Vodcast on killing for conservation

24 02 2010

The inaugural issue of Methods in Ecology and Evolution came out today (see first issue editorial) and I am very pleased not only that our paper (Spatially explicit spreadsheet modelling for optimizing the efficiency of reducing invasive animal density) made it into the the paper line-up (see previous ConservationBytes.com post on the paper here), we also managed to score the journal’s cover image (buffalo image shown right: Asian swamp buffalo Bubalus bubalis introduced to Australia in the early 19th Century now populate much of the tropical north and cause severe environmental disturbances to savanna and wetland ecosystems. Despite a broad-scale cull of hundreds of thousands of free-ranging buffalo occurring in the 1980s and 1990s to eradicate brucellosis and tuberculosis, the population is recovering and continuing to threaten protected areas such as Kakadu National Park. A small wild harvest of several thousand buffalo occurs each year in Arnhem Land where mustering is aided by helicopters and on-ground vehicles. The buffalo pictured are housed in temporary holding pens and then shipped for live export. Photo credit: Jesse Northfield).

I also had the opportunity to chat with Journal Coordinator, Graziella Iossa, via Skype about the paper, and they have put up a YouTube vodcast of the interview itself. You can also check it out here.

Summary: Corey Bradshaw answers what is the main idea behind his work with co-authors, “Spatially explicit spreadsheet modelling for optimising the efficiency of reducing invasive animal density”. Further, he explains how their model advances methodology in ecology and evolution and finally shows how it could be applied by wildlife manager and practitioners with basic knowledge of computer models. Their Excel-spreadsheet ‘Spatio-Temporal Animal Reduction’ (S.T.A.R.) model is designed specifically to optimise the culling strategies for feral pigs, buffalo and horses in Kakadu National Park (northern Australia), but Corey explains how their aim was to make it easy enough for anyone to use and modify it so that it could be applied to any invasive species anywhere.

Congratulations to Editor-in-Chief Rob Freckleton, Graziella and the Associate Editors for a great first issue. Other titles include:

Keep them coming!

CJA Bradshaw

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Cartoon guide to biodiversity loss VII

23 02 2010

And the silliness continues…

See also full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


CJA Bradshaw

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Inbreeding bad for invasives too

18 02 2010

I just came across this little gem of a paper in Molecular Ecology (not, by any stretch, a common forum for biodiversity conservation-related papers). It’s another one of those wonderful little experimental manipulation studies I love so much (see previous examples here and here).

I’ve written a lot before about the loss of genetic diversity as a contributing factor to extinction risk, via things like Allee effects and inbreeding depression. I’ve also posted blurbs about our work and that of others on what makes particular species prone to become extinct or invasive (i.e., the two sides of the same evolutionary coin). Now Crawford and Whitney bring these two themes together in their paper entitled Population genetic diversity influences colonization success.

Yes, the evolved traits of a particular species will set it up either to do well or very badly under rapid environmental change, and invasive species tend to be those with rapid generation times, defence mechanisms, heightened dispersal capacity and rapid growth. However, such traits generally only predict a small amount in the variation in invasion success – the other being of course propagule pressure (a composite measure of the number of individuals of a non-native species [propagule size] introduced to a novel environment and the number of introduction events [propagule number] into the new host environment).

But, that’s not all. It turns out that just as reduced genetic diversity enhances a threatened species’ risk of extinction, so too does it reduce the ‘invasiveness’ of a weed. Using experimentally manipulated populations of the weedy herb Arabidopsis thaliana (mouse-ear cress; see if you get the joke), Crawford & Whitney measured greater population-level seedling emergence rates, biomass production, flowering duration and reproduction in high-diversity populations compared to lower-diversity ones. Maintain a high genetic diversity and your invasive species has a much higher potential to colonise a novel environment and spread throughout it.

Of course, this is related to propagule pressure because the more individuals that invade/are introduced the more times, the higher the likelihood that different genomes will be introduced as well. This is extremely important from a management perspective because it means that well-mixed (outbred) samples of invasive species probably can do a lot more damage to native biodiversity than a few, genetically similar individuals alone. Indeed, most introductions probably don’t result in a successful invasion mainly because they don’t have the genetic diversity to get over the hump of inbreeding depression in the first place.

The higher genetic (and therefore, phenotypic) variation in your pool of introduced individuals, the great the chance that at least a few will survive and proliferate. This is also a good bit of extra proof for our proposal that invasion and extinction are two sides of the same evolutionary coin.

CJA Bradshaw

ResearchBlogging.orgCrawford, K., & Whitney, K. (2010). Population genetic diversity influences colonization success Molecular Ecology DOI: 10.1111/j.1365-294X.2010.04550.x

Bradshaw, C., Giam, X., Tan, H., Brook, B., & Sodhi, N. (2008). Threat or invasive status in legumes is related to opposite extremes of the same ecological and life-history attributes Journal of Ecology, 96, 869-883 DOI: 10.1111/j.1365-2745.2008.01408.x

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February Issue of Conservation Letters

13 02 2010

Diver at Great Barrier Reef, Australia

Hard to believe we’re already at Volume 3 – introducing the latest issue of Conservation Letters (Volume 3, Issue 1, February 2010). For full access, click here.

Note too we’ve jumped from 5 to 6 papers per issue. Congratulations to all our authors. Keep those submissions coming!

CJA Bradshaw

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ERA rankings for Conservation and Ecology journals

11 02 2010

The much-touted Excellence in Research for Australia (ERA) initiative was established in 2008 to “…assesses research quality within Australia’s higher education institutions using a combination of indicators and expert review by committees comprising experienced, internationally-recognised experts”. Following on the heels of the United Kingdom’s Research Assessment Exercise (RAE) and Australia’s previous attempt at such a ranking (the now-defunct Research Quality Framework), we will now have a system that ranks research performance and universities in this country. Overall I think it’s a good thing so that the dead-wood can lift their game or go home, but no ranking system is perfect. Some well-deserving people will be left out in the cold.

Opinions aside, I thought it would be useful to provide the ERA journal ranking categories in conservation and ecology for my readers, particularly for those in Australia. See also my Journals page for conservation journals, their impact factors and links. The ERA has ranked 20,712 unique peer-reviewed journals, with each given a single quality rating (or is not ranked). The ERA is careful to say that “A journal’s quality rating represents the overall quality of the journal. This is defined in terms of how it compares with other journals and should not be confused with its relevance or importance to a particular discipline.”.

They provide four tiers of quality rating:

  • A* =  Typically one of the best in its field or subfield in which to publish and would typically cover the entire field/subfield. Virtually all papers they publish will be of a very high quality. These are journals where most of the work is important (it will really shape the field) and where researchers boast about getting accepted. Acceptance rates would typically be low and the editorial board would be dominated by field leaders, including many from top institutions.
  • A =  The majority of papers in a Tier A journal will be of very high quality. Publishing in an A journal would enhance the author’s standing, showing they have real engagement with the global research community and that they have something to say about problems of some significance. Typical signs of an A journal are lowish acceptance rates and an editorial board which includes a reasonable fraction of well known researchers from top institutions.
  • B = Tier B covers journals with a solid, though not outstanding, reputation. Generally, in a Tier B journal, one would expect only a few papers of very high quality. They are often important outlets for the work of PhD students and early career researchers. Typical examples would be regional journals with high acceptance rates, and editorial boards that have few leading researchers from top international institutions.
  • C =  Tier C includes quality, peer reviewed, journals that do not meet the criteria of the higher tiers.

If you’re an Australian conservation ecologist, then you’d be wise to target the higher-end journals for publication over the next few years (it will affect your rank).

So, here goes:

Conservation Journals

Ecology Journals (in addition to those listed above; only A* and A)

  • A*: Annual Review of Ecology, Evolution and Systematics, Biological Reviews, Ecological Monographs, Ecology, Ecology Letters, Environment International, Fish and Fisheries, Global Ecology and Biogeography, Philosophical Transactions of the Royal Society of London: Biological Sciences, PLoS Biology, Proceedings of the Royal Society of London: Biological Sciences, The American Naturalist, The Quarterly Review of Biology
  • A: Agriculture, Ecosystems and Environment, Animal Behaviour, American Journal of Primatology, Auk, Behavioral Ecology, Behavioral Ecology and Sociobiology, BioEssays, Biology Letters, Bioscience, BMC Biology, Canadian Journal of Fisheries and Aquatic Sciences, Coral Reefs, Diversity and Distributions, Ecography, Ecological Applications, Fisheries, Freshwater Biology, Functional Ecology, International Journal of Primatology, Journal of Applied Ecology, Journal of Animal Ecology, Journal of Avian Biology, Journal of Biogeography, Journal of Ecology, Journal of Experimental Biology, Journal of Fish Biology, Journal of Mammalogy, Journal of the North American Benthological Society, Journal of Zoology, Molecular Ecology, Oecologia, Oikos, Physiological and Biochemical Zoology, Perspectives in Plant Ecology, Evolution and Systematics, Reviews in Fisheries Science, Wildlife Monographs, Zoological Journal of the Linnean Society

I’m sure I’ve missed a few, but that’ll cover most of the relevant journals. For the full, tortuous list of journals in Excel format, click here. Happy publishing!

CJA Bradshaw

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Every extra human means fewer animals

8 02 2010

© The Sun

As promised some time ago when I blogged about the imminent release of the book Conservation Biology for All (edited by Navjot Sodhi and Paul Ehrlich), I am now posting a few titbits from the book.

Today’s post is a blurb from Paul Ehrlich on the human population problem for conservation of biodiversity.

The size of the human population is approaching 7 billion people, and its most fundamental connection with conservation is simple: people compete with other animals., which unlike green plants cannot make their own food. At present Homo sapiens uses, coopts, or destroys close to half of all the food available to the rest of the animal kingdom. That means that, in essence, every human being added to the population means fewer individuals can be supported in the remaining fauna.

But human population growth does much more than simply cause a proportional decline in animal biodiversity – since as you know, we degrade nature in many ways besides competing with animals for food. Each additional person will have a disproportionate negative impact on biodiversity in general. The first farmers started farming the richest soils they could find and utilised the richest and most accessible resources first (Ehrlich & Ehrlich 2005). Now much of the soil that people first farmed has been eroded away or paved over, and agriculturalists increasingly are forced to turn to marginal land to grow more food.

Equally, deeper and poorer ore deposits must be mined and smelted today, water and petroleum must come from lower quality resources, deeper wells, or (for oil) from deep beneath the ocean and must be transported over longer distances, all at ever-greater environmental cost [my addition – this is exactly why we need to embrace the cheap, safe and carbon-free energy provided by nuclear energy].

The tasks of conservation biologists are made more difficult by human population growth, as is readily seen in the I=PAT equation (Holdren & Ehrlich 1974; Ehrlich & Ehrlich 1981). Impact (I) on biodiversity is not only a result of population size (P), but of that size multiplied by affluence (A) measured as per capita consumption, and that product multiplied by another factor (T), which summarises the technologies  and socio-political-economic arrangements to service that consumption. More people surrounding a rainforest reserve in a poor nation often means more individuals invading the reserve to gather firewood or bush meat. More poeple in a rich country may mean more off-road vehicles (ORVs) assulting the biota – especially if the ORV manufacturers are politically powerful and can succesfully fight bans on their use. As poor countries’ populations grow and segments of them become more affluent, demand rises for meat and automobiles, with domesticated animals competing with or devouring native biota, cars causing all sorts of assults on biodiversity, and both adding to climate disruption. Globally, as a growing population demands greater quantities of plastics, industrial chemicals, pesticides, fertilisers, cosmetics, and medicines, the toxification of the planet escalates, bringing frightening problems for organisms ranging from polar bears to frogs (to say nothing of people!).

In sum, population growth (along with escalating consumption and the use of environmentally malign technologies) is a major driver of the ongoing destruction of populations, species, and communities that is a salient feature of the Anthropocene. Humanity , as the dominant animal (Ehrlich & Ehrlich 2008), simply out competes other animals for the planet’s productivity, and often both plants and animals for its freshwater. While dealing with more limited problems, it therefore behoves every conservation biologist to put part of her time into restraining those drivers, including working to humanely lower [sic] birth rates until population growth stops and begins a slow decline twoard a sustainable size (Daily et al. 1994).

Incidentally, Paul Ehrlich is travelling to Adelaide this year (November 2010) for some high-profile talks and meetings. Stay tuned for coverage of the events.

CJA Bradshaw

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Salamander Longshanks – breed them out

3 02 2010

© M. Dawson

Patrick McGoohan in his role as the less-than-sentimental King Edward ‘Longshanks’ in the 1995 production of ‘Braveheart’ said it best in his references to the invocation of ius primæ noctis:

If we can’t get them out, we’ll breed them out

What a charmer.

Dabbling in molecular ecology myself over the past few years with some gel-jockey types (e.g., Dick Frankham [author of Introduction to Conservation Genetics], Melanie Lancaster, Paul Sunnucks, Yuji Isagi inter alios), I’m quite fascinated by the application of good molecular techniques in conservation biology. So when I came across the paper by Fitzpatrick and colleagues entitled Rapid spread of invasive genes into a threatened native species in PNAS, I was quite pleased.

When people usually think about invasive species, they tend to think ‘predator eating naïve native prey’ or ‘weed outcompeting native plant’. These are all big problems (e.g., think feral cats in Australia or knapweed in the USA), but what people probably don’t think about is the insidious concept of ‘genomic extinction’. This is essentially a congener invasive species breeding with a native one, thus ‘diluting’ the native’s genome until it no longer resembles its former self. A veritable case of ‘breeding them out’.

Who cares if at least some of the original genome remains? Some would argue that ‘biodiversity’ should be measured in terms of genetic diversity, not just species richness (I tend to agree), so any loss of genes is a loss of biodiversity. Perhaps more practically, hybridisation can lead to reduced fitness, like we observed in hybridised fur seals on Macquarie Island.

Fitzpatrick and colleagues measured the introgression of alleles from the deliberately introduced barred tiger salamander (Ambystoma tigrinum mavortium) into threatened California tiger salamanders (A. californiense) out from the initial introduction site. While most invasive alleles neatly stopped appearing in sampled salamanders not far from the introduction site, three invasive alleles persisted up to 100 km from the introduction site. Not only was the distance remarkable for such a small, non-dispersing beastie, the rate of introgression was much faster than would be expected by chance (60 years), suggesting selection rather than passive genetic drift. Almost none of the native alleles persisted in the face of the three super-aggressive invasive alleles.

The authors claim that the effects on native salamander fitness are complex and it would probably be premature to claim that the introgression is contributing to their threatened status, but they do raise an important management conundrum. If species identification rests on the characterisation of a specific genome, then none of the native salamanders would qualify for protection under the USA’s Endangered Species Act. They believe then that so-called ‘genetic purity’ is an impractical conservation goal, but it can be used to shield remaining ‘mostly native’ populations from further introgression.

Nice study.

CJA Bradshaw

ResearchBlogging.orgFitzpatrick, B., Johnson, J., Kump, D., Smith, J., Voss, S., & Shaffer, H. (2010). Rapid spread of invasive genes into a threatened native species Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0911802107

Lancaster, M., Bradshaw, C.J.A., Goldsworthy, S.D., & Sunnucks, P. (2007). Lower reproductive success in hybrid fur seal males indicates fitness costs to hybridization Molecular Ecology, 16 (15), 3187-3197 DOI: 10.1111/j.1365-294X.2007.03339.x

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