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 »

InvaCost – estimating the economic damage of invasive insects

7 11 2014

insectinvasionThis is a blosh (rehash of someone else’s blog post) of Franck Courchamp‘s posts on an exciting new initiative of which I am excited to be a part. Incidentally, Franck’s spending the week here in Adelaide.

Don’t forgot to vote for the project to receive 50 000 € public-communication grant!

Climate change will make winters milder and habitats climatically more suitable year-round for cold-blooded animals like insects, but there are many questions remaining regarding whether such insects will be able to invade other regions as the climate shifts. There are many nasty bugs out there.

For example, the Asian predatory wasp is an invasive hornet in Europe that butchers pollinating insects, especially bees, thereby affecting the production of many wild and cultivated plants. I hope that we all remember what Einstein said about pollinators:

If bees were to disappear, humans will disappear within a few years.

(we all should remember that because it’s one of the few things he said that most of us understood). The highly invasive red fire ant is feared for its impacts on biodiversity, agriculture and cattle breeding, and the thousands of anaphylactic shocks inflicted to people by painful stings every year (with hundreds of deaths). Between the USA and Australia, over US$10 billion is spent yearly on the control of this insect alone. Tiger mosquitoes are vectors of pathogens that cause dengue fever, chikungunya virus and of about 30 other viruses. We could go on.

Most of these nasty creatures are now unable to colonise northern regions of Europe or America, or southern regions of Australia, for example, because they cannot survive cold temperatures. But how will this change? Where, when and which species will invade with rising temperatures? What will be the costs in terms of species loss? In terms of agricultural or forestry loss? In terms of diseases to cattle, domestic animals and humans? What will be the death toll if insects that are vectors of malaria can establish in new, highly populated areas?

We’ve proposed to study these and others from a list of 20 of the worst invasive insect species worldwide, and we got selected (i.e., financed!) by the Fondation BNP Paribas. In addition, the Fondation BNP Paribas has selected five scientific programmes on climate change and will give 50,000 € (that’s US$62,000) to the one selected by the public, for a communication project on their scientific programme. This is why we need you to vote for our project: InvaCost. Read the rest of this entry »

Ecological processes depend on …

14 05 2014
© Cagan Sekercioglu

© Cagan Sekercioglu

I have been known to say (ok – I say it all the time) that ecologists should never equivocate when speaking to the public. Whether it’s in a media release, blog post, television presentation or newspaper article, just stick to ‘yes’ or ‘no’. In other words, don’t qualify your answer with some horrid statistical statement (i.e., in 95% of cases …) or say something like “… but it really depends on …”. People don’t understand uncertainty – to most people, ‘uncertainty’ means “I don’t know” or worse, “I made it all up”.

But that’s only in the movies.

In real ‘ecological’ life, things are vastly different. It’s never as straightforward as ‘yes’ or ‘no’, because ecology is complex. There are times that I forget this important aspect when testing a new hypothesis with what seem like unequivocal data, but then reality always hits.

Our latest paper is the epitome of this emergent complexity from what started out as a fairly simple question using some amazing data. What makes birds change their range1? We looked at this question from a slightly different angle than had been done before because we had access to climate data, life-history data and most importantly, actual range change data. It’s that latter titbit that is typically missing from studies aiming to understand what drives species toward a particular fate; whether it’s a species distribution model predicting the future habitat suitability of some species as a function of climate change, or the past dynamics of some species related to its life history pace, most often the combined dynamics are missing. Read the rest of this entry »

Get boreal

7 06 2012

I’ve been a little quiet this last week because I’ve had to travel to the other side of the planet for what turned out to be a very interesting and scientifically lucrative workshop. After travelling 31 hours from Adelaide to Umeå in northern Sweden, I wondered to myself if it was going to be worth it for a 2.5-day workshop on a little island (Norrbyskär) in the Baltic Sea (which, as it turned out, didn’t have internet access).

The answer is a categorical ‘yes’!

Many of you know that I’ve dabbled in boreal forest conservation in the past, but I could never claim any real expertise in the area. Hence it came as something of a shock when Jon Moen of Umeå University asked me to attend a specialist workshop focused loosely on making the plight and importance of the boreal forest more widely acknowledged. I dragged my feet initially, but Jon convinced me that I could add something to the mix.

It was a small workshop, but well-represented by all boreal countries save Norway (i.e., we had Russians, Swedes, Finns, Canadians and Americans – this Australian was indeed the odd one out). We also had a wide array of expertise, from carbon accountants, political scientists, political economists, native cultures experts, ecologists to foresters. Our mandate – justify why we should pay more attention to this globally important region.

Just how important is the boreal forest? We managed to unearth some little-appreciated facts: Read the rest of this entry »

Reforesting wealthy countries for the common good

29 06 2011

The Coalition of Financially Challenged Countries with Lots of Trees, known as ‘CoFCCLoT’, representing most of the world’s remaining tropical forests, is asking wealthy nations to share global responsibilities and reforest their land for the common good of stabilizing climate and protecting biodiversity.

“We are willing to play our part, but we require a level playing field in which we all commit to equal sacrifices,” a coalition spokeswoman says. “Returning forest cover in the G8 countries and the European Union back to historic coverage will benefit all of us in the long-term.”

Seventy-five per cent of Europe was once forested. Now it is 45 per cent. Some countries such as Ireland saw forest cover reduced to near zero. Most forest cover in the developed world is now often planted with stands of alien trees, turning them into deserts for biodiversity. Remaining natural forests are often highly fragmented and have few native species. Read the rest of this entry »

Silence of the birds

2 05 2011

Yet another contribution from my PhD student, Salvador Herrando-Pérez (see his previous posts on micro-evolution and pollination).

In the 1960s, Rachel Carson preoccupied (to put it mildly) the political and economic powers of the United States with the publication of her book, Silent Spring, an overwhelming essay highlighting the environmental impacts caused by the pesticide industry. Half a century later, the metaphor of that book – a spring devoid of bird song – stands in force as farmland birds keep declining worldwide at the mercy of agricultural practices insensitive to the ecosystem services biodiversity procures. The problem has been best studied in Europe where non-government organisations, such as the British Trust for Ornithology or the Sociedad Española de Ornitología, have been monitoring bird populations for decades, and the European Union has sumptuously financed research and management actions.

Sparrows are the commonest among common birds. Worldwide we see them wherever humans live, travel and take leisure, from mountains and beaches to stadiums and underground trains. These feathery dwarfs snick even through security checks and sliding doors at airports and shopping malls, and it is no one’s surprise to be overflown by one of them carrying a chip from the leftovers of a nearby food court. However, the deterioration of their populations has sown alarm among European politicians, society, and the scientific community. Read the rest of this entry »

No chance Europe will recover fish stocks

19 01 2010

Alternate title: When pigs fly and fish say ‘hi’.

I’m covering a quick little review of a paper just published online in Fish and Fisheries about the two chances Europe has of meeting its legal obligations of rebuilding its North East Atlantic fish stocks by 2015 (i.e., Buckley’s and none).

The paper entitled Rebuilding fish stocks no later than 2015: will Europe meet the deadline? by Froese & Proelß describes briefly the likelihood Europe will meet the obligations set out under the United Nations’ Law of the Sea (UNCLOS) of “maintaining or restoring fish stocks at levels that are capable of producing maximum sustainable yield” by 2015 as set out in the Johannesburg Plan of Implementation of 2002.

Using fish stock assessment data and several criteria (3 methods for estimating maximum sustainable yield [MSY], 3 methods for estimating fishing mortality [Fmsy] & 2 methods for estimating spawning biomass [Bmsy]), they conclude that 49 (91 %) of the examined European stocks will fail to meet the goal under a ‘business as usual’ scenario.

The upshot is that European fisheries authorities have been and continue to set their total allowable catches (TACs) too high. We’ve seen this before with Atlantic bluefin tuna and the International Conspiracy to Catch All Tunas. Seems like most populations of exploited fishes are in fact in the same boat (quite literally!).

It’s amazing, really, the lack of ‘political will’ in fisheries – driving your source of income into oblivion doesn’t seem to register in the short-sighted vision of those earning their associated living or those supposedly looking out for their long-term interests.

CJA Bradshaw

ResearchBlogging.orgFroese, R., & Proelß, A. (2010). Rebuilding fish stocks no later than 2015: will Europe meet the deadline? Fish and Fisheries DOI: 10.1111/j.1467-2979.2009.00349.x

Pitcher, T., Kalikoski, D., Pramod, G., & Short, K. (2009). Not honouring the code Nature, 457 (7230), 658-659 DOI: 10.1038/457658a

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