Six million hectares of threatened species habitat up in smoke



At least 250 threatened species have had their habitat hit by fires.
Gena Dray

Michelle Ward, The University of Queensland; Aaron Greenville, University of Sydney; April Reside, The University of Queensland; Ayesha Tulloch, University of Sydney; Brooke Williams, The University of Queensland; Emily Massingham, The University of Queensland; Helen Mayfield, The University of Queensland; Hugh Possingham, The University of Queensland; James Watson, The University of Queensland; Jim Radford, La Trobe University, and Laura Sonter, The University of Queensland

More than one billion mammals, birds, and reptiles across eastern Australia are estimated to have been affected by the current fire catastrophe.

Many animals and plants have been incinerated or suffocated by smoke and ash. Others may have escaped the blaze only to die of exhaustion or starvation, or be picked off by predators.



But even these huge losses of individual animals and plants do not reveal the full scale of impact that the recent fires have had on biodiversity.

Plants, invertebrates, freshwater fish, and frogs have also been affected, and the impact of the fires is likely to be disproportionately greater for threatened species.




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


To delve deeper into the conservation impact, we used publicly available satellite imagery to look at the burnt areas (up to January 7, 2020) and see how they overlapped with the approximate distributions of all the threatened animals and plants listed under the Environment Protection and Biodiversity Conservation Act.

We restricted our analysis to the mediterranean and temperate zone of south-east and south-west Australia.

The bad news

We found that 99% of the area burned in the current fires contains potential habitat for at least one nationally listed threatened species. We conservatively estimate that six million hectares of threatened species habitat has been burned.



Given that many fires are still burning and it is not yet clear how severe the burning has been in many areas, the number of species affected and the extent of the impact may yet change.

What we do know is that these species are already on the brink of extinction due to other threats, such as land clearing, invasive species, climate change, disease, or previous fires.

Approximately 70 nationally threatened species have had at least 50% of their range burnt, while nearly 160 threatened species have had more than 20% of their range burnt.

More threatened plants have been affected than other groups: 209 threatened plant species have had more than 5% of their range burnt compared to 16 mammals, ten frogs, six birds, four reptiles, and four freshwater fish.


Author supplied

Twenty-nine of the 30 species that have had more than 80% of their range burnt are plants. Several species have had their entire range consumed by the fires, such as the Mountain Trachymene, a fire-sensitive plant found in only four locations in the South Eastern Highlands of NSW.

Other species that have been severely impacted include the Kangaroo Island dunnart and the Kangaroo Island glossy black cockatoo. These species’ entire populations numbered only in the hundreds prior to these bushfires that have burned more than 50% of their habitat.

The Kangaroo Island glossy black cockatoo has had more than 50% its habitat impacted by fire.
Mike Barth

Glossy black cockatoos have a highly specialised diet. They eat the seeds of the drooping sheoak (Allocasuarina verticillata). These trees may take anywhere from 10 to 50 years to recover enough to produce sufficient food for the black cockatoos.

The populations of many species will need careful management and protection to give their habitats enough time to recover and re-supply critical resources.

The figures above do not account for cumulative impacts of previous fires. For example, the critically endangered western ground parrot had around 6,000 hectares of potential habitat burnt in these fires, which exacerbates the impact of earlier extensive fires in 2015 and early 2019.

Threatened species vary in their ability to cope with fire. For fire-sensitive species, almost every individual dies or is displaced. The long-term consequences are likely to be dire, particularly if vegetation composition is irrevocably changed by severe fire or the area is subject to repeat fires.

More than 50% of the habitat of several species known to be susceptible to fire has been burnt – these include the long-footed potoroo and Littlejohn’s tree frog.

The endangered long-footed potoroo has had more than 50% of its potential habitat impacted by fire.
George Bayliss

Some species are likely to thrive after fire. Indeed, of the top 30 most impacted species on our list, almost 20% will likely flourish due to low competition in their burnt environments – these are all re-sprouting plants. Others will do well if they are not burnt again before they can set seed.

Rising from the ashes

For fire-sensitive threatened species, these fires could have substantially increased the probability of extinction by virtue of direct mortality in the fires or reducing the amount of suitable habitat. However, after the embers settle, with enough investment and conservation actions, guided by evidence-based science, it may be possible to help threatened species recover.

For species on the brink of extinction, insurance populations need to be established. Captive breeding and release can complement wild populations, as occurs for the regent honeyeater.
Dean Ingwersen / BirdLife Australia

Protection and conservation-focussed management of areas that have not burned will be the single most important action if threatened species are to have any chance of persistence and eventual recovery.

Management of threatening processes (such as weeds, feral predators, introduced herbivores, and habitat loss through logging or thinning) must occur not just at key sites, but across the landscapes they sit in. Maintaining only small pockets of habitat in a landscape of destruction will lock many species on the pathway to extinction.

In some cases, rigorous post-fire restoration will be necessary to allow species to re-colonise burnt areas. This may include intensive weed control and assisted regeneration of threatened flora and specific food sources for fauna, installing nest boxes and artificial cover, or even targeted supplementary feeding.

Unconventional recovery actions will be needed because this unique situation calls for outside-the-box thinking.




Read more:
The science of drought is complex but the message on climate change is clear


Playing the long game

These fires were made larger and more severe by record hot, dry conditions. Global temperatures have so far risen by approximately 1°C from pre-industrial levels.

Current projections indicate that we are on track for a 3°C increase. What will that look like?

We are in a moment of collective grief for what has been lost. A species lost is not just a word on a page, but an entire world of unique traits, behaviours, connections to other living things, and beauty.

These losses do not need to be in vain. We have an opportunity to transform our collective grief into collective action.

Australians are now personally experiencing climate impacts in an unprecedented way. We must use this moment to galvanise our leaders to act on climate change, here in Australia and on the world stage.

The futures of our beloved plants and animals, and our own, depend on it.The Conversation

Michelle Ward, PhD Candidate, The University of Queensland; Aaron Greenville, Lecturer in Spatial Agricultural and Environmental Sciences, University of Sydney; April Reside, Researcher, Centre for Biodiversity and Conservation Science, The University of Queensland; Ayesha Tulloch, DECRA Research Fellow, University of Sydney; Brooke Williams, PhD Candidate, The University of Queensland; Emily Massingham, PhD Student, The University of Queensland; Helen Mayfield, Postdoctoral Research Fellow School of Earth and Environmental Sciences, The University of Queensland; Hugh Possingham, Professor, The University of Queensland; James Watson, Professor, The University of Queensland; Jim Radford, Principal Research Fellow, Research Centre for Future Landscapes, La Trobe University, and Laura Sonter, PhD Candidate in Global Environmental Change, The University of Queensland

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

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



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

Mike Lee, Flinders University

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

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

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




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


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

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

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

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

Using insects to estimate true extinction numbers

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

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

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

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

How many mammals are critically affected?

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

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

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

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

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

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

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

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

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




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


How do our estimates compare?

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

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

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




Read more:
How to unleash the wisdom of crowds


Why simplistic models can still be very useful

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

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

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

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

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

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

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

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

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

You can leave water out for wildlife without attracting mosquitoes, if you take a few precautions



Leaving water out for wildlife is important during droughts and bushfires but if it’s not changed regularly it can be a breeding ground for mosquitoes.
Roger Smith/Flickr, CC BY-NC

Cameron Webb, University of Sydney

Australia is in for a long, hot summer. The recent bushfires have been devastating for communities and wildlife. Drought is also impacting many regions.

Understandably, people want to leave water out for thirsty birds and animals.

Health authorities generally warn against collecting and storing water in backyards as one measure to protect against mosquito bites and mosquito-borne diseases caused by, for example, dengue and Ross River viruses.




Read more:
How Australian wildlife spread and suppress Ross River virus


But it’s possible to leave water out for wildlife – and save water for your garden – without supplying a breeding ground for mosquitoes, if you take a few precautions.

For some mozzies, any water will do

Mosquitoes often look for wetlands and ponds to lay their eggs. But sometimes, anything that holds water – a bucket, bird bath, drain or rainwater tank – will do.

When the immature stages of mosquitoes hatch out of those eggs, they wriggle about in the water for a week or so before emerging to fly off in search of blood.

While there are many mosquitoes found in wetlands and bushland areas, Aedes notoscriptus and Culex quinquefasciatus are the mosquitoes most commonly found in our backyards and have been shown to transmit pathogens that cause mosquito-borne disease.

The Australian backyard mosquito (Aedes notoscriptus) is quick to take advantage of water-filled containers around the home.
Cameron Webb (NSW Health Pathology)

In central and north Queensland, mosquitoes such as Aedes aegypti can bring more serious health threats, such as dengue, to some towns.




Read more:
After decades away, dengue returns to central Queensland


Mosquitoes can also impact our quality of life through bites as well as the nuisance of simply buzzing about our bedrooms and backyards.

So how can you stop mozzies making a home in your backyard?

Empty water containers once a week

Mosquitoes need access to standing water for about a week or so. Reduce the number of water-filled containers available or how long that water is available to mosquitoes.

Emptying a water-filled container once a week will stop the immature mosquitoes from completing their development and emerging as adults.

If you’re leaving water out for pets or wildlife, use smaller volume containers that will allow for easy emptying once a week. You can tip any remaining water into the garden, as mosquito larvae won’t survive if they’re “stranded” on soil.

For larger or heavier items, such as bird baths, flushing them out once a week with the hose will knock out most of the wrigglers and stop the mosquitoes completing their life cycle.

Make sure garden water doesn’t slosh about

Be careful with self-watering planter boxes. These often have a reservoir of water in their base and, while it may seem like a water-wise idea, these can turn into tiny mozzie hotels!

A simple trick to keep water available to plants, but not mosquitoes, is to fill your potted plant saucers with sand. The sand traps and stores some moisture but there is no water sloshing about for mosquitoes.

If you’re collecting water from showers, baths, or washing machines (commonly known as grey water), use it immediately on the garden, don’t store it outside in buckets or other containers.




Read more:
How drought is affecting water supply in Australia’s capital cities


Gutters, ponds, tanks and pools

Make sure your roof gutters and drains are free of leaves and other debris that will trap water and provide opportunities for mosquitoes.

Ensure rainwater tanks (and other large water-storage containers) are appropriately screened to prevent access by mosquitoes.

Rainwater tanks can be a useful way to conserve water in our cities but they can also be a source of mosquitoes.
Cameron Webb (NSW Health Pathology)

A well maintained swimming pool won’t be a source of mosquitoes. But if it’s turning “green”, through neglect and not intent, it may become a problem. Mosquitoes don’t like the chlorine or salt treatments typically used for swimming pools but when there is a build up of leaves and other detritus, as well as algae, the mosquitoes will move in.




Read more:
As heat strikes, here’s one way to help fight disease-carrying and nuisance mosquitoes


For backyard ponds, introducing native fish can help keep mosquito numbers down.

But if you want your pond to be a home for frogs, avoid fish as they may eat the tadpoles. Instead, try to encourage other wildlife that may help keep mosquito numbers down by creating habitats for spiders and other predatory insects, reptiles, frogs, birds, and bats.

Avoiding excessive use of insecticides around the backyard will help encourage and protect that wildlife too.

Mozzies can still come

There isn’t much that can be done about those mosquitoes flying in from over the back fences from local bushland or wetland areas.

Mosquitoes are generally most active at dusk and dawn so keep that in mind when planning time outdoors. But when mosquito populations are peaking, they’ll be active almost all day long.

Applying an insect repellent can be a safe and effective way to stop those bites.




Read more:
The best (and worst) ways to beat mosquito bites


Covering up with long pants, long-sleeved shirt and shoes will provide a physical barrier to mosquitoes. If you’re spending a lot of time outdoors, perhaps even consider treating your clothing with insecticide to add that extra little bit of protection.

Make sure insect screens are installed, and in good condition, on windows and doors. Mosquitoes outdoors can be bad; you don’t want them inside as well.The Conversation

Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of Sydney

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

Emperor Penguins could march to extinction if nations fail to halt climate change



Emperor Penguin in Antarctica.
Stephanie Jenouvrier, CC BY-ND

Stephanie Jenouvrier, Woods Hole Oceanographic Institution

The concept of a canary in a coal mine – a sensitive species that provides an alert to danger – originated with British miners, who carried actual canaries underground through the mid-1980s to detect the presence of deadly carbon monoxide gas. Today another bird, the Emperor Penguin, is providing a similar warning about the planetary effects of burning fossil fuels.

As a seabird ecologist, I develop mathematical models to understand and predict how seabirds respond to environmental change. My research integrates many areas of science, including the expertise of climatologists, to improve our ability to anticipate future ecological consequences of climate change.

Most recently, I worked with colleagues to combine what we know about the life history of Emperor Penguins with different potential climate scenarios outlined in the 2015 Paris Agreement, to combat climate change and adapt to its effects. We wanted to understand how climate change could affect this iconic species, whose unique life habits were documented in the award-winning film “March of the Penguins.”

Our newly published study found that if climate change continues at its current rate, Emperor Penguins could virtually disappear by the year 2100 due to loss of Antarctic sea ice. However, a more aggressive global climate policy can halt the penguins’ march to extinction.

Emperor Penguins breeding on sea ice in Terre Adélie, Antarctica.
Stephanie Jenouvrier, CC BY-ND

Carbon dioxide in Earth’s atmosphere

As many scientific reports have shown, human activities are increasing carbon dioxide concentrations in Earth’s atmosphere, which is warming the planet. Today atmospheric CO2 levels stand at slightly over 410 parts per million, well above anything the planet has experienced in millions of years.

If this trend continues, scientists project that CO2 in the atmosphere could reach 950 parts per million by 2100. These conditions would produce a very different world from today’s.

Emperor Penguins are living indicators whose population trends can illustrate the consequences of these changes. Although they are found in Antarctica, far from human civilization, they live in such delicate balance with their rapidly changing environment that they have become modern-day canaries.

A fate tied to sea ice

I have spent almost 20 years studying Emperor Penguins’ unique adaptations to the harsh conditions of their sea ice home. Each year, the surface of the ocean around Antarctica freezes over in the winter and melts back in summer. Penguins use the ice as a home base for breeding, feeding and molting, arriving at their colony from ocean waters in March or April after sea ice has formed for the Southern Hemisphere’s winter season.

54 known Emperor Penguin colonies around Antarctica (black dots) and sea ice cover (blue color).
Stephanie Jenouvrier, CC BY-ND

In mid-May the female lays a single egg. Throughout the winter, males keep the eggs warm while females make a long trek to open water to feed during the most unforgiving weather on Earth.

When female penguins return to their newly hatched chicks with food, the males have fasted for four months and lost almost half their weight. After the egg hatches, both parents take turns feeding and protecting their chick. In September, the adults leave their young so that they can both forage to meet their chick’s growing appetite. In December, everyone leaves the colony and returns to the ocean.

Emperor Penguin fathers incubate a single egg until it hatches.

Throughout this annual cycle, the penguins rely on a sea ice “Goldilocks zone” of conditions to thrive. They need openings in the ice that provide access to the water so they can feed, but also a thick, stable platform of ice to raise their chicks.

Penguin population trends

For more than 60 years, scientists have extensively studied one Emperor Penguin colony in Antarctica, called Terre Adélie. This research has enabled us to understand how sea ice conditions affect the birds’ population dynamics. In the 1970s, for example, the population experienced a dramatic decline when several consecutive years of low sea ice cover caused widespread deaths among male penguins.

Over the past 10 years, my colleagues and I have combined what we know about these relationships between sea ice and fluctuations in penguin life histories to create a demographic model that allows us to understand how sea ice conditions affect the abundance of Emperor Penguins, and to project their numbers based on forecasts of future sea ice cover in Antarctica.

Once we confirmed that our model successfully reproduced past observed trends in Emperor Penguin populations around all Antarctica, we expanded our analysis into a species-level threat assessment.

Climate conditions determine emperor penguins’ fate

When we used a climate model linked to our population model to project what is likely to happen to sea ice if greenhouse gas emissions continue on their present trend, we found that all 54 known Emperor Penguin colonies would be in decline by 2100, and 80% of them would be quasi-extinct. Accordingly, we estimate that the total number of Emperor Penguins will decline by 86% relative to its current size of roughly 250,000 if nations fail to reduce their carbon dioxide emissions.

Without action to reduce global carbon dioxide emissions, sea ice loss (shown in blue) will eradicate most Emperor Penguin colonies by 2100.
Stephanie Jenouvrier, CC BY-ND

However, if the global community acts to reduce greenhouse gas emissions and succeeds in stabilizing average global temperatures at 1.5 degrees Celsius (3 degrees Faherenheit) above pre-industrial levels, we estimate that Emperor Penguin numbers would decline by 31% – still drastic, but viable.

Less-stringent cuts in greenhouse gas emissions, leading to a global temperature rise of 2°C, would result in a 44% decline.

Our model indicates that these population declines will occur predominately in the first half of this century. Nonetheless, in a scenario in which the world meets the Paris climate targets, we project that the global Emperor Penguin population would nearly stabilize by 2100, and that viable refuges would remain available to support some colonies.

Global action to limit climate change through 2100 could greatly improve Emperor Penguins’ persistence/viability.
Stephanie Jenouvrier, CC BY-ND

In a changing climate, individual penguins may move to new locations to find more suitable conditions. Our population model included complex dispersal processes to account for these movements. However, we find that these actions are not enough to offset climate-driven global population declines. In short, global climate policy has much more influence over the future of Emperor Penguins than the penguins’ ability to move to better habitat.

Our findings starkly illustrate the far-reaching implications of national climate policy decisions. Curbing carbon dioxide emissions has critical implications for Emperor Penguins and an untold number of other species for which science has yet to document such a plain-spoken warning.

[ You’re smart and curious about the world. So are The Conversation’s authors and editors. You can read us daily by subscribing to our newsletter. ]The Conversation

Stephanie Jenouvrier, Associate Scientist, Woods Hole Oceanographic Institution

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

Hunter, hunted: when the world catches on fire, how do predators respond?



Some predators, including red foxes, move into burnt areas after fires pass through.
Alexandre Roux/Flickr, CC BY-NC-SA

Euan Ritchie, Deakin University; Ayesha Tulloch, University of Sydney; Dale Nimmo, Charles Sturt University; Tim Doherty, Deakin University, and William Geary, Deakin University

2019 might well be remembered as the year the world caught fire. Some 2.9 million hectares of eastern Australia have been incinerated in the past few months, an area roughly the same size as Belgium. Fires in the Amazon, the Arctic, and California captured global attention.

As climate change continues, large, intense, and severe fires will become more common. But what does this mean for the animals living in fire-prone environments?




Read more:
Drought and climate change were the kindling, and now the east coast is ablaze


Our new research, published recently in the Journal of Animal Ecology, looked at studies from around the world to identify how predators respond to fire.

We found some species seem to benefit from fires, others appear to be vulnerable, and some seem indifferent. In a changing climate, it’s urgent we understand how fires affect predators – and hence potentially their prey –in order to keep ecosystems healthy.

Predators: the good and the bad

Large predators, like wolves and lions, often play important roles in ecosystems, regulating food webs by reducing the numbers or changing the behaviour of herbivores and smaller predators. Many large predators are in dire straits within their native range, while introduced predators, such as feral cats and red foxes, have spread to new regions, where they have devastated native wildlife .

Fires can offer new opportunities as well as problems to predators. Some predators take advantage of charred, more open landscapes to hunt vulnerable prey; others rely on thick vegetation to launch an ambush.

But until now, we have not known which predators are drawn to fire, which are repelled by it, and which don’t care either way. Synthesising information on how different kinds of predators (for example, large or small, pursuit or ambush) respond to fire is vital for both the conservation of top predators and to help protect native prey from introduced predators.

Predators are reacting differently to fire.
Adam Stevenson/Reuters

Some like it hot

Our research reviewed studies from around the world to identify how different vertebrate predators (birds, mammals and reptiles) respond to fire in different ecosystems.

We found 160 studies on the response of 188 predator species to fire, including wolves, coyotes, foxes, cats, hawks, owls, goannas and snakes, amongst others. The studies came from 20 different countries, although most were from North America or Australia, and focused on canine and feline species.

Some predators seem to like fire: they are more abundant, or spend more time in, recently burnt areas than areas that escape fire. Our review found red foxes (Vulpes vulpes) mostly responded positively to fire and become more active in burned areas.

Raptors have even been observed in Northern Australia carrying burning sticks, helping to spread fire and targeting prey as they flee the fire.

For other predators, fire is bad news. Following Californian wildfires, numbers of eastern racer snakes fell in burnt areas. Likewise, lions avoid recently burned areas, because they rely on dense vegetation from which to ambush prey.

A global summary of studies examining predators and fire.

The authors of the papers we reviewed thought food availability, vegetation cover, and competition with other predators were the most important things affecting species’ responses to fire.

But perhaps more surprising was that most species, including bobcats and the striped skunk, appeared largely unaffected by fire. Of the affected species, some (such as spotted owls) responded differently to fire in different places.

Overall, we found it is difficult to predict how a predator species will respond to fire.

We still have a lot to learn

Our results show while many predators appear to adapt to the changes that fires bring about, some species are impacted by fire, both negatively and positively. The problem is that, with a few exceptions, we will struggle to know how a given fire will affect a predator species without local knowledge. This means environmental managers need to monitor the local outcomes of fire management, such as fuel reduction burns.

There may be situations in which predator management needs to be coupled with fire management to help prevent native wildlife becoming fox food after fire. There has even been trials to see if artificial shelters can help protect native wildlife from introduced predators after fire.

Getting our knowledge base right

One thing that has hampered our research is the lack of contextual information in many studies. No two fires are the same – they differ in size, intensity, severity, and season – but these details are often absent. The literature is also biased towards dog-like and cat species, and there are few studies on the response of predators to fire in Africa, Asia, and South America.

It is important to note that some predator responses to fire may be overlooked due to the way experiments were carried out, or because monitoring happened too long after the fire.

Unifying how fire, predator numbers and environmental features are recorded would help future studies predict how predators might react to different types of fires in various situations.




Read more:
Bushfires are pushing species towards extinction


As wildfires become more frequent and severe under climate change, understanding how fire intensity and frequency shapes predator populations and their prey will be critical for effective and informed ecosystem management and conservation.The Conversation

Euan Ritchie, Associate Professor in Wildlife Ecology and Conservation, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University; Ayesha Tulloch, DECRA Research Fellow, University of Sydney; Dale Nimmo, Associate professor/ARC DECRA fellow, Charles Sturt University; Tim Doherty, Alfred Deakin Post-doctoral Research Fellow, Deakin University, and William Geary, , Deakin University

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

Curious Kids: how do magpies detect worms and other food underground?



Magpies have a few clever tricks to help them find food.
Gisela Kaplan, Author provided

Gisela Kaplan, University of New England


How do magpies detect worms and other food sources underground? I often see them look or listen, then rapidly hop across the ground and start digging with their beak and extract a worm or bug from the earth – Catherine, age 10, Perth.



You have posed a very good question.

Foraging for food can involve sight, hearing and even smell. In almost all cases learning is involved. Magpies are ground foragers, setting one foot before the other looking for food while walking, called walk-foraging. It looks like this:

This is called walk-foraging.
Gisela Kaplan, Author provided

Finding food on the ground, such as beetles and other insects, is not as easy as it may sound. The ground can be uneven and covered with leaves, grasses and rocks. Insects may be hiding, camouflaged, or staying so still it is hard for a magpie to notice them.




Read more:
Curious Kids: why is a magpie’s poo black and white?


Detecting a small object on the ground requires keen vision and experience, to discriminate between the parts that are important and those that are not.

Magpie eyes, as for most birds, are on the side of the head (humans and other birds of prey, by contrast, have eyes that face forward).

A magpie’s eyes are at the side of its head and it can only see something with both eyes if that is straight in front of the bird.
Shutterstock/Webb Photography

To see a small area in front of them, close to the ground, birds use both eyes together (scientists call this binocular vision). But birds mostly see via the eyes looking out to the side (which is called monocular vision).

This picture gives you an idea of what a magpie can see with its left eye, what it can see with its right eye and what area it can see with both eyes working together (binocular vision).

Here’s how a magpie’s field of vision works.
Gisela Kaplan, Author provided

You asked about underground foraging. Some of that foraging can also be done by sight. Worms, for instance, may leave a small mound (called a cast) on the surface and, to the experienced bird, this indicates that a worm is just below.

Magpies can also go a huge step further. They can identify big scarab larvae underground without any visual help at all.

Here is a scarab larva.
Gisela Kaplan, Author provided

Scarab larvae look like grubs. They munch on grassroots and can kill entire grazing fields. Once they transform into beetles (commonly called Christmas beetles) they can do even more damage by eating all the leaves off eucalyptus trees.

Here is the secret: magpies have such good hearing, they can hear the very faint sound of grass roots being chewed.

We know this from experiments using small speakers under the soil playing back recorded sounds of scarab beetle larvae. Magpies located the speaker every time and dug it up.

An Australian magpie digging for food in a lawn.
Flickr/Lance, CC BY-NC-ND

So how do they do it? Several movements are involved.

To make certain that a jab with its beak will hit the exact spot where the juicy grub is, the magpie first walks slowly and scans the ground. It then stops and looks closely at the ground – seemingly with both eyes working together.

Then, holding absolutely still, the magpie turns its head so the left side of the head and ear is close to the ground for a final confirming listen.

Finally, the bird straightens up, then executes a powerful jab into the ground before retrieving the grub.

An Australian magpie digging for food gets a grub.
Wikimedia/Toby Hudson, CC BY-SA

That is very clever of the magpies. Very few animals can extract food they can’t see. Only great apes and humans were thought to have this ability. Clever magpies indeed. And farmers love them for keeping a major pest under control.




Read more:
Curious Kids: Why do birds sing?


Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.auThe Conversation

Gisela Kaplan, Emeritus Professor in Animal Behaviour, University of New England

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

Australia’s threatened birds declined by 59% over the past 30 years


Elisa Bayraktarov, The University of Queensland and Jaana Dielenberg, The University of Queensland

Australia’s threatened birds declined by nearly 60% on average over 30 years, according to new research that reveals the true impact on native wildlife of habitat loss, introduced pests, and other human-caused pressures.

Alarmingly, migratory shorebirds have declined by 72%. Many of these species inhabit our mudflats and coasts on their migration from Siberia, Alaska or China each year.




Read more:
For the first time we’ve looked at every threatened bird in Australia side-by-side


These concerning figures are revealed in our world-first Threatened Bird Index. The index, now updated with its second year of data, combines over 400,000 surveys at more than 17,000 locations.

It’s hoped the results will shed light on where conservation efforts are having success, and where more work must be done.

Bringing conservation efforts together

The index found a 59% fall in Australia’s threatened and near threatened bird populations between 1985 and 2016.

Migratory shorebirds in South Australia and New South Wales have been worst hit, losing 82% and 88% of their populations, respectively. In contrast, shorebirds in the Northern Territory have increased by 147% since 1985, potentially due to the safe roosting habitat at Darwin Harbour where human access to the site is restricted.

Habitat loss and pest species (particularly feral cats) are the most common reasons for these dramatic population declines.

Many of Australia’s threatened species are monitored by various organisations across the country. In the past there has never been a way to combine and analyse all of this evidence in one place.




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The Threatened Species Recovery Hub created the index to bring this information together. It combines 17,328 monitoring “time series” for threatened and near threatened bird species and subspecies. This means going back to the same sites in different years and using the same monitoring method, so results over time can be compared.

Over the past year the amount of data underpinning the index has grown considerably and now includes more than 400,000 surveys, across 43 monitoring programs on 65 bird species and subspecies, increasing our confidence in these alarming trends.

Threatened species like the Gilbert’s Whistler, Chestnut quail-thrush and Swift parrot are all on the decline.
Glenn Ehmke, BirdLife Australia, Author provided

About one-third of Australia’s threatened and near threatened birds are in the index but that proportion is expected to grow. As more quality data becomes available, the index will get more powerful, meaningful and representative. For the first time Australia will be able to tell how our threatened species are going overall, and which groups are doing better or worse, which is vital to identifying which groups and regions most need help.

Finding the trends

Trends can be calculated for any grouping with at least three species. A grouping might include all threatened species in a state or territory, all woodland birds or all migratory shorebirds.

The 59% average decrease in threatened bird relative abundance over the last 30 years is very similar to the global wildlife trends reported by the 2018 Living Planet Report. Between 1970 and 2014, global average mammal, fish, bird, amphibian and reptile populations fell by 60%.

One valuable feature of the Threatened Species Index is a visualisation tool which allows anyone to explore the wealth of data, and to look at trends for states and territories.

For instance, in Victoria by 2002 threatened birds had dropped to a bit more than half of their numbers in 1985 on average (60%), but they have remained fairly constant since then.

We can also look at different bird groups. Threatened migratory shorebirds have had the largest declines, with their numbers down by more than 72% since 1985. Threatened terrestrial birds, on the other hand, have decreased in relative abundance by about 51% between 2000 and the year 2016, and show a relatively stable trend since 2006.

Eastern Great Egret, and Bar-tailed Godwit. Pictures kindly provided by Glenn Ehmke, BirdLife Australia.

Making the index better

The index is being expanded to reveal trends in species other than birds. Monitoring data on threatened mammals and threatened plants is being assembled. Trends for these groups will be released in 2020, providing new insights into how a broader range of Australia’s threatened species are faring.

This research is led by the University of Queensland in close partnership with BirdLife Australia, and more than 40 partners from research, government, and non-government organisations. Collaboration on such a scale is unprecedented, and provides extremely detailed information.




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Citizen scientists count nearly 2 million birds and reveal a possible kookaburra decline


The index team are continuing to work with monitoring organisations across Australia to expand the amount of sites, and the number of species included in the index. We applaud the dedicated researchers, managers and citizen scientists from every corner of the country who have been assembling this data for the nation.

We’d also like to hear from community groups, consultants and other groups that have been monitoring threatened or near-threatened species, collecting data at the same site with the same method in multiple years.

The Threatened Species Index represents more than just data. Over time it will give us a window into the results of our collective conservation efforts.


This article also received input from James O’Connor (BirdLife Australia) and Hugh Possingham (The Nature Conservancy).The Conversation

Elisa Bayraktarov, Postdoctoral Research Fellow in Conservation Biology, The University of Queensland and Jaana Dielenberg, Science Communication Manager, The University of Queensland

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