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 »





It’s not all about cats

20 10 2014

Snake+OilIf you follow any of the environment news in Australia, you will most certainly have seen a lot about feral cats in the last few weeks. I’ve come across dozens of articles in the last week alone talking about the horrendous toll feral cats have had on Australian wildlife since European arrival. In principle, this is a good thing because finally Australians are groggily waking to the fact that our house moggies and their descendants have royally buggered our biodiversity. As a result, we have the highest mammal extinction rate of any country.

But I argue that the newfound enthusiasm for killing anything feline is being peddled mainly as a distraction from bigger environmental issues and to camouflage the complete incompetence of the current government and their all-out war on the environment.

Call me cynical, but when I read headlines like “Australia aims to end extinction of native wildlife by 2020” and Environment Minister Hunt’s recent speech that he has “… set a goal of ending the loss of mammal species by 2020“, I get more than just a little sick to the stomach.

What a preposterous load of shite. Moreover, what a blatant wool-pulling-over-the-eyes public stunt. Read the rest of this entry »





South Australia’s tattered environmental remains

16 04 2014
State budget percentage expenditures for health, education and environment

South Australia State budget percentage expenditures for health, education and environment

Yesterday I gave the second keynote address at the South Australia Natural Resource Management (NRM) Science Conference at the University of Adelaide (see also a brief synopsis of Day 1 here). Unfortunately, I’m missing today’s talks because of an acute case of man cold, but at least I can stay at home and work while sipping cups of hot tea.

Many people came up afterwards and congratulated me for “being brave enough to tell the truth”, which both encouraged and distressed me – I am encouraged by the positive feedback, but distressed by the lack of action on the part of our natural resource management leaders.

The simple truth is that South Australia’s biodiversity and ecosystems are in shambles, yet few seem to appreciate this.

So for the benefit of those who couldn’t attend, I’ve uploaded the podcast of my slideshow for general viewing here. I’ve also highlighted some key points from the talk below: Read the rest of this entry »





More species = more resilience

8 01 2014

reef fishWhile still ostensibly ‘on leave’ (side note: Does any scientist really ever take a proper holiday? Perhaps a subject for a future blog post), I cannot resist the temptation to blog about our lab’s latest paper that just came online today. In particular, I am particularly proud of Dr Camille Mellin, lead author of the study and all-round kick-arse quantitative ecologist, who has outdone herself on this one.

Today’s subject is one I’ve touched on before, but to my knowledge, the relationship between ‘diversity’ (simply put, ‘more species’) and ecosystem resilience (i.e., resisting extinction) has never been demonstrated so elegantly. Not only is the study elegant (admission: I am a co-author and therefore my opinion is likely to be biased toward the positive), it demonstrates the biodiversity-stability hypothesis in a natural setting (not experimental) over a range of thousands of kilometres. Finally, there’s an interesting little twist at the end demonstrating yet again that ecology is more complex than rocket science.

Despite a legacy of debate, the so-called diversity-stability hypothesis is now a widely used rule of thumb, and its even implicit in most conservation planning tools (i.e., set aside areas with more species because we assume more is better). Why should ‘more’ be ‘better’? Well, when a lot of species are interacting and competing in an ecosystem, the ‘average’ interactions that any one species experiences are likely to be weaker than in a simpler, less diverse system. When there are a lot of different niches occupied by different species, we also expect different responses to environmental fluctuations among the community, meaning that some species inherently do better than others depending on the specific disturbance. Species-rich systems also tend to have more of what we call ‘functional redundancy‘, meaning that if one species providing an essential ecosystem function (e.g., like predation) goes extinct, there’s another, similar species ready to take its place. Read the rest of this entry »





Too small to avoid catastrophic biodiversity meltdown

27 09 2013
Chiew Larn

Chiew Larn Reservoir is surrounded by Khlong Saeng Wildlife Sanctuary and Khao Sok National Park, which together make up part of the largest block of rainforest habitat in southern Thailand (> 3500 km2). Photo: Antony Lynam

One of the perennial and probably most controversial topics in conservation ecology is when is something “too small’. By ‘something’ I mean many things, including population abundance and patch size. We’ve certainly written about the former on many occasions (see here, here, here and here for our work on minimum viable population size), with the associated controversy it elicited.

Now I (sadly) report on the tragedy of the second issue – when is a habitat fragment too small to be of much good to biodiversity?

Published today in the journal Science, Luke Gibson (of No substitute for primary forest fame) and a group of us report disturbing results about the ecological meltdown that has occurred on islands created when the Chiew Larn Reservoir of southern Thailand was flooded nearly 30 years ago by a hydroelectric dam.

As is the case in many parts of the world (e.g., Three Gorges Dam, China), hydroelectric dams can cause major ecological problems merely by flooding vast areas. In the case of Charn Liew, co-author Tony Lynam of Wildlife Conservation Society passed along to me a bit of poignant and emotive history about the local struggle to prevent the disaster.

“As the waters behind the dam were rising in 1987, Seub Nakasathien, the Superintendent of the Khlong Saeng Wildlife Sanctuary, his staff and conservationist friends, mounted an operation to capture and release animals that were caught in the flood waters.

It turned out to be distressing experience for all involved as you can see from the clips here, with the rescuers having only nets and longtail boats, and many animals dying. Ultimately most of the larger mammals disappeared quickly from the islands, leaving just the smaller fauna.

Later Seub moved to Huai Kha Khaeng Wildlife Sanctuary and fought an unsuccessful battle with poachers and loggers, which ended in him taking his own life in despair in 1990. A sad story, and his friend, a famous folk singer called Aed Carabao, wrote a song about Seub, the music of which plays in the video. Read the rest of this entry »





Biogeography comes of age

22 08 2013

penguin biogeographyThis week has been all about biogeography for me. While I wouldn’t call myself a ‘biogeographer’, I certainly do apply a lot of the discipline’s techniques.

This week I’m attending the 2013 Association of Ecology’s (INTECOL) and British Ecological Society’s joint Congress of Ecology in London, and I have purposefully sought out more of the biogeographical talks than pretty much anything else because the speakers were engaging and the topics fascinating. As it happens, even my own presentation had a strong biogeographical flavour this year.

Although the species-area relationship (SAR) is only one small aspect of biogeography, I’ve been slightly amazed that after more than 50 years since MacArthur & Wilson’s famous book, our discipline is still obsessed with SAR.

I’ve blogged about SAR issues before – what makes it so engaging and controversial is that SAR is the principal tool to estimate overall extinction rates, even though it is perhaps one of the bluntest tools in the ecological toolbox. I suppose its popularity stems from its superficial simplicity – as the area of an (classically oceanic) island increases, so too does the total number of species it can hold. The controversies surrounding such as basic relationship centre on describing the rate of that species richness increase with area – in other words, just how nonlinear the SAR itself is.

Even a cursory understanding of maths reveals the importance of estimating this curve correctly. As the area of an ‘island’ (habitat fragment) decreases due to human disturbance, estimating how many species end up going extinct as a result depends entirely on the shape of the SAR. Get the SAR wrong, and you can over- or under-estimate the extinction rate. This was the crux of the palaver over Fangliang He (not attending INTECOL) & Stephen Hubbell’s (attending INTECOL) paper in Nature in 2011.

The first real engagement of SAR happened with John Harte’s maximum entropy talk in the process macroecology session on Tuesday. What was notable to me was his adamant claim that the power-law form of SAR should never be used, despite its commonness in the literature. I took this with a grain of salt because I know all about how messy area-richness data can be, and why one needs to consider alternate models (see an example here). But then yesterday I listened to one of the greats of biogeography – Robert Whittaker – who said pretty much the complete opposite of Harte’s contention. Whittaker showed results from one of his papers last year that the power law was in fact the most commonly supported SAR among many datasets (granted, there was substantial variability in overall model performance). My conclusion remains firm – make sure you use multiple models for each individual dataset and try to infer the SAR from model-averaging. Read the rest of this entry »





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

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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