It’s not always best to be the big fish

3 02 2016

obrien_fish_2Loosely following the theme of last week’s post, it’s now fairly well established that humans tend to pick on the big species first.

From fewer big trees, declines of big carnivores, elephant & rhino poaching, to fishing down the web, big species tend to cop it hardest when it comes to human-caused ecological disturbance.

While there are a lot of different combinations of traits that make some species more vulnerable to extinction than others (see examples for legumes, amphibians, sharks & teleosts, and mammals), one of the main ones is species size.

Generally speaking, larger species tend to produce fewer offspring and breed later in life than smaller species. This means that despite larger species tending to live longer than their smaller counterparts, their ‘slow’ reproductive output means that they are generally more susceptible to rapid environmental change (mainly via human intervention). In other words, their capacity for self-replacement is often too low to counteract the offtake from direct exploitation or habitat loss.

Despite a reasonable scientific understanding of this extinction-risk principle, the degree to which human disturbance affects species’ distributions is much less well quantified, and this is especially true for marine species.

I’m proud to announce another fascinating paper led by my postdoc, Camille Mellin, that has just come out online in Nature CommunicationsHumans and seasonal climate variability threaten large-bodied coral reef fish with small ranges.

With the world’s largest combined dataset of coral reef fish surveys for the entire Indo-Pacific (including the coral reef fish biodiversity hotspot — the Coral Triangle), we examined which conditions best described the distribution of fishes over a range of body sizes. Read the rest of this entry »





Getting your conservation science to the right people

22 01 2016

argument-cartoon-yellingA perennial lament of nearly every conservation scientist — at least at some point (often later in one’s career) — is that the years of blood, sweat and tears spent to obtain those precious results count for nought in terms of improving real biodiversity conservation.

Conservation scientists often claim, especially in the first and last paragraphs of their papers and research proposals, that by collecting such-and-such data and doing such-and-such analyses they will transform how we manage landscapes and species to the overall betterment of biodiversity. Unfortunately, most of these claims are hollow (or just plain bullshit) because the results are either: (i) never read by people who actually make conservation decisions, (ii) not understood by them even if they read the work, or (iii) never implemented because they are too vague or too unrealistic to translate into a tangible, positive shift in policy.

A depressing state of being, I know.

This isn’t any sort of novel revelation, for we’ve been discussing the divide between policy makers and scientists for donkey’s years. Regardless, the whinges can be summarised succinctly: Read the rest of this entry »





Outright bans of trophy hunting could do more harm than good

5 01 2016

In July 2015 an American dentist shot and killed a male lion called ‘Cecil’ with a hunting bow and arrow, an act that sparked a storm of social media outrage. Cecil was a favourite of tourists visiting Hwange National Park in Zimbabwe, and so the allegation that he was lured out of the Park to neighbouring farmland added considerable fuel to the flames of condemnation. Several other aspects of the hunt, such as baiting close to national park boundaries, were allegedly done illegally and against the spirit and ethical norms of a managed trophy hunt.

In May 2015, a Texan legally shot a critically endangered black rhino in Namibia, which also generated considerable online ire. The backlash ensued even though the male rhino was considered ‘surplus’ to Namibia’s black rhino populations, and the US$350,000 generated from the managed hunt was to be re-invested in conservation. Together, these two incidents have triggered vociferous appeals to ban trophy hunting throughout Africa.

These highly politicized events are but a small component of a large industry in Africa worth > US$215 million per year that ‘sells’ iconic animals to (mainly foreign) hunters as a means of generating otherwise scarce funds. While to most people this might seem like an abhorrent way to generate money, we argue in a new paper that sustainable-use activities, such as trophy hunting, can be an important tool in the conservationist’s toolbox. Conserving biodiversity can be expensive, so generating money is a central preoccupation of many environmental NGOs, conservation-minded individuals, government agencies and scientists. Making money for conservation in Africa is even more challenging, and so we argue that trophy hunting should and could fill some of that gap. Read the rest of this entry »





When science is ignored: Mauritius starts culling 18,000 threatened fruit bats

8 11 2015

JS7D2844aRrHere’s a depressing emergency post by Fabiola Monty.

I started working on this article to discuss how useful science is being ignored in Mauritius.

The Mauritian government has decided to implement a fruit bat cull as an ‘urgent response’ to the claims of huge economic losses by fruit farmers, a decision not supported by scientific evidence. We have now received confirmation in Mauritius through a local press communiqué that on 7 November 2015, The Mauritian Ministry of Agro Industry and Food Security in collaboration with the local Police Department and Special Mobile Force will start the culling of 18,000 bats in their natural habitats “with a view to reducing the extent of damages caused to fruits by bats”.

Tackling human-wildlife conflicts can indeed be challenging, but can the culling of 18,000 endemic Mauritian flying fox (Pteropus niger) resolve ‘human-wildlife conflict’ in the land of the dodo? In the case of Mauritius, scientific evidence not only demonstrates that the situation has been exaggerated, but that there are alternatives to bat culling that have been completely brushed aside by policy makers.

JS7D3726aRrAre the Mauritius fruit bats agricultural pests?

While fruit bats are being labelled as serious pests, scientific evidence shows instead that their impacts have been exaggerated. A recent (2014) study indicates that bats damage only 3-11% of fruit production, with birds also contributing to 1-8% of fruit loss. Rats are also probable contributors to fruit damage, but the extent remains unquantified. Interestingly, more fruits are lost (13-20%) because they are not collected in time and are left to over-ripen.

While the results of the study were communicated to legislators a few months before they made the decision to cull, it is clear that these were ignored in favour of preconceived assumptions.

Are there too many fruit bats? Read the rest of this entry »





Game bird madness

4 11 2015

Gamecart_largeI just returned to Paris after a brief visit to the University of Aberdeen over the weekend. My hosts, Xavier Lambin and Beth Scott, were not only marvellously welcoming, I also learned a lot about the travesty that is game bird management in the United Kingdom, and especially in Scotland.

As you might already know, the Great Britons are a little cuckoo for birds — I’d even wager that the country produces more twitchers than any other country on Earth. The plus side is that there are few national taxa better censused and studied that British birds, because so many non-scientists get into the spirit of data collection. Hell, I’ve even had a play with some of their datasets.

The other side of this bird madness is not so good — I’m talking about the massive biomass of game birds reared, released and shot every year in the United Kingdom. It’s not the hunting per se with which I take issue, it’s the insane manipulation of an entire ecosystem for the benefit of a few species. Read the rest of this entry »





What conservationists should recommend to philanthropists

24 08 2015

business-people-forest-sqIt probably won’t come as too much of a surprise that most of the people I know reasonably well (mates included) are also scientists of some description. I therefore think that I fall into the extremely normal and mundane category of associating the most with people at work. Sure, I’ve also got very good mates who are et alia plumbers, chefs, winemakers (I do live in South Australia, after all), mechanics, coffee roasters and farmers (I also live on a small farm), so at least a get out of the office a bit. In summary, I tend to befriend and hang around people who are for the most part making ends meet, but who are by no means in a position to spend oodles of cash on anything remotely related to the conservation of biodiversity.

From time to time, however, I do meet extremely wealthy people, but we generally do not operate in the same social circles (I know, another big surprise). Nonetheless, I keep finding myself in conversations with such people that start along the lines of the following question:

“What’s the most effective way to invest money to save species from going extinct?”

As the Australian saying goes: “How long is a piece of string” – in other words, it’s a difficult, multi-dimensional answer at best, or a confused non sequitur one at worst.

Those reading this might be thinking right now, “Oh, I know exactly what I’d spend it on if I had that kind of money”, but after a few moments of contemplation, you might not be so sure. This is the dilemma in which I’ve found myself now on more than a few occasions.

So, with the benefit of a little contemplation, here are a few of my thoughts on the subject. Read the rest of this entry »





Ice Age? No. Abrupt warmings and hunting together polished off Holarctic megafauna

24 07 2015
Oh shit oh shit oh shit ...

Oh shit oh shit oh shit …

Did ice ages cause the Pleistocene megafauna to go extinct? Contrary to popular opinion, no, they didn’t. But climate change did have something to do with them, only it was global warming events instead.

Just out today in Science, our long-time-coming (9 years in total if you count the time from the original idea to today) paper ‘Abrupt warmings drove Late Pleistocene Holarctic megafaunal turnover‘ led by Alan Cooper of the Australian Centre for Ancient DNA and Chris Turney of the UNSW Climate Change Research Centre demonstrates for the first time that abrupt warming periods over the last 60,000 years were at least partially responsible for the collapse of the megafauna in Eurasia and North America.

You might recall that I’ve been a bit sceptical of claims that climate changes had much to do with megafauna extinctions during the Late Pleistocene and early Holocene, mainly because of the overwhelming evidence that humans had a big part to play in their demise (surprise, surprise). What I’ve rejected though isn’t so much that climate had nothing to do with the extinctions; rather, I took issue with claims that climate change was the dominant driver. I’ve also had problems with blanket claims that it was ‘always this’ or ‘always that’, when the complexity of biogeography and community dynamics means that it was most assuredly more complicated than most people think.

I’m happy to say that our latest paper indeed demonstrates the complexity of megafauna extinctions, and that it took a heap of fairly complex datasets and analyses to demonstrate. Not only were the data varied – the combination of scientists involved was just as eclectic, with ancient DNA specialists, palaeo-climatologists and ecological modellers (including yours truly) assembled to make sense of the complicated story that the data ultimately revealed. Read the rest of this entry »








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