No need for disease

7 01 2013

dead or alive thylacineIt’s human nature to abhor admitting an error, and I’d wager that it’s even harder for the average person (psycho- and sociopaths perhaps excepted) to admit being a bastard responsible for the demise of someone, or something else. Examples abound. Think of much of society’s unwillingness to accept responsibility for global climate disruption (how could my trips to work and occasional holiday flight be killing people on the other side of the planet?). Or, how about fishers refusing to believe that they could be responsible for reductions in fish stocks? After all, killing fish couldn’t possibly …er, kill fish? Another one is that bastion of reverse racism maintaining that ancient or traditionally living peoples (‘noble savages’) could never have wiped out other species.

If you’re a rational person driven by evidence rather than hearsay, vested interest or faith, then the above examples probably sound ridiculous. But rest assured, millions of people adhere to these points of view because of the phenomenon mentioned in the first sentence above. With this background then, I introduce a paper that’s almost available online (i.e., we have the DOI, but the online version is yet to appear). Produced by our extremely clever post-doc, Tom Prowse, the paper is entitled: No need for disease: testing extinction hypotheses for the thylacine using multispecies metamodels, and will soon appear in Journal of Animal Ecology.

Of course, I am biased being a co-author, but I think this paper really demonstrates the amazing power of retrospective multi-species systems modelling to provide insight into phenomena that are impossible to test empirically – i.e., questions of prehistoric (and in some cases, even data-poor historic) ecological change. The megafauna die-off controversy is one we’ve covered before here on ConservationBytes.com, and this is a related issue with respect to a charismatic extinction in Australia’s recent history – the loss of the Tasmanian thylacine (‘tiger’, ‘wolf’ or whatever inappropriate eutherian epithet one unfortunately chooses to apply). Read the rest of this entry »





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 »





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 »





When did it go extinct?

11 01 2012

It was bound to happen. After years of successful avoidance I have finally succumbed to the dark side: palaeo-ecology.

I suppose the delve from historical/modern ecology into prehistory was inevitable given (a) my long-term association with brain-the-size-of-a-planet Barry Brook (who, incidentally, has reinvented his research career many times) and (b) there is no logic to contend that palaeo extinction patterns differ in any meaningful way from modern biodiversity extinctions (except, of course, that the latter are caused mainly by human endeavour).

So while the last, fleeting days of my holiday break accelerate worringly toward office-incarceration next week, I take this moment to present a brand-new paper of ours that has just come out online in (wait for it) Quaternary Science Reviews entitled Robust estimates of extinction time in the geological record.

Let me explain my reasons for this strange departure.

It all started after a few drinks (doesn’t it always) discussing the uncertainties associated with the timing of megafauna extinctions – you might be aware that traditionally there have been two schools of thought on late-Pleistocene extinction pulses: (1) those who think there were mainly caused by massive climate shifts not to dissimilar to what we are experiencing now and (2) those who believe that the arrival of humans into naïve regions lead to a ‘blitzkrieg‘ of hunting and overkill. Rarely do adherents of each stance agree (and sometimes, the ‘debate’ can get ugly given the political incorrectness of inferring that prehistoric peoples were as destructive as we are today – cf. the concept of the ‘noble savage‘). Read the rest of this entry »





Resolving the Environmentalist’s Paradox

7 04 2011

Here’s an extremely thought-provoking guest post by Megan Evans, Research Assistant at the University of Queensland in Kerrie Wilson‘s lab. Megan did her Honours degree with Hugh Possingham and Kerrie, and has already published heaps from that and other work. I met Megan first in 2009 and have been extremely impressed with her insights, broad range of interests and knowledge, and her finely honed grasp of social media in science. Smarter than your average PhD student, without a doubt (and she has even done one yet). Take it away, Megan.

© T. Toles

Resolving the ‘Environmentalist’s Paradox’, and the role of ecologists in advancing economic thinking

Aldo Leopold famously described the curse of an ecological education as “to be the doctor who sees the marks of death in a community that believes itself well and does not want to be told otherwise”. Ecologists do have a tendency for making dire warnings for the future, but for anyone concerned about the myriad of problems currently facing the Earth – climate change, an ongoing wave of species extinctions and impending peak oil, phosphate, water , (everything?) crises – the continued ignorance or ridicule of such warnings can be a frustrating experience. Environmental degradation and ecological overshoot isn’t just about losing cute plants and animals, given the widespread acceptance that long-term human well-being ultimately rests on the ability for the Earth to supply us with ecosystem services.

In light of this doom and gloom, things were shaken up a bit late last year when an article1 published in Bioscience pointed out that in spite of declines in the majority of ecosystem services considered essential to human well-being by The Millenium Ecosystem Assessment (MA), aggregate human well-being (as measured by the Human Development Index) has risen continuously over the last 50 years. Ciara Raudsepp-Hearne and the co-authors of the study suggested that these conflicting trends presented an ‘environmentalist’s paradox’ of sorts – do we really depend on nature to the extent that ecologists have led everyone to believe? Read the rest of this entry »





‘Amplify’ and ‘Lungs’ – William Laurance podcasts

1 04 2010

William Laurance has been here at the University of Adelaide for the past 4 days and has just left. He had a marathon talk-fest while here, and a very full social calendar. I bet he’s happy he’s back home so he can wind down a little.

Just a quick post to provide the links to the podcasts of his two public talks: “Amplify your Voice” and “Lungs of the Planet”, plus a radio interview he did yesterday on ABC.

The first public talk was split into two parts:

  1. How to be more prolific: strategies for writing and publishing scientific papers
  2. Further ways to maximise your scientific impact- interacting with the popular media and how to promote yourself

Part 1 MP3

Part 1 Slideshow

Part 2 MP3

Part 2 Slideshow

The other main talk ‘Lungs of our Planet’ was also in two bits (a more academically orientated one on Monday, and the public lecture on Wednesday):

  1. Emerging Challenges for Environmental Research in the Tropics
  2. Diagnosis critical – the lungs of the planet

Part 1 MP3

Part 1 Slideshow

Part 2 MP3

Part 2 Slideshow

And finally, the radio interview he did on ABC 891 Afternoons with Carole Whitelock (audio file courtesy of ABC 891, Afternoons with Carole Whitelock):

Enjoy!

CJA Bradshaw

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Classics: Extinction from Climate Change

22 03 2010

© A. Wong

Amidst the mildly annoying, yet functionally irrelevant sensationalism of climate change politics, conservation biologists are taking the problem seriously and attempting to predict (and prevent) extinctions arising from a rapidly heating planet (see BraveNewClimate.com‘s excellent summary here, as well as his general category of ‘ecological impacts of climate change‘).

This week’s Conservation Classic describes the first high-impact paper to signal just how bad it biodiversity could fare from climate change alone (ignoring, for the moment, synergies with other drivers of extinction).

From about the 1990s onward, conservation biologists had been accumulating a large number of case studies quantifying the extent to which species had shifted in their geographic ranges, phenology and behaviour in response to a rapidly warming planet (Parmesan & Yohe 2003). Read the rest of this entry »