Human population size: speeding cars can’t stop quickly

28 10 2014

Stop breeding cartoon-Steve Bell 1994Here at ConservationBytes.com, I write about pretty much anything that has anything remotely to do with biodiversity’s prospects. Whether it is something to do with ancient processes, community dynamics or the wider effects of human endeavour, anything is fair game. It’s a little strange then that despite cutting my teeth in population biology, I have never before tackled human demography. Well as of today, I have.

The press embargo has just lifted on our (Barry Brook and my) new paper in PNAS where we examine various future scenarios of the human population trajectory over the coming century. Why is this important? Simple – I’ve argued before that we could essentially stop all conservation research tomorrow and still know enough to deal with most biodiversity problems. If we could only get a handle on the socio-economic components of the threats, then we might be able to make some real progress. In other words, we need to find out how to manage humans much more than we need to know about the particulars of subtle and complex ecological processes to do the most benefit for biodiversity. Ecologists tend to navel-gaze in this arena far too much.

So I called my own bluff and turned my attention to humans. Our question was simple – how quickly could the human population be reduced to a more ‘sustainable’ size (i.e., something substantially smaller than now)? The main reason we posed that simple, yet deceptively loaded question was that both of us have at various times been faced with the question by someone in the audience that we were “ignoring the elephant in the room” of human over-population.

Read the rest of this entry »





Demonising the hellbender

19 09 2014
Not 'Hellraiser', FFS - 'hellbender'

Not ‘Hellraiser’, FFS – ‘hellbender’

Here’s one by my new PhD student, Leah Collett:

I have never heard of the hellbender before. “Brilliant name”, I thought. Then I saw it mentioned again a few days later, in company with honey badgers and blue-footed boobies, in a recent article on why we need to see nature as useless in order to ‘save’ it.

So what is it? The hellbender is a species of salamander found in eastern North America, the only species of its genus it turns out, and one of only three left in its family (Cryptobranchidae – ‘hidden gills’). It is assessed as Near Threatened with possible extinction in the near future by the IUCN Red List. Along with the, sadly all too often, habitat degradation it is suffering due to it being highly sensitive to environmental change, it is still believed to be poisonous and that it will kill other fish and their eggs with this poison. In this day and age, some people will kill these salamanders when they come across them when they are out fishing, due to inaccurate held beliefs. I think I found it more incredible that this still occurs in a country where people have quick access to research and information denouncing such a myth.

This wonderful document on the biology and ecology of the hellbenders includes a section titled ‘Man and Hellbenders’ and highlights the likely culprit for starting the ‘hellbenders are poisonous – kill them all’ campaign:

“Dr N. Bayard Green (1971) related how a former editor of the Pocahontas Times (Pocahontas, West Virginia) in 1926 continually tried to vilify the hellbender as a destroyer of game fish and their eggs. Throughout West Virginia many sportsmen’s groups attempted to eradicate many of the so-called enemies of fish and game.”

(I could not read the original paper of Dr Green’s, although it might be available in the collections section). Read the rest of this entry »





We generally ignore the big issues

11 08 2014

I’ve had a good week at Stanford University with Paul Ehrlich where we’ve been putting the final touches1 on our book. It’s been taking a while to put together, but we’re both pretty happy with the result, which should be published by The University of Chicago Press within the first quarter of 2015.

It has indeed been a pleasure and a privilege to work with one of the greatest thinkers of our age, and let me tell you that at 82, he’s still a force with which to be reckoned. While I won’t divulge much of our discussions here given they’ll appear soon-ish in the book, I did want to raise one subject that I think we all need to think about a little more.

The issue is what we, as ecologists (I’m including conservation scientists here), choose to study and contemplate in our professional life.

I’m just as guilty as most of the rest of you, but I argue that our discipline is caught in a rut of irrelevancy on the grander scale. We spend a lot of time refining the basics of what we essentially already know pretty well. While there will be an eternity of processes to understand, species to describe, and relationships to measure, can our discipline really afford to avoid the biggest issues while biodiversity (and our society included) are flushed down the drain?

Read the rest of this entry »





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 »





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 »





Australia’s (latest) war on the environment

3 03 2014

monkYes, the signs were there, but they weren’t clandestine messages written in the stars or in the chaos of tea-leaf dregs. We saw this one coming, but Australians chose to ignore the warning signs and opt for the American political model of extremism, religiosity, plutocracy and science denial.

Enter the ‘Tea Party’ of Australia – the ‘new’ Coalition where reigning Rex perditor Prime Minister Tony The Monk Abbott1 has, in just a few short months, turned back the clock on Australian environmental protection some 40 years.

Yes, we saw it coming, but it wasn’t a tautological fait accompli just because it concerned a ‘conservative’ government. It’s difficult to remember, I know, that conservative governments of yesteryear implemented some strikingly powerful and effective environmental legislation. Indeed, it was the former incarnation of the Coalition government that implemented the once-formidable Environmental Protection and Biodiversity Conservation (EPBC) Act under the direction of then Environment Minister, Robert Hill. A colossus of sorts, the EPBC suffers from many ailments. While it’s the only really bitey environmental legislation we’ve got, that colossus is a lumbering, limping giant missing more than a few teeth – it needs a complete overhaul.

As most Australians are unfortunately aware, The Monk repeatedly and defiantly promised to repeal the Labor-government carbon price implemented in July 2012, despite the absolute necessity to tax the heaviest pollutersWhile somewhat sheepish about his recent climate disruption denialism following his election in 2013, a denialist he remains:

Let us re-familiarise ourselves with some of his historical pearlers: 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 »








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