Category Archives: Research

Scepticism towards the Living Planet Index is unwarranted

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The most recent Living Planet Report was released last year, which showed that vertebrate populations around the world have declined by 68% on average. At the time, Brian McGill wrote a post at Dynamic Ecology expressing his scepticism over these large declines. His doubts stemmed from several related papers, which all showed that vertebrate populations tended to be quite stable on average. While some populations have declined, most have remained stable and others have actually increased.

My understanding of Brian’s message (and the messages of the published papers supporting him) was that while humans do affect vertebrate populations, these effects are not consistently negative. Instead, some species benefit from human actions, so human’s ultimate legacy will be rearranging relative population structure, rather than causing wholesale declines.

While I agree with this interpretation, I worry that it is causing unwarranted mistrust of the Living Planet Index. I was reminded of this last week by a passing comment by Mark Vellend:

“If biodiversity seems intractable, then just think about recent discussions of the Living Planet Index, which is based on pretty simple underlying data.”

His remark was in the context of his post suggesting that ecologists have subconscious biases that cause us to exaggerate how much humans harm biodiversity. Ecologists probably do have subconscious biases, but the Living Planet index shouldn’t be used as evidence of this.

I don’t believe the Living Planet Index exaggerates population declines. However, I also recognise that populations are stable on average. This probably seems contradictory, so I’ll use the rest of this post to explain why it isn’t.

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Scientific journals should be judged, not ranked

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Aspiring scientists quickly learn that where they publish their hard earned data is important for career progression. A paper in a prestigious journal pushes them up the professional ladder faster than the same paper in an obscure one.

This has led to an obsession with quantifying the prestige of a journal using impact metrics. Over at Conservation Bytes, Corey Bradshaw presents a RShiny App to rank ecology and conservation journals using a composite of different citation metrics. His app is based on a published paper, so you can be sure that it technically sound. It is not my intention to criticise these efforts; if you want to rank jounals, then this composite approach is definitely the way to go.

However, I don’t think there is much to gain from ranking journals based on their impact metrics. Moreover, scientists – especially early-career scientists – would be better off judging journals based on whether is will ensure that their paper reaches the right audience.

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Boasting about backyard biodiversity

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The easiest way for an aspiring naturalist to explore wildlife is by stepping out into their own backyard. Try it yourself. As I write this, I can look through my window at a Karoo Thrush hopping about my garden. But this post is not about the tiny garden surrounding my current apartment, but rather about my childhood home. I was tremendously fortunate to grow up on a 60 hectare farm, where  first discovered my love for nature.

Between wrapping up my PhD and starting my current lecturing position, I spent a few months of unemployment back in the house I grew up in. During that time, I discovered the thrill of recording unobtrusive nocturnal critters using a camera trap. Every afternoon, I set up the camera trap and eagerly explored the footage the following morning. It was so much fun.

After enough time, even I was amazed by the variety of species that lived on this relatively small farm. Perhaps, I should rephrase that last sentence. You see, calling it a farm is not accurate because it hasn’t been used for agricultural in more than ten years. The last cows were removed back in 2004 and since then the land was left dormant and only managed to minimise the risk of wild fire.

Still, I captured footage of 18 different mammal species, which is remarkably high for such a small area. Moreover, the camera trap is unlikely to capture any footage of bats and small rodents, so the total mammal diversity is probably even higher. I decided to write up these observations and the results have just been published online in the African Journal of Ecology. Continue reading →

Transdisciplinary research is not a solution to environmental problems

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Over the weekend, Joern Fischer wrote a criticism of transdisciplinary research. I was very eager to read it because it is something I have been wondering about over the last few months too. I began commenting on his blog, but, as my comment grew longer, I thought it is perhaps a better idea to flesh out my thoughts into a full post. Overall, I agree with Joern’s misgivings, but I would go even further to suggest that he was perhaps too forgiving towards transdisciplinary research.

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How do correlations between climate and biodiversity arise? UPDATED

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Anyone who as ever watched a David Attenborough documentary knows that biodiversity differs in areas with different climates. Only a few species an survive in hot and dry deserts whereas warm and wet tropical forests are teeming with life. But have you every stopped to wonder why this is so?

Why are certain climate conditions able to support many species and others not? More specifically, how does this work mechanistically?

This was the question my co-authors and I set out to answer in our most recent paper just published online at Global Ecology and Biogeography.

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What can Sudoku teach us about ecology and evolution?

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Evolution is creeping into several different aspects of ecology. The latest buzz is all about integrating ecology and evolution. Perhaps you’ve heard of the  latest research trends in eco-evolutionary dynamics or community phylogenetics?

Theodosius Dobzhansky famously stated that “Nothing in biology makes sense except in the light of evolution“. This claim is undoubtedly true, but I’ve recently found myself wondering whether our obsession with evolution is actually clouding our ability to do good ecological research.

Please don’t misunderstand me, I am not implying that evolution is not important in explaining patterns in nature, nor am I suggesting that we should disregard evolutionary explanations for these patterns. Instead, I believe that in order to gain a deeper understanding of ecology, we should perhaps partially blind our views using “evolution blinkers”. In fact, I’d even be so bold as to claim that unless we blind ourselves to evolution, we will never be able to fully grasp the true nature of ecological processes. Unifying ecology and evolution might actual limit our ability to build ecology as a science.

Richard Feynman used a useful chess analogy to explain how physics works. I’ll borrow this style of argument to explain my stance on ecology and evolution. However, since chess is too complicated for my liking, I’ll use an even simpler game: Sudoku. Continue reading →

The scalability of macroecology

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Russian Dolls

No matter at which scale you look at it, nature is remarkable.

Like many others, I was taught ecology in a very hierarchical way: individual organisms are part of a wider populations of species, collections of species form communities and communities come together to make up ecosystems. Similarly, single trees are nested within forests, which aggregate to form biomes. I’m sure you can come up with many comparable examples.

The trouble with such neat spatial hierarchies is that they lure us into believing that if patterns appear similar at several different spatial scales, then the processes leading to these patterns should also be similar. It’s so easy to assume that nature is like a set of Russian Dolls: each daughter exactly the same as its mother, only slightly smaller. But this is not necessarily the case.

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Some motivation to get you through your PhD

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If there is one thing I hate, it’s the stereotype that PhD students are pathetic, dependent, helpless creatures bogged down by self-doubt and self-pity. It annoys me even more that PhD students are responsible for perpetuating this myth. We laugh along with popular websites like Piled Higher and Deeper (a.k.a PhD comics) and What Should We Call Grad School, which regularly make jokes about the futility of grad school.

Sure, these sites are funny because there is an element of truth in them, but I believe that they cause more harm than good. Although they are well-meaning and try to foster a culture of solidarity among students, they are more likely to cause complacency than empowerment.

We don’t need another shoulder to cry on, we need a kick in the arse!

As I am nearing the end of my PhD experience, I thought I’d share a bit of motivational advice I found especially useful. It is the final chapter of Adam Ruben’s book, Surviving your stupid, stupid decision to go to grad school. Some of you may be familiar with Ruben’s writing, because he also writes a monthly column in Science Magazine, Experimental Error.

Here it is, enjoy.

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The startup culture of conservation entrepreneurship

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I’ve written about the need for self-started conservation initiatives on this blog before. And now I am pleased to boast that some of these ideas have just been published online in Conservation Biology. (If you don’t have subscription access through the publisher’s website, feel free to leave a comment below and I’ll forward the article to you as a PDF).

It’s a short opinion piece that is mainly intended to introduce the concept of social entrepreneurship to an audience of conservation scientists. The article should definitely not be considered as a how-to guide to conservation entrepreneurship, nor is it a comprehensive review of all the ways entrepreneurship can help to protect biodiversity. Instead, I hoped to convey three key points:

(1) there are conservation problems that are especially amenable to small, fast bootstrapped solutions;

(2) there are new ways of funding conservation initiatives that weren’t available 10 years ago; and

(3) most early-career conservation biologists in the current employment landscape will, at some point, be unemployed, so self-started conservation initiatives could become a necessity.

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MacArthur and Wilson’s Radical Theory wasn’t actually radical (even great ideas in ecology go unnoticed)

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Most ecologists know about the Theory of Island Biogeography; the theory that diversity patterns on islands are the consequence of dispersal from a mainland source. Robert MacArthur and E.O. Wilson presented this theory first as a research paper in 1963 and then as a monograph in 1967. The rest, as they say, is history.

The Theory of Island Biogeography is remarkable because it suggests that patterns of species co-existence are the consequence of chance, history and random dispersal. Before its publication, community ecologists generally assumed that species co-existence was due to deterministic niche-assembly, where the number and relative abundance of species were a result of ecological niches and the functional roles of each species.

The theory placed randomness at the forefront to community ecology. It also paved the way for Stephen Hubbell’s Unified Neutral Theory of Biodiversity and Biogeography; one of the most influential ecological theories in 21st century. In fact, the introductory chapter of Hubbell’s monograph (like this blog post) was titled “MacArthur and Wilson’s Radical Theory” in reverence to their path-breaking work.

Like the theory itself, MacArthur and Wilson have also reached cult-like status. Perhaps a most telling way of illustrating this fact is not by listing the prizes awarded to these two men (and there were many), but rather by listing the academic prizes named after them! The Ecological Society of America, for instance, awards the ‘Robert H. MacArthur Award‘ to eminent mid-career ecologists and the American Society of Naturalists grants the ‘Edward O. Wilson Naturalist Award‘ to mid-career researchers who make significant contributions to a particular ecosystem of group of organisms. Similarly, the International Biogeography Society has the ‘MacArthur & Wilson Award‘ for notable contributions to the field of biogeography.  Needless to say, MacArthur and Wilson are very influential and well-respected by contemporary ecologists (well, in most cases…).

The funny thing is that their paradigm shifting idea was actually proposed two decades earlier, by the less well-known lepidopterist Eugene Munroe. Continue reading →