Most native bird species are losing their homes, even the ones you see every day



Eastern-yellow robin. Some 60 per cent of the native birds of south-east mainland Australia have lost more than half of their natural habitat.
Graham Winterflood/Wikimedia Commons

Jeremy Simmonds, The University of Queensland; Alvaro Salazar, The University of Queensland; James Watson, The University of Queensland, and Martine Maron, The University of Queensland

Across parts of Australia, vast areas of native vegetation have been cleared and replaced by our cities, farms and infrastructure. When native vegetation is removed, the habitat and resources that it provides for native wildlife are invariably lost.

Our environmental laws and most conservation efforts tend to focus on what this loss means for species that are threatened with extinction. This emphasis is understandable – the loss of the last individual of a species is profoundly sad and can be ecologically devastating.




Read more:
An end to endings: how to stop more Australian species going extinct


But what about the numerous other species also affected by habitat loss, that have not yet become rare enough to be listed as endangered? These animals and plants — variously described as “common” or of “least concern” — are having their habitat chipped away. This loss usually escapes our attention.

These common species have intrinsic ecological value. But they also provide important opportunities for people to connect with nature – experiences that are under threat.

A chain used for land clearing is dragged over a pile of burning wood at a Queensland property.
Dan Peled/AAP

The “loss index”: tracking the destruction

We developed a measure called the loss index to communicate how habitat loss affects multiple Australian bird species. Our measure showed that across Victoria, and into South Australia and New South Wales, more than 60% of 262 native birds have each lost more than half of their original natural habitat. The vast majority of these species are not formally recognised as being threatened with extinction.

It is a similar story in the Brigalow Belt of central New South Wales and Queensland. The picture is brighter in the northern savannas across the top of Australia, where large tracts of native vegetation remain – notwithstanding pervasive threats such as inappropriate fire regimes.




Read more:
Fixing Australia’s extinction crisis means thinking bigger than individual species


We also found that in some areas, such as Southeast Queensland and the Wet Tropics region of north Queensland, the removal of a single hectare of forest habitat can affect up to 180 different species. In other words, small amounts of loss can affect large numbers of (mostly common) species.

Our index allowed us to compare how different groups of birds are impacted by habitat loss. Australia’s iconic parrots have been hit hard by habitat loss, because many of these birds occur in the places where we live and grow our food. Birds of prey such as eagles and owls have, as a group, been less affected. This is because many of these birds occur widely across Australia’s less developed arid interior.

This map shows the number of bird species affected by habitat loss in any region. Grey zones indicate parts of Australia where habitat loss has not occurred. Blue zones have up to 90 species affected by habitat loss, yellow is up to 120 species affected, while the highest category, red, is up to 187 species affected.
Conservation Biology

Habitat loss means far fewer birds

Our study shows many species have lost lots of habitat in certain parts of Australia. We know habitat loss is a major driver of population declines and freefalling numbers of animals globally. A measure of vertebrate population trends — the Living Planet Index — reveals that populations of more than 4,000 vertebrate species around the world are on average less than half of what they were in 1970.

In Australia, the trend is no different. Populations of our threatened birds declined by an average of 52% between 1985 and 2015. Alarmingly, populations for many common Australian birds are also trending downwards, and habitat loss is a major cause. Along Australia’s heavily populated east coast, population declines have been noted for many common species including rainbow bee-eater, double-barred finch, and pale-headed rosella.

Decling common species – rainbow bee-eater (left); double-barred finch (top right); pale-headed rosella (bottom right)
Jim Bendon, G. Winterflood, Aviceda



Read more:
Cats are not scared off by dingoes. We must find another way to protect native animals


This is a major problem for ecosystem health. Common species tend to be more numerous and so perform many roles that we depend on. Our parrots, pigeons, honeyeaters, robins, and many others help pollinate flowers, spread seeds, and keep pest insects in check. In both Europe and Australia, declines in common species have been linked to a reduction in the provision of these vital ecosystem services.

Common species are also the ones that we most associate with. Because they are more abundant and familiar, these animals provide important opportunities for people to connect with nature. Think of the simple pleasure of seeing a colourful robin atop a rural fence post, or a vibrant parrot dashing above the treetops of a suburban creek. The decline of common species may contribute to diminished opportunities for us to interact with nature, leading to an “extinction of experience”, with associated negative implications for our health and well-being.

We mustn’t wait until it’s too late

Our study aims to put the spotlight on common species. They are crucially important, and yet the erosion of their habitat gets little focus. Conserving them now is sensible. Waiting until they have declined before we act will be costly.

These species need more formal recognition and protection in conservation and environmental regulation. For example, greater attention on common species, and the role they play in ecosystem health, should be given in the assessment of new infrastructure developments under Australia’s federal environment laws (formally known as the Environment Protection and Biodiversity Conservation Act 1999).

We should be acting now to conserve common species before they slide towards endangerment. Without dedicated attention, we risk these species declining before our eyes, without us even noticing.The Conversation

Jeremy Simmonds, Postdoctoral Research Fellow in Conservation Science, The University of Queensland; Alvaro Salazar, Postdoctoral Research Fellow, The University of Queensland; James Watson, Professor, The University of Queensland, and Martine Maron, ARC Future Fellow and Professor of Environmental Management, The University of Queensland

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

Hot as shell: birds in cooler climates lay darker eggs to keep their embryos warm


The colour and brightness of birds’ eggs plays a key role in keeping them at the right temperature.
Anne Kitzman / Shutterstock

Phill Cassey, University of Adelaide and Daniel Hanley, Long Island University Post

Birds lay eggs with a huge variety of colours and patterns, from immaculate white to a range of blue-greens and reddish browns.

The need to conceal eggs from predators is one factor that gives rise to all kinds of camouflaged and hard-to-spot appearances.

Yet our research, published today in Nature Ecology & Evolution, shows that climate is even more important.

Dark colours play a crucial role in regulating temperatures in many biological systems. This is particularly common for animals like reptiles, which rely on environmental sources of heat to keep themselves warm.




Read more:
Curious Kids: why do eggs have a yolk?


Darker colours absorb more heat from sunlight, and animals with these colours are more commonly found in colder climates with less sunlight. This broad pattern is known as Bogert’s rule.

Birds’ eggs are useful for studying this pattern because the developing embryo can only survive in a narrow range of temperatures. But eggs cannot regulate their own temperature and, in most cases, the parent does it by sitting atop the clutch of eggs.

In colder environments, where the risk of predators is lower and the risk of chilling in cold temperatures is greater, parents spend less time away from the nest.

We predicted that if eggshell colour does play an important role in regulating the temperature of the embryo, birds living in colder environments should have darker eggs.

The average colour of eggshells in different areas around the world.
Wisocki et al. 2019 ‘The global distribution of avian eggshell colours suggests a thermoregulatory benefit of darker pigmentation’, Nature Ecology & Evolution, Author provided

To test the prediction, we measured eggshell brightness and colour for 634 species of birds. That’s more than 5% of all bird species, representing 36 of the 40 large groups of species called orders.

We mapped these within each species’ breeding range and found that eggs in the coldest environments (those with the least sunlight) were significantly darker. This was true for all nest types.

We also conducted experiments using domestic chicken eggs to confirm that darker eggshells heated up more rapidly and maintained their incubation temperatures for longer than white eggshells.




Read more:
It isn’t easy being blue – the cost of colour in fairy wrens


Our results show that darker eggshells are found in places with less sunlight and lower temperatures, and that these darker colours may help keep the developing embryo warm.

How future climate change will affect eggshell appearance, as well as the timing of reproduction and incubation behaviour, will be an important and fruitful avenue for future research.The Conversation

Phill Cassey, Assoc Prof in Invasion Biogeography and Biosecurity, University of Adelaide and Daniel Hanley, Assistant Professor, Long Island University Post

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

Whales and dolphins found in the Great Pacific Garbage Patch for the first time



Adult and infant sperm whales have been spotted in the Great Pacific Garbage Patch.
Inf-Lite Teacher/Flickr, CC BY-SA

Chandra Salgado Kent, Edith Cowan University

Scientific research doesn’t usually mean being strapped in a harness by the open paratroop doors of a Vietnam-war-era Hercules plane. But that’s the situation I found myself in several years ago, the result of which has just been published in the journal Marine Biodiversity.

As part of the Ocean Cleanup’s Aerial Expedition, I was coordinating a visual survey team assessing the largest accumulation of ocean plastic in the world: the Great Pacific Garbage Patch.




Read more:
The ocean’s plastic problem is closer to home than scientists first thought


When the aircraft’s doors opened in front of me over the Pacific Ocean for the first time, my heart jumped into my throat. Not because I was looking 400m straight down to the wild sea below as it passed at 260km per hour, but because of what I saw.

This was one of the most remote regions of the Pacific Ocean, and the amount of floating plastic nets, ropes, containers and who-knows-what below was mind-boggling.

However, it wasn’t just debris down there. For the first time, we found proof of whales and dolphins in the Great Pacific Garbage Patch, which means it’s highly likely they are eating or getting tangled in the huge amount of plastic in the area.

The Great Pacific Garbage Patch

The Great Pacific Garbage Patch is said to be the largest accumulation of ocean plastic in the world. It is located between Hawaii and California, where huge ocean currents meet to form the North Pacific subtropical gyre. An estimated 80,000 tonnes of plastic are floating in the Great Pacific Garbage Patch.




Read more:
The major source of ocean plastic pollution you’ve probably never heard of


Our overall project was overseen and led by The Ocean Cleanup’s founder Boyan Slat and then-chief scientist Julia Reisser. We conducted two visual survey flights, each taking an entire day to travel from San Francisco’s Moffett Airfield, survey for around two hours, and travel home. Along with our visual observations, the aircraft was fitted with a range of sensors, including a short-wave infrared imager, a Lidar system (which uses the pulse from lasers to map objects on land or at sea), and a high-resolution camera.

Both visual and technical surveys found whales and dolphins, including sperm and beaked whales and their young calves. This is the first direct evidence of whales and dolphins in the heart of the Great Pacific Garbage Patch.

Mating green turtles in a sea of plastics.
photo by Chandra P. Salgado Kent, Author provided

Plastics in the ocean are a growing problem for marine life. Many species can mistake plastics for food, consume them accidentally along with their prey or simply eat fish that have themselves eaten plastic.

Both beaked and sperm whales have been recently found with heavy plastic loads in their stomachs. In the Philippines, a dying beaked whale was found with 40kg of plastic in its stomach, and in Indonesia, a dead sperm whale washed ashore with 115 drinking cups, 25 plastic bags, plastic bottles, two flip-flops, and more than 1,000 pieces of string in its stomach.

The danger of ghost nets

The most common debris we were able to identify by eye was discarded or lost fishing nets, often called “ghost nets”. Ghost nets can drift in the ocean for years, trapping animals and causing injuries, starvation and death.

Crew sorts plastic debris collected from the Great Pacific Garbage Patch on a voyage in July 2019.
EPA/THE OCEAN CLEANUP

Whales and dolphins are often found snared in debris. Earlier this year, a young sperm whale almost died after spending three years tangled in a rope from a fishing net.

During our observation we saw young calves with their mothers. Calves are especially vulnerable to becoming trapped. With the wide range of ocean plastics in the garbage patch, it is highly likely animals in the area ingest and become tangled in it.

It’s believed the amount of plastics in the ocean could triple over the next decade. It is clear the problem of plastic pollution has no political or geographic boundaries.




Read more:
There are some single-use plastics we truly need. The rest we can live without


While plastics enter the sea from populated areas, global currents transport them across oceans. Plastics can kill animals, promote disease, and harm the environment, our food sources and people.

The most devastating effects fall on communities in poverty. New research shows the Great Pacific Garbage Patch is rapidly growing, posing a greater threat to wildlife. It reinforces the global movement to reduce, recycle and remove plastics from the environment.

But to really tackle this problem we need creative solutions at every level of society, from communities to industries to governments and international organisations.

To take one possibility, what if we invested in fast-growing, sustainably cultivated bamboo to replace millions of single-use plastics? It could be produced by the very countries most affected by this crisis: poorer and developing nations.




Read more:
Designing new ways to make use of ocean plastic


It is only one of many opportunities to dramatically reduce plastic waste, improve the health of our environments and people, and to help communities most susceptible to plastic pollution.The Conversation

Chandra Salgado Kent, Associate Professor, School of Science, Edith Cowan University

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

The Blinky Bill effect: when gum trees are cut down, where do the koalas go?


Kita Ashman, Deakin University

In the past two decades there has been an unprecedented increase in the area of blue gum (Eucalyptus globulus) plantations in southern Australia. In southwest Victoria alone, some additional 80,000 hectares of commercial blue gum have been planted.

This expansion has significantly increased the habitat available for koalas. In fact, my research, published in the journal Landscape and Urban Planning, has found there are more koalas in plantations than in surrounding native habitat.




Read more:
A report claims koalas are ‘functionally extinct’ – but what does that mean?


More koalas may seem like a good thing, but perversely this could ultimately harm their welfare (and the welfare of other native animals and plants), and disrupt the plantation industry.

Blinky Bill had to leave his home after the trees were bulldozed.

Plantations

Koalas are protected in Victoria, so when plantation managers harvest the mature trees they must have a permit and a koala management plan. These plans focus on locating koalas, ensuring that the trees koalas are sitting in at harvest are not felled, and post-harvest surveys to find any injured koalas.

However, these plans don’t consider where the koalas go after the plantation has been cut down, and what effects their movement has on the landscape and surrounding native vegetation.

A recently harvested blue gum plantation showing remnant trees left due to koalas.
Author provided

To work out how factors such as plantation cover affect koala populations, my colleagues and I surveyed 72 sites across southwest Victoria. We found more koalas in plantations than in blocks of native vegetation or in native roadside vegetation.

We then spatially modelled koala numbers for the region, and found several high-priority areas for population management, as well as significant conservation habitat for koalas and other wildlife in the region that overlap with high koala population densities.




Read more:
What does a koala’s nose know? A bit about food, and a lot about making friends


Our mapping predicted high koala numbers in the southeast, where there are important remnant bushland areas such as Kurtonitj Indigenous Protected Area and Mount Napier State Park. This highlights the importance of considering the overall landscape when establishing and harvesting plantations, and the arrangement of plantations near remnant forest.

Harvest rates in much of southwest Victoria are set to increase. This may result in increased koala numbers in the native vegetation surrounding harvested sites, which could then put pressure on food trees in remnant forests.

Local landholders are already seeing the effect of more koalas on native vegetation. Many trees on private land or beside roads are being stripped of leaves.

Canopy defoliation of remnant trees due to increased numbers of koalas in south-west Victoria.
Author provided

More koalas are also likely to mean more injuries or other welfare issues. As plantations have a responsibility to avoid these, koala injuries could threaten the future of one of the main industries in this region. More than 4,000 people are directly employed in the regional forestry industry, with a further 4,500 in associated service industries.




Read more:
Koala-detecting dogs sniff out flaws in Australia’s threatened species protection


The bigger picture

To meet this challenge, we argue management plans need to consider the larger landscape. What native forest is near a plantation? Where are the koalas likely to go after the harvest? How might they affect other native species?

A female koala being released in Bessiebelle, south-west Victoria, after undergoing a health check.
Esther Wong, Author provided

Such plans could include some areas of plantations set aside for koala habitat, harvesting plans that consider adjacent habitat that koalas may move into, or increasing areas of native food trees. These would all benefit other wildlife in the area, as well as koalas.

Currently, there is something of a negative feedback loop in southwest Victoria. When plantations are established koalas move in and reproduce. When plantations are later harvested, the koalas move into surrounding areas. As a result, populations can rapidly increase in some areas, affecting native trees and creating welfare issues for the forest industry.




Read more:
Victorian koalas are eating themselves out of house and home


We have seen the devastating effects high density koala populations can have on native forests in places like Cape Otway, which saw mass starvation and widespread forest death in 2013 and 2014. Current state regulations could disrupt the forestry industry, especially with koala numbers increasing in plantations but with no plan to really manage koala numbers in southwest Victoria in sight.The Conversation

Kita Ashman, PhD candidate in koala conservation, Deakin University

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

What if we measured the thing that matters most: “carbon productivity”


Carbon productivity is the measure that matters, but we are hung up on the productivity of our workers.
pixabay/pexels

David Peetz, Griffith University

Ask any economist a question, and you will usually get the answer: “productivity”.

The winner of the 2008 Nobel Prize in Economics, Paul Krugman, set the standard in 1994:

Productivity isn’t everything, but, in the long run, it is almost everything. A country’s ability to improve its standard of living over time depends almost entirely on its ability to raise its output per worker.

The new head of Australia’s treasury, Steven Kennedy, said much the same thing this week:

The most important long-term contribution to wage growth is labour productivity.

For my money, they could say the same about “carbon productivity”, a idea that is going to matter to us more.

Labour productivity is notoriously hard to measure; measuring changes in it is harder still.

It’s relatively easy to measure in the jobs we are doing less of these days, such as making washing machines; harder to measure in the jobs we are doing more of, such as caring for people.

And it’s less important than you might think. People aren’t a particularly finite resource. Allowable carbon emissions are.

Carbon is the input that matters

Economist Paul Krugman. ‘In the long run productivity is almost everything.’
CHRISTOPHER BARTH/EPA

The Intergovernmental Panel on Climate Change says net carbon emissions will have to be reduced to zero.

That means we’ve a carbon budget, a limited amount of greenhouse gas we can emit from here on. It would make sense to use it wisely.

What I am proposing is a target for “carbon productivity”, the amount of production we achieve from each remaining unit of emissions – as a means of helping us cut overall carbon emissions.

It’s easy to calculate: gross domestic product divided by net emissions. We already measure GDP, and we already measure emissions in tonnes, albeit unevenly.

We are going to need huge increases in carbon productivity, much more so as a result of cutting emissions than increasing production.

Things that are good for labour productivity might well be bad for carbon productivity. For example, replacing a sweeper with an air blower is good on the first count, bad on the second.

Measuring carbon productivity…

If introduced at a national level, a target, or at least a widely published measure, could start to focus government minds on what’s important and what’s not, and assist in allocating resources. Solar farms would become more likely to gain support than coal-fired power plants.

Regulatory resources might be redirected in surprising ways. While a small number of large emitters constitutes an easy target for policymakers, if those large emitters are efficient, the government might find it has to move its focus to the larger number of small inefficient emitters.

It could also help us think about how we resolve the conflict between the perceived need for economic growth and the need to substantially cut emissions. Both would be important, the measures that achieved both would be the most important.

Accounting debates about whether to carry carry forward international credits would be rendered meaningless.




Read more:
We can be a carbon-neutral nation by 2050, if we just get on with it


Giving national attention to measuring carbon productivity would put more pressure on more firms to measure all of their emissions. Many already measure their “scope 1” direct emissions. A smaller number measure “scope 2” emissions (from things such as electricity used by the firm).

A much smaller number measure “scope 3” emissions (from sources they do not own, such as air travel, waste and water). They’re the hardest to measure.

…might just produce results

For some, sustainable economic growth is a contradiction in terms.

They argue that economic growth is incompatible with ecological survival.

But the population appears to want both, and the political and social consequences of failing to achieve both could be devastating for democratic society and the planet. It has already been established that rising unemployment reduces support for action on climate change.




Read more:
There’s evidence that climate activism could be swaying public opinion in the US


Targeting or measuring carbon productivity by itself won’t achieve those goals.

For that, we would need some form of carbon pricing and a government committed to the uptake of low-emission technologies.

But if we are to have a shot at achieving both, we’ll need to know where we are going.The Conversation

David Peetz, Professor of Employment Relations, Centre for Work, Organisation and Wellbeing, Griffith University

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