Biowealth

24 02 2016

frogWhile I’ve blogged about this before in general terms (here and here), I thought it wise to reproduce the (open-access) chapter of the same name published in late 2013 in the unfortunately rather obscure book The Curious Country produced by the Office of the Chief Scientist of Australia. I think it deserves a little more limelight.

As I stepped off the helicopter’s pontoon and into the swamp’s chest-deep, tepid and opaque water, I experienced for the first time what it must feel like to be some other life form’s dinner. As the helicopter flittered away, the last vestiges of that protective blanket of human technological innovation flew away with it.

Two other similarly susceptible, hairless, clawless and fangless Homo sapiens and I were now in the middle of one of the Northern Territory’s largest swamps at the height of the crocodile-nesting season. We were there to collect crocodile eggs for a local crocodile farm that, ironically, has assisted the amazing recovery of the species since its near-extinction in the 1960s. Removing the commercial incentive to hunt wild crocodiles by flooding the international market with scar-free, farmed skins gave the dwindling population a chance to recover.

redwoodConservation scientists like me rejoice at these rare recoveries, while many of our fellow humans ponder why we want to encourage the proliferation of animals that can easily kill and eat us. The problem is, once people put a value on a species, it is usually consigned to one of two states. It either flourishes as do domestic crops, dogs, cats and livestock, or dwindles towards or to extinction. Consider bison, passenger pigeons, crocodiles and caviar sturgeon.

As a conservation scientist, it’s my job not only to document these declines, but to find ways to prevent them. Through careful measurement and experiments, we provide evidence to support smart policy decisions on land and in the sea. We advise on the best way to protect species in reserves, inform hunters and fishers on how to avoid over-harvesting, and demonstrate the ways in which humans benefit from maintaining healthy ecosystems. Read the rest of this entry »





How things have (not) changed

13 04 2015

The other night I had the pleasure of dining with the former Australian Democrats leader and senator, Dr John Coulter, at the home of Dr Paul Willis (Director of the Royal Institution of Australia). It was an enlightening evening.

While we discussed many things, the 84 year-old Dr Coulter showed me a rather amazing advert that he and several hundred other scientists, technologists and economists constructed to alert the leaders of Australia that it was heading down the wrong path. It was amazing for three reasons: (i) it was written in 1971, (ii) it was published in The Australian, and (iii) it could have, with a few modifications, been written for today’s Australia.

If you’re an Australian and have even a modicum of environmental understanding, you’ll know that The Australian is a Murdochian rag infamous for its war on science and reason. Even I have had a run-in with its outdated, consumerist and blinkered editorial board. You certainly wouldn’t find an article like Dr Coulter’s in today’s Australian.

More importantly, this 44 year-old article has a lot today that is still relevant. While the language is a little outdated (and sexist), the grammar could use a few updates, and there are some predictions that clearly never came true, it’s telling that scientists and others have been worrying about the same things for quite some time.

In reading the article (reproduced below), one could challenge the authors for being naïve about how society can survive and even prosper despite a declining ecological life-support system. As I once queried Paul Ehrlich about some of his particularly doomerist predictions from over 50 years ago, he politely pointed out that much of what he predicted did, in fact, come true. There are over 1 billion people today that are starving, and another billion or so that are malnourished; combined, this is greater than the entire world population when Paul was born.

So while we might have delayed the crises, we certainly haven’t averted them. Technology does potentially play a positive role, but it can also increase our short-term carrying capacity and buffer the system against shocks. We then tend to ignore the indirect causes of failures like wars, famines and political instability because we do not recognise the real drivers: resource scarcity and ecosystem malfunction.

Australia has yet to learn its lesson.

To Those Who Shape Australia’s Destiny

We believe that western technological society has ignored two vital facts: Read the rest of this entry »





Earth’s second lung has emphysema

19 02 2015
© WWF

© WWF

Many consider forests as the ‘lungs’ of the planet – the idea that trees and other plants take up carbon and produce oxygen (the carbon and oxygen cycles). If we are to be fair though, the oceans store about 93% of the Earth’s carbon pool (excluding the lithosphere and fossil fuels) and oceanic phytoplankton produces between 50 and 80% of the oxygen in the atmosphere. For comparison, the terrestrial biosphere – including forests – stores only about 5% of the Earth’s carbon, and produces most of the remainder of atmospheric oxygen.

So there’s no denying that the biggest player in these cycles is the ocean, but that’s not the topic of today’s post. Instead, I’m going to focus on the terrestrial biosphere, and in particular, the carbon storage and flux of forests.

Now it’s pretty well established that tropical forests are major players in the terrestrial carbon cycle, with the most accepted estimates of about 55% the terrestrial carbon stock stored therein. The extensive boreal forest, covering most of the northern half of North America, most of Scandinavia and a huge chunk of Russia, comes in globally at about 33%, and temperate forests store most of the remainder.

That is, until now. Read the rest of this entry »





What’s in a name? The dingo’s sorry saga

30 01 2015

bad dingoThe more I delve into the science of predator management, the more I realise that the science itself takes a distant back seat to the politics. It would be naïve to think that the management of dingoes in Australia is any more politically charged than elsewhere, but once you start scratching beneath the surface, you quickly realise that there’s something rotten in Dubbo.

My latest contribution to this saga is a co-authored paper led by Dale Nimmo of Deakin University (along with Simon Watson of La Trobe and Dave Forsyth of Arthur Rylah) that came out just the other day. It was a response to a rather dismissive paper by Matt Hayward and Nicky Marlow claiming that all the accumulated evidence demonstrating that dingoes benefit native biodiversity was somehow incorrect.

Their two arguments were that: (1) dingoes don’t eradicate the main culprits of biodiversity decline in Australia (cats & foxes), so they cannot benefit native species; (2) proxy indices of relative dingo abundance are flawed and not related to actual abundance, so all the previous experiments and surveys are wrong.

Some strong accusations, for sure. Unfortunately, they hold no water at all. Read the rest of this entry »





It’s all about the variation, stupid

12 01 2015

val-1-3It is one of my long-suffering ecological quests to demonstrate to the buffoons in government and industry that you can’t simply offset deforestation by planting another forest elsewhere. While it sounds attractive, like carbon offsetting or even water neutrality, you can’t recreate a perfectly functioning, resilient native forest no matter how hard you try.

I’m not for a moment suggesting that we shouldn’t reforest much of what we’ve already cut down over the last few centuries; reforestation is an essential element of any semblance of meaningful terrestrial ecological restoration. Indeed, without a major commitment to reforestation worldwide, the extinction crisis will continue to spiral out of control.

What I am concerned about, however, is that administrators continue to push for so-called ‘biodiversity offsets’ – clearing a forest patch here for some such development, while reforesting or even afforesting another degraded patch there. However, I’ve blogged before about studies, including some of my own, showing that one simply cannot replace primary forests in terms of biodiversity and long-term carbon storage. Now we can add resilience to that list.

While I came across this paper a while ago, I’ve only found the time to blog about it now. Published in PLoS One in early December, the paper Does forest continuity enhance the resilience of trees to environmental change?1 by von Oheimb and colleagues shows clearly that German oak forests that had been untouched for over 100 years were more resilient to climate variation than forests planted since that time. I’ll let that little fact sink in for a moment … Read the rest of this entry »





Using ecological theory to make more money

1 12 2014

huge.9.46974Let’s face it: Australia doesn’t have the best international reputation for good ecological management. We’ve been particularly loathsome in our protection of forests, we have an appalling record of mammal extinctions, we’re degenerate water wasters and carbon emitters, our country is overrun with feral animals and weeds, and we have a long-term love affair with archaic, deadly, cruel, counter-productive and xenophobic predator management. To top it all off, we have a government hell-bent on screwing our already screwed environment even more.

Still, we soldier on and try to fix the damages already done or convince people that archaic policies should be scrapped and redrawn. One such policy that I’ve written about extensively is the idiocy and cruelty of the dingo fence.

The ecological evidence that dingoes are good for Australian wildlife and that they pose less threat to livestock than purported by some evidence-less graziers is becoming too big to ignore any longer. Poisoning and fencing are not only counter-productive, they are cruel, ineffective and costly.

So just when ecologists thought that dingoes couldn’t get any cooler, out comes our latest paper demonstrating that letting dingoes do their thing results in a net profit for cattle graziers.

Come again? Read the rest of this entry »





It’s not all about cats

20 10 2014

Snake+OilIf you follow any of the environment news in Australia, you will most certainly have seen a lot about feral cats in the last few weeks. I’ve come across dozens of articles in the last week alone talking about the horrendous toll feral cats have had on Australian wildlife since European arrival. In principle, this is a good thing because finally Australians are groggily waking to the fact that our house moggies and their descendants have royally buggered our biodiversity. As a result, we have the highest mammal extinction rate of any country.

But I argue that the newfound enthusiasm for killing anything feline is being peddled mainly as a distraction from bigger environmental issues and to camouflage the complete incompetence of the current government and their all-out war on the environment.

Call me cynical, but when I read headlines like “Australia aims to end extinction of native wildlife by 2020” and Environment Minister Hunt’s recent speech that he has “… set a goal of ending the loss of mammal species by 2020“, I get more than just a little sick to the stomach.

What a preposterous load of shite. Moreover, what a blatant wool-pulling-over-the-eyes public stunt. Read the rest of this entry »





High-altitude ecology

28 08 2014
A constant hazard in the Tibetan Plateau - yakjam

A constant hazard in the Tibetan Plateau – yakjam

I’ve been out of the social-media loop for a few weeks, hence the abnormally long interval since my last post. As you might recall, I’ve been travelling overseas and most recently blogged from Monterey, California where I was attending a symposium on invasion genetics.

The next phase of my travels couldn’t have been more different.

The reason I couldn’t access the blog was because I was well behind the Great Firewall of China. I was, in fact, in the Tibetan region of Gansu and Sichuan Provinces in western China for most of the last 10 days. While I’ve travelled to China many times before, this was by far the most evocative, interesting and unique experience I’ve ever had in this country. Reflecting on the past 10 days while waiting in Hong Kong for my flight back to Australia, I am still reeling a little from what I saw.

Top bloke: Jiajia Liu of Fudan University

Top bloke: Jiajia Liu of Fudan University

What the hell was I doing at 3500-4000 m elevation on the Tibetan Plateau? Good question. I have been most fortunate to be included in a crack team of Chinese ecologists who have designed and implemented a most impressive set of experiments in plant community ecology. The team, led by Professor Shurong Zhou and Dr. Jiajia Lui of Fudan University, has been working relentlessly to put together some of the sexiest plant ecology experiments going in China.

Having now so far published two papers from the some of the experiments (see here and here), my Chinese colleagues thought it was high time I visited the famous site. Situated at 3500 m in the Tibetan region of Gansu Province in western China, the Lanzhou University research station Azi Shi Yan Zhan is about a 20-hectare area of meadow fenced off from the grazing of the ubiquitous domestic yaks herded by the local Tibetans. If that sounds pretty exotic, let me assure you that it is. Read the rest of this entry »





A convenient truth: global push for carbon-based conservation

19 05 2014

Eucalyptus viminalis (Manna Gum) - leaf, adultI’ve just written an article for the Australian River Restoration Centre‘s RipRap magazine, and they have given me permission to reproduce it here.

The brave, new green world of the carbon economy hasn’t exactly taken off as desired. Perhaps it’s because it wasn’t really planned from the outset, or maybe it is still too abstract for most people to accept, digest and incorporate into their daily lives. An emergent property of society’s generally slow awakening to the challenge of climate disruption, is that it will be a long time before we accept its full suite of incarnations.

The infant carbon economy is, however, well and truly alive and kicking, so it is important to try and plan for its growing influence on our decision making. Bumps in the road aside, the carbon economy has mostly been a blessing (actual and potential) for biodiversity conservation projects the world over.

In principle, the aim of the carbon economy is rather straight-forward: charge people a certain amount for each unit of carbon dioxide equivalents they release, and then use that money to develop approaches that further increase carbon sequestration or limit emissions. It’s a ‘build-it-and-they-will-come’ framework, where increasing financial impetus to restrict emissions is enhanced by society’s evolution towards better approaches and technology.

The operational side of the carbon economy is unfortunately much more muddled, with vested interests and political gaming weakening its implementation. Nonetheless, we persevere. Read the rest of this entry »





Australian League of Environmental Organisations

6 05 2014
Shades of Green

Shades of Green

ALEO – the acronym has a nice ring to it. Although I must confess that said organisation doesn’t yet exist, but it bloody well should.

Australia is in dire need of a united front to tackle the massive anti-environment sentiment gripping this country’s band of irresponsible and short-sighted libertarian politicians. Only yesterday I was chatting to a student in the tea room about my ‘State of South Australia’s Environment‘ talk when he asked “So, what can we do about it?”. Isn’t that the 1 per cent1 question?

Apart from the obvious: (1) keep up the pressure on bad government plans (petitions, letters, blogs, reports, e-mails), (2) don’t vote for the Coalition and (3) if you’re a scientist, place some economic or well-being value on environmental processes so that even politicians can understand that maintaining ecosystems makes good economic sense, I almost casually mentioned that we need a united front in Australia against this latest right-wing wave of anti-environmentalism.

I’ve thought about this before, but my latest conversation got me reflecting on the problem a little more – why don’t we have a united league of environmental organisations in Australia? Read the rest of this entry »





South Australia’s tattered environmental remains

16 04 2014
State budget percentage expenditures for health, education and environment

South Australia State budget percentage expenditures for health, education and environment

Yesterday I gave the second keynote address at the South Australia Natural Resource Management (NRM) Science Conference at the University of Adelaide (see also a brief synopsis of Day 1 here). Unfortunately, I’m missing today’s talks because of an acute case of man cold, but at least I can stay at home and work while sipping cups of hot tea.

Many people came up afterwards and congratulated me for “being brave enough to tell the truth”, which both encouraged and distressed me – I am encouraged by the positive feedback, but distressed by the lack of action on the part of our natural resource management leaders.

The simple truth is that South Australia’s biodiversity and ecosystems are in shambles, yet few seem to appreciate this.

So for the benefit of those who couldn’t attend, I’ve uploaded the podcast of my slideshow for general viewing here. I’ve also highlighted some key points from the talk below: Read the rest of this entry »





Lose biodiversity and you’ll get sick

14 03 2014

dengueHere’s a (paraphrased) recommendation I did recently for F1000 about a cool avenue of research I’ve been following for a few years now. Very interesting, but much, much more to do.

The core concepts of conservation ecology are well-established: we know that habitat lossfragmentation, invasive species, over-exploitation and of course, climate change, are bad for biodiversity. This well-quantified scientific baseline has led the discipline recently to embark on questions pertaining more to the (a) implications of biodiversity loss for humanity and (b) what we can do to offset these. A recent paper by Morand and colleagues addresses perhaps one of the most compelling reasons that human society should appreciate biodiversity beyond its intrinsic value; as biodiversity degrades, so too does human health.

Some argue that the only way to convince society in general that biodiversity is worth protecting is that we link its loss directly to degrading human health, wealth and well-being. Confirmation of such relationships at a variety of spatial and temporal scales is therefore essential. Morand and colleagues used data from a variety of sources to test two predictions: (1) that the number of infectious disease should increase as overall biodiversity increases and (2) that biodiversity loss, inferred from species threat and deforestation data, should increase the number of infectious disease outbreaks in humans. Using data from 28 countries in the Asia-Pacific region, they confirmed both predictions. Read the rest of this entry »





Incentivise to keep primary forests intact

7 02 2014

The Amazon rainforest. Photo by Rhett A. Butler

I know – ‘incentivise’ is one of those terrible wank words of business speak. But to be heard by the economically driven, one must learn their guttural and insensitive language. I digress …

Today’s post is merely a repost of an interview I did for the new Mongabay.com series ‘Next Big Idea in Forest Conservation‘. I’m honoured to have been selected for an interview along with the likes of Bill Laurance and Stuart Pimm.

Consider this my conservation selfie.

An Interview with Corey Bradshaw

Mongabay.com: What is your background?

Corey Bradshaw: I have a rather eclectic background in conservation ecology. I grew up in the wilds of western Canada, the son of a trapper. My childhood experiences initially gave me a primarily consumptive view of the environment from trapping, fishing and hunting, but I learned that without intact environmental functions, these precious resources quickly degrade or disappear. This ironic appreciation of natural processes would later lead me into academia and the pursuit of reducing the rate of the extinction crisis.

I completed my first degrees in ecology in Montréal and the University of Alberta, followed by a PhD in New Zealand at the University of Otago. After deciding to pursue the rest of my career in the Southern Hemisphere, I completed my postdoctoral fellowship at the University of Tasmania. Multiple field seasons in the subantarctic and Antarctica probably assisted in a giving me a burgeoning desire to change gears, so I left for the tropics of northern Australia to begin a position at Charles Darwin University. Being introduced there to conservation greats like Navjot Sodhi (sadly, now deceased), Barry Brook and David Bowman turned my research interests on their ear. I quickly became enamoured with quantitative conservation ecology, applying my skills in mathematics to the plight of the world’s ecosystems. Nowhere did the problems seem more intractable than in the tropics.

I am now based at the University of Adelaide (since 2008) and have a vibrant research lab where we apply our quantitative skills to everything from conservation ecology, climate change, energy provision, human population trends, ecosystem services, sustainable agriculture, human health, palaeoecology, carbon-based conservation initiatives and restoration techniques.

Mongabay.com: How long have you worked in tropical forest conservation and in what geographies? What is the focus of your work? Read the rest of this entry »





Essential role of carnivores on the wane

10 01 2014
© Luca Galuzzi www.galuzzi.it

© Luca Galuzzi http://www.galuzzi.it

This interesting review has just come out in Science, and because I was given a heads-up about it, I decided to do a F1000 recommendation. That’s more or less what follows, with some additional thoughts.

Ripple and colleagues can perhaps be excused for stating what might appear to many ‘in the biz’ to be blatantly obvious, but their in-depth review of the status of the world’s carnivores is a comprehensive overview of this essential guild’s worldwide plight. It not only represents an excellent teaching tool, the review elegantly summarises the current status of these essential ecosystem engineers.

The world’s 245 terrestrial carnivores might seem to be ecologically redundant to the informed given their natural rarity, low densities and cryptic behaviour, but nothing could be farther from the truth. Ecologists have only within the last decade or so revealed the essential ecosystem functions of these species (see former posts on CB.com here, here and here). The review focuses on the largest and most well-studied species, but the trends likely apply across most of the order. Read the rest of this entry »





More species = more resilience

8 01 2014

reef fishWhile still ostensibly ‘on leave’ (side note: Does any scientist really ever take a proper holiday? Perhaps a subject for a future blog post), I cannot resist the temptation to blog about our lab’s latest paper that just came online today. In particular, I am particularly proud of Dr Camille Mellin, lead author of the study and all-round kick-arse quantitative ecologist, who has outdone herself on this one.

Today’s subject is one I’ve touched on before, but to my knowledge, the relationship between ‘diversity’ (simply put, ‘more species’) and ecosystem resilience (i.e., resisting extinction) has never been demonstrated so elegantly. Not only is the study elegant (admission: I am a co-author and therefore my opinion is likely to be biased toward the positive), it demonstrates the biodiversity-stability hypothesis in a natural setting (not experimental) over a range of thousands of kilometres. Finally, there’s an interesting little twist at the end demonstrating yet again that ecology is more complex than rocket science.

Despite a legacy of debate, the so-called diversity-stability hypothesis is now a widely used rule of thumb, and its even implicit in most conservation planning tools (i.e., set aside areas with more species because we assume more is better). Why should ‘more’ be ‘better’? Well, when a lot of species are interacting and competing in an ecosystem, the ‘average’ interactions that any one species experiences are likely to be weaker than in a simpler, less diverse system. When there are a lot of different niches occupied by different species, we also expect different responses to environmental fluctuations among the community, meaning that some species inherently do better than others depending on the specific disturbance. Species-rich systems also tend to have more of what we call ‘functional redundancy‘, meaning that if one species providing an essential ecosystem function (e.g., like predation) goes extinct, there’s another, similar species ready to take its place. Read the rest of this entry »





Biowealth: all creatures great and small

4 12 2013

Curious Country flyer“So consider the crocodiles, sharks and snakes, the small and the squirmy, the smelly, slimy and scaly. Consider the fanged and the hairy, the ugly and the cute alike. The more we degrade this astonishing diversity of evolved life and all its interactions on our only home, the more we expose ourselves to the ravages of a universe that is inherently hostile to life.”

excerpt from ‘Biowealth: all creatures great and small’ The Curious Country (C.J.A. Bradshaw 2013).

I’ve spent the last few days on the east coast with my science partner-in-crime, Barry Brook, and one of our newest research associates (Marta Rodrigues-Rey Gomez). We first flew into Sydney at sparrow’s on Monday, then drove a hire car down to The ‘Gong to follow up on some Australian megafauna databasing & writing with Bert Roberts & Zenobia Jacobs. On Tuesday morning we then flitted over to Canberra where we had the opportunity to attend the official launch of a new book that Barry and I had co-authored.

The book, The Curious Country, is an interesting experiment in science communication and teaching dreamed up by Australia’s Chief Scientist, Professor Ian Chubb. Realising that the average Aussie has quite a few questions about ‘how stuff works’, but has little idea how to answer those questions, Ian engaged former Quantum star and science editor, Leigh Dayton, to put together a short, punchy, topical and easily understood book about why science is good for the country.

Yes, intuitive for most of you out there reading this, but science appreciation isn’t always as high as it should be amongst the so-called ‘general public’. Ian thought this might be one way to get more people engaged.

When honoured with the request to write an interesting chapter on biodiversity for the book, I naturally accepted. It turns out Barry was asked to do one on energy provision at the same time (but we didn’t know we had both been asked at the time). Our former lab head, Professor David Bowman, was also asked to write a chapter about fire risk, so it was like a mini-reunion yesterday for the three of us.

Read the rest of this entry »





Science immortalised in cartoon Version 2.0

24 09 2013

© Seppo Leinonen

I’m in the middle of participating in a short-course on science communication based at the University of Helsinki‘s Lammi Biological Station (about 1.5 hours north of Helsinki by car). Organised by two fantastic people, Mar Cabeza and Tomas Roslin, it’s an eclectic mix of instruction for (mainly) PhD students on how to promote yourself and your science in print, in media, in illustration, in citizen science and for policy makers.

While we aren’t yet finished, I wanted to report that I had the immense pleasure of finally meeting the immeasurably talented environmental cartoonist, Seppo Leinonen. Not only is he an extremely talented artist and a dedicated environmentalist, he’s just a top bloke.

If you haven’t checked out Seppo.net and his cartoons yet, you should.

This is just a brief post to spruik his fine work, and show off his parting cartoon gift to me: Read the rest of this entry »





Conservation: So easy a child could do it

13 09 2013

child's playI don’t like to talk about my family online. Call me paranoid, but there are a lot of crazy people out there who don’t like what scientists like me are saying (bugger the evidence). Yes, like many climate scientists, I’ve also been threatened. That’s why my personal life remains anonymous except for a select group of people.

But I’ve mentioned my daughter before on this blog, and despite a few people insinuating that I am a bad parent because of what I said, I am happy that I made the point that climate change is a scary concept of which our children must at least be cognisant.

My daughter’s story today is a little less confronting, but equally enlightening. It’s also a little embarrassing as a scientist who has dedicated my entire research career to the discipline of conservation biology.

As a normal six year-old without the ability to refrain from talking – even for a moment – I hear a lot of stories. Many of them are of course fantastical and ridiculous, but those are just part of a healthy, imaginative childhood (I am proud to say though that she is quite clear about the non-existence of fictitious entities like faeries, easter bunnies and gods).

Every once in a while, however, there are snippets of wisdom that ooze out from the cracks in the dross. In the last few months, my daughter has independently and with no prompting from me come up with two pillars of conservation science: (i) protected areas and (ii) biodiversity corridors. Read the rest of this entry »





Fast-lane mesopredators

29 07 2013

Another post from Alejandro Frid (a modified excerpt from a chapter of his forthcoming book).

I fall in love easy. Must be my Latino upbringing. Whatever it is, I have no choice on the matter. So for five years and counting, I have been passionate about lingcod (Ophiodon elongatus) and rockfish (Sebastes spp.), upper- and mid-level predatory fishes on rocky reefs of the Northeast Pacific.

Lingcod are beautiful and fierce. Rockfish are cosmic. Both taste mighty good and—surprise, surprise—have been overfished to smithereens throughout much of their range. Howe Sound, my field site near Vancouver, British Columbia, is no exception, although new protective legislation might be starting to give them some slack.

Our dive surveys1 and earlier studies, in combination, have pieced together a story of ecosystem change. In the Howe Sound of today, lingcod rarely exceed body lengths of 80 cm. But up to 30 years ago, when overfishing had yet to inflict the full extent of its current damage, lingcod with lengths of 90 to 100 cm had been common in the area. There is nothing unique about this; most fisheries target the biggest individuals, ultimately reducing maximum body size within each species of predatory fish.

As predators shrink, the vibrant tension of predation risk slips away. The mechanism of change has a lot to do with mouth size. Predatory fishes swallow prey whole, usually head or tail first, so it is impossible for them to eat prey bigger than the width and height of their open jaws. And bigger fishes have bigger jaws, which makes them capable not only of consuming larger prey, but also of scaring bigger prey into using antipredator behaviours, such as hiding in rocky crevices. As predators shrink, big prey enter a size refuge and only small prey remain at risk, which can alter trophic cascades and other indirect species interactions. Read the rest of this entry »





Our national parks must be more than playgrounds or paddocks

24 05 2013

Convo TweetsIt’s interesting when a semi-random tweet by a colleague ends up mobilising a small army of scientists to get pissed off enough to co-write an article. Euan Ritchie of Deakin University started it off, and quickly recruited me, Mick McCarthy, David Watson, Ian Lunt, Hugh Possingham, Bill Laurance and Emma Johnston to put together the article. It’s a hugely important topic, so I hope it generates a lot of discussion and finally, some bloody action to stop the rapid destruction of this country’s national parks system.

Note: Published simultaneously on The Conversation.

It’s make or break time for Australia’s national parks.

National parks on land and in the ocean are dying a death of a thousand cuts, in the form of bullets, hooks, hotels, logging concessions and grazing licences. It’s been an extraordinary last few months, with various governments in eastern states proposing new uses for these critically important areas.

Australia’s first “National Park”, established in 1879, was akin to a glorified country club. Now called the “Royal National Park” on the outskirts of Sydney, it was created as a recreational escape for Sydney-siders, with ornamental plantations, a zoo, race courses, artillery ranges, livestock paddocks, deer farms, logging leases and mines.

Australians since realised that national parks should focus on protecting the species and natural landscapes they contain. However, we are now in danger of regressing to the misguided ideals of the 19th Century.

Parks under attack

In Victoria, new rules will allow developers to build hotels and other ventures in national parks. In New South Wales, legislation has been introduced to allow recreational shooting in national parks, and there is pressure to log these areas too. Read the rest of this entry »