Zoos aren’t Victorian-era throwbacks: they’re important in saving species



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A meerkat at the National Zoo and Aquarium in Canberra. The Zoo has recently announced an expansion that will double its size.
AAP Image/Stefan Postles

Alienor Chauvenet, The University of Queensland

The National Zoo and Aquarium in Canberra recently announced a new expansion that will double its size, with open range space for large animals like white rhinos and cheetahs.

As well as improving visitors’ experience, the expansion is touted as a way to improve the zoo’s breeding program for threatened animals. However, zoos have received plenty of criticism over their capacity to educate, conserve, or even keep animals alive.

But while zoos began as 19th-century menageries, they’ve come a long way since then. They’re responsible for saving 10 iconic species worldwide. Without captive breeding and reintroduction efforts, there might be no Californian Condor or Przewalski’s Horse – the only truly wild horse – left in the wild.

Australian zoos form part of a vital global network that keeps our most vulnerable species alive.

What is the role of zoos for conservation?

Although Canberra Zoo is relatively new compared with others in Australia – Melbourne zoo, for example, was opened in 1862 – it adds to a collection of conservation-orientated establishments.

In Australia, Taronga Conservation Society Australia, the Royal Melbourne Zoological Gardens, Adelaide Zoo and Perth Zoo are all members of the World Association of Zoos and Aquariums (WAZA). WAZA is an international organisation that aims to guide and support zoos in their conservation missions, including captive breeding, reintroductions into the wild, habitat restoration, and genetic management.

From the perspective of nature conservation, zoos have two major roles: educating the public about the plight of our fauna, and contributing to species recovery in the wild.

Conservation education is deeply embedded in the values of many zoos, especially in Australia. The evidence for the link between zoo education and conservation outcomes is mixed, however zoos are, above anybody else, aimed at children. Evidence shows that after guided experiences in zoos children know more about nature and are more likely to have a positive attitude towards it. Importantly, this attitude is transferable to their parents.

Zoos contribute unique knowledge and research to support field conservation programs, and thus species recovery. In Australia, zoos are directly involved in monitoring of free-ranging native fauna and investigations into emerging diseases. Without zoos many fundamental questions about a species’ biology could not be answered, and we would lack essential knowledge on animal handling, husbandry and care.

Through captive breeding, zoos can secure healthy animals that can be introduced to old or new habitats, or bolster existing wild populations. For example, a conservation manager at Taronga Zoo told me they’ve released more than 50,000 animals that were either bred on-site or rehabilitated in their wildlife hospitals (another important function of zoos).

Criticisms of captive breeding programs

The critics of captive breeding as a conservation strategy raise several concerns. Captive bred population can lose essential behavioural and cultural adaptations, as well as genetic diversity. Large predators – cats, bears and wolves – are more likely to be affected.

Some species, such as frogs, do well in captivity, breed fast, and are able to be released into nature with limited or no training. For others, there is usually a concerted effort to maintain wild behaviour.

There’s a higher chance of disease wiping out zoo populations due to animal proximity. In 2004 the largest tiger zoo in Thailand experienced an outbreak of H5N1 bird flu after 16 tigers were fed contaminated raw chicken; ultimately 147 tigers died or were put down.

However, despite these risks, research shows that reintroduction campaigns improve the prospects of endangered species, and zoos can play a crucial role in conservation. Zoos are continually improving their management of the genetics, behaviour and epidemiology of captive populations.

They are the last resort for species on the brink of extinction, such as the Orange-bellied Parrot or the Scimitar-horned Oryx, and for those facing a threat that we cannot stop yet, such as amphibians threatened by the deadly Chytrid fungus.

Orange-bellied parrots are ranked among the most endangered species on the planet – their survival depends on zoos.
Chris Tzaros/AAP

Zoos need clear priorities

A cost-benefit approach can help zoos prioritise their actions. Taronga, for example, uses a prioritisation system to decide which projects to take on, with and without captive breeding. Their aim is to a foresee threats to wildlife and ecosystems and implement strategies that ensure sustainability.

Developing prioritisation systems relies on clearly defined objectives. Is there value in keeping a species in captivity indefinitely, perhaps focusing only on education? Is contributing to a wild population the end goal, requiring both education and active conservation?

Once this is defined, zoos can assess the benefit and costs of different actions, by asking sometimes difficult questions. Is a particular species declining in the wild? Can we secure a genetically diverse sample before it is too late? Will capturing animals impact the viability of the wild population? How likely is successful reintroduction? Can we provide enough space and stimulation for the animals, and how expensive are they to keep?

Decision science can help zoos navigate these many factors to identify the best species to target for active captive conservation. In Australia, some of the rapidly declining northern mammals, which currently do not have viable zoo populations, could be a good place to start.

Partnerships with governmental agencies, universities and other groups are essential to all of these activities. Zoos in Australia are experts at engaging with these groups to help answer and address wildlife issues.


The ConversationAlienor Chauvenet would like to acknowledge the contribution of Hugh Possingham to this article, and thank Nick Boyle and Justine O’Brien from Taronga Conservation Society Australia for the information they provided.

Alienor Chauvenet, Postdoctoral Research Fellow, The University of Queensland

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

Scientists are accidentally helping poachers drive rare species to extinction



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The beautiful Chinese cave gecko, or Goniurosaurus luii, is highly prized by poachers.
Carola Jucknies

Benjamin Scheele, Australian National University and David Lindenmayer, Australian National University

If you open Google and start typing “Chinese cave gecko”, the text will auto-populate to “Chinese cave gecko for sale” – just US$150, with delivery. This extremely rare species is just one of an increasingly large number of animals being pushed to extinction in the wild by animal trafficking.

What’s shocking is that the illegal trade in Chinese cave geckoes began so soon after they were first scientifically described in the early 2000s.

It’s not an isolated case; poachers are trawling scientific papers for information on the location and habits of new, rare species.

As we argue in an essay published today in Science, scientists may have to rethink how much information we publicly publish. Ironically, the principles of open access and transparency have led to the creation of detailed online databases that pose a very real threat to endangered species.

We have personally experienced this, in our research on the endangered pink-tailed worm-lizard, a startling creature that resembles a snake. Biologists working in New South Wales are required to provide location data on all species they discover during scientific surveys to an online wildlife atlas.

But after we published our data, the landowners with whom we worked began to find trespassers on their properties. The interlopers had scoured online wildlife atlases. As well as putting animals at risk, this undermines vital long-term relationships between researchers and landowners.

The endangered pink-tailed worm-lizard (Aprasia parapulchella).
Author provided

The illegal trade in wildlife has exploded online. Several recently described species have been devastated by poaching almost immediately after appearing in the scientific literature. Particularly at risk are animals with small geographic ranges and specialised habitats, which can be most easily pinpointed.

Poaching isn’t the only problem that is exacerbated by unrestricted access to information on rare and endangered species. Overzealous wildlife enthusiasts are increasingly scanning scientific papers, government and NGO reports, and wildlife atlases to track down unusual species to photograph or handle.

This can seriously disturb the animals, destroy specialised microhabitats, and spread disease. A striking example is the recent outbreak in Europe of a amphibian chytrid fungus, which essentially “eats” the skin of salamanders.

This pathogen was introduced from Asia through wildlife trade, and has already driven some fire salamander populations to extinction.

Fire salamanders have been devastated by diseases introduced through the wildlife trade.
Erwin Gruber

Rethinking unrestricted access

In an era when poachers can arm themselves with the latest scientific data, we must urgently rethink whether it is appropriate to put detailed location and habitat information into the public domain.

We argue that before publishing, scientists must ask themselves: will this information aid or harm conservation efforts? Is this species particularly vulnerable to disruption? Is it slow-growing and long-lived? Is it likely to be poached?

Fortunately, this calculus will only be relevant in a few cases. Researchers might feel an intellectual passion for the least lovable subjects, but when it comes to poaching, it is generally only charismatic and attractive animals that have broad commercial appeal.

But in high-risk cases, where economically valuable species lack adequate protection, scientists need to consider censoring themselves to avoid unintentionally contributing to species declines.

Restricting information on rare and endangered species has trade-offs, and might inhibit some conservation efforts. Yet, much useful information can still be openly published without including specific details that could help the nefarious (or misguided) to find a vulnerable species.

There are signs people are beginning to recognise this problem and adapt to it. For example, new species descriptions are now being published without location data or habitat descriptions.

Biologists can take a lesson from other fields such as palaeontology, where important fossil sites are often kept secret to avoid illegal collection. Similar practices are also common in archaeology.

Restricting the open publication of scientifically and socially important information brings its own challenges, and we don’t have all the answers. For example, the dilemma of organising secure databases to collate data on a global scale remains unresolved.

For the most part, the move towards making research freely available is positive; encouraging collaboration and driving new discoveries. But legal or academic requirements to publish location data may be dangerously out of step with real-life risks.

The ConversationBiologists have a centuries-old tradition of publishing information on rare and endangered species. For much of this history it was an innocuous practice, but as the world changes, scientists must rethink old norms.

Benjamin Scheele, Postdoctoral Research Fellow in Ecology, Australian National University and David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University

This article was originally published on The Conversation. 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.

The bark side: domestic dogs threaten endangered species worldwide



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A feral dog chasing a wild boar, Banni grasslands, India.
Chetan Misher/Facebook

Tim Doherty, Deakin University; Aaron J. Wirsing, University of Washington; Chris Dickman, University of Sydney; Dale Nimmo, Charles Sturt University; Euan Ritchie, Deakin University, and Thomas Newsome, Deakin University

Humans and their canine companions share many close bonds. Wolves (Canis lupus) were the first animal domesticated by people, some time between 15,000 and 50,000 years ago. The Conversation

There are now an estimated 1 billion domestic dogs across their near-global distribution.

Domestic dogs include feral and free-ranging animals (such as village and camp dogs), as well as those that are owned by and completely dependent on humans (pet dogs).

Our latest research reveals that the ecological “pawprint” of domestic dogs is much greater than previously realised.

Using the IUCN Red List of Threatened Species, we counted how many species are negatively affected by dogs, assessed the prevalence of different types of impacts, and identified regions with the greatest number of affected species.

A dog with a black-naped hare, Maharashtra, India.
Hari Somashekhar/Facebook

Dogs are third-most-damaging mammal

We found that dogs are implicated in the extinction of at least 11 species, including the Hawaiian Rail and the Tonga Ground Skink. Dogs are also a known or potential threat to 188 threatened species worldwide: 96 mammal, 78 bird, 22 reptile and three amphibian species. This includes 30 critically endangered species, two of which are classed as “possibly extinct”.

These numbers place dogs in the number three spot after cats and rodents as the world’s most damaging invasive mammalian predators.

Even though dogs have an almost global distribution, the threatened species they are known to affect are concentrated in certain parts of the globe. South-East Asia, South America, Central America and the Caribbean each contain 28 to 30 threatened species impacted by dogs. Other hotspots include Australia, Micro/Mela/Polynesia and the remainder of Asia.

Lethal and non-lethal impacts

Predation was the most commonly reported impact of dogs on wildlife. The typically omnivorous diet of dogs means they have strong potential to affect a diversity of species. For instance, dogs killed at least 19 endangered Kagu (a ground-dwelling bird) in New Caledonia in 14 weeks. Threatened species with small population sizes are particularly vulnerable to such intense bouts of predation.

The frequency of different types of dog impact on threatened species.
https://authors.elsevier.com/a/1Uxs~1R~e71Xl

Aside from simply killing animals, dogs can harm wildlife in other ways, such as by spreading disease, interbreeding with other canids, competing for resources such as food or shelter, and causing disturbances by chasing or harassment. For example, contact with domestic dogs increases disease risk for endangered African Wild Dogs in Kenya.

Part of the problem is that when wild animals perceive dogs as a threat, they may change their behaviour to avoid them. One study near Sydney found that dog walking in parklands and national parks reduced the abundance and species richness of birds, even when dogs were restrained on leads.

None of the Red List assessments mentioned such indirect risk effects, which suggests that their frequency is likely to be much higher than reported.

Feral dogs chasing Indian wild ass at Little Rann of Kutch, India.
Kalyan Varma/Facebook

Friend and foe

Despite their widespread and sometimes severe impacts on biodiversity, dogs can also benefit some species and ecosystems.

For example, in Australia, the closely related dingo (Canis dingo) can suppress populations of introduced predators such as red foxes (Vulpes vulpes), and in doing so can benefit smaller native prey. It is possible that domestic dogs could perform similar ecological roles in some situations.

In some regions, dogs and their keen noses have been trained to help scientists find threatened species such as Tiger Quolls. Elsewhere they are helping to flush out and control feral cats.

An emerging and exciting conservation role for dogs is their growing use as “guardian animals” for wildlife, with the remarkable story of Oddball being the most well known.

Managing the problem

Dogs not only interact with wildlife, but can also attack and spread disease to humans, livestock and other domestic animals. As such, managing the problem requires looking at ecological, cultural and social perspectives.

Some of the regions with high numbers of species threatened by dogs are also hotspots for urbanisation and road building, which make it easier for dogs to access the habitats of threatened species. Urban development increases food waste, which feeds higher numbers of dogs. As dogs expand into new areas, the number of species they impact is likely to grow.

Street dogs scavenging food waste in India.
Achat1234/wikimedia

We can protect wildlife by integrating human health and animal welfare objectives into dog management. Vaccination and desexing campaigns can reduce disease risk and overpopulation problems. We should also focus on responsible dog ownership, removing dogs without owners, and reducing access to food waste.

Given the close relationship between humans and dogs, community engagement should form the basis of any management program. More research is needed to get a better picture of the scale of the problem, and of how dogs interact with other threats such as habitat loss. Such actions are critically important for ensuring the conservation of wildlife threatened by dogs around the world.


This article was co-authored by Dr Al Glen from Landcare Research, New Zealand and Dr Abi Vanak from the Ashoka Trust for Research in Ecology and the Environment, India. These institutions had no role in the design or funding of this research.

Tim Doherty, Research Fellow, Deakin University; Aaron J. Wirsing, Assistant Professor, School of Environmental and Forest Sciences, University of Washington; Chris Dickman, Professor in Terrestrial Ecology, University of Sydney; Dale Nimmo, ARC DECRA Fellow, Charles Sturt University; Euan Ritchie, Senior Lecturer in Ecology, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University, and Thomas Newsome, Fulbright Scholar and Postdoctoral Research Fellow, Deakin University

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

Climate-driven species on the move are changing (almost) everything


Gretta Pecl, University of Tasmania; Adriana Vergés, UNSW; Ekaterina Popova, National Oceanography Centre, and Jan McDonald, University of Tasmania

Last year in Paris, for the very first time, English sparkling wine beat champagne in a blind tasting event. Well established French Champagne houses have started buying fields in Britain to grow grapes, and even the royal family is investing in this new venture. The Conversation

At the same time, coffee-growing regions are shrinking and shifting. Farmers are being forced to move to higher altitudes, as the band in which to grow tasty coffee moves up the mountain.

The evidence that climate change is affecting some of our most prized beverages is simply too great to be ignored. So while British sparkling wine and the beginning of the “coffeepocalypse” were inconceivable just a few decades ago, they are now a reality. It’s unlikely that you’ll find many climate deniers among winemakers and coffee connoisseurs. But there are far greater impacts in store for human society than disruptions to our favourite drinks.

Dramatic examples of climate-mediated change to species distributions are not exceptions; they are fast becoming the rule. As our study published last week in the journal Science shows, climate change is driving a universal major redistribution of life on Earth.

Documented and predicted changes in species distribution are occurring all over the globe.
Pecl et al. 2017

These changes are already having serious consequences for economic development, livelihoods, food security, human health, and culture. They are even influencing the pace of climate change itself, producing feedbacks to the climate system.

Species on the move

Species have, of course, been on the move since the dawn of life on Earth. The geographical ranges of species are naturally dynamic and fluctuate over time. But the critical issue here is the magnitude and rate of climatic changes for the 21st century, which are comparable to the largest global changes in the past 65 million years. Species have often adapted to changes in their physical environment, but never before have they been expected to do it so fast, and to accommodate so many human needs along the way.

For most species – marine, freshwater, and terrestrial species alike – the first response to rapid changes in climate is a shift in location, to stay within their preferred environmental conditions. On average, species are moving towards the poles at 17km per decade on land and 78km per decade in the ocean. On land, species are also moving to cooler, higher elevations, while in the ocean some fish are venturing deeper in search of cooler water.

Why does it matter?

Different species respond at different rates and to different degrees, with the result that new ecological communities are starting to emerge. Species that had never before interacted are now intermingled, and species that previously depended on one another for food or shelter are forced apart.

Why do changes in species distribution matter?

This global reshuffling of species can lead to pervasive and often unexpected consequences for both biological and human communities. For example, the range expansion of plant-eating tropical fish can have catastrophic impacts by overgrazing kelp forests, affecting biodiversity and important fisheries.

In wealthier countries these changes will create substantial challenges. For developing countries, the impacts may be devastating.

Knock-on effects

Many changes in species distribution have implications that are immediately obvious, like the spread of disease vectors such as mosquitoes or agricultural pests. However, other changes that may initially appear more subtle can also have great effects via impacting global climate feedbacks.

Mangroves, which store more carbon per unit area than most tropical forests, are moving towards the poles. Spring blooms of microscopic sea algae are projected to weaken and shift into the Arctic Ocean, as the global temperature rises and the seasonal Arctic sea ice retreats. This will change the patterns of “biological carbon sequestration” over Earth’s surface, and may lead to less carbon dioxide being removed from the atmosphere.

Redistribution of the vegetation on land is also expected to influence climate change. With more vegetation, less solar radiation is reflected back into the atmosphere, resulting in further warming. “Greening of the Arctic”, where larger shrubs are taking over from mosses and lichens, is expected to substantially change the reflectivity of the surface.

These changes in the distribution of vegetation are also affecting the culture of Indigenous Arctic communities. The northward growth of shrubs is leading to declines in the low-lying mosses and lichens eaten by caribou and reindeer. The opportunities for Indigenous reindeer herding and hunting are greatly reduced, with economic and cultural implications.

Reindeer in the Arctic are very important components of Indigenous and traditional ways of life.
Snowchange 2016 /Tero Mustonen

Winners and losers

Not all changes in distribution will be harmful. There will be winners and losers for species, and for the human communities and economic activities that rely on them. For example, coastal fishing communities in northern India are benefiting from the northward shift in the oil sardine’s range. In contrast, skipjack tuna is projected to become less abundant in western areas of the Pacific, where many countries depend on this fishery for economic development and food security.

Local communities can help forge solutions to these challenges. Citizen science initiatives like Redmap are boosting traditional scientific research and can be used as an early indication of how species distributions are changing. Having local communities engaged in such participatory monitoring can also increase the chances of timely and site-specific management interventions.

Even with improved monitoring and communication, we face an enormous challenge in addressing these changes in species distribution, to reduce their adverse impacts and maximise any opportunities. Responses will be needed at all levels of governance.

Internationally, the impacts of species on the move will affect our capacity to achieve virtually all of the United Nations Sustainable Development Goals, including good health, poverty reduction, economic growth, and gender equity.

Currently, these goals do not yet adequately consider effects of climate-driven changes in species distributions. This needs to change if we are to have any chance of achieving them in the future.

National development plans, economic strategies, conservation priorities, and supporting policies and governance arrangements will all need to be recalibrated to reflect the realities of climate change impacts on our natural systems. At the regional and local levels, a range of responses may be needed to enable affected places and communities to survive or thrive under new conditions.

For communities, this might include changed farming, forestry or fishing practices, new health interventions, and, in some cases, alternative livelihoods. Management responses such as relocating coffee production will itself have spillover effects on other communities or natural areas, so adaptation responses may need to anticipate indirect effects and negotiate these trade-offs.

To promote global biodiversity, protected areas will need to be managed to explicitly recognise novel ecological communities, and to promote connectivity across the landscape. For some species, managed relocations or direct interventions may be needed. Our commitment to conservation will need to be reflected in funding levels and priorities.

The success of human societies has always depended on the living components of natural and managed systems. For all our development and modernisation, this hasn’t changed. But human society has yet to appreciate the full implications for life on Earth, including human lives, of our current unprecedented climate-driven species redistribution. Enhanced awareness, supported by appropriate governance, will provide the best chance of minimising negative consequences while maximising opportunities arising from species movements.

Gretta Pecl, Deputy Associate Dean Research, ARC Future Fellow & Editor in Chief (Reviews in Fish Biology & Fisheries), University of Tasmania; Adriana Vergés, Senior Lecturer in marine ecology, UNSW; Ekaterina Popova, Senior Scientist, ocean modelling, National Oceanography Centre, and Jan McDonald, Professor of Environmental Law, University of Tasmania

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

How Australia’s animals and plants are changing to keep up with the climate



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Flora and fauna can adapt to climate change, but some are more successful than others.
allstars/shutterstock

Ary Hoffmann, University of Melbourne

Climate change is one of the greatest threats facing Australia’s wildlife, plants and ecosystems, a point driven home by two consecutive years of mass coral bleaching on the Great Barrier Reef. The Conversation

Yet among this growing destruction there is a degree of resilience to climate change, as Australian animals and plants evolve and adapt.

Some of this resilience is genetic, at the DNA level. Natural selection favours forms of genes that help organisms withstand hotter and drier conditions more effectively.

Over time, the environmental selection for certain forms of genes over others leads to genetic changes. These genetic changes can be complex, involving many genes interacting together, but they are sufficient to make organisms highly tolerant to extreme conditions.

Some of this resilience is unrelated to DNA. These are “plastic” changes – temporary changes in organisms’ physical and biochemical functions that help them deal with adverse conditions or shifts in the timing of environmental events.

Plastic changes occur more quickly than genetic changes but are not permanent – the organisms return to their previous state once the environment shifts back. These changes also may not be enough to protect organisms from even more extreme climates.

What about Australia?

In Australia there is evidence of both genetic and plastic adaptation.

Some of the first evidence of genetic adaptation under climate change have been in vinegar flies on the east coast of Australia. These flies have a gene that encodes the enzyme alcohol dehydrogenase. This gene has two major forms: the tropical form and the temperate form. Over the past 30 years, the tropical form of the gene has become more common at the expense of the temperate one.

Plastic adaptation due to climate change has been demonstrated in common brown butterflies in southern Australia. Female butterflies are emerging from their cocoons earlier as higher temperatures have been speeding up their growth and development by 1.6 days every decade. According to overseas research, this faster development allows butterfly caterpillars to take advantage of earlier plant growth.

Higher temperatures are causing the common brown butterflies in southern Australia to come out of their cocoons earlier.
John Tann/Wikimedia Commons, CC BY-SA

In many cases, it is not clear if the adaptation is genetic or plastic.

The average body size of Australian birds has changed over the the past 100 years. Usually, when comparing birds of the same species, birds from the tropics are smaller than those from temperate areas. In several widespread species, however, the birds from temperate areas have recently become smaller. This might be the direct result of environmental changes or a consequence of natural selection on the genes that affect size.

In the case of long-lived species like eucalypts, it is hard to see any adaptive changes. However, there is evidence from experimental plots that eucalypts have the potential to adapt.

Different eucalypt species from across Australia were planted together in experimental forestry plots located in various environments. These plots have unwittingly become climate change adaptation experiments. By monitoring the plots, we can identify species that are better at growing and surviving in extreme climatic conditions.

Plot results together with other forms of DNA-based evidence indicate that some trees unexpectedly grow and survive much better, and are therefore likely to survive into the future.

What’s next?

We still have much to learn about the resilience of our flora and fauna.

There will always be species with low resilience or slow adaptive ability. Nevertheless, plastic and genetic changes can provide some resilience, which will change the predictions of likely losses in biodiversity.

Much like how our worst weeds and pests adapted to local climate conditions, as demonstrated many years ago, our local plants and animals will also adapt.

Species with short generation times – a short time between one generation (the parent) and the next (the offspring) – are able to adapt more quickly than species with longer lifespans and generation times.

For species with short generation times, recent models suggest that the ability to adapt may help reduce the impacts of climate change and decrease local extinction rates.

However, species with long generation times and species that cannot easily move to more habitable environments continue to have a high risk of extinction under climate change.

In those cases, management strategies, such as increasing the prevalence of gene forms helpful for surviving extreme conditions and moving species to locations to which they are better adapted, can help species survive.

Unfortunately, this means doing more than simply protecting nature, the hallmark of our biodiversity strategy to date. We need to act quickly to help our animals and plants adapt and survive.

Ary Hoffmann, Professor, School of BioSciences and Bio21 Institute, University of Melbourne

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