Biden moves to protect the Tongass, North America’s largest rainforest, from logging and road building


View of Hobart Bay off Stephens Passage in Tongass National Forest, southeastern Alaska.
Wolfgang Kaehler/LightRocket via Getty Images

Beverly Law, Oregon State UniversityAsk people to find the world’s rainforests on a globe, and most will probably point to South America. But North America has rainforests too – and like their tropical counterparts, these temperate rainforests are ecological treasures.

The Biden administration recently announced new policies to protect the Tongass National Forest, the largest intact temperate rainforest in the world and the biggest U.S. national forest. It spreads over more than 26,000 square miles (67,340 square kilometers) – roughly the size of West Virginia – and covers most of southeast Alaska. The Tongass has thousands of watersheds and fjords, and more than a thousand forested islands.

Map overlaying Alaska on the continental U.S.
Alaska’s national forests, the Chugach and the Tongass, compared with the lower 48 states.
USFS

For over 20 years the Tongass has been at the center of political battles over two key conservation issues: old-growth logging and designating large forest zones as roadless areas to prevent development. As a scientist specializing in forest ecosystems, I see protecting the Tongass as the kind of bold action that’s needed to address climate change and biodiversity loss.

An ecological gem

The Tongass as we know it today began forming at the end of the Little Ice Age in the mid-1700s, which left much of what is now southern Alaska as barren land. Gradually, the area repopulated with plants and animals to become a swath of diverse, rich old-growth forests. President Theodore Roosevelt designated the Tongass as a forest reserve in 1902, and then as a national forest in 1907.

The Tongass is the traditional homeland of the Tlingit, Haida and Tsimshian people. It is named for the Tongass group of the Tlingit people, who have continuously occupied the area for over 10,000 years. Alaska Natives relied on the forest’s rich diversity of plants and animals for their survival and traditions. Today the Tongass has abundant populations of animals that have become uncommon in other parts of the U.S., such as brown bears and wolves.

Most of the 900 watersheds within the Tongass are in near-natural condition. This ensures that they can provide habitat for many wild species and recover from or adapt to stresses, such as warmer temperatures due to climate change. They support salmon that spawn in the forest’s creeks and rivers, providing food for bears, eagles and other predators. Such ecosystems are incredibly rare around the world today.

The Tongass National Forest is home to bears, bald eagles and five species of salmon.

How roads threaten forests

Intact old-growth forests, with trees hundreds of years old, are essential for carbon storage, biodiversity and climate resilience. They have fully developed root systems that can reach water in deep soils, and are more resistant than young forests to drought, fire, insects and strong winds – effects that are all likely to increase with climate change.

Because old-growth forests have accumulated massive amounts of carbon in their trees and soils over centuries, protecting them is an important strategy for curbing climate change. Today, however, scientists estimate that logging, agriculture and urban development have left only 6% to 14% of the forest area in the U.S. intact. And only 7% of total U.S. forest area is more than a century old.

Old-growth logging is controversial because intact forests are so rare. And forest losses often start when roads are cut through them to access timber. The roads are effectively long clear-cuts across the landscape.

Building roads through moist temperate forests can make it easier for warm air, wind and sunlight to penetrate from the edges to the interior, drying soil, mosses and ferns. It also provides entry points for invasive plants carried in by vehicles.

And roads’ negative effects extend beyond the actual driving surface. A road 30 feet (9 meters) wide may influence an additional 80 to 100 feet (25 to 30 meters) of adjacent land because of land disturbance during construction and wide buffer zones created for vehicle safety.

Road building can harm animals like brown bears through collisions with vehicles and increased poaching and trapping. In the Tongass, a strip a quarter-mile (0.4 kilometer) wide on each side of the highway system is closed to big game hunting, but this can mitigate only some of roads’ pervasive effects.

Bulldozers grade land next to a gravel logging road.
Upgrading a logging road into State Highway 43 on Prince of Wales Island in the Tongass National Forest.
Jack Olen, USFS Alaska Region/Flickr, CC BY

Decades of controversy

In its final days in January 2001, the Clinton administration adopted the Roadless Area Conservation Rule, which barred logging, timber sales, mining and road construction within inventoried roadless areas in most national forests across the U.S. About 9.2 million acres (37,231 square kilometers) of the Tongass – more than half of its area – were designated and managed as inventoried roadless areas.

This step launched 20 years of debate and litigation. The Bush and Trump administrations, supported by conservative Western state officials, sought to limit the roadless rule and exempt the Tongass from it. The Obama administration generally supported the rule and defended it in court.

In 2020, the Trump administration opened the Tongass to extensive new logging, mining and road construction activities. Critics, including environmental advocates and tribal governments, argued that Alaska’s economy was better served by outdoor recreation and commercial fishing than by clear-cutting its remaining old-growth forests.

Now the Biden administration has restored protection for roadless areas of the Tongass. It also has pledged to end large-scale old-growth timber sales and focus on restoration, recreation and other noncommercial activities. It will permit old-growth logging only for cultural uses, such as totem poles and canoes, and for small sales that serve community needs. It also proposes a US$25 million investment in sustainable economic opportunities, with particular focus on investments that are responsive to Indigenous needs.

Forest advocates have welcomed this action and the administration’s plan to publish a new version of the roadless rule. But it remains to be seen how permanent this shift will be.

A strategic climate reserve

New hope for protecting the Tongass comes amid growing alarm over two converging environmental crises: climate change and accelerated extinctions of plant and animal species. In my view, protecting ecological treasures like the Tongass is a critical way to address both issues at once, as scientists have recommended.

The southeastern and south-central regions of Alaska, which contain the Tongass and Chugach national forests, store about 1 billion metric tons of carbon in live and dead tree biomass. This amount could increase by 27% by 2100 if the forest is allowed to continue to grow and accumulate carbon.

I believe the Tongass’ vast intactness, rich biodiversity and significant carbon storage make it an excellent choice as the first of a series of strategic climate reserves – areas that scientists have proposed setting aside to protect large carbon sinks and biodiversity of plant and animal species. U.S. old-growth forests are disappearing rapidly, but with smart management they can deliver ecological benefits for decades to come.

[Like what you’ve read? Want more? Sign up for The Conversation’s daily newsletter.]The Conversation

Beverly Law, Professor Emeritus of Global Change Biology and Terrestrial Systems Science, Oregon State University

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

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Victoria’s new feral horse plan could actually protect the high country. NSW’s method remains cruel and ineffective


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Don Driscoll, Deakin UniversityFeral horses are a catastrophic problem for the environment, particularly in the high country that crosses the New South Wales and Victoria border. To deal with this growing issue, the Victorian government has released a draft feral horse action plan, which is open for comment until April 23.

It comes after Victoria’s old action plan from 2018 proved ineffective, with feral horse numbers increasing in the most recent counts in 2019. This is similar to New South Wales’ current performance, where feral horses are legally protected and numbers are essentially unmanaged.

This new Victorian plan has flaws, but it’s still likely to perform better than the old plan (and the very low benchmark set by NSW), as it generally aims to deploy evidence-based management of national parks.

As Victoria gets on top of its feral horse problem, NSW will be left further behind with a degrading environment and rising costs of horse management.

The feral horse threat

Feral horses degrade ecosystems and threaten native Australian species with their heavy trampling and excessive grazing. They damage waterways and streamside vegetation which, in turn, threatens species that live in and alongside the streams, such as the alpine spiny crayfish, the alpine water skink and the Tooarrana broad-toothed rat. All of these are threatened species.

Damage from feral horses could worsen as ecosystems recover from the extensive 2019-20 eastern Australian bushfires. Horse grazing could delay animals’ habitat recovery and horse trampling could exacerbate stream degradation after fires.

In fact, there are 24 species that need protection from feral horses after the fires, as identified by the Australian government’s wildlife and threatened species bushfire recovery expert panel in September.

All of this ecosystem destruction translates into substantial economic costs. Frontier Economics released a report in January this year showing the potential benefits of horse control in Kosciuszko National Park was A$19-50 million per year. The benefits accrue through improved recreational opportunities, improved water quality and reduced car crashes involving feral horses.

In contrast, horse control could cost as little as A$1 million per year and up to $71 million, depending on the methods used. Frontier Economics concluded the costs that are incurred by keeping feral horses far outweigh the cost of eradication.

Alpine water skink
Alpine water skinks are among the vulnerable native species threatened by feral horses.
DEPI/Flickr, CC BY-SA

Victoria’s new feral horse plan

The draft Victorian feral horse action plan aims to:

  1. remove isolated populations on the Bogong High Plains within three years and prevent new populations from establishing
  2. contain and reduce feral horses in the eastern Alps by removing 500 horses in the first year
  3. use the most humane, safe and effective horse control methods.

The first aim makes complete sense. Removing small populations will always be more humane, cheaper and better for the environment than leaving them uncontrolled.

The second aim is perplexing. Based on 2019 surveys, the draft action plan says there are approximately 5,000 horses in the eastern Alps and the population is growing at 15% per year. If the government continues to remove 500 horses per year after the first year, it could see the population rise to more than 9,000 over ten years, despite culling 5,000 horses in that time.




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Double trouble as feral horse numbers gallop past 25,000 in the Australian Alps


In contrast, removing 2,000 horses per year could see the population controlled within three years. Reducing horse numbers rapidly results in the fewest horses having to be culled in the long term.

The third aim of the Victorian draft action plan gives appropriate and strong emphasis to animal welfare. Controlling horse numbers can be morally challenging, and requires a clear understanding of the trade-offs.

Without horse control, native animals are killed when their habitat is destroyed, unique Australian ecosystems are degraded, horses themselves starve or die of thirst in droughts, and the economic costs of inaction escalate. To avoid these costs, horse numbers must be reduced by culling.

This is the grim reality, but with careful attention to animal welfare, the draft strategy will ensure horse control is managed humanely, with control methods based on evidence rather than hyperbole.

Money wasting in NSW

Victoria’s plan is in stark contrast to the NSW government’s approach. In 2018, the NSW government passed the so-called “brumby bill”, which protects feral horses in Kosciuszko National Park.




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Passing the brumby bill is a backward step for environmental protection in Australia


The current method of control in NSW is to capture the horses and transport them to an abattoir if they cannot be re-homed. But evidence shows culling has fewer animal welfare concerns than this method.

And in the latest round of money-wasting horse management, the NSW government trapped 574 horses over the past year, but released 192 females and foals back into the park. If the program is aimed at reducing horse numbers, releasing the most fertile animals back into the population is counter-productive.

Regenerating plants and burnt trees in fire-damaged alpine region
Feral horses are exacerbating the damage from recent bushfires in the High Country.
Shutterstock

What’s more, removing 300-400 horses per year has little impact on overall numbers. There are around 14,000 horses in Kosciuszko National Park, with a growth rate of 23% per year. This means more than 3,000 horses must be removed just to prevent the population from getting bigger.

The high country without feral horses

If the Victorian draft plan can be improved to invest in rapid horse reduction and ecosystem restoration, we can expect to see quagmires created by trampling horses return to functioning ecosystems and the recovery of threatened species.

Stream banks can be stabilised and then dense grass tussocks and sedges will return, creating homes for threatened skinks, crayfish and the Tooarrana broad-toothed rat.

While Kosciuszko’s alpine ecosystems continue to decline under the NSW government’s political impasse, the Victorian Alps will become the favoured destination for tourists who want to see Australia’s nature thriving when they visit national parks.




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The Conversation


Don Driscoll, Professor in Terrestrial Ecology, Deakin University

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

It’s not too late to save them: 5 ways to improve the government’s plan to protect threatened wildlife



Numbats are among 20 mammals on the federal government’s priority list.
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Euan Ritchie, Deakin University; Ayesha Tulloch, University of Sydney; Don Driscoll, Deakin University; Megan C Evans, UNSW, and Tim Doherty, University of Sydney

Australia’s Threatened Species Strategy — a five-year plan for protecting our imperilled species and ecosystems — fizzled to an end last year. A new 10-year plan is being developed to take its place, likely from March.

It comes as Australia’s list of threatened species continues to grow. Relatively recent extinctions, such as the Christmas Island forest skink, Bramble Cay melomys and smooth handfish, add to an already heavy toll.

Red handfish (Thymichthys politus), cousin of the recently extinct smooth handfish, are critically endangered. They’re small, bottom-dwelling fish that tend to ‘walk’ on their pectoral and pelvic fins rather than swim.
CSIRO Science Image, CC BY-SA

Now, more than ever, Australia’s remarkable species and environments need strong and effective policies to strengthen their protection and boost their recovery.

So as we settle into the new year, let’s reflect on what’s worked and what must urgently be improved upon, to turn around Australia’s extinction crisis.




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How effective was the first Threatened Species Strategy?

The Threatened Species Strategy is a key guiding document for biodiversity conservation at the national level. It identifies 70 priority species for conservation, made up of 20 birds, 20 mammals and 30 plants, such as the plains-wanderer, malleefowl, eastern quoll, greater bilby, black grevillea and Kakadu hibiscus.

These were considered among the most urgent in need of assistance of the more than 1,800 threatened species in Australia.

The strategy also identifies targets such as numbers of feral cats to be culled, and partnerships across industry, academia and government key to making the strategy successful.

The original strategy (2015-20) was eagerly welcomed for putting the national spotlight on threatened species conservation. It has certainly helped raise awareness of its priority species.

However, there’s little evidence the strategy has had a significant impact on threatened species conservation to date.

The midterm report in 2019 found only 35% of the priority species (14 in total) had improving trajectories compared to before the strategy (pre-2015). This number included six species — such as the brush-tailed rabbit-rat and western ringtail possum — that were still declining, but just at a slower rate.

Threatened Species Index trends for mammals (left) and birds (right) from 2000 to 2017. The index and y axes show the average change in populations (not actual population numbers) through time.
The Theatened Species Recovery Hub, Author provided

On average, the trends of threatened mammal and bird populations across Australia are not increasing.

Other targets, such as killing two million feral cats by 2020, were not explicitly linked to measurable conservation outcomes, such as an increase in populations of threatened native animals. Because of this, it’s difficult to judge their success.




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What needs to change?

The previous strategy focused very heavily on feral cats as a threat and less so on other important and potentially compounding threats, particularly habitat destruction and degradation.

Targets from the first Threatened Species Strategy.
Department of Agriculture, Water and the Environment

For instance, land clearing has contributed to a similar number of extinctions in Australia (62 species) as introduced animals such as feral cats (64).

In fact, 2018 research found agricultural activities affect at least 73% of invertebrates, 82% of birds, 69% of amphibians and 73% of mammals listed as threatened in Australia. Urban development and climate change threaten up to 33% and 56% of threatened species, respectively.




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Other important threats to native Australian species include pollution, feral herbivores (such as horses and goats), very frequent or hot bushfires and weeds. Buffel grass was recently identified as a major emerging threat to Australia’s biodiversity, with the risk being as high as the threat posed by cats and foxes.

Five vital improvements

We made a submission to the Morrison government when the Threatened Species Strategy was under review. Below, we detail our key recommendations.

1. A holistic and evidence-based approach encompassing the full range of threats

This includes reducing rates of land clearing — a major and ongoing issue, but largely overlooked in the previous strategy.

A Leadbeater's possum peers out from behind a tree trunk.
Leadbeater’s possums are critically endangered. Their biggest threat is the destruction of hollow-bearing trees.
Shutterstock

2. Formal prioritisation of focal species, threats and actions

The previous strategy focused heavily on a small subset of the more than 1,800 threatened species and ecosystems in Australia. It mostly disregarded frog, reptile, fish and invertebrate species also threatened with extinction.

To reduce bias towards primarily “charismatic” species, the federal government should use an evidence-based prioritisation approach, known as “decision science”, like they do in New South Wales, New Zealand and Canada. This would ensure funds are spent on the most feasible and beneficial recovery efforts.

3. Targets linked to clear and measurable conservation outcomes

Some targets in the first Threatened Species Strategy were difficult to measure, not explicitly linked to conservation outcomes, or weak. Targets need to be more specific.

For example, a target to “improve the trajectory” of threatened species could be achieved if extinction is occurring at a slightly slower rate. Alternatively, a target to “improve the conservation status” of a species is achieved if new assessments rate it as “vulnerable” rather than “endangered”.

The ant plant (Myrmecodia beccarii) is one of the 30 plants on the federal government’s list of priority species. It is an ‘epiphyte’ (grows on other plants), and is threatened by habitat loss, invasive weeds, and removal by plant and butterfly collectors.
Dave Kimble/Wikimedia, CC BY-SA

4. Significant financial investment from government

Investing in conservation reduces biodiversity loss. A 2019 study found Australia’s listed threatened species could be recovered for about A$1.7 billion per year. This money could be raised by removing harmful subsidies that directly threaten biodiversity, such as those to industries emitting large volumes of greenhouse gases.

The first strategy featured a call for co-investment from industry. But this failed to attract much private sector interest, meaning many important projects aimed at conserving species did not proceed.

5. Government leadership, coordination and policy alignment

The Threatened Species Strategy should be aligned with Australia’s international obligations such as the United Nation’s Sustainable Development Goals and the federal Environment Protection and Biodiversity Conservation Act 1999 (which is also currently being reviewed). This will help foster a more coherent and efficient national approach to threatened species conservation.

The biggest threat to the critically endangered swift parrot is the clearing of their foraging and breeding habitat.
Shutterstock

There are also incredible opportunities to better align threatened species conservation with policies and investment in climate change mitigation and sustainable agriculture.

The benefits of investing heavily in wildlife reach beyond preventing extinctions. It would generate many jobs, including in regional and Indigenous communities.

Protecting our natural heritage is an investment, not a cost. Now is the time to seize this opportunity.




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The Conversation


Euan Ritchie, 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; Don Driscoll, Professor in Terrestrial Ecology, Deakin University; Megan C Evans, Lecturer and ARC DECRA Fellow, UNSW, and Tim Doherty, ARC DECRA Fellow, University of Sydney

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

UN report says up to 850,000 animal viruses could be caught by humans, unless we protect nature



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Katie Woolaston, Queensland University of Technology and Judith Lorraine Fisher

Human damage to biodiversity is leading us into a pandemic era. The virus that causes COVID-19, for example, is linked to similar viruses in bats, which may have been passed to humans via pangolins or another species.

Environmental destruction such as land clearing, deforestation, climate change, intense agriculture and the wildlife trade is putting humans into closer contact with wildlife. Animals carry microbes that can be transferred to people during these encounters.

A major report released today says up to 850,000 undiscovered viruses which could be transferred to humans are thought to exist in mammal and avian hosts.

The report, by The United Nations’ Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), says to avoid future pandemics, humans must urgently transform our relationship with the environment.

Covid-19 graphic
Microbes can pass from animals to humans, causing disease pandemics.
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Humans costs are mounting

The report is the result of a week-long virtual workshop in July this year, attended by leading experts. It says a review of scientific evidence shows:

…pandemics are becoming more frequent, driven by a continued rise in the underlying emerging disease events that spark them. Without preventative strategies, pandemics will emerge more often, spread more rapidly, kill more people, and affect the global economy with more devastating impact than ever before.

The report says, on average, five new diseases are transferred from animals to humans every year – all with pandemic potential. In the past century, these have included:

  • the Ebola virus (from fruit bats),
  • AIDS (from chimpazees)
  • Lyme disease (from ticks)
  • the Hendra virus (which first erupted at a Brisbane racing stable in 1994).

The report says an estimated 1.7 million currently undiscovered viruses are thought to exist in mammal and avian hosts. Of these, 540,000-850,000 could infect humans.

But rather than prioritising the prevention of pandemic outbreaks, governments around the world primarily focus on responding – through early detection, containment and hope for rapid development of vaccines and medicines.

Doctor giving injection to patient
Governments are focused on pandemic responses such as developing vaccines, rather than prevention.
Shutterstock

As the report states, COVID-19 demonstrates:

…this is a slow and uncertain path, and as the global population waits for vaccines to become available, the human costs are mounting, in lives lost, sickness endured, economic collapse, and lost livelihoods.

This approach can also damage biodiversity – for example, leading to large culls of identified carrier-species. Tens of thousands of wild animals were culled in China after the SARS outbreak and bats continue to be persecuted after the onset of COVID-19.

The report says women and Indigenous communities are particularly disadvantaged by pandemics. Women represent more then 70% of social and health-care workers globally, and past pandemics have disproportionately harmed indigenous people, often due to geographical isolation.




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It says pandemics and other emerging zoonoses (diseases that have jumped from animals to humans) likely cause more than US$1 trillion in economic damages annually. As of July 2020, the cost of COVID-19 was estimated at US $8-16 trillion globally. The costs of preventing the next pandemic are likely to be 100 times less than that.

People wearing masks in a crowd
The cost to governments of dealing with pandemics far outweighs the cost of prevention.
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A way forward

The IPBES report identifies potential ways forward. These include:

• increased intergovernmental cooperation, such as a council on pandemic prevention, that could lead to a binding international agreement on targets for pandemic prevention measures

• global implementation of OneHealth policies – policies on human health, animal health and the environment which are integrated, rather than “siloed” and considered in isolation

• a reduction in land-use change, by expanding protected areas, restoring habitat and implementing financial disincentives such as taxes on meat consumption

• policies to reduce wildlife trade and the risks associated with it, such as increasing sanitation and safety in wild animal markets, increased biosecurity measures and enhanced enforcement around illegal trade.

Societal and individual behaviour change will also be needed. Exponential growth in consumption, often driven by developed countries, has led to the repeated emergence of diseases from less-developed countries where the commodities are produced.

So how do we bring about social change that can reduce consumption? Measures proposed in the report include:

  • education policies

  • labelling high pandemic-risk consumption patterns, such as captive wildlife for sale as pets as either “wild-caught” or “captive-bred” with information on the country where it was bred or captured

  • providing incentives for sustainable behaviour

  • increasing food security to reduce the need for wildlife consumption.

People inspecting haul of wildlife products
Cracking down on the illegal wildlife trade will help prevent pandemics.
AP

An Australian response

Australia was one of the founding member countries of IPBES in 2012 and so has made an informal, non-binding commitment to follow its science and policy evidence.

However, there are no guarantees it will accept the recommendations of the IPBES report, given the Australian government’s underwhelming recent record on environmental policy.

For example, in recent months the government has so far refused to sign the Leaders’ Pledge for Nature. The pledge, instigated by the UN, includes a commitment to taking a OneHealth approach – which considers health and environmental sustainability together – when devising policies and making decisions.

The government cut funding of environmental studies courses by 30%. It has sought to reduce so called “green tape” in national environmental legislation, and its economic response to the pandemic will be led by industry and mining – a focus that creates further pandemic potential.




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Finally, Australia is one of few countries without a national centre for disease control and pandemics.

But there are good reasons for hope. It’s within Australia’s means to build an organisation focused on a OneHealth approach. Australia is one of the most biologically diverse countries on the planet and Australians are willing to protect it. Further, many investors believe proper environmental policy will aid Australia’s economic recovery.

Finally, we have countless passionate experts and traditional owners willing to do the hard work around policy design and implementation.

As this new report demonstrates, we know the origins of pandemics, and this gives us the power to prevent them.The Conversation

Katie Woolaston, Lawyer, Queensland University of Technology and Judith Lorraine Fisher, Adjunct Professor University of Western Australia, Institute of Agriculture

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

Scientists capture rare footage of mother skink fighting a deadly brown snake to protect her babies



Author provided

Gregory Watson, University of the Sunshine Coast and Jolanta Watson, University of the Sunshine Coast

Unlike many mammals and birds, most reptiles show little sign of being caring parents. But our new research shows one lizard species may be more doting parents than we thought – the adults risking their own safety to protect their babies.

We used cameras in the Snowy Mountains of New South Wales to study the Cunningham’s skink. We were surprised to record evidence of the lizards actively defending their newborn offspring against formidable predators. Our findings are outlined in a paper released today.

Most startlingly, we recorded a mother skink aggressively attacking a large, deadly brown snake while her babies watched on. We also witnessed 12 incidents of skinks chasing magpies away from their young.

We originally set out to record how species such as skinks will cope with climate change. But this evolved into a study of the fascinating and surprising social bonds between lizard offspring and their parents.

Adult and young skinks sun-baking together
Sun-loving skinks live together in social groups.
Authors provided

What is the Cunningham’s skink?

The Cunningham’s skink (Egernia cunninghami) is a large, sun-loving, spiny lizard native to southeast Australia. It’s named after Alan Cunningham, an explorer who collected the first specimen in the Blue Mountains.

The skinks are active during the day. They feed on invertebrates such as insects, snails and slugs, as well as vegetation.

The Cunningham’s skink lives in social groups – a behaviour very rare among lizards and reptiles. In these groups, mothers give birth to live young (rather than eggs) then live alongside their kids, sometimes for several years.

The species has strength in numbers – living in a group makes it easier to spot threats, which helps the group survive.

Adult and young skinks sun-baking together
Thew offspring of Cunningham’s skinks can stay with the parents for several years.

The mother of all discoveries

Using video and thermal imaging, we observed the skinks on 32 days over three years.

Among reptiles, evidence of parental protection in their natural environment has been rare and typically anecdotal. We witnessed four birthing sessions, and then monitored skink encounters in the presence of their offspring.




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Videoing nature can be tricky. Often, the action takes place away from where you’ve directed your camera. So when we saw a snake, it was a scramble to get a free video camera and start recording.

We witnessed two separate encounters with an eastern brown snake. The first involved the snake sneaking up on six-day-old skinks basking in the sun (see footage below). We recorded the mother running towards the predator and biting it for several seconds. The snake writhes around before the mother releases her grip and returns unharmed to her young.

The following year, we encountered two adult skinks attacking another eastern brown snake in bushes. Juvenile skinks were nearby. The skinks bit tight to the snake’s body, and the snake dragged them for more than 15 metres before the skinks released their grip.

Snakes were not the only predator vanquished by the protective skink parents – Cunningham’s skinks regularly chased magpies away from their young. We observed 12 encounters between skinks and magpies. In each case, an adult skink aggressively chased and/or attacked the magpie after the bird came close to the group.

Thermal camera image showing the mother skink attacking the snake while her babies watch on
Thermal camera image showing the mother skink attacking the snake while her babies watch on.

What does this all mean?

Some animals rarely interact with others of the same species, even their offspring. In fact, available data suggests infanticide – where mature animals kill young offspring of the same species – can occur among some skink species.

We saw no such behaviour among the Cunningham’s skink, or aggression towards each other.

While the aggression of the adult skinks towards predators took place in the presence of young, the adults may have been exhibiting self-defence or territorial behaviour. Regardless, the attacks on predators in the presence of newborns does reflect parental care, either directly or indirectly. Our future field excursions will hopefully shed more light on this.

Understanding the factors that bring parents and offspring together, and keep them together, is important in our broader understanding of social evolution – that is, how social interactions of species arise, change and are maintained.

It will also help us understand how animals cooperating with and caring for each other can benefit both the individual, and the whole.




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The Conversation


Gregory Watson, Senior Lecturer, Science, University of the Sunshine Coast and Jolanta Watson, Lecturer in Science, University of the Sunshine Coast

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

Want to beat climate change? Protect our natural forests



Natural forest systems are far better at adapting to change conditions than young, degraded or plantation forests.
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Kate Dooley, University of Melbourne and Brendan Mackey, Griffith University

Tomorrow a special report on how land use affects climate change will be released by the Intergovernmental Panel on Climate Change.

Land degradation, deforestation, and the expansion of our deserts, along with agriculture and the other ways people shape land, are all major contributors to global climate change.

Conversely, trees remove carbon dioxide and store it safely in their trunks, roots and branches. Research published in July estimated that planting a trillion trees could be a powerful tool against climate change.




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However, planting new trees as a climate action pales in comparison to protecting existing forests. Restoring degraded forests and expanding them by 350 million hectares will store a comparable amount of carbon as 900 million hectares of new trees.

Natural climate solutions

Using ecological mechanisms for reducing and storing carbon is a growing field of study. Broadly known as “natural climate solutions”, carbon can be stored in wetlands, grasslands, natural forests and agriculture.

This is called “sequestration”, and the more diverse and longer-lived the ecosystem, the more it helps mitigate the effect of climate change.

Allowing trees to regenerate naturally is a more effective, immediate and low-cost method of removing and storing atmospheric carbon than planting new trees.
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Research has estimated these natural carbon sinks can provide 37% of the CO₂ reduction needed to keep the rise in global temperatures below 2℃.

But this research can be wrongly interpreted to imply that the priority is to plant young trees. In fact, the major climate solution is the protection and recovery of carbon-rich and long-lived ecosystems, especially natural forests.




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With the imminent release of the new IPCC report, now is a good time to prioritise the protection and recovery of existing ecosystems over planting trees.

Forest ecosystems (including the soil) store more carbon than the atmosphere. Their loss would trigger emissions that would exceed the remaining carbon budget for limiting global warming to less than the 2℃ above pre-industrial levels, let alone 1.5℃, threshold.




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Natural forest systems, with their rich and complex biodiversity, the product of ecological and evolutionary processes, are stable, resilient, far better at adapting to changing conditions and store more carbon than young, degraded or plantation forests.

Protect existing trees

Forest degradation is caused by selective logging, temporary clearing, and other human land use. In some areas, emissions from degradation can exceed those of deforestation. Once damaged, natural ecosystems are more vulnerable to drought, fires and climate change.

Recently published research found helping natural forest regrow can have a globally significant effect on carbon dioxide levels. This approach – called proforestation – is a more effective, immediate and low-cost method for removing and storing atmospheric carbon in the long-term than tree planting. And it can be used across many different kinds of forests around the world.

Avoiding further loss and degradation of primary forests and intact forest landscapes, and allowing degraded forests to naturally regrow, would reduce global carbon emissions.
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Avoiding further loss and degradation of primary forests and intact forest landscapes, and allowing degraded forests to naturally regrow, would reduce global carbon emissions annually by about 1 gigatonnes (Gt), and reduce another 2-4 Gt of carbon emissions just through natural regrowth.




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Research has predicted that protecting primary forests while allowing degraded forests to recover, along with limited expansion of natural forests, would remove 153 billion tonnes of carbon from the atmosphere between now and 2150.

Every country with forests can contribute to this effort. In fact, research shows that community land management is the best way to improve natural forests and help trees recover from degradation.

By the numbers

Tree planting carries more limited climate benefits. The recent Science paper focused on mapping and quantifying increases in tree canopy cover in areas that naturally support trees. However, increasing canopy cover through natural forest regeneration can sequester 40 times more carbon over the course of the century than establishing new plantations.




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We need to think very carefully about how we use land that has already been cleared: land is a finite resource, and we need to grow food and resources for a global population set to hit 9 billion by 2050.

We need to understand land as a finite resource and accomodate for a global population set to hit 9 billion by 2050.
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Any expansion of natural forest area is best achieved through allowing degraded forests to naturally recover. Allowing trees to regenerate naturally, using nearby remnants of primary forests and seed banks in the soil of recently cleared forests, is more likely to result in a resilient and diverse forest than planting massive numbers of seedlings.

Instead of planting entirely new areas, we should prioritise reconnecting forested areas and restoring the edges of forest, to protect their mature core. This means our carbon-storing forests will be more resilient and longer-lasting.




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For forests to effectively help avert dangerous climate change, global and regional policies are needed to protect, restore and regenerate natural forests, alongside a carbon-zero energy economy.


A version of this article was co-published with Pursuit.The Conversation

Kate Dooley, Research Fellow, Climate and Energy College, University of Melbourne and Brendan Mackey, Director of the Griffith Climate Change Response Program, Griffith University

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

Reducing food waste can protect our health, as well as our planet’s



File 20180830 195298 whfufy.jpg?ixlib=rb 1.1
Smaller portions reduce food waste and waistlines.
from http://www.shutterstock.com

Liza Barbour, Monash University and Julia McCartan, Monash University

Globally, one-third of food produced for human consumption is wasted. Food waste costs Australia A$20 billion each year and is damaging our planet’s resources by contributing to climate change and inefficient land, fertiliser and freshwater use.

And it’s estimated if no further action is taken to slow rising obesity rates, it will cost Australia A$87.7 billion over the next ten years. Preventable chronic diseases are Australia’s leading cause of ill health, and conditions such as coronary heart disease, stroke, high blood pressure, some forms of cancer and type 2 diabetes are linked to obesity and unhealthy diets.

But we can tackle these two major issues of obesity and food waste together.




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Avoid over-consumption of food

Described as metabolic food waste, the consumption of food in excess of nutritional requirements uses valuable food system resources and manifests as overweight and obesity.

The first of the Australian dietary guidelines is:

To achieve and maintain a healthy weight, be physically active and choose amounts of nutritious food and drinks to meet your energy needs.

In 2013, researchers defined three principles for a healthy and sustainable diet. The first was:

Any food that is consumed above a person’s energy requirement represents an avoidable environmental burden in the form of greenhouse gas emissions, use of natural resources and pressure on biodiversity.




Read more:
Portion size affects how much you eat despite your appetite


Reduce consumption of processed, packaged foods

Ultra-processed foods are not only promoting obesity, they pose a great threat to our environment. The damage to our planet not only lies in the manufacture and distribution of these foods but also in their disposal. Food packaging (bottles, containers, wrappers) accounts for almost two-thirds of total packaging waste by volume.

Ultra-processed foods are high in calories, refined sugar, saturated fat and salt, and they’re dominating Australia’s food supply. These products are formulated and marketed to promote over-consumption, contributing to our obesity epidemic.

Processed foods promote over-consumption and leave packaging behind.
from http://www.shutterstock.com

Healthy and sustainable dietary recommendations promote the consumption of fewer processed foods, which are energy-dense, highly processed and packaged. This ultimately reduces both the risk of dietary imbalances and the unnecessary use of environmental resources.

Author Michael Pollan put it best when he said, “Don’t eat anything your great-grandmother wouldn’t recognise as food.”




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So what do we need to do?

In response to the financial and environmental burden of food waste, the federal government’s National Food Waste Strategy aims to halve food waste in Australia by 2030. A$133 million has been allocated over the next decade to a research centre which can assist the environment, public health and economic sectors to work together to address both food waste and obesity.

Other countries, including Brazil and the United Kingdom acknowledge the link between health and environmental sustainability prominently in their dietary guidelines.

One of Brazil’s five guiding principles states that dietary recommendations must take into account the impact of the means of production and distribution on social justice and the environment. The Qatar national dietary guidelines explicitly state “reduce leftovers and waste”.

Many would be surprised to learn Australia’s dietary guidelines include tips to minimise food waste:

store food appropriately, dispose of food waste appropriately (e.g. compost, worm farms), keep food safely and select foods with appropriate packaging and recycle.

These recommendations are hidden in Appendix G of our guidelines, despite efforts from leading advocates to give them a more prominent position. To follow international precedence, these recommendations should be moved to a prominent location in our guidelines.




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At a local government level, councils can encourage responsible practices to minimise food waste by subsidising worm farms and compost bins, arranging kerbside collection of food scraps and enabling better access to soft plastic recycling programs such as Red Cycle.




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Portion and serving sizes should be considered by commercial food settings. Every year Australians eat 2.5 billion meals out and waste 2.2 million tonnes of food via the commercial and industrial sectors. Evidence shows reducing portion sizes in food service settings leads to a reduction in both plate waste and over-consumption.

Given the cost of food waste and obesity to the economy, and the impact on the health of our people and our planet, reducing food waste can address two major problems facing humanity today.The Conversation

Liza Barbour, Lecturer, Monash University and Julia McCartan, Research Officer, Monash University

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

The plan to protect wildlife displaced by the Hume Highway has failed



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Hundreds of large old trees were removed when the Hume Highway was widened.
Brian Yap/Flickr, CC BY-NC

David Lindenmayer, Australian National University; Martine Maron, The University of Queensland; Megan C Evans, The University of Queensland, and Philip Gibbons, Australian National University

It’s no secret that human development frequently comes at a cost to other creatures. As our urban footprint expands, native habitat contracts. To compensate for this, most Australian governments require developers to invest in biodiversity offsetting, where habitat is created or protected elsewhere to counterbalance the impact of construction.

Researchers monitored hundreds of nest boxes used to offset habitat loss.
Mason Crane, Author provided

Although biodiversity offsetting is frequently used in Australia – and is becoming increasingly popular around the world – we rarely know whether offsets are actually effective.

That’s why we spent four years monitoring the program designed to offset the environmental losses caused by widening the Hume Highway between Holbrook and Coolac, New South Wales. Our research has found it was completely ineffective.


Map courtesy Google/The Conversation, CC BY-ND

Trading trees for boxes

The roadworks required the removal of large, old, hollow-bearing trees, which are critical nesting sites for many animals, including several threatened species. To compensate for these losses, the developer was required to install one nest box for every hollow that was lost – roughly 600 nest boxes were installed.

Wild honeybees occupied many nest boxes.
Mason Crane, Author provided

Many of the boxes were specifically designed for three threatened species: the squirrel glider, the superb parrot and the brown treecreeper. We monitored the offset for four years to see whether local wildlife used the nest boxes.

We found that the nest boxes were rarely used, with just seven records of the squirrel glider, two of the brown treecreeper, and none of the superb parrot. We often saw all three species in large old tree hollows in the area around the boxes we monitored.

Even more worryingly, almost 10% of the boxes collapsed, were stolen or otherwise rendered ineffective just four years after being installed. Perversely, we found that invasive species such as feral bees and black rats frequently occupied the nest boxes.

The offset clearly failed to deliver the environmental outcomes that were promised. Indeed, researchers have been concerned for some time now that offsetting can be misused and abused.

What can be done?

It’s worth noting that research supports using nest boxes as a habitat replacement. However, they may never be effective for species such as the superb parrot. It’s not quite clear why some animals use nest boxes and others don’t, but earlier monitoring projects in the same area found superb parrots consistently avoid them.

Still, concrete steps can – and should – be taken to improve similar offset programs.

First, the one-to-one ratio of nest boxes to tree hollows was inadequate; far more nest boxes needed to be installed to replace the natural hollows that were lost.

There also was no requirement to regularly replace nest boxes as they degrade. It can take a hundred years or more for trees to develop natural hollows suitable for nesting wildlife. To truly offset their removal, thousands of boxes may be required over many decades.

An old hollow-bearing river red gum. Trees like this are vital habitat for many species.
Peter Halasz/Wikimedia commons, CC BY-SA

Second, nest boxes clearly cannot compensate for the many other key ecological values of large old trees (such as carbon storage, flowering pulses or foraging habitat). This suggests that more effort is needed at the beginning of a development proposal to avoid damaging environmental assets that are extremely difficult to replace – such as large old trees.

Third, where it is simply impossible to protect key features of the environment during infrastructure development, more holistic strategies should be considered. For example, in the case of the woodlands around the Hume Highway, encouraging natural regeneration can help replace old trees.

Tree planting on farms can also make a significant contribution to biodiversity – and some of these may eventually become hollow-bearing trees. A combination of planting new trees and maintaining adequate artificial hollows while those trees mature might be a better approach.

Being accountable for failure

When an offset program fails, it’s unlikely anyone will be asked to rectify the situation. This is because developers are only required to initiate an offset, and are not responsible for their long-term outcomes.

In the case of the Hume Highway development, the conditions of approval specified that nest boxes were to be installed, but not that they be effective.

Despite the ecological failure of the offset (and over A$200,000 invested), the developer has met these legal obligations.

This distinction between offset compliance and offset effectiveness is a real problem. The Australian government has produced a draft policy of outcomes-based conditions, but using these conditions isn’t mandatory.

The poor results of the Hume Highway offset program are sobering. However, organisations like Roads and Maritime Services are to be commended for ensuring that monitoring was completed and for making the data available for public scrutiny – many agencies do not even do that.

The ConversationIndeed, through monitoring and evaluation we can often learn more from failures than successes. There are salutary lessons here, critical to ensuring mistakes are not repeated.

David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University; Martine Maron, ARC Future Fellow and Associate Professor of Environmental Management, The University of Queensland; Megan C Evans, Postdoctoral Research Fellow, Environmental Policy, The University of Queensland, and Philip Gibbons, Senior Lecturer, Australian National University

This article was originally published on The Conversation. Read the original article.

Marine parks and fishery management: what’s the best way to protect fish?


Caleb Gardner, University of Tasmania

The federal government is considering changes to Australia’s marine reserves to implement a national system. This week The Conversation is looking at the science behind marine reserves and how to protect our oceans.


While academics often focus on biodiversity objectives for marine parks, the public and political debate tends to come down to one thing: fishing.

When former federal MP Rob Oakeshott cast one of the deciding votes in support of the Commonwealth marine parks plan in 2013, he explained that he believed they benefit fisheries. The federal government has also emphasised the benefit of marine parks to fisheries production.

There’s also an academic debate. When a study showed that the Great Barrier Reef marine park had harmed fisheries production, there was a passionate response from other experts. This is despite advocates arguing that reserves are primarily about biodiversity conservation, rather than fishing production.

Clearly, fishing is a hot issue for marine parks. So what does the science say?

How do marine parks protect fish?

The proposed benefits to fisheries from marine parks include: protection or insurance against overfishing; “spillover”, where larvae or juveniles from the parks move out and increase the overall production; habitat protection from damaging fishing gear; and managing the ecosystem effects of fishing such as resilience against climate change.

Marine parks regulate activities, mainly fishing, within a specified area. They come in a variety of categories. Some allow fishing, but the most contentious are “no-take” marine parks.

Fishery managers also sometimes close areas of the ocean to fishing. This is different to how no-take marine parks work in two ways: the legislative authority is different (being through fisheries rather than environmental legislation); and the closures usually target a specific fishery, whereas no-take marine parks usually ban all fishing.

Fishery closures, rather than no-take marine parks, are usually applied to protect special areas for particular fish, such as spawning sites or nursery areas. They are also used to protect habitats, such as in the case of trawl closures, which allow the use of other gear such as longlines in the same location.

Fisheries legislation bans damaging fishing gear outright, while benign gears are allowed. In contrast, no-take marine parks tend to exclude all gear types.

Displacing fishers

Neither marine parks nor fishery closures regulate the amount of catch and fishing effort. They only control the location. Commercial fishers take most fish caught in Commonwealth waters and most of this is limited by catch quotas.

When a no-take marine park closes an area to fishing, fishers and their catch are displaced into other areas of the ocean. This occurs for all types of fishing, including recreational fishing. Recreational fishers displaced by marine parks don’t stop fishing, they just fish somewhere else – and the same number of fishers are squeezed into a smaller space.

Marine parks increase the intensity of fishing impacts across the wider coast, which is an uncomfortable outcome for marine park advocates. Modelling of Victorian marine parks showed that displaced catch would harm lobster stocks and associated ecosystems, and was counterproductive to their fishery management objective of rebuilding stock.

Because ecosystems don’t respond in predictable ways, depletion of fish stocks from the fishing displaced from marine parks could lead to severe ecosystem outcomes.

For this reason, a second and separate management change is often needed after marine parks are declared, which is to reduce the number of fishers and fish caught to prevent risk of impacts from the park.

Controlling how many fish are caught (which is what traditional fisheries management does) has substantially more influence on overall fish abundance than controlling where fish are caught with parks, as shown recently on the Great Barrier Reef.

Public cost

Commonwealth fisheries catch quotas are routinely reduced if a fishery harms the sustainability of the marine environment. There’s no compensation to fishers, so there’s no cost to the public, other than a possible reduced supply of fish.

Catches can also be reduced to manage fishing displaced by marine reserves and the outcome is identical except in terms of the public cost. Creation of the Great Barrier Reef Marine Park led to over A$200 million in payments to displaced fishers. Another publicly funded package is planned for the Commonwealth marine reserves.

Marine parks also have high recurring public cost because boundaries need to be policed at sea. Catch quotas can be policed at the wharf, with compliance costs fully recovered from industry.

Do marine parks help fish and fishers?

Evidence of a benefit to fisheries from marine parks is scarce. However, there are some clear examples of fishing displacement that is so minor that there has been an overall increase in fish inside and outside the park.

These examples show that marine parks can sometimes benefit fish stocks, the fishery and also the overall marine ecosystem. However, these examples come from situations where traditional fishery management has not been applied to prevent overfishing.

This is consistent with modelling of marine parks that shows they only increase overall fish populations when there has been severe overfishing. This generally means that if there’s already effective traditional fisheries management, marine reserves cannot benefit fish stocks and fisheries, or restock fish outside the reserve (spillover) (see also here).

In jurisdictions where fisheries management is lacking, any regulation, including through marine reserves, is better than nothing. But this isn’t the situation with Australia’s Commonwealth fisheries where harvest strategies are used and overfishing has been eliminated.

The conclusions from modelling of marine reserves mean that the areas of the reserves that limit fishing would be expected to reduce fishery production and harm our ability to contribute to global food security.

The Coral Sea marine reserve, in particular, represents an area with known large stocks of fish, especially tuna, that could be harvested sustainably. Limiting fishing in the Coral Sea eliminates any potential for these resources to help feed Australians or contribute to global food supplies.

The potential sustainable, ecologically acceptable harvest from the Coral Sea is unknown, so we don’t know the full scale of what’s being lost and how much the recent changes reduce this problem, although Papua New Guinea sustainably harvests 150,000-300,000 tonnes of tuna in its part of the sea.

Allowing fishing doesn’t mean the oceans aren’t protected. Existing fisheries management is already obliged to ensure fishing doesn’t affect sustainability of the marine environment.

The Conversation

Caleb Gardner, Principal Research Fellow, Institute for Marine and Antarctic Studies, University of Tasmania

This article was originally published on The Conversation. Read the original article.

Whale of a problem: why do humpback whales protect other species from attack?


Tracey Rogers, UNSW Australia

A group of killer whales are on the hunt. They work together to submerge and drown a whale calf. But then more whales appear.

The newly arrived humpbacks bellow a trumpet-like call, and wield their five-metre-long pectoral flippers like swords against the prowling killer whales.

The killer whales are driven away from the calf, and the humpbacks also move away. As they do, the killer whales turn back and descend on the calf once more. In response, the humpbacks swing around and return to the calf’s defence.

The humpbacks position themselves close to the calf, between it and the killer whales, potentially putting themselves in harm’s way.

This process continues and repeats for many hours, but it is not a calf of their own species, it is a grey whale calf.

You can see the drama unfold as the humpbacks fend off the killer whales.

This is not an isolated case. Robert Pitman, from the National Oceanic and Atmospheric Administration in the US, and his colleagues report more than 100 incidents where humpback whales have approached or actively intervened in killer whale hunting attempts.

Surprisingly, most of these have been predation attempts on other species, such as seals, other whales or even fish.

The question is: why would these humpback whales place themselves in danger by interposing themselves between one of their few predators – killer whales – and an individual of an entirely different species?

You scratch my back…

Altruistic behaviour is some of the most difficult to explain in evolutionary terms. In a biological context, altruism refers to cases where one individual’s behaviour provides a benefit to another individual at a cost to itself.

It doesn’t need to be as dramatic as throwing themselves on a grenade, but even placing themselves at a small disadvantage could jeopardise their chances of surviving and reproducing.

And if they don’t reproduce, then neither do the genes that encouraged the individual to be altruistic. This is why – all else being equal – you would expect altruistic genes to slowly disappear from a population over multiple generations.

But there are cases of altruistic behaviour in nature, particularly among closely related groups. One example is an individual meerkat who calls to alert its group to the presence of a predator, particularly as that call could make the predator more likely to notice the vigilant meerkat.

This kind of behaviour can evolve and remain stable in a population due to a process called kin selection. This is because the meerkat is closely related to the other members of its group, so it shares many genes with them. Even if it does end up sacrificing itself, if it helps its relatives survive, they may also be carrying the genes that encourage altruism.

Other cases of altruism in nature are supported by recriprocation: you scratch my back and I’ll scratch yours.

An example would be vampire bats that share blood meals. They do so on the assumption that their friend will return the favour at some later date.

However, for kin selection or reciprocal altruism to evolve, there needs to be a high level of social cohesion within the group.

For example, individuals need to be able to recognise who is a relative or a friend, and who is not. Presumably, you are less likely to put your neck on the line for a distant relative or for someone who is not likely to repay the favour.

So it might not be surprising that a humpback mother would vigorously defend her own calf from attacking killer whales. But why would a humpback approach and position itself between attacking killer whales and another whale’s calf?

Killer whales are a dangerous predator but they pose little threat to an adult humpback whale.

Spillover

As mentioned above, if an individual is prone to behave in a way that reduces their chance of surviving and reproducing, we would expect the genes that promote that behaviour to dwindle over generations and eventually vanish from the population. And even if an adult humpback puts itself at minimal risk by interfering with killer whales, minimal risk is more than zero risk by avoiding them altogether.

Pitman and his colleagues think there might be more social cohesion among humpbacks than we previously thought, and kin selection and/or reciprocal altruism could be playing a part.

Individual humpback whales return to the same region to breed. This means that there is a good possibility that humpbacks are related to their immediate neighbours. Pitman suggests this means it may be worth a humpback helping other humpbacks to protect their calves from killer whale attacks.

However, it is trickier to explain apparent altruism directed towards other species. Pitman and his colleagues explain that for the humpback whale, this intervention on behalf of other species is a “spillover” behaviour. They suggest it is an extension of the humpback whales’ “drive” to protect their own calves.

Humpbacks may have learned to respond to vocalisations of attacking killer whales, which trigger them to drive the killer whales away, regardless of the species being attacked.

If this tendency to drive away killer whales whenever they are attacking has helped humpbacks to protect their own calves, then the genes that promote it could be maintained in the population, even if other species benefit at times.

This interspecies altruistic behaviour may be “inadvertent” altruism – it can be altruism in the individual case but it is ultimately driven by self-interest.

The Conversation

Tracey Rogers, Associate Professor Evolution & Ecology, UNSW Australia

This article was originally published on The Conversation. Read the original article.