Want to work with us?

22 03 2013
© Beboy-Fotolia

© Beboy-Fotolia

Today we announced a HEAP of positions in our Global Ecology Lab for hot-shot, up-and-coming ecologists. If you think you’ve got what it takes, I encourage you to apply. The positions are all financed by the Australian Research Council from grants that Barry Brook, Phill Cassey, Damien Fordham and I have all been awarded in the last few years. We decided to do a bulk advertisement so that we maximise the opportunity for good science talent out there.

We’re looking for bright, mathematically adept people in palaeo-ecology, wildlife population modelling, disease modelling, climate change modelling and species distribution modelling.

The positions are self explanatory, but if you want more information, just follow the links and contacts given below. For my own selfish interests, I provide a little more detail for two of the positions for which I’m directly responsible – but please have a look at the lot.

Good luck!

CJA Bradshaw

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Job Reference Number: 17986 & 17987

The world-leading Global Ecology Group within the School of Earth and Environmental Sciences currently has multiple academic opportunities. For these two positions, we are seeking a Postdoctoral Research Associate and a Research Associate to work in palaeo-ecological modelling. Read the rest of this entry »


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Categories : alien species, Australia, biodiversity, climate change, conservation, conservation biology, demography, disease, environmental science, extinction, harvest, invasive species, population dynamics, population viability analysis, PVA, science, scientific writing, stochasticity, synergies, The University of Adelaide, threatened species

The biggest go first

11 12 2012
© James Cameron

© James Cameron

The saying “it isn’t rocket science” is a common cliché in English to state, rather sarcastically, that something isn’t that difficult (with the implication that the person complaining about it, well, shouldn’t). But I really think we should change the saying to “it isn’t ecology”, for ecology is perhaps one of the most complex disciplines in science (whereas rocket science is just ‘complicated’). One of our main goals is to predict how ecosystems will respond to change, yet what we’re trying to simplify when predicting is the interactions of millions of species and individuals, all responding to each other and to their outside environment. It becomes quickly evident that we’re dealing with a system of chaos. Rocket science is following recipes in comparison.

Because of this complexity, ecology is a discipline plagued by a lack of generalities. Few, if any, ecological laws exist. However, we do have an abundance of rules of thumb that mostly apply in most systems. I’ve written about a few of them here on ConservationBytes.com, such as the effect of habitat patch size on species diversity, the importance of predators for maintaining ecosystem stability, and that low genetic diversity doesn’t exactly help your chances of persisting. Another big one is, of course, that in an era of rapid change, big things tend to (but not always – there’s that lovely complexity again) drop off the perch before smaller things do.

The prevailing wisdom is that big species have slower life history rates (reproduction, age at first breeding, growth, etc.), and so cannot replace themselves fast enough when the pace of their environment’s change is too high. Small, rapidly reproducing species, on the other hand, can compensate for higher mortality rates and hold on (better) through the disturbance. Read the rest of this entry »


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Categories : alien species, Australia, biodiversity, climate change, conservation, decline, deforestation, disease, ecology, ecosystem function, exploitation, extinction, fisheries, fragmentation, genetic diversity, genetics, habitat loss, harvest, logging, rain forests, synergies

Native invaders divide loyalties

7 09 2012

California sea lion at Bonneville fish ladder. Credit: U.S. National Oceanic and Atmospheric Administration

As if to mimic the weirder and weirder weather human-caused climate disruption is cooking up for us, related science stories seem to come in floods and droughts. Yes, research trends become fashionable too (imagine a science fashion show? – but I digress…).

Only yesterday, the ABC published an opinion piece on the controversies surrounding which species we call ‘native’ and ‘invasive’ (based on a recent paper published in Global Ecology and Biogeography), and in June this year, Salvador Herrando-Pérez wrote a great little article on the topic entitled “The invader’s double edge“.

Then today, I received a request to publish a guest post here on ConservationBytes.com from Lauren Kuehne, a research scientist in Julian Olden‘s lab at the University of Washington in Seattle. The topic? Why, the controversies surrounding invasive species, of course! Lauren’s following article demonstrates yet again that it’s not that simple.

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A drawback to the attention garnered by high-profile invasive species is the tendency to infer that every non-native species is bad news, the inverse assumption being that all native species must be ‘good’. While this storyline works well for Hollywood films and faerie tales, in ecology the truth is rarely that simple. A new review article in the September issue of Frontiers in Ecology and the Environment, describes the challenges and heartbreaks when native species run amok in the sense of having negative ecological impacts we typically associate with non-native species. Examples in the paper range from unchecked expansions of juniper trees in sagebrush ecosystems with wildfire suppression, to overgrazing by elk (wapiti) released from predation following the removal of wolves and mountain lions. Read the rest of this entry »


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Categories : alien species, climate change, conservation, fish, invasive species, management, threatened species, USA

Degraded States of Ausmerica

20 08 2012

You might remember that I’ve been in California for several weeks now. The principal reason for my visit was to finish a book that Paul Ehrlich and I started last year. So, without the major distractions of everyday university life, I’ve spent much of my time lately at Stanford University in a little office next to Paul’s trying to finish (I also attended a conference in Portland, Oregon).

Yesterday, we wrote the last few paragraphs. A giant gorilla has now lumbered its way off my back.

So. What is the book about, you might ask? I can’t give away too many details, but I will give a few teasers. The book is called, at least for now, ‘Oz & US’, which is a bit of a play of words. In the book we contrast the environmental histories, current state of affairs, and likely futures of our respective nations. It’s written in a popular style so that non-specialists can learn a little something about how bad the environment has become in our two countries.

At first glance, one might wonder why we chose to contrast the U.S. and Australia – they are quite different beasts, indeed. Their histories are immensely different, from the aboriginal populations, through to European colonisation (timing and drivers), biological (including agricultural) productivities, carrying capacities, population sizes and politics. But these differences belie too many convergences in the environmental states of each nation – we now both have increasingly degraded environments, we have both pushed the boundaries of our carrying capacities, and our environmental politics are in a shambles. In other words, despite having started with completely different conditions, our toll on nature’s life-support systems is now remarkably similar.

And anyone who knows Paul and me will appreciate that the book is completely irreverent. We have taken off the gloves in preparation for a bare-knuckle fight with the plutocrats and theocrats now threatening the lives of our grandchildren. We pull no punches here. Read the rest of this entry »


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Categories : alien species, anthropocene, Australia, biodiversity, climate change, conservation, economics, ecosystem services, environmental economics, environmental policy, environmental science, exploitation, habitat loss, human overpopulation, poverty, synergies, The University of Adelaide, USA

Global Ecology postgraduate opportunities

12 08 2012

I should have published these ages ago, but like many things I have should have done earlier, I didn’t.

I also apologise for a bit of silence over the past week. After coming back from the ESP Conference in Portland, I’m now back at Stanford University working with Paul Ehrlich trying to finish our book (no sneak peaks yet, I’m afraid). I have to report that we’ve completed about about 75 % it, and I’m starting to feel like the end is in sight. We hope to have it published early in 2013.

So here they are – the latest 9 PhD offerings from us at the Global Ecology Laboratory. If you want to get more information, contact the first person listed as the first supervisor at the end of each project’s description.

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1. Optimal survey and harvest models for South Australian macropods (I’ve advertised this before, but so far, no takers):

The South Australia Department of Environment, Water and Natural Resources (DEWNR) is custodian of a long-term macropod database derived from the State’s management of the commercial kangaroo harvest industry. The dataset entails aerial survey data for most of the State from 1978 to present, annual population estimates, quotas and harvests for three species: red kangaroo (Macropus rufus), western grey kangaroo (Macropus fuliginosus), and the euro (Macropus robustus erubescens).

DEWNR wishes to improve the efficiency of surveys and increase the precision of population estimates, as well as provide a more quantitative basis for setting harvest quotas.

We envisage that the PhD candidate will design and construct population models:

  • to predict population size/densities with associated uncertainty, linking fluctuations to environmental variability (including future climate change projections)
  • to evaluate the efficiency of spatially explicit aerial surveys
  • to estimate demographic parameters (e.g., survival rate) from life tables and
  • to estimate spatially explicit sustainable harvest quotas

 Supervisors: me, A/Prof. Phill Cassey, Dr Damien Fordham, Dr Brad Page (DEWNR), Professor Michelle Waycott (DEWNR).

2. Correcting for the Signor-Lipps effect

The ‘Signor-Lipps effect’ in palaeontology is the notion that the last organism of a given species will never be recorded as a fossil given the incomplete nature of the fossil record (the mirror problem is the ‘Jaanusson effect’, where the first occurrence is delayed past the true time of origination). This problem makes inference about the timing and speed of mass extinctions (and evolutionary diversification events) elusive. The problem is further complicated by the concept known as the ‘pull of the recent’, which states that the more time since an event occurred, the greater the probability that evidence of that event will have disappeared (e.g., erased by erosion, hidden by deep burial, etc.).

In a deep-time context, these problems confound the patterns of mass extinctions – i.e., the abruptness of extinction and the dynamics of recovery and speciation. This PhD project will apply a simulation approach to marine fossil time series (for genera and families, and some individual species) covering the Phanerozoic Aeon, as well as other taxa straddling the K-T boundary (Cretaceous mass extinction). The project will seek to correct for taphonomic biases and assess the degree to which extinction events for different major taxa were synchronous.

The results will also have implications for the famous Sepkoski curve, which describes the apparent logistic increase in marine species diversity over geological time with an approximate ‘carrying capacity’ reached during the Cenozoic. Despite recent demonstration that this increase is partially a taphonomic artefact, a far greater development and validation/sensitivity analysis of underlying statistical models is needed to resolve the true patterns of extinction and speciation over this period.

The approach will be to develop a series of models describing the interaction of the processes of speciation, local extinction and taphonomic ‘erasure’ (pull of the recent) to simulate how these processes interact to create the appearance of growth in numbers of taxa over time (Sepkoski curve) and the abruptness of mass extinction events. The candidate will estimate key parameters in the model to test whether the taphonomic effect is strong enough to be the sole explanation of the apparent temporal increase in species diversity, or whether true diversification accounts for this.

Supervisors: me, Prof. Barry Brook

3. Genotypic relationships of Australian rabbit populations and consequences for disease dynamics

Historical evidence suggests that there were multiple introduction events of European rabbits into Australia. In non-animal model weed systems it is clear that biocontrol efficacy is strongly influenced by the degree of genetic diversity and number of breed variants in the population.

The PhD candidate will build phylogenetic relationships for Australian rabbit populations and develop landscape genetic models for exploring the influence of myxomatosis and rabbit haemorrhagic disease virus (RHDV) on rabbit vital rates (survival, reproduction and dispersal) at regional and local scales. Multi-model synthesis will be used to quantify the relative roles of environment (including climate) and genotype on disease prevalence and virulence in rabbit populations.

Supervisors: A/Prof Phill Cassey, Dr Damien Fordham, Prof Barry Brook Read the rest of this entry »


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Categories : alien species, Australia, conservation, conservation biology, disease, environmental science, health, invasive species, kangaroo, mathematics, niche model, population dynamics, science, South Australia, The University of Adelaide

The invisible hand of ecosystem services

4 08 2012

I’ve just spent nearly an entire week trying to get my head around ecosystem services (ES).

You’d think that would have been a given based on my experience, my research, my writings and the fact that I’ve just spent the last week with 400 ES specialists from around the world at the 5th international Ecosystem Services Partnership (ESP) Conference in Portland, Oregon, USA.

Well, prior to this week I thought I knew what ES were, but now I think I’m just a little more confused.

Of course, I’m not talking about the concept of ES or what they are (hell, I’ve written enough about them on this blog and in my papers); my problem is understanding how we as society end up valuing them in a practical, sensible and feasible way.

So I’m going to describe the ESP Conference as I saw it, and not necessarily in chronological order.

First up is the term ‘ecosystem services’ itself – horrible name, and something rammed home again after attending the conference. Most people on the planet that are not scientists (that would be nearly everyone) just might have the most tenuous and ethereal of grasps of ‘ecosystem’ in the first place, and I’d bet that 99 % of most undergraduate students couldn’t provide a comprehensive description. This is because ecosystems are mind-bogglingly, chaotically and awesomely complex. Just ask any ecosystem ecologist.

The second part of the term – services – is particularly offensive in its presumption and arrogance. It’s not like you ring up an ecosystem and get it to clean your carpets, or fill your water tank or gas cylinder. No, the natural world did not evolve to pamper humanity; we are merely part of it (and bloody efficient at modifying it, I might add).

So try to sell this ‘incredibly complex thingy’ that is ‘there to do some (intangible) shit for us’ to the public, policy makers and politicians, and you mostly get a dog’s regurgitated breakfast and some blank, slack-jawed stares. Read the rest of this entry »


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Categories : agriculture, alien species, biocarbon, biosequestration, carbon, carbon trading, conference, conservation, deforestation, economics, ecosystem, ecosystem services, environmental economics, environmental policy, fisheries, flood, food, harvest, health, invasive species, investment, logging

Threats to biodiversity insurance from protected areas

26 07 2012

A red-eyed tree frog (Agalychnis callidryas) from Barro Colorado Island in Panama. This small island, just 1500 ha (3700 acres) in area, is one of the tropical protected areas evaluated in this study (photo © Christian Ziegler <zieglerphoto@yahoo.co>, Smithsonian Tropical Research Institute). Note: It is prohibited for any third party or agency to use or license this image; any use other then described above shall be subject to usage fees as determined solely by the photographer.

Much of conservation science boils down to good decision making: when, where and how we ‘set aside’ terrestrial or marine areas for specific protection against the ravages of human endeavour. This is the basis for the entire sub-discipline of conservation planning and prioritisation, and features prominantly in most aspects of applied conservation and restoration.

In other words, we do all this science to determine where we should emplace protected areas, lobby for getting more land and sea set aside so that we have ‘representative’ amounts (i.e., to prevent extinctions), and argue over the best way to manage these areas once established.

But what if this pinnacle of conservation achievement is itself under threat? What if many of our protected areas are struggling to insure biodiversity against human consumption? Well, it’d be a scary prospect, to say the least.

Think of it this way. We buy insurance policies to buffer our investments against tragedy; this applies to everything from our houses, worldly possessions, cars, livestock, health, to forest carbon stores. We buy the policies to give us peace of mind that in the event of a disaster, we’ll be bailed out of the mess with a much-needed cash injection. But what if following the disaster we learn that the policy is no good? What if there isn’t enough pay-out to fix the mess?

In biodiversity conservation, our ‘insurance’ is largely provided by protected areas. We believe that come what may, at least in these (relatively) rare places, biodiversity will persist despite our relentless consumerism.

Unfortunately, what we believe isn’t necessarily true.

Today I’m both proud and alarmed to present our latest research on the performance of tropical protected areas around the world. Published online in Nature this morning (evening, for you Europeans) is the 216-author (yes, that is correct – 216 of us) paper entitled “Averting biodiversity collapse in tropical forest protected areas” led by Bill Laurance. Read the rest of this entry »


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Categories : Africa, alien species, Amazon, amphibian, Asia, biodiversity, conservation, conservation biology, decline, deforestation, disease, environmental policy, fire, fragmentation, governance, habitat loss, harvest, human overpopulation, invasive species, logging, monitoring, predator, protected area, rain forests, reserve, South America

The invader’s double edge

15 06 2012

The Ogasawara Archipelago (Bonin Islands,) encompasses several tens of small islands ~ 1000 km from mainland Japan. In 2011, UNESCO declared this archipelago a World Heritage Site. Some regard them as the “Galapagos of the Orient”, owing to their biological singularity, e.g., endemism rates of ~ 50 % of > 500 species of plants, or ~ 90 % of > 100 species of terrestrial snails. Photos show patches of native scrub (left) and introduced sheoak forest (right), close-ups of the two study species Ogasawarana discrepans (left) and O. optima (right), and empty shells with (top right, bottom) and without (top left) rat scars (Courtesy of Satoshi Chiba).

Another great post by Salvador Herrando-Pérez that challenges our views on invasive species (some would do well to heed his words when it comes to species like dingos). I mentioned in his last post that he had just recently submitted his PhD thesis, and now I’m proud to say that it has been examined with no recommended changes required. What a truly rare accolade. Congratulations, Salva.

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A blunt instrument of ecological restoration is the elimination of introduced species. However, when introduced species become custodians of native wildlife, a dilemma emerges between re-establishing historical ecosystem conditions or instead, accepting foreign species for the benefits they might also bring.

Right after birth, we all enter a culture where what is ‘good’ or ‘bad’ has already been determined. Later on, if those values remain unchallenged, individuals assume them to be true and act accordingly (which is neither ‘good’ nor ‘bad’ necessarily… it is just so). Science is therefore the only recourse humans have to check such values by  reducing the subjectivity of our judgements about why natural phenomena occur.

But scientists also work in a context of ‘pre-established truths’ (because, believe it or not, most of us are human too). The late Larry Slobodkin referred to our professional biases as ‘reifications’; i.e.,

“…reification consists of accepting a designation as if it has empirical meaning when, in fact, its existence has either never been tested or it has been found empty” (1).

Slobodkin underlined invasive species as an icon of reification. Indeed, people (with and without a scientific background) tend to demonise species that are not native and extremely abundant – experts even debate whether this is another sort of xenophobia (2). Thus, zebra mussels (Dreissena polymorpha), cane toads (Rhinella marinus) or caulerpa algae (Caulerpa taxifolia) are commonly referred to as ‘alien’, ‘invasive’ or ‘noxious’. Technically, we now call them ‘biological pollution’ (3). Such epithets are loaded with moral and pejorative connotations to qualify organisms that affect the range of facets of human well-being (aesthetics, economy, ethics, health). Read the rest of this entry »


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Categories : alien species, conservation, ecosystem function, function, invasive species

Give way to the invader

25 01 2012

By weird coincidence, Salvador Herrando-Pérez (student blogger extra-ordinaire – see his previous posts on evolution, pollination, bird losses, taxonomic inflation, niche conservatism, historical biogeography, ecological traps and ocean giants) has produced a post this week expanding on the problem of roads. Also weirdly coincidental is that both Salva and I are in his home country of Spain this week.

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Australia’s > 800,000-km road network would go 60 times around the equator of our planet. Confined to the boundaries of any one country, roads are a conspicuous component of the landscape, and shape the dispersion, survival and reproduction of many plants and animals in urban and remote areas.

Those who drive (or are driven by) will be familiar with the image of a crushed kangaroo on the roadside (a hedgehog in Europe), or the sticky mosaic of insects smashed against the windscreen after a high-speed run. Mortality by collision is one of the many effects that roads can have on the demography of organisms – including humans. Those effects encompass

  • physical alteration of terrestrial and aquatic habitats,
  • chemical pollution leakage during road construction and maintenance, and from asphalt compounds during storms,
  • alteration of animal behaviour (e.g., change in home range, or in patterns of flight or vocalisation),
  • access to remote areas by hunters, fishermen and gatherers in general, and
  • intense habitat fragmentation1-3.

However, some species get around those negative impacts by using the roads as pathways to new territories, thereby eluding barriers like seas, mountains, rivers, dense vegetation, or competition for vital resources with other species. Read the rest of this entry »


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Categories : alien species, Australia, conservation, demography, environmental engineering, environmental policy, evolution, fragmentation, invasive species, management, predator, temperate, tropical

Surgical conservation: gain requires some pain

21 12 2011

© 2008-2011 ~Hiuki http://fav.me/d1j3ns9

I apologise to CB readers for the unusually low frequency of posts this month. With the International Congress for Conservation Biology taking up a lot of my time earlier this month, and the standard palaver of xmas preparations (i.e., getting shit done before the end of the year), I’m afraid the blog has taken a back seat. Now officially ‘on leave’ (whatever that means for an academic), I have found a brief window during which I can put a few thoughts together.

For this post I must take you back to October 2011 when, if you were in Australia, you might have heard about the so-called ‘debacle‘ of the Macquarie Island rabbit/rate/mouse-eradication programme in which it was identified that a few thousand seabirds had become the collateral damage.

To recap, an intense poisoning programme was initiated on subantarctic Macquarie Island to eradicate these pests after years of massive environmental degradation had finally forced the government’s (of Tasmania and the Commonwealth) hand to do something. What caught my eye in all this was the sheer stupidity and politicking associated with the programme, in which hyper-conservative Eric Abetz (Liberal Senator for Tasmania) managed to turn this amazing success into a Labor-bashing political sledge-hammer.

Abetz is no stranger to anti-environmentalism and fights vehemently for Tasmania’s forest-raping industry; he considers political parties such as the Greens, environmental groups such as The Wilderness Society and pro-democracy groups such as Get Up! his mortal enemies. He’s even had a go at esteemed author Richard Flanagan for supporting the anti-deforestation movement in Tasmania! Read the rest of this entry »


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Categories : alien species, Australia, conservation, environmental policy, extinction, invasive species, management, research, science

Know thy threat

9 06 2011

Here’s another great guest post by Megan Evans of UQ – her previous post on resolving the environmentalist’s paradox was a real hit, so I hope you enjoy this one too.

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The reasons for the decline of Australia’s unique biodiversity are many, and most are well known. Clearing of vegetation for urban and agricultural land uses, introduced species and changed fire patterns are regularly cited in State of the Environment reports, recovery plans and published studies as major threats to biodiversity. But, while these threats are widely acknowledged, little has been done to quantify them in terms of the proportion of species affected, or their spatial extent at a national, state or local scale. To understand why such information on threats may be useful, consider for instance how resources are allocated in public health care1.

Threat knowledge

Conditions such as cancer, heart disease and mental health are regarded as National Health Priority Areas in Australia, and have been given special attention when prioritising funds since the late 1980s. The burden of disease in these priority areas are quantified according to the incidence or prevalence of disease or condition, and its social and economic costs. Estimates of burden of disease and their geographic distribution (often according to local government areas) can assist in communicating broad trends in disease burden, but also in prioritising efforts to achieve the best outcomes for public health. An approach similar to that used in healthcare could help to identify priorities for biodiversity conservation – using information on the species which are impacted by key threats, the spatial distributions of species and threats, and the costs of implementing specific management actions to address these threats. Read the rest of this entry »


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Categories : alien species, Australia, biodiversity, conservation, deforestation, environmental policy, extinction, fire, fox, habitat loss, harvest, health, invasive species, planning, threatened species

The evil sextet

18 05 2011

This post doubles as a Conservation Classic and a new take on an old concept. It’s new in the sense that it updates what we believe is an advance on a major milestone in conservation biology, even though some of the add-on concepts themselves have been around for a while.

First, the classic.

The ‘evil quartet’, or ‘four horsemen of the ecological apocalypse’, was probably the first treatment of extinction dynamics as a biological discipline in its own right. Jarod Diamond (1984) took a sweeping historical and contemporary view of extinction, then simplified the problem to four principal mechanisms:

  1. overhunting (or overexploitation),
  2. introduced species,
  3. habitat destruction and
  4. chains of linked extinctions (trophic cascades, or co-extinctions).

Far from a mere review or list of unrelated mechanisms, Diamond’s evil quartet crystallized conservation biologists’ thinking about key mechanisms and, more importantly, directed attention towards those factors likely to drive extinctions in the future. The unique combination of prehistorical through to modern examples gave conservation biologists a holistic view of extinction dynamics and helped spawn many of the papers described hereafter. Read the rest of this entry »


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Categories : alien species, anthropocene, biodiversity, bushmeat, climate change, conservation, decline, deforestation, exploitation, extinction, habitat loss, harvest, invasive species, threatened species

生态学 = ‘Ecology’ in China

13 05 2011

I’m just heading home after a very inspiring workshop organised by Fangliang He at Sun Yat-sen University in Guangzhou, China (I’m writing this from the Qantas Club in the Hong Kong airport).

Before I proceed to regale you with the salient details of the ‘International Symposium for Biodiversity and Theoretical Ecology‘, I am compelled to state publicly that I offer my sincerest condolences to Fangliang and his family; unfortunately Fangliang’s brother passed away while we were at the workshop and so Fangliang wasn’t able to spend much time reaping the fruits of his organisational labour. If you know Fangliang, please send him a supporting email.

That sad note aside, I am delighted to say that the workshop was compelling, challenging and also rather fortuitous. I was one of many overseas invitees, and I must say that I was at times overwhelmed by the size of the brains they managed to pack into the auditorium. Many colleagues I didn’t know attended, and I hope that many will become collaborators. The international invitees were: Read the rest of this entry »


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Categories : alien species, biodiversity, biogeography, China, climate change, conference, demography, ecology, ecosystem function, extinction, invasive species, mathematics, modelling, neutral theory, niche model, population dynamics, speciation, tropical

Government pulls plug on Asian honeybee eradication

3 03 2011

Here’s another one from the bee man, Tobias Smith (PhD candidate at the University of Queensland). Tobias recently blogged about bee basics here on ConservationBytes.com (something I highly recommend for anyone interested on brushing up on bee facts and dispelling a few myths), so I asked him to follow up with this very important piece on the future of pollination in Australia. It concerns a nasty little invader recently dubbed the “flying cane toad” (not my analogy).

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http://www.flickr.com/photos/angela-and-andrew/1196369580/in/faves-lornet/

© 中國蜂

Over the last few weeks there has been much media attention given to the Asian honeybee (Apis cerana) incursion in far north Queensland. The Asian honeybee was first detected near Cairns in May 2007. Since then an effort to eradicate the bee has been made. This peaked during 2010, when over 40 bee eradication personnel were employed to hunt and destroy in areas around Cairns, the Atherton Tablelands, and other nearby locations.

In late January this year, the committee established to manage the eradication program (governments and industry), decided to pull the plug on eradication efforts (on money to pay for efforts that is). They decided it was no longer possible to achieve eradication (a majority decision, not a unanimous decision). The position to stop resources for eradication is not supported by industry, or ecological commentators. Arguments have been made that this is the only window of opportunity for eradication (for ever!), and that more resources need to be put towards it now, while there is still a chance of success.

A few points to be made about the Asian honeybee in Australia: Read the rest of this entry »


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Categories : alien species, biodiversity, conservation, disease, ecosystem function, ecosystem services, invasive species, pollination

Invaders beware

1 11 2010

Recently, the Global Ecology Group at the University of Adelaide has had the immense privilege and pleasure of welcoming a new senior member to the fold – Dr. Phill Cassey. The slightly Pommefied-Kiwi-Now-Coming-To-Terms-With-Being-Australian ;-)  represents a wonderful new addition to our lab’s expertise and vision.

Phill is a distinguished Australian Research Council Future Fellow. He conducts research on the subject of human contributions to changes in biodiversity through the dual processes of species extinction and introduction. Phill’s research encompasses a broad range of analytical and applied skills and has led to significant advances in the discipline of global change biology.

Phill has also hit the ground running here in Adelaide, and now offers two PhD projects for people interested to work at the forefront of invasive species research in Australia. Students will be members of the School for Earth and Environmental Sciences, which includes world-class researchers in the disciplines of Ecology and Evolutionary Biology and Global Ecology as well as ongoing research links with the South Australian Museum, Adelaide Zoo, and State Herbarium of South Australia. Successful candidates will be part of a strong research group with a highly successful and innovative culture of scientific communication and study. Read the rest of this entry »


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Categories : alien species, Australia, climate change, conservation, conservation biology, invasive species, The University of Adelaide

Ecosystem functions breaking down from climate change

17 05 2010

I’m particularly proud to present to ConservationBytes.com readers a new paper we’ve just had published online in Journal of Animal Ecology: Mechanisms driving change: altered species interactions and ecosystem function through global warming (Lochran Traill, Matt Lim, Navjot Sodhi and me).

It wasn’t easy to write a review discussing climate change effects on biodiversity, mainly because so many have been written already and we needed to examine the issue from a fresh perspective. The evidence for single species’ responses to rapidly shifting climates around the world is overwhelming (see for a few thousand examples, see the following: Stenseth et al. 2002; Parmesan et al. 2003, 2006; Roessig et al. 2004; Thomas et al. 2004; Poloczanska et al. 2007; Skelly et al. 2004; Dunn et al. 2009). It’s rather remarkable how many things are moving in response, with reduction in range size being more common than expansion.

However, predicting extinction risk from climate change is far more problematic because traditionally there have been too few data on species interactions to make heads or tails of a particular species’ eventual response (e.g., see comment on Chris Thomas’ famous paper regarding this matter). As systems heat up, some species will change in abundance, thereby affecting the abundance of others (think predators and prey, pollinators and their host plants, etc.) – this whole complicated process combined with single-species’ responses makes predicting what a future ecosystem might look like nearly impossible. Add in all the other ecosystem damage we’ve done from forest clearance, invasive species and over-harvesting, it’s a right mess.

It is for this reason we focussed on reviewing the links between species rather than on the species’ responses per se. We looked specifically at ecosystem function, that is, “the processes that facilitate energy transfer along food webs, and the major processes that allow the cycling of carbon, oxygen and nitrogen. ‘Function’ also includes ecosystem services.” Read the rest of this entry »


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Categories : alien species, bioclimatic envelope, biodiversity, climate change, climate shift, conservation, ecosystem function, ecosystem services

Fanciful mathematics and ecological fantasy

3 05 2010

© flickr/themadlolscientist

Bear with me here, dear reader – this one’s a bit of a stretch for conservation relevance at first glance, but it is important. Also, it’s one of my own papers so I have the prerogative :-)

As some of you probably know, I dabble quite a bit in population dynamics theory, which basically means examining the mathematics people use to decipher ecological patterns. Why is this important? Well, most models predicting extinction risk, estimating optimal harvest rates, determining minimum viable population size and metapopulation dynamics for species’ persistence rely on good mathematical abstraction to be realistic. Get the maths wrong, and you could end up overharvesting a species (e.g., 99.99 % of fisheries management), underestimating extinction risk from habitat degradation, and getting your predictions wrong about the effects of invasive species. Expressed as an equation itself, (conservation) ecology = mathematics.

A long-standing family of models known as ‘phenomenological’ models (i.e., because they deal with the phenomenon of population size which is an emergent property of the mechanisms of birth, death and immigration) has been used to estimate everything from maximum sustainable yield targets, temporal abundance patterns, wildlife management interventions, extinction risk to epidemiological patterns. The basic form of the model describes the growth response, or the relationship between the population’s rate of change (growth) and its size. The simplest form (known as the Ricker), assumes a linear decline in population growth rate (r) as the number of individuals increases, which basically means that populations can’t grow indefinitely (i.e., they fluctuate around some carrying capacity if unperturbed). Read the rest of this entry »


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Categories : alien species, conservation, demography, exploitation, extinction, fisheries, harvest, invasive species, management, metapopulation, minimum viable population, modelling, mvp, population dynamics, population viability analysis, PVA

Classics: Mesopredator Release

17 03 2010

© J. Short

Although popularised by Crooks & Soulé (1999), Soulé et al. (1988) first gave us the term that described how entire ecosystems can become unbalanced by a reduction of a higher trophic-level predator exerting so-called ‘top-down’ control on the abundance of species occupying lower trophic levels.

The idea had theoretical support in ecology (Wright et al. 1994; Litvaitis & Villafuerte 1996), but it was not until Soulé and colleagues described how the decline of dominant predators combines with habitat fragmentation to release top-down pressure on smaller predators, thereby increasing predation rates on prey lower down the trophic web.

Crooks & Soulé (1999) described an example where the decline in coyotes (Canis latrans) in combination with urbanisation-driven habitat fragmentation led to an increase in cat (Felis catus) densities and the subsequent decline in scrub-breeding birds. More recent examples attest to the importance of the mesopredator release phenomenon: Myers et al. (2007) described how the decline in large coastal shark species has allowed mesopredator cownose rays (Rhinoptera bonasus) to increase, leading to a reduction in commercially important shellfish densities; and Johnson et al. (2007) showed how dingoes (Canis lupus dingo) in Australia suppress populations of exotic predators such as cats and foxes, leading to more locally abundant populations of native marsupials (see previous post).

Conservation biologists have benefited from this knowledge because we’ve realised that top-order predators affect far more than their immediate prey. These examples really hit home how a fully functional community is required for ecosystem stability, so we should strive to preserve complete complements of communities, not just our favourite species.

CJA Bradshaw

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Categories : alien species, Australia, cat, conservation, exploitation, extinction, fisheries, harvest, invasive species, predator, shark, trophic cascades

Global pollinator declines

11 03 2010

Mention anything about ecosystem services – those ecological functions arising from the interactions between species that provide some benefit (source of food/clean water, health, etc.) to humanity1 – and one of the most cited examples is pollination.

It’s really a no-brainer, hence its popularity as an example. Pollinators (mainly insects, but birds, bats and other assorted species too) don’t exist to pollinate plants; rather, their principal source of food acquisition happens to spread around the gametes of the plants they regularly visit. Evolution has favoured the dependence of species in such ways because the mutualism benefits all involved, and in some cases, this dependence has become obligate. So when the habitats that pollinators need to survive are reduced or destroyed, inevitably their population sizes decline and the plants on which they feed lose their main sources of gene-spreading.

So what? Well, about 80 % of all wild plant species require insect pollinators for fruit and seed set, and about 75 % of all human crops require pollination by insects (mostly bees). So it’s pretty frightening to consider that although our global population is at 6.8 billion and growing rapidly, our main food pollinators (bees) are declining globally (see also previous post on bee declines). Indeed, domestic honey bee stocks have declined in the USA by 59 % since 1947 and in Europe by 25 % since 1985. Scared yet?

Another thing people don’t tend to get is that a bee cannot live on rapeseed alone. Most pollinators require intact forests to complete many of their other life history requirements (breeding, shelter, etc.) and merely forage occasionally in crop lands. Cut down all the adjacent bush, and your crops will suffer accordingly.

These, and other titbits to keep you awake at night and worry about what your grandchildren might eat are highlighted in a recent review in Trends in Ecology and Evolution by Potts and colleagues entitled Global pollinator declines: trends, impacts and drivers.

What’s driving all this loss? Several things, but it’s mainly due to ‘land-use change’ (a bullshit word people use generally to mean habitat loss, fragmentation and degradation). However, invasive species competition, pathogens and parasites, and climate change (and the synergies amongst all of these) are all contributing.

It always amazes me when people ask me why biodiversity is important. Despite the overwhelming knowledge we’ve accumulated about how functioning ecosystems make the planet liveable, despite it just being plainly stupid to think that humans are somehow removed from normal biological processes, and even with such in-your-face examples of global pollinator declines and the real, extremely worrying implication for food supplies, many people just don’t seem to get it. Every tree you cut down, every molecule of carbon dioxide you release, every drop of water you waste will punish you and your family directly for generations to come. How much more self-evident can you get?

Humanity seems to have a very poorly developed sense of self-preservation.

CJA Bradshaw

1It’s amazingly arrogant and anthropocentric to think of anything in ecosystems as ‘providing benefits to humanity’. After all, we’re just another species in a complex array of species within ecosystems – we just happen to be one of the numerically dominant ones, excel at ecosystem ‘engineering’ and as far as we know, are the only (semi-) sentient of the biologicals. Although the concept of ecosystem services is, I think, an essential abstraction to place emphasis on the importance of biodiversity conservation to the biodiversity ignorant, it does rub me a little the wrong way. It’s almost ascribing some sort of illogical religious perspective that the Earth was placed in its current form for our eventual benefit. We might be a fairly new species in geological time scales, but don’t think of ecosystems as mere provisions for our well-being.

ResearchBlogging.orgPotts, S., Biesmeijer, J., Kremen, C., Neumann, P., Schweiger, O., & Kunin, W. (2010). Global pollinator declines: trends, impacts and drivers Trends in Ecology & Evolution DOI: 10.1016/j.tree.2010.01.007

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Categories : agriculture, alien species, biodiversity, climate change, conservation, decline, deforestation, disease, ecosystem function, ecosystem services, habitat loss, invasive species, pollination

Vodcast on killing for conservation

24 02 2010

The inaugural issue of Methods in Ecology and Evolution came out today (see first issue editorial) and I am very pleased not only that our paper (Spatially explicit spreadsheet modelling for optimizing the efficiency of reducing invasive animal density) made it into the the paper line-up (see previous ConservationBytes.com post on the paper here), we also managed to score the journal’s cover image (buffalo image shown right: Asian swamp buffalo Bubalus bubalis introduced to Australia in the early 19th Century now populate much of the tropical north and cause severe environmental disturbances to savanna and wetland ecosystems. Despite a broad-scale cull of hundreds of thousands of free-ranging buffalo occurring in the 1980s and 1990s to eradicate brucellosis and tuberculosis, the population is recovering and continuing to threaten protected areas such as Kakadu National Park. A small wild harvest of several thousand buffalo occurs each year in Arnhem Land where mustering is aided by helicopters and on-ground vehicles. The buffalo pictured are housed in temporary holding pens and then shipped for live export. Photo credit: Jesse Northfield).

I also had the opportunity to chat with Journal Coordinator, Graziella Iossa, via Skype about the paper, and they have put up a YouTube vodcast of the interview itself. You can also check it out here.

Summary: Corey Bradshaw answers what is the main idea behind his work with co-authors, “Spatially explicit spreadsheet modelling for optimising the efficiency of reducing invasive animal density”. Further, he explains how their model advances methodology in ecology and evolution and finally shows how it could be applied by wildlife manager and practitioners with basic knowledge of computer models. Their Excel-spreadsheet ‘Spatio-Temporal Animal Reduction’ (S.T.A.R.) model is designed specifically to optimise the culling strategies for feral pigs, buffalo and horses in Kakadu National Park (northern Australia), but Corey explains how their aim was to make it easy enough for anyone to use and modify it so that it could be applied to any invasive species anywhere.

Congratulations to Editor-in-Chief Rob Freckleton, Graziella and the Associate Editors for a great first issue. Other titles include:

Keep them coming!

CJA Bradshaw

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Categories : alien species, Australia, biodiversity, buffalo, conservation, invasive species, mathematics, modelling, population dynamics, tropical

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