Malady of numbers

30 07 2012

Organism abundance is the parameter most often requiring statistical treatment. Statistics turn our field/lab notes into estimates of population density after considering the individuals we can see and those we can’t. Later, statistical analyses will relate our density estimates to other factors (climate, demography, genetics, human impacts), allowing the examination of key issues such as extinction risk, biomonitoring or ecosystem services (humus formation, photosynthesis, pollination, fishing, etc.). Photos – top: a patch of fungi (Lacandon Jungle, Mexico), next down: a palm forest (Belize river, Belize), next down: an aggregation of butterflies (Amazon, Peru), and bottom: a group of river dolphins (Amazon, Colombia). Photos by Salvador Herrando-Pérez.

Another interesting and provocative post from my (now ex-) PhD student, Dr. Salvador Herrando-Pérez. After reading this post, you might be surprised to know that Salva was one of my more quantitative students, and although he struggled to keep up with the maths at times, he eventually become quite an efficient ecological modeller (see for yourself in his recent publications here and here).

When an undergraduate faces the prospect of a postgraduate degree (MSc/PhD), he or she is often presented with an overwhelming contradiction: the host university expects the student to have statistical skills for which he/she might never have received instruction. This void in the education system forges professionals lacking statistical expertise, skills that are mandatory for cutting-edge research!

Universities could provide the best of their societal services if, instead of operating in isolation, they integrated the different phases of academic training students go through until they enter the professional world. Far from such integration in the last 20 years, universities have become a genuine form of business and therefore operate competitively. Thus, they seek public and private funding by means of student fees (lecturing), as well as publications and projects developed by their staff (research). In this kind of market-driven academia, we need indicators of education quality that quantify the degree by which early-career training methods make researchers useful, innovative and cost-effective for our societies, particularly in the long term.

More than a century ago, the geologist and educator Thomas Chamberlin (1) distinguished acquisitive from creative learning methods. The former are “an attempt to follow by close imitation the processes of other thinkers and to acquire the results of their investigation by memorising”. The latter represent “the endeavour… to discover new truth or to make a new combination of truth or at least to develop by one’s own effort an individualised assemblage of truth… to think for one’s self”. From the onset of their academic training, students of many countries are instructed in acquisitive methods of learning that reward the retention of information, much of which falls into oblivion after being regurgitated during an exam. Apart from being a colossal waste of resources (because it yields near null individual or societal benefits), this vicious machinery is reinforced by reward and punishment in convoluted manners. For instance, one of my primary-school teachers had boys seated in class by a ‘ranking of intelligence’; so one could lose the first seat if the classmate in the second seat answered a question correctly, which the up-to-then ‘most intelligent’ had failed to hit. Read the rest of this entry »





Threats to biodiversity insurance from protected areas

26 07 2012

A red-eyed tree frog (Agalychnis callidryas) from Barro Colorado Island in Panama. This small island, just 1500 ha (3700 acres) in area, is one of the tropical protected areas evaluated in this study (photo © Christian Ziegler <zieglerphoto@yahoo.co>, Smithsonian Tropical Research Institute). Note: It is prohibited for any third party or agency to use or license this image; any use other then described above shall be subject to usage fees as determined solely by the photographer.

Much of conservation science boils down to good decision making: when, where and how we ‘set aside’ terrestrial or marine areas for specific protection against the ravages of human endeavour. This is the basis for the entire sub-discipline of conservation planning and prioritisation, and features prominantly in most aspects of applied conservation and restoration.

In other words, we do all this science to determine where we should emplace protected areas, lobby for getting more land and sea set aside so that we have ‘representative’ amounts (i.e., to prevent extinctions), and argue over the best way to manage these areas once established.

But what if this pinnacle of conservation achievement is itself under threat? What if many of our protected areas are struggling to insure biodiversity against human consumption? Well, it’d be a scary prospect, to say the least.

Think of it this way. We buy insurance policies to buffer our investments against tragedy; this applies to everything from our houses, worldly possessions, cars, livestock, health, to forest carbon stores. We buy the policies to give us peace of mind that in the event of a disaster, we’ll be bailed out of the mess with a much-needed cash injection. But what if following the disaster we learn that the policy is no good? What if there isn’t enough pay-out to fix the mess?

In biodiversity conservation, our ‘insurance’ is largely provided by protected areas. We believe that come what may, at least in these (relatively) rare places, biodiversity will persist despite our relentless consumerism.

Unfortunately, what we believe isn’t necessarily true.

Today I’m both proud and alarmed to present our latest research on the performance of tropical protected areas around the world. Published online in Nature this morning (evening, for you Europeans) is the 216-author (yes, that is correct – 216 of us) paper entitled “Averting biodiversity collapse in tropical forest protected areas” led by Bill Laurance. Read the rest of this entry »





Biodiversity conservation and behaviour change

23 07 2012

I have been asked by Diogo Veríssimo, a PhD student at the Durrell Institute of Conservation and Ecology (DICE) based at the University of Kent, to post a call for papers for a special issue of Conservation Evidence (details below). I’ve bumped into Diogo at a few conferences, and learnt a few weeks ago that he won the IUCN/Thomson Reuters Environmental Award for his essay entitled Greening the crisis: turning trouble into opportunity. Well done, Diogo.

Dear Colleagues,

I am inviting you to submit case-studies on behaviour change and biodiversity and conservation for a special issue in the journal Conservation Evidence, an online and open-access scientific journal that focuses on project-level conservation interventions with the aim of sharing lessons learned. The aim of this special issue is to document specific conservation interventions that delivered changes in behaviours relevant to the management and conservation of biodiversity and in this way share lessons learned.

Interventions that have not been successful are especially of interest as these allow for an understanding and discussion of what does not work and why. All case studies need to include an evaluation of the impacts of the intervention and are written by, or in partnership with, those who did the conservation work. Read the rest of this entry »





Experiments in carbon-biodiversity trade-offs

19 07 2012

Last month I covered a topic that is not only becoming the latest fashion-trend in conservation, it is also where much of the research funding is going. Whether or not this is the best use of limited research resources is largely irrelevant – as I always preach to fledgling grant writers: “Write about what the funding agency wants to fund, not what you want to do”. Cynical, I know, but it is oh-so-true.

The topic in question is how we as conservation biologists ensure that the new carbon economy drives positive change for biodiversity, rather than the converse. Hell knows we really can’t afford for land-use change to get any worse for biodiversity; worldwide we are on trajectory for a mass extinction within our lifetime, so anything that potentially makes it worse should be squashed completely.

But it seems that land- and seascape changes that might arise from trading carbon (including carbon pricing) are on a knife-edge as far as biodiversity is concerned. I described this dilemma in my previous post, and I am happy to say that the manuscript arising is almost complete. Briefly, if we as a society decide to try to reduce greenhouse gas emissions and capture as much carbon as possible by altering land-use practices, then it is likely that our forests will become vast monocultures incapable of sustaining much biodiversity at all. In other words, there’s a balance to be struck between what is good for carbon sequestration and what is good for biodiversity. While not always mutually exclusive, neither are they mutually attainable goals. Read the rest of this entry »





Empty seas coming to a shore near you

12 07 2012

Last week I had the pleasure of entertaining some old friends and colleagues for a writing workshop in Adelaide (don’t worry – they all came from southern Australia locations, so no massive carbon footprints for overseas travel). I’m happy to report it was a productive (and epicurean) week, but that’s not really the point of today’s post.

One of those participants was long-time colleague, Dr. Rik Buckworth. Rik and I first met in Darwin back in the early 2000s when he was lead fisheries scientist for Northern Territory Fisheries; this collaboration and friendship blossomed into an ARC Linkage Project (with Dr. Mark Meekan of AIMS) on shark fisheries (see some of the scientific outputs from that here, here, here and here). Rik has since moved to CSIRO in Brisbane, but keeps a hand in NT fisheries’ affairs. Incidentally, Rik trained under one of the most well-known fisheries modellers in the world – Carl Walters – when he did his PhD at the University of British Columbia back in the early 1990s.

During our workshop, Rik pointed out a paper he had co-authored back in 2009 in Reviews in Fish Biology and Fisheries that had completely escaped my attention – it’s a frightening and apocalyptic view of the Australasian marine tropics that seems to confirm our predictions about northern Australia’s marine future. Just take a look at the following two figures from their paper (Elasmobranchs in southern Indonesian fisheries: the fisheries, the status of the stocks and management options): Read the rest of this entry »





Ghost extinctions

5 07 2012

The Philippine bare-backed fruit bat (Dobsonia chapmani; body size = < 220 mm, < 150 g; IUCN status: ‘Critically Endangered A2cd’) is endemic to lowland rain forests [top habitat image] from Negros and Cebu islands. This species of flying fox had been missing from the 1970s and was declared extinct in 2002 (34). In May 2003, five specimens [one shown in the picture above] were trapped in night nets in the Calatong forest (Negros Island), a ~ 1,000-ha fragment of secondary rain forest and agricultural lands [bottom habitat image] (35). The species is reliant on fruit-bearing vegetation and caves for feeding and roosting, respectively. As with many other Philippine bats, it suffers from habitat degradation and hunting. The family Pteropodidae comprises > 150 species. Despite their Draculian look, they all feed on fruits and nectar, and act as important plant pollinators (36), as well as disease vectors such as Ebola virus (37). Flying foxes are distributed in the tropics and subtropics from the Eastern Mediterranean, through the Arabian Peninsula, Asia, Australia, and many islands of the Indian Ocean. Photos courtesy of Ely L. Alcala.

Jared Diamond (1) coined the expression ‘evil quartet’ for the four main human causes of species extinctions: habitat loss/fragmentation, overkill, introduced species and extinction chains [with climate change and extinction synergies (2), the updated expression would be ‘evil sextet”]. However, one third of ‘extinct’ mammal species has been ‘found’ again. Recent studies reveal that the probability of rediscovery depends on the cause of extinction.

Arriving in a city to search for an old friend, I would first look in the suburb where he lived, the pub where we enjoyed a drink and some music, or the park where we used to play football. But if my friend was an outlaw, or had recently gone through a traumatic experience, my chances of finding him at his favourite spots would shrink.

If, instead of a friend, we are searching for the last survivors of an extinct-declared species, surveys also tend to take place in the habitat in which the species was previously found. Such a strategy rests on the classical hypothesis that, given the spatial distribution of a species, its gradual decline must occur from the periphery to the core of its distribution (‘range collapse’) where, in theory, the habitat should be of better quality and the number of individuals higher (3). In contrast, recent work supports that the trajectory of demise of threatened vertebrates progresses from the core to the periphery (‘range eclipse’) (4), because many perturbations make their way as a progressive wave, e.g, fire, logging or urbanisation.

Diana Fisher (5) supports the ‘range eclipse’ hypothesis for ‘extinct’ mammals which have been rediscovered. She quantifies that 60% of the new records are made from peripheral habitats, mainly when the principal cause of extirpation is habitat loss. Not only that, on average species are rediscovered at altitudes 35 % higher than historical records, and only in 5 % of the cases at the locality where it had been last seen.

Read the rest of this entry »