50/500 or 100/1000 debate not about time frame

26 06 2014

Not enough individualsAs you might recall, Dick Frankham, Barry Brook and I recently wrote a review in Biological Conservation challenging the status quo regarding the famous 50/500 ‘rule’ in conservation management (effective population size [Ne] = 50 to avoid inbreeding depression in the short-term, and Ne = 500 to retain the ability to evolve in perpetuity). Well, it inevitably led to some comments arising in the same journal, but we were only permitted by Biological Conservation to respond to one of them. In our opinion, the other comment was just as problematic, and only further muddied the waters, so it too required a response. In a first for me, we have therefore decided to publish our response on the arXiv pre-print server as well as here on ConservationBytes.com.

50/500 or 100/1000 debate is not about the time frame – Reply to Rosenfeld

cite as: Frankham, R, Bradshaw CJA, Brook BW. 2014. 50/500 or 100/1000 debate is not about the time frame – Reply to Rosenfeld. arXiv: 1406.6424 [q-bio.PE] 25 June 2014.

The Letter from Rosenfeld (2014) in response to Jamieson and Allendorf (2012) and Frankham et al. (2014) and related papers is misleading in places and requires clarification and correction, as follows: Read the rest of this entry »





We’re sorry, but 50/500 is still too few

28 01 2014

too fewSome of you who are familiar with my colleagues’ and my work will know that we have been investigating the minimum viable population size concept for years (see references at the end of this post). Little did I know when I started this line of scientific inquiry that it would end up creating more than a few adversaries.

It might be a philosophical perspective that people adopt when refusing to believe that there is any such thing as a ‘minimum’ number of individuals in a population required to guarantee a high (i.e., almost assured) probability of persistence. I’m not sure. For whatever reason though, there have been some fierce opponents to the concept, or any application of it.

Yet a sizeable chunk of quantitative conservation ecology develops – in various forms – population viability analyses to estimate the probability that a population (or entire species) will go extinct. When the probability is unacceptably high, then various management approaches can be employed (and modelled) to improve the population’s fate. The flip side of such an analysis is, of course, seeing at what population size the probability of extinction becomes negligible.

‘Negligible’ is a subjective term in itself, just like the word ‘very‘ can mean different things to different people. This is why we looked into standardising the criteria for ‘negligible’ for minimum viable population sizes, almost exactly what the near universally accepted IUCN Red List attempts to do with its various (categorical) extinction risk categories.

But most reasonable people are likely to agree that < 1 % chance of going extinct over many generations (40, in the case of our suggestion) is an acceptable target. I’d feel pretty safe personally if my own family’s probability of surviving was > 99 % over the next 40 generations.

Some people, however, baulk at the notion of making generalisations in ecology (funny – I was always under the impression that was exactly what we were supposed to be doing as scientists – finding how things worked in most situations, such that the mechanisms become clearer and clearer – call me a dreamer).

So when we were attacked in several high-profile journals, it came as something of a surprise. The latest lashing came in the form of a Trends in Ecology and Evolution article. We wrote a (necessarily short) response to that article, identifying its inaccuracies and contradictions, but we were unable to expand completely on the inadequacies of that article. However, I’m happy to say that now we have, and we have expanded our commentary on that paper into a broader review. Read the rest of this entry »





Making the scientific workshop work

28 10 2013
I don't mean this

I don’t mean this

I’ve been a little delayed in blogging this month, but for a very good reason – I’ve just experienced one of the best workshops of my career. I’d like to share a little of that perfect science recipe with you now.

I’ve said it before, but it can stand being repeated: done right, workshops can be some of the most efficient structures for doing big science.

First, let me define ‘workshop’ for those of you who might have only a vague notion of what it entails. To me, a workshop is a small group of like-minded scientists – all of whom possess different skills and specialities – who are brought together to achieve one goal. That goal is writing the superlative manuscript for publication.

So I don’t mean just a bog-standard chin-wag infected with motherhoods and diatribes. Workshops are not mini-conferences; neither are they soap boxes. It is my personal view that nothing can waste a scientist’s precious time more than an ill-planned and aimless workshop.

But with a little planning and some key ingredients that I’ll list shortly, you can turn a moderately good idea into something that can potentially shake the foundations of an entire discipline. So what are these secret ingredients? Read the rest of this entry »





Advice for getting your dream job in conservation science

4 12 2012

people management

A few weeks ago I heard from an early-career researcher in the U.S. who had some intelligent things to say about getting jobs in conservation science based on a recent Conservation Biology paper she co-wrote. Of course, for all the PhDs universities are pumping out into the workforce, there will never be enough positions in academia for them all. Thus, many find their way into non-academic positions. But – does a PhD in science prepare you well enough for the non-academic world? Apparently not.

Many post-graduate students don’t start looking at job advertisements until we are actually ready to apply for a job. How often do we gleam the list of required skills and say, “If only I had done something to acquire project management skills or fundraising skills, then I could apply for this position…”? Many of us start post-graduate degrees assuming that our disciplinary training for that higher degree will prepare us appropriately for the job market. In conservation science, however, many non-disciplinary skills (i.e., beyond those needed to be a good scientist) are required to compete successfully for non-academic positions. What are these skills?

Our recent paper in Conservation Biology (Graduate student’s guide to necessary skills for nonacademic conservation careers) sifted through U.S. job advertisements and quantified how often different skills are required across three job sectors: nonprofit, government and private. Our analysis revealed that several non-disciplinary skills are particularly critical for job applicants in conservation science. The top five non-disciplinary skills were project management, interpersonal, written communication, program leadership and networking. Approximately 75% of the average job advertisement focused on disciplinary training and these five skills. In addition, the importance of certain skills differed across the different job sectors.

Below, we outline the paper’s major findings with regard to the top five skills, differences among sectors, and advice for how to achieve appropriate training while still in university. Read the rest of this entry »





Protected areas work, but only when you put in the effort

15 11 2012

Apologies for the delay in getting this latest post out. If you read my last one, you’ll know that I’ve been in the United Kingdom for the last week. I’m writing this entry in the train down from York to Heathrow, from which I’ll shortly begin the gruelling 30-hour trip home to Adelaide.

Eight days on the other side of the planet is a bit of a cyclonic trip, but I can honestly say that it was entirely worth it. My first port of call was London where I attended the Zoological Society of London’s Protected Areas Symposium, which is the main topic on which I’ll elaborate shortly.

But I also visited my friend and colleague, Dr. Kate Parr at the University of Liverpool, where I also had the pleasure of talking with Rob Marrs and Mike Begon. Liverpool was also where I first observed the habits of a peculiar, yet extremely common species – the greater flabby, orange-skinned, mini-skirted, black-eyed scouser. Fascinating.

I then had the privilege and serendipitous indulgence of visiting the beautiful and quaint city of York where I gave another talk to the Environment Department at the University of York. My host, Dr. Kate Arnold was simply lovely, and I got to speak with a host of other very clever people including Callum Roberts, Phil Platts, Andy Marshall and Murray Rudd. Between the chats and real ales, mushy peas, pork pies and visits to the Minster, I was in north English heaven.

Enough of the cultural compliments – the title of this post was the take-home message of the ZSL symposium. There I gave a 25-minute talk summarising our recent paper on the performance of tropical protected areas around the globe, and added a few extra analyses in the process. One interesting result that was missing from the original paper was the country-level characteristics that explain variation in protected area ‘health’ (as we defined it in the Nature paper). After looking at a number of potential drives, including per-capita wealth, governance quality, environmental performance, human population density and the proportion of high conservation-value protected areas (IUCN Ia, Ib, II and IV categories), it came out that at least at that coarse country scale that only the proportion of high conservation-value protected areas explained any additional variation in health. In other words, the more category Ia, Ib, II and IV protected areas a country has (relative to the total), the better their protected areas do on average (and remember, we’re talking largely about developing and tropical nations here). Read the rest of this entry »





Linking disease, demography and climate

1 08 2010

Last week I mentioned that a group of us from Australia were travelling to Chicago to work with Bob Lacy, Phil Miller, JP Pollak and Resit Akcakaya to make some pretty exciting developments in next-generation conservation ecology and management software. Also attending were Barry Brook, our postdocs: Damien Fordham, Thomas Prowse and Mike Watts, our colleague (and former postdoc) Clive McMahon, and a student of Phil’s, Michelle Verant. At the closing of the week-long workshop, I thought I’d share my thoughts on how it all went.

In a word, it was ‘productive’. It’s not often that you can spend 1 week locked in a tiny room with 10 other geeks and produce so many good and state-of-the-art models, but we certainly achieved more than we had anticipated.

Let me explain in brief why it’s so exciting. First, I must say that even the semi-quantitative among you should be ready for the appearance of ‘Meta-Model Manager (MMM)’ in the coming months. This clever piece of software was devised by JP, Bob and Phil to make disparate models ‘talk’ to each other during a population projection run. We had dabbled with MMM a little last year, but its value really came to light this week.

We used MMM to combine several different models that individually fail to capture the full behaviour of a population. Most of you will be familiar with the individual-based population viability (PVA) software Vortex that allows relatively easy PVA model building and is particular useful for predicting extinction risk of small populations. What you most likely don’t know exists is what Phil, Bob and JP call Outbreak – an epidemiological modelling software based on the classic susceptible-exposed-infectious-recovered framework. Outbreak is also an individual-based model that can talk directly to Vortex, but only through MMM. Read the rest of this entry »





Put the bite back into biodiversity conservation

2 07 2010

Today’s guest post is by Dr. Euan Ritchie, formerly of James Cook University, but who is now firmly entrenched at Deakin University in Victoria as a new Lecturer in ecology. Euan’s exciting research over the course of his memorable PhD (under the tutelage of renowned ecologist-guru, Professor Chris Johnson) has produced some whoppingly high-impact research. This latest instalment highlights a series of related papers he and his colleagues have just produced. We’re fortunate he agreed to give us his thoughts. Interestingly, the topic was just highlighted in the last issue of NatureDon’t damage dingos.

Corey has invited me to report on a recent paper published in Ecology Letters and another related study in PloS One, which together show how a better understanding of dingoes and their social structure and associated behaviour can help us to maintain or improve the health of our terrestrial ecosystems. This work, led by PhD student Arian Wallach (University of Adelaide), and involving collaborations with John Read (University of Adelaide), Adam O’Neill (C&A Environmental Services) and Christopher Johnson and me (James Cook University), offers some of the strongest evidence yet of the key roles top predators play in maintaining the balance.

Invasive species, along with habitat loss and the impacts of climate change, are among the greatest threats to the continued survival of many species. Because of this, millions of dollars and time is spent each year to control their populations. The impacts of invasive species in Australia are sadly all too obvious, with nearly half of the world’s mammal extinctions in the last 200 years occurring in Australia, with the prime suspects being the introduced domestic cat and red fox. However, despite massive, costly and ongoing attempts to control fox and cat populations successfully, we continue to witness the decline of many of our native species. Why? We would argue that the problem is that for too long much of our conservation and management efforts have been focused on treating symptoms and not the cause, which is the loss of ecosystem resilience (the natural ability of ecosystems to withstand change).

Read the rest of this entry »








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