Classics: Tragedy of the Commons

28 02 2011

Although not a conservation biology paper per se, Hardin’s classic essay (Hardin, 1968) changed the way we think about managing natural resources that lack definitive ownership.

The thesis of the “tragedy of the commons” is that individuals are inherently selfish and usually place their own interests first in using commonly owned resources, thereby resulting in their depletion. Hardin used a hypothetical and simplified situation based on medieval land tenure in Europe (herders sharing a common parcel of land) on which each herder was entitled to graze his cattle. Each herder maximized his gains by putting additional cattle onto the land, even if the carrying capacity of the common was exceeded and overgrazing ensued. The herder, by making an “individually rational decision,” received all the benefits from his cattle, but could in the process deplete the common resource for the entire group. If all herders make such selfish decisions then the common will be depleted, jeopardizing the livelihoods of all.

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Categories : biodiversity, conservation, corruption, environmental economics, fisheries, harvest, human overpopulation

Disaster coming to a coastline near you

24 02 2011

Many of you already know that against all better judgement, the spectacularly audacious Australian Commonwealth government has granted BP offshore drilling rights in our southern waters.

You’d think that with all the evidence that BP is a company that cannot be trusted with this particular form of resource exploitation, we’d be a little bit more discerning when granting exploration permits to them. Apparently not.

In protest and within my rights as an Australian citizen, I wrote to the Minister responsible for the decision, MP Martin Ferguson (Federal Minister for Resources and Energy) to register my protest:

Dear Minister Ferguson,

As an ecologist, academic and citizen, I find it rather astounding that Australia has permitted the deep-sea exploration of oil by BP in our own back garden. The unreasonable environmental risk aside, it simply equates to poor economics – the very real probability of a disaster on the same scale (or larger) than the Gulf of Mexico’s fiasco last year will effectively destroy the commercial fishing and aquaculture industry of our southern coastline overnight. The loss of tourism dollars could arguably exceed even that.

This is most definitely not in Australia’s best interest, and will represent yet another blight on our already poor environmental record (see http://wp.me/phhT4-1cf and http://wp.me/phhT4-Zt). I urge you to reconsider your permission and revoke the licence to drill in our waters. It is a mistake you and your government will regret for decades, and will make the recent flooding disaster in Queensland appear mild in comparison.

Sincerely,
Professor Corey J. A. Bradshaw

I certainly wasn’t expecting the Minister to say suddenly “Oh my. You are right, Prof. Bradshaw. It is a bad decision. I’ll revoke that permission forthwith”, but I was expecting a little bit more than the jumbled form letter I received in reply: Read the rest of this entry »


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Categories : biodiversity, coasts, conservation, corruption, marine

What the hell is a banteng?

21 02 2011

A few years ago (ok, 6 years), ABC‘s Catalyst did a piece on our banteng research programme in Garig Gunak Barlu National Park in the Northern Territory. The show basically talks about the conservation and management conundrum of having a successful feral species in Australia that is also highly endangered in its native range (South East Asia). Do we shoot them all, or legislate them as an endangered species? It’s for Australians to decide.

I finally got around to uploading it on Youtube. I hope I haven’t contravened some copyright law, but I figure after such a lag, no one will care. I await the imminent contradiction from the ABC’s lawyers…

I hope you enjoy.

For the scientific papers arising from the work, see: Read the rest of this entry »


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Categories : Australia, bushmeat, conservation, extinction, harvest, invasive species, management, population dynamics, research, science, tropical

Evolution here and now

17 02 2011

Here’s a guest post from one of my PhD students, Salvador Herrando-Peréz. Salva is working on theoretical aspects of density feedback mechanisms among different species, and is especially eclectic with his interests in biology. Salva regularly contributes to lay natural history magazines, especially in his native tongue Castellano (Spanish), and he is an active member of the Spanish organisation Bioestudios Saganta, a non-profit national organisation fully devoted to scientific research and its popularisation with a focus on biodiversity conservation.

I’ve asked my students to start contributing to ConservationBytes.com, and Salva is leading the charge.

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Evolution evokes ideas such as fossils, geological eras and time scales of hundreds of thousands to millions of years. Only recently have we started to appreciate that such ‘macro-evolution’ is the result of accumulated changes in the morphology and genes of species from one generation to the next: days for HIV strands, months for a planktonic rotifer, or years for a poplar.

The Britons Peter and Rose Mary Grant published in 2002 a 30-year study on Darwin’s finches from Daphne Major (Galapagos, Ecuador) – a popular study organism since Charles Darwin’s Origin of species (Grant & Grant 2002). In such a short period of time, covering only six generations of these granivorous birds, several extreme droughts altered the type and abundance of seeds, and potentially triggered the evolution of body size, and beak shape and size, up to three times (Figure 1). The two biologists from Princeton reveal that:

  1. evolution is reversible – generations of finches experiencing overall increase in body and beak sizes can lead to future generations with smaller sizes (of course within limits; a finch will never develop the beak of a stork or a hummingbird), and
  2. phenological shifts across generations are unpredictable in so far as they respond to random climatic fluctuations – should droughts of contrasting intensity have occurred in different years over the study period, beaks and bodies might have evolved in other particular fashions. Read the rest of this entry »

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Categories : climate shift, conservation, extinction

Classics: Shifting baselines

14 02 2011

The Conservation Classics series will soon be collated and published in a special chapter for the book ‘Biodiversity’ to be published later this year by InTech. The chapter is co-authored by Barry Brook, Navjot Sodhi, Bill Laurance and me. This is a snippet of one ‘classic’ I haven’t yet really covered extensively on ConservationBytes.com.

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Daniel Pauly’s (1995) concept describes the way that changes to a system are measured against baselines which themselves are often degraded versions of the original state of the system. Pauly (1995) originally meant it in a fisheries context, where “… fisheries scientists sometimes fail to identify the correct ‘baseline’ population size (e.g., how abundant a fish species population was before human exploitation) and thus work with a shifted baseline”. It is now considered a mantra in fisheries and marine science (Jackson et al., 2001), but it has been extended to many other conservation issues. Yet, quantifying shifting baselines in conservation is difficult, with little empirical evidence (but see Jackson et al., 2001), despite the logic and general acceptance of its ubiquity by conservation scientists. Read the rest of this entry »


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Categories : conservation, decline, fish, fisheries, marine

More to bees than queens and honey

11 02 2011

Another great guest post, this time from Tobias Smith, a PhD candidate at the University of Queensland’s School of Biological Sciences. Tobias is investigating bee community shifts across a fragmented tropical landscape in far north Queensland, aiming to identify landscape variation in community composition of two important rainforest pollinator groups, bees and flies. I met Tobias a few years ago as part of the Thiaki rainforest reforestation project for which he is doing baseline surveys of bees and flies.

I asked him a while ago to write a ‘primer’ on bees for ConservationBytes.com since so many people really don’t much about the taxon (I include myself in that group). He’s done a brilliant job – everything you wanted to know about bees but were afraid to ask (in 1000 words).

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The frequently reported, gloomy news about bee declines is hard not to notice. Bees are in dire trouble around the world, and this trend has worrying implications for both ecosystems and human food production. As a result, popular media often reports on the plight of bees, regularly reciting the figure of one in three mouthfuls of food being dependent on the work of bees. While bees certainly are in major trouble, it can be easy to misinterpret statements often made in these kind of articles without a little general bee knowledge. So here are a few bee facts that, at the very least, we ecological representatives should be familiar with. This information should help give some perspective when interpreting bee news, and when engaging in exciting bee conversations at the shops.

There are approximately 20,000 bees species globally. Yet when most people think of bees they think of a single species, Apis mellifera, the western honey bee (introduced in most of its range, and also referred to as the European honeybee). This bee is certainly an important bee. It is managed as the usual pollinator of crops requiring biotic pollination, and it makes the honey we usually eat here in the developed world. Some say our domestication of this bee has been an important contributing factor in achieving the level of development that we humans have. There are however, about 19,999 other bee species out there, and most of them are very different to the western honeybee. Read the rest of this entry »


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Categories : Asia, Australia, biodiversity, conservation, disease, ecosystem services, food, pollination, reforestation

Colour-blind sharks

3 02 2011

A few weeks ago I was interviewed on Channel 10 (Adelaide) about some new research coming out of the University of Western Australia regarding shark colour vision.

I’ve received permission from Channel 1o to reproduce the news snippet here. The first bloke interviewed is Associate Professor Nathan Hart, the study‘s lead author. I’m the bald one appearing in the middle at at the end.

It certainly was an interesting story, although two claims were made that probably needed better contextualisation.

First, the authors claim that because of this taxon’s colour blindness, they probably notice pigment transitions more when using visual cues to identify potential prey. What this means is that bright colours set against duller backgrounds might provide that contrast enough to attract sharks. The upshot from the interview is that brightly coloured and patterned togs (bathers) might make sharks think you are potentially a tasty treat. Read the rest of this entry »


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Categories : biodiversity, conservation, exploitation, fish, fisheries, marine, southern Australia


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