive through flooded roads, crossings, or causeways.

This is not unique to Australia. A study of flood fatalities in Texas, covering the period from 1959 to 2009, shows around 80% of flood deaths with known circumstances were vehicle-related.

These deaths often occur when drivers underestimate water depth or flow speed, assume the road ahead is still passable, or follow other vehicles into floodwater. This can quickly lead to vehicles stalling, being swept away, or trapping occupants in fast-moving water.

What people experience inside a vehicle

To gain a first-person view of what actually unfolds on the road in these situations, we analysed hundreds of self-recorded evacuation videos.

On bushfire-affected roads, conversations inside vehicles revealed uncertainty as conditions changed quickly. Many drivers showed fear and stress – some prayed, while others tried to stay calm for their families.

Videos show people caught in intense heat and heavy smoke, struggling with poor visibility and concern over falling trees or bursting tyres. Some said they were struggling to breathe while others decided to stop or turn around.

Conditions appeared hazardous even for firefighters. Conversations between drivers and passengers often reflected the complexity of the environment and a lack of certainty about what to do.

Some drivers travelled with their windows open and suddenly realised how hot the air was.

Drivers struggled with visibility and some cases showed families expressing extreme distress. Parents comforted their children and sometimes sang to them.

On flood-affected roads, drivers showed signs of distress and intense emotion, often reflected in swearing and expressions of regret, or praying.

They sought reassurance from the actions of others, reflecting an “if they can do it, we can too” sentiment. Extreme cases showed water entering the vehicle, causing the vehicle to become unstable or dysfunctional, with water levels reaching the windshield.

Some drivers could not make it through and were forced to escape.

Importantly, these flood and fire videos only represented those who managed to escape and survive.

The best way to stay safe

In our analysis of these flood and fire videos, we found a recurring theme – surprise. People found themselves in a very different situation to the one they imagined when they began driving.

Driving on roads affected by floods and fires is risky, and the situation can escalate very quickly. Flash flooding is aptly named: torrential rain can trigger floods in just minutes. Bushfires, too, can intensify quickly

The clearest advice remains to avoid these situations altogether by evacuating early. But if you do find yourself in a vehicle on a fire-affected road, existing Country Fire Authority guidance can make a critical difference to survival.

Stop when it’s no longer safe to continue, park well off the road and away from vegetation if possible. Stay inside the car with windows and doors closed, turn off vents and air conditioning, get below window level and protect yourself from radiant heat using woollen blankets or clothing.

In floods, if rising water traps your vehicle, get out early and move to higher ground. As a last resort, climb onto the roof.

Ultimately, the safest option is to avoid hazardous driving wherever possible. Because once you’re on the road, it may already be too late.

Sara Fazeli, PhD Candidate, UNSW Sydney; Milad Haghani, Associate Professor and Principal Fellow in Urban Risk and Resilience, The University of Melbourne; Moe Mohammad Mojtahedi, Senior lecturer, School of Built Environment, UNSW Sydney, and Taha Hossein Rashidi, Professor of Transport Engineering, UNSW Sydney

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

A single street tree can potentially increase an average Sydney house price by A$30,000, our new research shows. This echoes past research showing street trees not only help boost property prices, but offer other benefits, from improved scenery and privacy to increased shade.

But there’s a catch. Our analysis, published in the international Cities journal, also found that if a street tree is too close, it can actually reduce the selling price by more than $70,000.

Our study looked at more than 1,500 house sales in the City of Sydney from 2021 to 2024, then matched those with detailed council data on nearly 50,000 public trees.

After accounting for other, better known price factors – number of bedrooms, bathrooms, car parking, land size, proximity to the CBD, transport, schools and more – we found trees can be associated with higher house prices. But that price boost only occurred when the trees were about 10–20 metres from a home, such as across the street or near the frontage.

In contrast, trees planted too close – within a 10m radius from the centre of the property – were actually associated with lower sale prices.

This matters beyond Sydney. Every Australian capital city has set tree-planting goals, such as the City of Sydney’s target for 23% tree canopy cover in 2030 and 27% in 2050. Yet many will struggle to meet them, with some facing resistance from residents. Our research explains why tree placement will be crucial if we ever want to meet those targets.

What’s new about this research

Past studies in Perth, as well as several cities in the United States and Canada, have consistently shown trees tend to increase property values.

But what we didn’t know before now was where the benefits stop and the costs begin.

Our study identifies a clear “not in my backyard” (NIMBY) boundary, of around 10m, within which street trees’ economic value turns negative.

That finding is important, because that’s when resident resistance to street trees is likely to be strongest.

This is a first study of its kind to quantify the economic value of public trees by taking advantage of using individual tree-level data managed by the City of Sydney from 2023.

It allowed us to measure tree effects at the finest possible distance from the centre of property: under 10m, 10–20m, 20–50m, 50–100m, and beyond 100m. This is something previous studies could not do when relying on satellite or street imagery.

How tree location affects price

We controlled for all the usual factors that influence house prices, including property features and location amenities. This meant we could measure the impact of trees after accounting for everything else.

We found that distance matters. In dollar terms, one additional tree within 10m of the centre of a property reduced its value by 2.96%. An average home sold in the City of Sydney from 2021 to 2024 was worth $2,613,000 – so that reduction worked out to be a $70,290 cost.

Given the average lot size of 176m² in the City of Sydney, the distance from the centre of an average property to its boundary is typically about 8m.

But if a tree was located 10-20 metres away, it increased the value by about 1.16%, worth an average of $30,310.

If the tree was further than 20 metres away, we found no price difference.

This show a clear proximity effect. Trees being too close to a house are a cost risk; trees at a moderate distance are a valued feature; and trees further away are neutral and just part of the neighbourhood amenity.

Our study used more precise data than ever before to calculate the distance between street trees and the centre of each property.

But future research could take this further by measuring the distance from each tree to the house. It could also incorporate resident surveys to better understand how people perceive and value trees near their homes.

Why trees being too close matters

It makes sense that people may see trees close to home as a financial risk.

Trees can cause structural damage to buildings and infrastructure, increase fire hazards, and safety concerns from falling branches.

Rather than dismissing residents’ concerns as NIMBYism, they should be seen as rational market responses to maintenance risks, structural damage, and amenity loss.

Planting plans need resident support

Every Australian capital city has adopted “urban forest” or tree planting strategies, many of them aiming to hit 30-40% canopy cover in coming decades. For example, the City of Melbourne’s target is 40% canopy cover by 2040, while Brisbane City Council is aiming for 50% shade for residential footpaths and bikeways by 2031.

However, there are doubts about whether many of those targets will be met.

There are good reasons for governments to invest in urban trees, as they can protect us from extreme heat and help as a response to climate change. But resistance from homeowners can undermine these policies.

Our research shows residents are more likely to welcome street trees if they’re planted not too close, and not too far, from their homes.

* Thanks to the coauthors of this paper, Qiulin Ke and Bin Chi from University College London.

Song Shi, Associate Professor, Property Economics, University of Technology Sydney

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

What do coffee, sugar, wheat, soy, eucalypts and paperbarks all have in common?

They are all susceptible to parasitic rust diseases caused by fungi. Plant rust disease can easily be spotted by the characteristic orange or yellow spores that cover plant leaves, making them look rusty.

The spores are easily transferred to your skin by touch or carried by the wind to other host plants.

Despite their symptomatic similarities, each species of rust fungus is restricted to a single type of plant host.

Farmers and nursery managers often use fungicide to tackle plant rust disease, but we need to find ways to decrease our reliance on fungicide treatment. Otherwise, we risk fuelling fungicide resistance.

Could treating with natural beneficial fungi be a viable alternative?

What we did and what we found

To find out, we grew 143 species of fungi that were living in association with the leaves of the Australian native scrub turpentine tree, a species now considered critically endangered due to the effects of myrtle rust disease.

Myrtle rust disease, cause by the exotic fungus Austropuccinia psidii is a type of plant rust disease, and it’s a huge problem. At least 380 Australian native plants are susceptible to it.

Myrtle rust threatens trees and shrubs in the Myrtaceae family of plants. This is Australia’s largest plant family in Australia, and includes tea tree and eucalypts. It also threatens several rainforest tree species.

The recent arrival of this disease into Australia, in 2010, means little is known about how we may feasibly control it within natural ecosystems.

Our research found that of the 143 species of fungi we grew, nine of them naturally stopped the germination of the myrtle rust spores in the lab.

This suggests native plants may already harbour beneficial fungi that could protect them from this deadly disease.

How? Our research shows one way beneficial fungi can protect the plant from the rust disease is by producing chemicals that attack the disease and prevent it from infecting the plant.

It’s like a biological machine, producing microscopic amounts of fungicide directly onto the rust as it grows.

Other ways these fungi can protect the plant are through competition for nutrients or by stimulating the plant’s immune system to protect itself.

One advantage over fungicides may be that if the fungi establishes a symbiotic relationship with the plant, repeated applications may not be necessary.

So far, we’ve only shown this in the lab. More research is clearly needed.

Now, we need to make sure the fungi can effectively do their job in the environment on our most susceptible plants. We may even one day be able to incorporate these fungi into our plant conservation breeding programs.

A growing body of research

A similar study of myrtle rust disease in Hawaii found that adding multiple beneficial fungi to the leaves of the native Hawaiian Koʻolau eugenia or nioi plant increased the effectiveness of the beneficial fungi over using a single strain alone.

This highlights that we have a lot to learn about how beneficial fungi can protect plants.

Our previous research also identified that fungi can protect crop plants such as wheat, barley and oats from rust disease.

Similar studies around the world have found fungi can also protect against coffee rust and soybean rust, among others.

Despite many successful lab studies, there remains a gap between lab studies and field applications. And even if it could be proven to work in the field, then we’d need to find efficient ways to get the beneficial fungi onto the plants that need it.

That said, it’s worth persevering. If we want strategies to reduce fungicide usage on farms and in the environment we must continue to learn more about beneficial fungi and how we can best use them to our advantage.

Michelle Moffitt, Associate Professor in Microbiology, Western Sydney University

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

New Zealand’s earlier efforts to safeguard marine or coastal environments, particularly as marine reserves and marine protected areas, typically focused on shallow ecosystems, largely because that is where most data exists.

But following the passing of the Hauraki Gulf Marine Protection Act last year, it was good to see many deep rocky reefs among the 12 new high protection areas (HPAs).

These areas prohibit recreational and commercial fishing while allowing certain customary practices in ways that reduce or eliminate extractive activities, helping ecosystems recover and rebuild.

This is important because deeper reefs often host protected species and this recognises the need to protect these habitats.

As our new research shows, even just 50 metres of depth can separate entirely different marine communities.

In this study at the Poor Knights Islands Marine Reserve off northeastern Aotearoa New Zealand, we examined sponge assemblages – a major component of temperate rocky reefs – from 5 to 65 metres in depth.

Sponges play an important role in filtering water, recycling nutrients and creating habitat for other organisms. They are also sensitive to environmental change, including marine heatwaves.

Reefs do not simply continue unchanged with greater depth. In fact, deeper communities in the “mesophotic” zone, typically found at 30–150 metres of depth, can host very distinct species that never occur in the shallows.

If conservation efforts don’t recognise this, we may be leaving a significant portion of marine biodiversity unprotected.

Different communities at depth

Our results were striking. Sponge assemblages were strongly structured by depth.

Most species were depth specialists, found either in shallow reefs less than 30 metres deep or in deeper mesophotic zones, but not both.

Across all sites we surveyed, we identified 64 sponge species or operational taxonomic units. Only 18 occurred across multiple depths spanning both shallow and mesophotic zones. In other words, less than a third of species had distributions broad enough to potentially link the two zones.

Differences between depths were driven mainly by species replacement, not by shallow communities simply becoming poorer versions of deeper ones. This means mesophotic reefs are not just extensions of shallow reefs. They are ecologically distinct systems.

Are deep reefs climate refuges?

For years, scientists have debated whether deeper reefs might serve as refuges during disturbances such as marine heatwaves, which can disproportionately affect shallower ecosystems.

The idea, known as the deep reef refugia hypothesis, suggests deeper populations could survive warming events and later reseed damaged shallow reefs.

There is some evidence this can occur for certain species. In our study, a small subset of depth generalist sponges occurred consistently across both zones. These species may have the potential to benefit if deeper habitats avoid disturbances that impact shallower waters.

But our findings suggest this refuge effect may apply only to a minority of species. Most sponges had narrow depth ranges. If shallow populations decline, deeper reefs will not automatically act as a backup for entire assemblages.

This challenges the common assumption that deeper reefs can safeguard shallow biodiversity at an ecosystem level.

Why this matters

Marine protected areas in shallow, accessible habitats are easier to survey, monitor and manage. But biodiversity does not stop at 30 metres.

If deeper reefs host distinct communities, then protecting only the shallows leaves much of that biodiversity exposed to fishing pressure and other anthropogenic impacts.

Our assessment of the current network of 44 marine reserves in New Zealand shows the majority contain areas of rocky reef, but only half have reefs below 50 metres.

Importantly, these include New Zealand’s larger offshore reserves (the Kermadec Islands, Auckland Islands, Bounty Islands, Campbell Island and Antipodes Island), which means the total protected area deeper than 50 metres comes to an impressive 16,294 square kilometres (about the size of the Auckland region).

However, these offshore marine reserves extend far deeper than the mesophotic zone and only a fraction of this area is rocky reef. When discounting the larger offshore reserves, the total area covered by marine reserves deeper than 50 metres is only 394 square kilometres, less than 1% of New Zealand’s territorial seas.

This has direct implications for marine spatial planning in Aotearoa New Zealand and globally.

Our research suggests ensuring the protection of both deep and shallow areas in the same geographical regions is essential if we want to safeguard the full spectrum of reef biodiversity. Protecting shallow reefs alone will not automatically protect deeper mesophotic species or vice versa.

Mesophotic reefs are often out of sight and out of mind. They lie beyond most recreational diving depths and are less studied than their shallow counterparts. Yet they can host rich sponge assemblages and other invertebrate communities that contribute significantly to ecosystem functioning.

They are also not immune to change. Ocean warming, shifting currents and sedimentation can all influence deeper habitats. While depth may buffer some disturbances, it does not guarantee protection.

Our findings add to a growing body of evidence that temperate mesophotic ecosystems should be managed as distinct ecological entities. They are not simply deeper versions of shallow reefs, nor are they universal refuges.

As climate change intensifies and marine heatwaves become more frequent, conservation planning must consider how biodiversity is structured across depth. This means designing protected areas that encompass entire reef profiles, from the surface to the limits of light penetration.

James J Bell, Professor of Marine Biology, Te Herenga Waka — Victoria University of Wellington and Manon Broadribb, Postdoctoral Researcher in Marine Science, Te Herenga Waka — Victoria University of Wellington

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

Rain is rare in Antarctica. Scientists doing fieldwork there dress for cold and glare, not wet weather – duvet jackets, snow trousers, goggles and sunscreen. Planes land on gravel runways which are rarely icy, since there is no precipitation to freeze. Historic huts remain well preserved in the dry air.

But this is beginning to change.

Rain is already falling more frequently on the narrow and mountainous Antarctic Peninsula, the northernmost finger of the continent pointing towards South America. Already the warmest part of Antarctica, the Peninsula is warming faster than the rest of the continent, and far faster than the global average. It provides an advanced sign of what coastal Antarctica – especially the fragile West Antarctic Ice Sheet – may experience in the coming decades.

I recently led a team of scientists looking at how the Antarctic Peninsula will change this century under three scenarios: high, medium and low greenhouse gas emissions. We found that, as the peninsula warms, precipitation will rise slightly – and will increasingly fall as rain rather than snow. As days above 0°C become more common, this rainfall will fundamentally change the peninsula.

When heat and rain arrive together

Extreme weather is already causing disruption. A heatwave in February 2020 brought temperatures of 18.6°C to the northern peninsula – T-shirt weather, for almost the first time in recorded Antarctic history – while the “ice shelf” surface alongside melted at a record pace.

Atmospheric rivers – long, thin corridors of warm, moist air that start at warmer latitudes – are playing a growing role. In February 2022, one resulted in record surface melt. Another, in July 2023, brought rainfall and temperatures of +2.7°C to the peninsula in the depths of winter. These events are happening more often, delivering rain and melt to regions where neither had been observed before.

What rain does to snow and ice

Snow does not like rain. We’ve all sadly watched snowfall melt away particularly rapidly when it rains.

On the Antarctic Peninsula, rain brings heat and melts and washes away snow, stripping glaciers of their nourishment. Meltwater can also reach the bed of the glacier, lubricating its base and making glaciers slide faster. This increases iceberg calving and the rate of glacier mass loss into the ocean.

On floating ice shelves, rain compacts the snow that has fallen on the surface, meaning water starts forming ponds. This ponded meltwater then warms, as it is less reflective than the surrounding snow and ice, and can melt downwards through the ice shelf to the ocean below, weakening the ice and causing more icebergs to break off.

This can destabilise the ice shelf. Meltwater ponding has been implicated in the collapse of the Larsen A and B ice shelves in the early 2000s.

Sea ice is vulnerable too. Rain reduces snow cover and surface reflectivity, making the ice melt faster. Loss of sea ice also weakens the natural buffers that dampen ocean waves and help prevent the ends of glaciers snapping off and becoming icebergs. It also means less habitat for algae and krill, and reduces breeding platforms for penguins and seals.

Ecosystems under stress

A rainier climate will have a series of ecological impacts.

Water can flood penguin nest sites. Penguins evolved in a polar desert and aren’t adapted for rain. Their chicks’ fluffy feathers are not waterproof, so heavy rain drenches them, sometimes leading to hypothermia and death.

Together with a warming ocean, decreased sea ice and decreased krill, this pressure will affect penguins across the continent. Iconic Antarctic species such as ice-dependent Adélie and chinstrap penguins are at risk of being replaced as more adaptable gentoo penguins expand southwards.

Rainfall also alters life on smaller scales. When it strips away snow cover, it disrupts snow algae – microscopic plants that contribute to Antarctic land ecosystems. These algae feed microbes and tiny invertebrates and can darken the snow surface, increasing solar absorption and accelerating melt.

Snow normally insulates the ground, buffering temperature swings and protecting the organisms underneath. Exposed surfaces face harsher, more variable conditions.

At the same time, warming seas may make it easier for invasive marine species such as certain mussels or crabs to colonise the area.

Challenges for scientists

Humans are also not immune to the challenges posed by a rainier Antarctic Peninsula.

With increasing geopolitical interest, it is likely that human infrastructure will increase, with potential new settlements and bases to serve emerging industries such as tourism or krill fishing.

Research infrastructure was designed for snow, not sustained rainfall. Rain freezing on airstrips renders them unusable until the ice is melted. Slush and meltwater can damage buildings, tents, instruments and vehicles. Clothing and equipment may need to be redesigned.

Some entire research sites may have to move. On nearby Alexander Island, increased surface melt has already disrupted access to long-running ecological research at Mars Oasis – continuously studied since the late 1990s – resulting in gaps in the scientific record.

Heritage at risk

Historic sites are especially vulnerable.

Antarctica contains 92 designated historic sites and monuments, the result of two centuries of exploration and research. Many of these timber huts, equipment stores and early scientific installations are clustered on the peninsula.

In a warmer and wetter climate, thawing permafrost and heavier rainfall threaten the structural integrity of these sites. Timber will deteriorate faster. Foundations will sink. These sites will need more frequent maintenance, in a part of the world where conservation work is already logistically difficult.

The Antarctic Peninsula is already undergoing rapid change. If global warming moves towards 2°C or 3°C this century, extreme weather, rainfall and surface melt will intensify. Damage to ecosystems, infrastructure, glaciers and heritage sites could be severe and potentially irreversible.

Rain, once a rarity in Antarctica, is becoming a force capable of reshaping life on the peninsula. Limiting warming to below 1.5°C won’t prevent these changes entirely. But it could slow how quickly rainfall transforms the frozen continent.

Bethan Davies, Professor of Glaciology, Newcastle University

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

In the summer of 2022, extreme heat and unprecedented drought drove parts of the world’s third largest river, the Yangtze, to dry up.

The impacts for hydropower, shipping and industry in China were severe, immediate and well-documented. Less visible were the ecological consequences for the many species that depend on the river.

The Yangtze is not an exception. Around the world, rivers are no longer changing gradually.

Rather, they are being increasingly transformed by extreme climatic events such as floods, droughts and heatwaves. Our newly published global review finds these events are pushing ecosystems beyond their limits and eroding biodiversity and core functions.

In bringing together global evidence, our research sets out a roadmap for how science and management can respond to these mounting ecological pressures.

When impacts cascade

Because rivers are connected systems, impacts rarely remain localised. Extreme climatic events can send impacts cascading through entire river networks, affecting communities far from where they begin.

A drought in headwaters can disrupt downstream processes for months, and when flows return, built-up material can trigger oxygen crashes and fish kills far downstream.

Recovery is often uneven and incomplete, with some species lost and communities permanently changed, especially where rivers are fragmented and species cannot escape to refuges or are lured into traps.

The consequences can be profound: extreme events can push ecosystems past tipping points, after which full recovery is unlikely and systems may follow new paths instead of returning to their past states.

In some cases, even the most ambitious restoration efforts of recent decades may struggle to reverse biodiversity loss if the frequency of extremes continues to rise.

Our review also shows that when extreme events happen together or in sequence – known as compound events – their impacts can be catastrophic for people and river biodiversity.

Whether that’s a flood following a drought, a drought and heatwave operating in unison, or a flood falling on saturated ground, the impacts of these compound events can multiply.

The Yangtze drought and heatwave collapsed plankton communities, while in New Mexico in 2011, wildfire followed by heavy rain damaged water quality in the Rio Grande far downstream. Repeated extremes were shown to have altered invertebrate communities in Alaska’s Wolf Point Creek for more than a decade.

In Europe’s Rhône River, a major heatwave in 2003 brought an increase in invasive species, which was amplified by damaging floods that followed. In California’s Klamath River, a wildfire and intense rain in 2022 led to widespread river failure and a long fish kill zone.

These impacts are often made worse by existing pressures such as pollution, land-use change and water withdrawals – as seen in the 2022 Oder River disaster in Germany and recent repeated die-offs in Australia’s Murray-Darling Basin.

Importantly, the severity of ecological impacts aren’t always proportional to that of the event that causes them. Instead, it is the order of events and existing stresses that often drive outsized impacts that are hard to predict and manage.

Moving from reactive to proactive

While extreme events are stretching the resilience of river ecosystems, they are also exposing gaps in the science needed to design lasting ecological solutions.

Right now, studying the effects of these events is challenging for researchers because they tend to strike without warning. As a result, the evidence base remains limited and also unevenly spread around the world.

For water managers, this creates real uncertainty about how to prepare river biodiversity for extreme events.

One common idea is to protect safe havens, such as cold streams, deep pools or shaded tributaries, which can offer species short-term relief from heat and drought.

Because of this, safeguarding these refuges is widely seen as a key part of river management. Nevertheless, questions are emerging about whether these refuges will persist or remain viable during extreme events.

Simply put, compounding extreme heatwaves and drought not only warm rivers, but also undermine the processes that create thermal refuges for freshwater species.

Engineered thermal refuges, such as via groundwater pumping or gravel trenches, are starting to show promise in early trials.

But better preparation for extreme events will require more proactive approaches, guided by adaptive frameworks such as the widely-used “resist-accept-direct” strategy.

This can mean building river resilience through habitat restoration, better connectivity, giving rivers more room to move and protecting or creating cold-water refuges at a catchment scale.

A mix of nature-based solutions and hard engineering will be needed. Approaches that restore connectivity and protect groundwater recharge zones are increasingly seen as some of the most effective ways to tackle the linked ecological challenges ahead.

Whatever tools are used, the bigger shift must be from local, reactive fixes to catchment-scale, resilience-focused strategies that anticipate extreme events rather than respond to them after the fact.

Rivers support billions of people but remain among the least protected parts of the natural world, and we urgently need to prepare them for a more extreme future.

Jonathan Tonkin, Professor of Ecology and Rutherford Discovery Fellow, University of Canterbury; Julian D. Olden, Professor of Aquatic and Fishery Sciences, University of Washington; Julian Merder, Postdoctoral Fellow in Biological Sciences, University of Canterbury; Julia Talbot-Jones, Senior Lecturer | School of Government, Te Herenga Waka — Victoria University of Wellington, and Thibault Datry, Directeur de Recherche, Inrae

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

South Africa is home to 88% of the world’s colonies of African penguins (Spheniscus demersus). The species is classified as Critically Endangered by the International Union for Conservation of Nature. This means there is a high risk the birds could go extinct in the wild following rapid population declines.

This species was once abundant along the coasts of South Africa and Namibia. But the population has fallen by about 78% over the last 30 years, driven by food scarcity, oil spills and climate-related shifts in the marine environment. African penguins mainly feed on anchovy and sardine. Changes in ocean conditions and overfishing have made it more difficult for the penguins to get enough food. In recent years, conservation organisations, scientists and government agencies have escalated efforts to halt this decline.

One of the most significant developments was a March 2025 court ruling that supported the introduction of improved no-fishing zones around key breeding colonies, to protect the penguins’ foraging grounds. Robben Island (11km north-west of Cape Town) is one of the colonies.

Protecting waters adjacent to breeding colonies is essential for the species’ long-term recovery. Food shortages in these areas, driven in part by competition with the purse-seine fishery (which uses a large net to surround schooling fish), have been directly linked to declining chick survival and the ongoing population collapse.

The court case (led by the organisations BirdLife South Africa and the Southern African Foundation for the Conservation of Coastal Birds) concluded that fish can no longer be caught within a 20km radius of Robben Island.

We are penguin researchers from the University of St Andrews, University of Exeter, the South African Department of Forestry, Fisheries and the Environment, and BirdLife South Africa. Our work has examined the interactions between penguins and fishing operations in detail, and can offer insights to guide the management of their respective needs.

Overlap with the fishing industry

Previous research into the effects of fishing on penguin populations has mostly looked at metrics such as the amount of fish removed by the fishery. But technology to track fishing locations and animal movement now enables us to look at the picture on a fine spatial scale. We can see where and how intensely commercial fishing and penguins overlaps, helping us identify areas that should be protected.

Our recent research used tracking data from penguins on Robben and Dassen islands, in the Western Cape of South Africa. We measured population-level spatial overlap between penguins and the local fishery. A small proportion of penguins were tracked using GPS devices, then we were able to simulate where more of the colony were going.

Knowing where a large proportion of the penguin population is sharing a particular space with fishing vessels makes it easier to target which areas to protect and when. It provides benefits for the fishing industry (allowing fishing in areas which are of lower importance to the penguins) and for the penguins (limiting competition with the fishery during the breeding season).

We also developed a new metric, “overlap intensity”, which captures not only how much space penguins share with fishing vessels, but how many individual penguins are affected. Traditional measures of spatial overlap simply calculate the percentage of area shared between predators (penguins) and fishing vessels. But this can dramatically underestimate the actual degree of interaction, especially when only a few areas are shared but many animals use them.

It reveals insight into ecological pressure and competition that area overlap alone misses. For example, it suggests stronger competition for prey than spatial overlap metrics imply. This method can not only be expanded to other colonies but more broadly to other species and ecosystems.

Our findings show that overlap increases sharply in years when fish are scarce. During 2016, a year of low fish abundance, around 20% of penguins foraged in the same areas as active fishing vessels. In years with healthier fish stocks, however, overlap dropped to just 4%. This pattern indicates that competition between penguins and the fishery intensifies when prey is limited. It poses the highest risk during sensitive periods such as chick-rearing, when adults must forage efficiently to provide for their young.

A new tool for risk and management

By quantifying overlap intensity at the population level, our study offers a powerful new tool for assessing ecological risk and supporting ecosystem-based fisheries management. It also provides practical guidance for designing dynamic marine protected areas that respond to real-time changes in predator–prey interactions.

Our results further show that the new no-fishing zone around Robben Island will protect a key foraging area to the north-east of the colony. This was previously one of the regions with the highest overlap between penguins and fishing vessels.

Continued monitoring will be essential to determine how overlap changes in response to the new ten-year purse-seine closures around both colonies. Similar assessments should also be conducted at additional breeding sites, including other islands involved in the closures. Foraging ranges of the penguins and the areas covered by the no-take zones vary from colony to colony.

Meanwhile, over the past few years, weighbridges have been installed at some colonies (including Robben Island) collecting penguin weights when they leave to feed and when they return. Data from these large scales will tell us more about how the closures affect penguin foraging success.

Jacqui Glencross, Seabird ecologist, University of St Andrews

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

It’s a question that has sparked the curiosity of scholars and bee lovers for decades: how many species of bees are there in the world?

This might, at first, seem like a silly question. But it is a topic of genuine importance – especially if we want to protect our pollinators.

Now, in a new paper published in Nature Communications, we provide the first statistically derived estimate of bee species richness around the world. But this work isn’t just about bees. It provides the tools needed for scientists to estimate the number of all species on Earth.

Why do bees matter?

Bees are the most important animal pollinators, so it’s crucial to know how many species there are in the world.

Globally, and corrected for inflation, pollination of crops is worth roughly A$745 billion per year. Pollination is also crucial for our diet and wellbeing with 75% of food crop diversity and 35% of total food production benefiting from animal pollination.

However, that’s far from the complete story.

Bees are what’s called a “keystone” group. That is, just like the keystone in a stone arch, removing that group would result in cascading ecological impacts – and potentially, as implied by the analogy, collapse.

Recent estimates have suggested that 90% of flowering plants (roughly 307,000 species) are pollinated by animals. Plants produce our oxygen and sequester carbon, moderate temperatures, prevent erosion, protect coastlines, form the foundation of food webs, and so much more.

Bees are also of immense cultural value. Humans have been working with honey bee products for at least 9,000 years and quite possibly longer for stingless bees.

Our current estimates

The European honey bee and bumblebee species are the best known bees in the world. But there are many more.

In his 2007 book, Bees of the World, US entomologist Charles Michener estimated there were more than 18,000 known bee species – and over 20,000 in total.

But we already have surpassed this number with roughly 21,000 named bee species globally.

Those are global estimates. But what about a more specific one?

Australia is a relatively well-understood region with at least four estimates of as high as 2,000.

But, these are all guesses without statistical backing.

How do we estimate undiscovered species?

Bee datasets around the world are growing thanks to both career and citizen scientists.

For our new study, we used more than 8.3 million bee records (where they’ve been found), a country-level checklist of bee species, and a species (taxonomy) list of roughly 21,000 species names.

We then used statistical modelling to estimate the “lower bound” of the possible number of species globally, by continent, and by country.

More simply, we look at how well we have sampled species to estimate the minimum number of new species that are still to be found.

Imagine that you go and sample two forests for bees. In the first, you find eight species, all in similarly high abundance. In the second, you also catch eight species – but while some are in high abundance, you also find some only a handful of times.

You might expect that you have discovered most of the species in the first forest because you are getting the same ones over and over again. In the second forest you’re finding many rarely occurring species, which hints that more diversity may be discovered if sampling continues.

Now expand this process to the level of countries, continents, and the globe.

So, how many bee species are there?

Globally, we estimated there are at least 24,705 to 26,164 bee species in the world (an 18–25% increase on previous estimates).

At current rates of description (roughly 117 species per year), it would take between 32 and 45 years to describe all of the world’s bee species. However, we may take much longer as our estimate is conservative, and we are likely to discover new species more slowly as fewer remain to be found.

Importantly, most new bee species are expected to be found in Asia and Africa.

Perhaps this is not surprising, as bee research in Asia has many challenges and data from Africa are very limited with some countries having zero usable bee data points.

Some species diversity is most easily detected using genetic techniques. This can easily go unnoticed — and means we shouldn’t be surprised if our estimates are surpassed in the future. Even in wealthy nations, such as Australia, we saw that not using genetic techniques might lead to lower estimates of species richness.

Highly valuable data

We have shown that it’s possible to estimate the total number of bee species, and indeed any species, on a country level using existing data.

These data are highly valuable in several respects.

A detailed cost-benefit analysis of investment in discovering and documenting new species in Australia found that every $1 invested in discovering all remaining Australian species will bring up to $35 of economic benefits to the nation.

These data can also be used to prioritise our discovery and taxonomic efforts, as well as prioritising conservation efforts to conserve our most important species.

Through the application of these methods we can, at long last, start to answer the question “how many species are there in the world?”.

James B. Dorey, Lecturer in Biological Sciences, University of Wollongong and Nikolas Johnston, Lecturer in Molecular Biology, School of Science, University of Wollongong

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

On average, Australia’s driest town, Oodnadatta, gets just 172mm of rain a year. But the small town in inland South Australia is likely to get two years’ worth of rain in a single week.

Rainfall records are likely to topple across inland areas, as rains of 150–300mm are predicted this week, following heavy rains in recent days.

Heavy rains are lashing swathes of arid central Australia, as intensely humid tropical air from the Top End is pushed south. Alice Springs is on flood watch. The Trans-Australian rail line is cut amid track washouts. The Northern Territory’s main highway is closed.

More is to come as extreme rains continue over the driest parts of Australia this week. Severe weather warnings for heavy rain have been issued for parts of Queensland, Northern Territory, New South Wales, South Australia and Victoria. Intense rainfall and damaging winds from localised severe thunderstorms will lead to flash flooding. Flood warnings have been issued for rivers and streams across the entire Lake Eyre Basin. The sheer scale of this event is remarkable – and concerning.

Many remote communities will be cut off for weeks and stock losses are likely to be significant. Western Queensland is already reeling after major floods earlier this year. In coming weeks, floodwaters will engorge rivers flowing to Australia’s lowest point, Kati Thanda-Lake Eyre, which could fill for the second year in a row – a rare occurrence. There’s even a possibility the lake could top its 1974 depth record of 6 metres.

What’s causing this?

In recent days, a very slow-moving tropical low has intensified as it moved southeast through the NT.

On the northern and eastern flanks of this weather system lies an incredibly humid airmass from the oceans off Indonesia. As this saturated air moves south, an upper trough extending into northwest New South Wales is forecast to deepen on Tuesday, increasing the risk of heavy falls.

This combination is a recipe for intense rain. As the strengthening upper trough intersects with the humid tropical airmass, it will push saturated air higher up in the atmosphere. Once high enough, the water vapour will condense and fall as heavy rain.

The warmer the air, the more water it can hold. The tropical low is likely to stay almost stationary over central Australia all week, which means it will dump most of its water before eventually weakening.

Two fillings of Kati Thanda-Lake Eyre?

Since European colonisation, Australia’s largest salt lake has only filled to near or full capacity four times – most recently in 2025.

There’s still water in many parts of Kati Thanda-Lake Eyre from last year’s floodwaters. At last year’s peak, the ephemeral lake covered about 80% of its maximum extent and was just over 2 metres deep in the two deepest parts of the lake, Belt Bay and Madigan Gulf.

As of February 10, many parts of the lake still hold water. These waters came from the torrential rains that hit western Queensland almost a year ago.

Floodwaters typically take months to snake through the lake’s often-dry inland tributaries. If the lake fills again this year, it will be highly unusual.

That’s because the La Niña climate driver in the Pacific Ocean is rapidly weakening and an El Niño is likely. La Niña years tend to bring colder, wetter conditions to Australia, while El Niño years tend to be hotter and drier.

Until now, every filling of Kati Thanda-Lake Eyre recorded has been linked to strong La Niña years. Last year’s partial filling took place during a moderate La Niña.

It’s getting harder to project what’s likely to happen based on past experience. When the lake filled to a record depth of 6m in 1974, widespread falls of 300–600mm fell on dry catchments. This year, many northern rivers and streams in the Lake Eyre basin were already at minor or moderate flood level before this huge rain-bearing system formed.

Is there a climate change link?

One of the most visible and devastating changes from global heating is what’s happening to the global water cycle, which moves water from lakes and oceans to clouds to rivers, lakes, snow and ice and back again.

Burning fossil fuels and other emissions have made the world 1.48°C hotter than the pre-industrial period. This is already supercharging the water cycle. This is why we’re witnessing extreme rainfall hitting more often and more intensely across the globe.

There’s a clear link between climate change and more extreme rains and floods. For every 1°C of warming, the atmosphere holds 7% more water vapour. But this figure could be even higher for short-duration rainfall, such as during severe thunderstorms.

Without attribution studies, we can’t say this week’s extreme rains have a direct climate change influence. But the overall trends are very clear.

For the dryland and desert towns, communities and stations bracing for impact, this will be small comfort. It’s crucial we don’t underestimate these rains. They are packing a punch.

Steve Turton, Adjunct Professor of Environmental Geography, CQUniversity Australia

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

Australia’s new fuel efficiency scheme has been in place for just seven months.

But the New Vehicle Efficiency Standard has already created a new, tradeable carbon currency applying just to cars and light commercial vehicles (utes and vans) market. In just months, the scheme has created a surplus of roughly 16 million “NVES unit” credits.

When manufacturers sell efficient cars, they earn credits. When they sell high-emitting ones, they rack up a debt. Any debts will have to be settled either by buying credits from car companies in surplus or by paying financial penalties.

As a result, brands such as BYD, Toyota and Tesla are already banking millions of credits, while others such as Mazda, Nissan and Subaru are building up debts which will get harder to ignore. We don’t know how much credits are worth yet as the market is too new and carmakers haven’t started trading them yet.

The architects of the scheme deliberately designed credit trading into the laws. But the speed and scale of these market dynamics has been surprising. From next year on, the legally binding targets will progressively tighten – and the average new car on the road will get cleaner and cleaner.

Promising signs

For decades, Australia was one of the few developed nations with no limit on how much carbon dioxide cars could belch out in their exhaust.

That changed on July 1 2025 when the New Vehicle Efficiency Standard came into effect. It sets a limit on total emissions a manufacturer’s range of models can produce (141 grams of carbon dioxide per kilometre for cars, 210g/km for utes and vans in 2025) and then lowers the limit every year.

The first results from the new fuel efficiency scheme tell an encouraging story: almost 70% of carmakers beat their fleet emissions targets.

The results come from the six months between July 1 and December 31 2025, when almost 621,000 new vehicles were registered. Around 71% were cars and 29% were light commercial vehicles.

The scheme likely contributed to the first fall in transport emissions since COVID.

The credit kings

At present, Australia has 59 brands active in the market. Of these, 40 beat their targets and 19 didn’t.

Many of these leaders should be no surprise. BYD stood out, earning a combined 6.3 million credits across its two registered entities from sales of battery-electric and plug-in hybrid vehicles. Tesla is a major credit generator too, banking 2.2 million credits.

But the real surprise is Toyota, which earned nearly 2.9 million. The Japanese carmaker has not been enthusiastic about EVs. Instead, it has flooded the market with hybrids, giving it a fleet emitting well under the current limit. But this advantage will be short-lived as limits tighten year on year. Eventually, even Toyota will have to shift to plug-in hybrids and battery-electric vehicles.

The scheme is not a zero-sum game – it can run in surplus. In 2025, credits generated outstripped liabilities by more than 15 to 1, reflecting deliberately easy first-year targets to ease industry into the system. But as targets tighten sharply from 2026, carmakers now in surplus will likely need those banked credits for their own future compliance - meaning the market is less unbalanced than the current numbers suggest. Unused credits expire after three years.

Who’s feeling the heat?

On the other side of the ledger, name brands are starting to sweat. Mazda has the largest debt at present, owing more than 500,000 units. Nissan has around 215,000, and Subaru is close behind.

These carmakers are facing a tough choice. Do they radically change the types of cars they ship and sell in Australia? Do they pay financial penalties to the government? Or do they buy credits from rivals? In practice, most will use a combination, gradually greening their fleet while buying credits to bridge the gap.

Cleaner models are a better business decision

Most likely, carmakers accruing debts under the scheme will pass the cost on to consumers, making cars from higher-polluting brands more expensive. Companies in surplus can sell credits, using the proceeds to lower prices and attract more customers.

Think of it as a stealth subsidy. Every time someone buys a less efficient car from a struggling brand, they could be making someone else’s new electric vehicle cheaper.

For the first time in Australia, fuel efficiency is rewarded and waste penalised. This means cleaner models are now a better business decision for carmakers. Volume of sales alone now isn’t enough for success in Australia’s highly competitive market. Model range and choice of technologies have become increasingly important.

Clearer air

Overall, new cars sold from July to December beat their emissions targets by 21%, emitting 114g of CO₂ per km on average against a target of 144g/km.

Light commercial vehicles also cleared the bar – though only just – averaging 199g/km against a target of 214g/km. Without a rapid influx of hybrid or electric utes, the sector could hit a compliance wall as early as next year, when targets tighten sharply.

In total, I estimate the new cleaner vehicles will stop between 190,000 and 220,000 tonnes of CO₂ entering the atmosphere every year they remain on the road. That’s the equivalent of taking 100,000 older, dirtier cars off the roads.

Impressive start, job far from done

This early good news doesn’t mean the job is done. The 2025 targets were set to be achievable to ease industry into the system, meaning credit kings could coast until 2027, delaying the launch of even cleaner models.

But the reprieve won’t last long. Targets will get harder and harder to meet. A car emitting just over the limit today will be significantly over it by 2028. Because penalties scale with emissions, highly polluting cars will cost makers more and more. A huge credit surplus could be wiped out surprisingly quickly if a manufacturer is slow to modernise.

What’s next?

Australian consumers can expect to see more fuel-efficient cars, more affordable EVs and fiercer competition as carmakers clean up their range.

Australia’s carbon market for cars has officially opened. In this game, standing still is the most expensive move any company can make.

Hussein Dia, Professor of Transport Technology and Sustainability, Swinburne University of Technology

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

St Francis of Assisi, who founded the Franciscan order, is one of Catholicism’s most revered saints. After Christ and the Virgin Mary, he is the most depicted figure within Catholic art, literature and film.

The patron saint of the environment, St Francis is best known for his love of animals and the natural world. Famously, he preached to the birds and referred to all creatures – including the stars and planets – as his beloved “brothers and sisters”.

When Francis died in 1226, fears that his body would be stolen meant that it was placed in an iron cage and buried so deep beneath the basilica in Assisi, Italy, that its whereabouts remained a mystery for 600 years. Aside from his fame for miracles and holiness, and subsequent canonisation in 1228, the reason Francis’s body was hidden was what it contained.

Two years before his death, it is said Francis experienced a vision of a crucified Seraphim (a six-winged angel) which marked his body with the stigmata – the wounds of the crucified Christ. The first recorded case of stigmata, medieval sources tell us that unlike later stigmatics, Francis did not just have holes in his hands and feet, but rather growths resembling nails.

St Francis’s earliest biographer Thomas of Celano wrote: “His hands and his feet seemed to be pierced by nails, the heads of the nails appearing on the insides of his hands and the upper side of his feet, and their points protruding on the other side … [His torso] was scarred as if it had been pierced by a spear, and it often seeped blood.”

Finding the the missing body

Numerous efforts to locate St Francis’s body over the centuries all failed. In 1818, though, excavations deep within the basilica’s foundations finally revealed the iron cage and the simple coffin containing the saint’s bones.

These were examined by ecclesial and scientific authorities which affirmed their authenticity. The last time the bones were examined was in 1978, when they were placed inside a nitrogen-filled perspex box to aid their preservation. An underground chapel was constructed to allow pilgrims to see St Francis’ tomb, though crucially not the bones themselves.

To commemorate the 800th anniversary of his death – known as the transitus – St Francis’s remains will go on extended display for the first time. From February 22 to March 22 2026, the perspex box containing his bones will rest at the foot of the main altar in the basilica in Assisi.

Hundreds of thousands of pilgrims are expected to come and see the bones, with their display opening a year-long series of events – both in Assisi and around the world – honouring the anniversary. The date itself falls on October 4 2026.

The 800th anniversary also marks a moment of national celebration for Italy. Giorgia Meloni welcomed the Vatican’s decision to allow the remains to go on display, noting that, “St Francis is one of the foundational figures of Italian identity”.

St Francis’s Canticle of the Creatures – a hymn which he composed as he lay dying – is one of the earliest works of Italian literature, with the oldest surviving copy being found in a 790-year-old manuscript housed in the Franciscan convent in Assisi.

The legacy of a much-loved saint

St Francis’s teachings have exerted a profound impact on modern Catholicism, particularly its teaching on the environment.

Pope Francis – who took the name in honour of the Italian saint – made the Canticle of the Creatures the cornerstone of his 2015 encyclical Laudato Si. The Catholic church’s first “green encyclical”, it praised the natural world as our “beautiful mother” and affirmed the church’s commitment to promoting environmental justice.

Likewise, a major joint document issued last July by the bishops of Asia, Africa and South America drew heavily on St Francis’s thinking, rejecting what it called the “false solutions” advanced by many western governments to address the climate crisis.

At the press conference marking the document’s publication, one of its authors, the Franciscan Cardinal Jaime Spengler, said: “From the heart of the Amazon, we hear a cry: how can we allow a market without ethical regulations decide the fate of the planet’s most vital ecosystems?”

When St Francis’ bones go on display, they will serve as a powerful reminder not only of his enduring relevance for Catholic spirituality, but also the vital role he has played in helping the contemporary Catholic church to become one of the leading advocates for meaningful climate reform.

The bones of St Francis will be on display at the Basilica of St Francis of Assisi, Umbria, Italy, from February 22 to March 22 2026

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William Crozier, Duns Scotus Assistant Professor of Franciscan Studies, Durham University

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

Amid the wet and grey gloom of February, gardeners across the UK are reporting that crocuses are pushing through their lawns and borders weeks ahead of schedule. This phenomenon is no quirk of nature. Crocuses flowering early in 2026 is a sign of shifting seasons, driven by a unique combination of biological triggers and record-breaking UK weather patterns.

Crocuses are thermoperiodic plants, which means they rely on temperature cues rather than day length to dictate their lifecycle. Their corms (a type of bulb) also usually need a cold spell in autumn to prompt an annual reset before they will start to grow toward flowering around March.

Do the seasons feel increasingly weird to you? You’re not alone. Climate change is distorting nature’s calendar, causing plants to flower early and animals to emerge at the wrong time.

This article is part of a series, Wild Seasons, on how the seasons are changing – and what they may eventually look like.

In a typical year, this process unfolds gradually. But if soil temperatures stay mild in autumn and through December and January, as they have this winter, the reset button is not hit and crocuses can reach their flowering threshold far sooner, emerging in late January and early February rather than March.

No cold reset usually means a “blind” corm – a corm that produces leaves but no flowers. That might be expected this year, although the prior weather the UK has experienced may mitigate this.

The past two years have perfectly primed bulbs already in the ground. The year 2024 was the UK’s fourth warmest year. And last year was the UK’s warmest year on record, featuring a scorching summer and exceptional sunshine, enabling crocuses to stockpile massive energy reserves in their bulbs.

Met Office data shows the UK has three weeks fewer ground frosts annually compared to 50 years ago, preventing some plants that grow from bulbs entering their normal state of dormancy over winter. There may be more blind bulbs and corms if this trend continues.

In 2022 researchers showed that UK plants flower a full month earlier than they did before 1987. The Botanical Society of Britain and Ireland’s 2026 New Year Plant Hunt confirmed this, with participants spotting wildflowers and spring bulbs blooming unexpectedly in January. This is a visible signal of climate disruption. Crocuses, being more sensitive than trees or shrubs, act as canaries in the coal mine for spring shifts.

There are other influences beyond climate change that may amplify this early flowering.

Urban heat-island effect

City plants can bloom days earlier than rural ones. Concrete and asphalt trap daytime heat, radiating it overnight, which elevates local soil temperatures. Each 1°C November-December rise adds to around 2.5 more species flowering earlier in the UK.

Light pollution

Light is fundamental to plant growth. Light pollution in cities may mimic longer days, disrupting plant circadian rhythms and prompting bulbs into earlier bud-burst.

Soil microbiome

Complex soil microbe communities that thrive in warmer weather may boost flowering. Mycorrhizal fungi and bacteria form connections with plant roots that can benefit the plant. They respond to warmer soils, too, and support plants’ natural processes and accelerating growth. So warmer winters, induced by climate change, may enhance these associations. Crocuses respond particularly well to this kind of association.

Gardener’s choice

Some growers prefer varieties that flower earlier in the season, and certain species – like Crocus chrysanthus – can bloom two weeks ahead of the more common Dutch hybrids (C vernus).

Energy reserves

The more sun and warmth the bulb gets the previous summer the more energy it stores – and the more energy it has in reserve, the earlier it can flower.

This early crocus bloom may seem delightful after months of drab grey winter, but gardeners should be wary of weather reversals. Buds and flowers are more exposed if colder conditions return, meaning they may whither. Early waking pollinators like bumblebees may benefit from the unusually early feast but these kinds of abnormal timings could disrupt ecosystems outside of gardens.

Spring seems to have arrived early in 2026. As crocuses begin to carpet lawns and borders prematurely, they underscore nature’s sensitivity to our warming world. Their purple and yellow petals, pushing through in January and February rather than March, are as clear a signal as any thermometer.

Lionel Smith, Horticulture lecturer, Anglia Ruskin University

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

For people living in temperate regions of Europe, the Americas and much of Asia, scorpion stings are rarely a concern. But for millions of children growing up across the subtropical belt, a scorpion sting can have devastating consequences.

While snakebites are receiving increasing international attention and funding under the leadership of the World Health Organization, scorpionism (the medical term for illness caused by scorpion venom) remains under-reported, under-funded and under-researched. Worse still, this silent epidemic appears to be growing, fuelled by a combination of climate change, urbanisation, global trade and human encroachment into natural habitats.

In Brazil, scorpion stings have tripled over the past decade, as scorpions settle in major cities around the country. In Sudan, the construction of the Merowe Dam in 2009 and the rapid development of gold mining complexes displaced scorpion populations into nearby settlements, triggering localised epidemics.

In November 2021, torrential rains in Aswan, southern Egypt, drove thousands of deathstalker scorpions into homes and in the streets, injuring more than 450 residents and overwhelming local hospitals.

Globally, at least 1.2 million scorpion stings are recorded each year. While most victims recover fully, an estimated 3,000 people die annually as a direct result of scorpion stings, mostly children under the age of 13, typically from poor rural communities.

Global hotspots for scorpion deaths:

Scorpionism is not evenly distributed across the tropics. Most fatal cases occur in a dozen geographic hotspots including parts of Latin America, north Africa, the Levant, Iran and western India. All these areas have warm climates with seasonal extremes that favour scorpion activity, as well as poor housing, rapid urbanisation and limited access to healthcare that also contribute to the problem.

Scorpions thrive where people live and work – in cracks in walls, beneath rubble, among stored goods, in outdoor latrines and across agricultural land. But they are not aggressive animals. Most stings occur defensively when a scorpion is accidentally trapped or pressed against the skin.

Lethal scorpions

Of the roughly 2,500 known scorpion species worldwide, only 50 to 100 are considered lethal to humans. Severe envenoming – cases that requiring extensive medical attention and a hospital stay – usually involves intense local pain rapidly followed by profuse sweating, excessive salivation, vomiting and irregular heartbeat. In severe cases, fluid accumulates in the lungs, leading to respiratory failure.

Intensive care beds, ventilation support and medications that stabilise heart and lung function are essential to help young patients withstand the first 24 to 36 hours following severe envenoming.

Antivenom serum developed over a century ago has significantly helped to reduce death rates in parts of Mexico, South America and Egypt. But it is not a magic bullet.

The antivenom must be administered early, requires trained personnel and appropriate facilities, and is only effective if it matches the venom of the species responsible for the sting. It can also cause severe allergic reactions including anaphylaxis. For many vulnerable communities, its cost and limited availability remain major barriers to effective treatment.

Morocco’s scorpion hotspots

Morocco illustrates the complexity of managing scorpion stings. The country hosts more than 55 scorpion species including some of the most dangerous in the world, such as members of the genus Androctonus (“man-killer” in Greek).

After years of limited success with antivenom therapy, in the early 2000s Moroccan health authorities shifted away from antivenom to focus on using respirators and other drugs to control patients’ heart rates and maintain vital organ function while in intensive care. They also began large-scale public education campaigns.

This led to a significant drop in the death rate due to scorpion stings.

Today, Morocco records around 25,000 stings annually, resulting in 50 to 100 deaths. But some areas are much more at risk than others. The rural district of Kalaat Sraghna on the northern slopes of the Atlas Mountains, for example, represents less than 2% of Morocco’s population but accounts for roughly 20% of stings nationwide. Geographic isolation, scorpion diversity and urban expansion are all likely to be contributing factors.

In most cases, the species responsible for a sting is never identified, yet this information can be critical for diagnosis and treatment. Scorpions often look similar and typically escape immediately after stinging. Neither victims nor healthcare workers can reasonably be expected to identify them accurately.

This is where zoology and ecology intersect with public health. In a new study, our team comprising Moroccan and Irish researchers conducted field surveys of 19 scorpion species and then used machine learning (a type of artificial intelligence) to understand where else they might be located throughout Morocco.

Our model identifies the environmental conditions scorpion hotspots might share, including average or extreme seasonal temperatures, annual rainfall, vegetation type and land use. It then scans the landscape for areas with similar conditions, generating probability maps of where each species is most likely to occur.

In our study, we found that soil type was the most important variable driving the distribution of high-risk scorpions across central Morocco.

We recently presented our results at the Pasteur Institute of Morocco in Casablanca, part of the country’s public health system. Our predictive maps can help prioritise intensive care capacity, ensure medications are available locally, and strengthen emergency response in rural areas by helping doctors anticipate which species have been responsible for the stings.

Importantly, this approach can be adapted to other countries facing similar challenges. Scorpionism is still overlooked on the global health agenda. But better integration of ecology, climate science and clinical sciences offers a powerful tool to prevent deaths, especially among vulnerable children.

Michel Dugon, Head of the Venom System Lab, University of Galway

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

A yellow disc with rays of white – an icon of childhood drawings and a flower with healing properties. We have picnics on it, play football on it and make daisy chains out of it.

The common or lawn daisy, Bellis perennis, is probably familiar to most people living in temperate climates. But there may be few things you do not know about this fascinating and perhaps under estimated flower.

A flower made of little flowers

Each daisy is actually an inflorescence – a multitude of tiny flowers called florets working together to set out a buffet for pollinators. There are two types of florets. The tube florets form the yellow centre of the inflorescence, about 100 in a typical daisy. You can see them open in sequence over several days from the outside inwards, revealing their treasures of nectar and pollen.

The ray florets have the long white petals. They are female, whereas each tiny tube floret has a set of male and female floral attributes. Every tube floret produces pollen and nectar as well as having an ovary which can make a tiny fruit at the bottom.

Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories. This article is part of a series, Plant Curious, exploring scientific studies that challenge the way you view plantlife.

The white and yellow contrast between the two types of florets is probably attractive to pollinators. Watch a pollinating insect land on a daisy and it will probe each open floret for a sip of nectar. The florets all sit on a capitulum (a cone-shaped platform), which is surrounded by green phyllaries (or bracts). The capitulum also bears the miniature fruits called achenes which are one-seeded fruits.

Unlike some members of the same family, such as the dandelion, the little seeds have no hairy parachute or pappus to help them disperse. This means that most probably drop close to the parent plant, although they can also be dispersed on muddy paws or shoes, and by worms, ants and birds.

Intrepid explorers

The formal name of the daisy – Bellis perennis – was chosen in the 18th century by biologist Carl Linnaeus, who invented the system by which botanists still name species. Bellis is probably from the Latin for beautiful and perennis for perennial or long-lasting. The word daisy is thought to come from “day’s eye”, a reflection of the fact that the flowers close at night.

However, the word daisy is applied to many other species with similar inflorescences and is used to describe a whole family of plants, the Asteraceae. This is the largest family of flowering plants, incorporating species from thistles to sunflowers, almost all of which have the same inflorescence structure of smaller florets collected on a capitulum. There are over 32,000 species in this family, from tiny daisies to large tropical trees. They are found in most ecosystems on earth, except Antarctica.

This indicates they have a successful evolutionary strategy that has allowed them to adapt and spread. The little lawn daisy has travelled around the world from its native distribution in Europe to be ubiquitous in temperate climates from New Zealand to the US.

Circadian strategy

Most flowers stay open all the time but some, like daisies, open towards the sun in the morning to maximise warmth. This may make them more attractive to insect pollinators who need heat to regulate their body temperatures.

The ray florets do the opening and closing, covering the inner disc florets when closed. On cloudy cool days the daisies might not open at all. The movement of the petals is likely to be as a result of cell growth on either side of the long white ligule of the ray floret, with the cells on both sides of the petals growing at different rates.

Resourceful

Gardeners who want the perfect lawn may see daisies as a nuisance. But a 2021 study showed that lawn daisies provided up to 11% of the nectar available to pollinators in some urban environments, making them important food for our urban bees, butterflies, hoverflies and other pollinating insects. These insects are, in turn, food for so many other animals along the food chain.

Daisies can self-pollinate. They can also clone themselves – sending stolons (runners) sideways to colonise a patch of ground. Bellis perennis seems to be well adapted to human-made habitats, with its short sward or dense mat. Daisies with longer swards tend to get outcompeted as they only produce leaves in a rosette near the ground. Its natural habitats include areas of low or disturbed vegetation such as trampled ground, stream edges and lake margins.

Bellis perennis, in common with most flowering plants, forms associations with fungi in its roots. Arbuscular mycorrhizal fungi have been co-evolving with plants for the last 400 million years, allowing the colonisation of land by early plants. The plant feeds the fungi with carbohydrates and in turn, the fungi reach out into the soil and supports the plant with nutrients. This ancient partnership between plants and soil fungi still mediates plant interactions with other soil microbes, and regulates plant-plant interactions.

Human connection

The Asteraceae is probably the most popular plant family in popular medicine containing a wide range of active plant chemicals or phytochemicals with antioxidant, anti-inflamatory, antimicrobial, diuretic and wound-healing properties. Bellis perennis itself has had many common names over the centuries including gardener’s friend, bruisewort and poor-man’s arnica.

It feels like daisies have always been part of our lives in the temperate parts of the world and always will be. Daisies have long featured in literature and poetry, mentioned by Chaucer (The Good Woman), Shakespeare (Ophelia’s flowers in Hamlet) and the 19th century poet John Clare.

But the species that are thriving today are not necessarily assured a future. For example, many once common species of birds, like swifts and skylarks, are in decline now in the UK. Arable weeds such as common corncockle (Agrostemma githago) or cornflower (Centaurea cyanus) that were once a nuisance in crops are now rare species that need intervention to prevent their extinction.

So, we must treasure and monitor these flowers, to ensure they are part of our future as well as our past.

Libby John, Professor of Sustainability, University of Lincoln and Sandra Varga, Associate Professor in Life Sciences, University of Lincoln

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