I’m not in any way formally involved in either the IPCC or IPBES, although I’ve been involved indirectly in analysing many elements of both the language of the reports and the science underlying their predictions.
Today, The Guardianreported that a leaked copy of an IPCC report scheduled for release soon indicated that, well, the climate-change situation is in fact worse than has been previously reported in IPCC documents.
If you’re a biologist, climatologist, or otherwise-informed person, this won’t come as much of a surprise. Why? Well, the latest report finally recognises that the biosphere is not just some big balloon that slowly inflates or deflates with the whims of long-term climate variation. Instead, climate records over millions of years show that the global climate can and often does shift rapidly between different states.
As someone who writes a lot of models — many for applied questions in conservation management (e.g., harvest quotas, eradication targets, minimum viable population sizes, etc.), and supervises people writing even more of them, I’ve had many different experiences with their uptake and implementation by management authorities.
Some of those experiences have involved catastrophic failures to influence any management or policy. One particularly painful memory relates to a model we wrote to assist with optimising approaches to eradicate (or at least, reduce the densities of) feral animals in Kakadu National Park. We even wrote the bloody thing in Visual Basic (horrible coding language) so people could run the module in Excel. As far as I’m aware, no one ever used it.
Others have been accepted more readily, such as a shark-harvest model, which (I think, but have no evidence to support) has been used to justify fishing quotas, and one we’ve done recently for the eradication of feral pigs on Kangaroo Island (as yet unpublished) has led directly to increased funding to the agency responsible for the programme.
According to Altmetrics (and the online tool I developed to get paper-level Altmetric information quickly), only 3 of the 16 of what I’d call my most ‘applied modelling’ papers have been cited in policy documents:
I’m pleased to announce the publication of a paper led by Kathryn Venning (KV) that was derived from her Honours work in the lab. Although she’s well into her PhD on an entirely different topic, I’m overjoyed that she persevered and saw this work to publication.
Feral cats occupy every habitat in the country, from the high tropics to the deserts, and from the mountains to the sea. They adapt to the cold just as easily as they adapt to the extreme heat, and they can eat just about anything that moves, from invertebrates to the carcases of much larger animals that they scavenge.
Cats are Australia’s bane, but you can’t help but be at least a little impressed with their resilience.
Still, we have to try our best to get rid of them where we can, or at least reduce their densities to the point where their ecological damage is limited.
Typically, the only efficient and cost-effective way to do that is via lethal control, but by using various means. These can include direct shooting, trapping, aerial poison-baiting, and a new ‘smart’ method of targeted poison delivery via a prototype device known as a Felixer™️. The latter are particularly useful for passive control in areas where ground-shooting access is difficult.
A live Felixer™️ deployed on Kangaroo Island (photo: CJA Bradshaw 2020)
A few years back the federal government committed what might seem like a sizeable amount of money to ‘eradicate’ cats from Australia. Yeah, good luck with that, although the money has been allocated to several places where cat reduction and perhaps even eradication is feasible. Namely, on islands.
We know it is more than 60,000 years since the first people entered the continent of Sahul — the giant landmass that connected New Guinea, Australia and Tasmania when sea levels were lower than today.
But where the earliest people moved across the landscape, how fast they moved, and how many were involved, have been shrouded in mystery.
Our latest research, published today shows the establishment of populations in every part of this giant continent could have occurred in as little as 5,000 years. And the entire population of Sahul could have been as high as 6.4 million people.
This translates to more than 3 million people in the area that is now modern-day Australia, far more than any previous estimate.
The first people could have entered through what is now western New Guinea or from the now-submerged Sahul Shelf off the modern-day Kimberley (or both).
But whichever the route, entire communities of people arrived, adapted to and established deep cultural connections with Country over 11 million square kilometres of land, from northwestern Sahul to Tasmania.
Map of what Australia looked like for most of the human history of the continent when sea levels were lower than today. Author provided
This equals a rate of population establishment of about 1km per year (based on a maximum straight-line distance of about 5,000km from the introduction point to the farthest point).
That’s doubly impressive when you consider the harshness of the Australian landscape in which people both survived and thrived.
For many years I’ve been interested in modelling the extinction dynamics of megafauna. Apart from co-authoring a few demographically simplified (or largely demographically free) models about how megafauna species could have gone extinct, I have never really tried to capture the full nuances of long-extinct species within a fully structured demographic framework.
That is, until now.
But how do you get the life-history data of an extinct animal that was never directly measured. Surely, things like survival, reproductive output, longevity and even environmental carrying capacity are impossible to discern, and aren’t these necessary for a stage-structured demographic model?
The answer to the first part of that question “it’s possible”, and to the second, it’s “yes”. The most important bit of information we palaeo modellers need to construct something that’s ecologically plausible for an extinct species is an estimate of body mass. Thankfully, palaeontologists are very good at estimating the mass of the things they dig up (with the associated caveats, of course). From such estimates, we can reconstruct everything from equilibrium densities, maximum rate of population growth, age at first breeding, and longevity.
But it’s more complicated than that, of course. In Australia anyway, we’re largely dealing with marsupials (and some monotremes), and they have a rather different life-history mode than most placentals. We therefore have to ‘correct’ the life-history estimates derived from living placental species. Thankfully, evolutionary biologists and ecologists have ways to do that too.
The Pleistocene kangaroo Procoptodon goliah, the largest and most heavily built of the short-faced kangaroos, was the largest and most heavily built kangaroo known. It had an unusually short, flat face and forwardly directed eyes, with a single large toe on each foot (reduced from the more normal count of four). Each forelimb had two long, clawed fingers that would have been used to bring leafy branches within reach.
So with a battery of ecological, demographic, and evolutionary tools, we can now create reasonable stochastic-demographic models for long-gone species, like wombat-like creatures as big as cars, birds more than two metres tall, and lizards more than seven metres long that once roamed the Australian continent.
Ancient clues, in the shape of fossils and archaeological evidence of varying quality scattered across Australia, have formed the basis of several hypotheses about the fate of megafauna that vanished during a peak about 42,000 years ago from the ancient continent of Sahul, comprising mainland Australia, Tasmania, New Guinea and neighbouring islands.
There is a growing consensus that multiple factors were at play, including climate change, the impact of people on the environment, and access to freshwater sources.
Just published in the open-access journal eLife, our latest CABAH paper applies these approaches to assess how susceptible different species were to extinction – and what it means for the survival of species today.
Using various characteristics such as body size, weight, lifespan, survival rate, and fertility, we (Chris Johnson, John Llewelyn, Vera Weisbecker, Giovanni Strona, Frédérik Saltré & me) created population simulation models to predict the likelihood of these species surviving under different types of environmental disturbance.
We compared the results to what we know about the timing of extinction for different megafauna species derived from dated fossil records. We expected to confirm that the most extinction-prone species were the first species to go extinct – but that wasn’t necessarily the case.
While we did find that slower-growing species with lower fertility, like the rhino-sized wombat relative Diprotodon, were generally more susceptible to extinction than more-fecund species like the marsupial ‘tiger’ thylacine, the relative susceptibility rank across species did not match the timing of their extinctions recorded in the fossil record.
Indeed, we found no clear relationship between a species’ inherent vulnerability to extinction — such as being slower and heavier and/or slower to reproduce — and the timing of its extinction in the fossil record.
In fact, we found that most of the living species used for comparison — such as short-beaked echidnas, emus, brush turkeys, and common wombats — were more susceptible on average than their now-extinct counterparts.
Easy. Don’t go swimming/surfing/snorkelling/diving in the ocean.
“Oh, shit”
Sure, that’s true, but if you’re like many Australians, the sea is not just a beautiful thing to look at from the window, it’s a way of life. Trying telling a surfer not to surf, or a diver not to dive. Good luck with that.
It turns out that many of the deterrents we tested failed to show any reduction in the probability of a shark biting, with only one type of electronic deterrent showing any effect at all (~ 60% reduction).
Great. But what might that mean in terms of how many people could be saved by wearing such electronic deterrents? While the probability of being bitten by a shark is low globally, even in Australia (despite public perceptions), we wondered if the number of lives saved and injuries avoided was substantial.
In a new paper just published today in Royal Society Open Science, we attempted to answer that question.
To predict how many people could avoid shark bites if they were using properly donned electronic deterrents that demonstrate some capacity to dissuade sharks from biting, we examined the century-scale time series of shark bites on humans in Australia. This database — the ‘Australian Shark Attack File‘ — is one of the most comprehensive databases of its kind.
My father was a hunter, and by proxy so was I when I was a lad. I wasn’t really a ‘good’ hunter in the sense that I rarely bagged my quarry, but during my childhood not only did I fail to question the morality of recreational hunting, I really thought that in fact it was by and large an important cultural endeavour.
It’s interesting how conditioned we become as children, for I couldn’t possibly conceive of hunting a wild, indigenous species for my own personal satisfaction now. I find the process not only morally and ethically reprehensible, I also think that most species don’t need the extra stress in an already environmentally stressed world.
I admit that I do shoot invasive European rabbits and foxes on my small farm from time to time — to reduce the grazing and browsing pressure on my trees from the former, and the predation pressure on the chooks from the latter. Of course, we eat the rabbits, but I tend just to bury the foxes. My dual perspective on the general issue of hunting in a way mirrors the two sides of the recreational hunting issue we report in our latest paper.
Wild boar (Sus scrofus). Photo: Valentin Panzirsch, CC BY-SA 3.0 AT, via Wikimedia Commons
I want to be clear here that our paper focuses exclusively on recreational hunting, and especially the hunting of charismatic species for their trophies. The activity is more than just a little controversial, for it raises many ethical and moral concerns at the very least. Yet, recreational hunting is frequently suggested as a way to conserve nature and support local people’s livelihoods.
This might be a little outside the realms of ‘conservation’ per se, but put has a lot of ecology-evolution components, with spin-off applications to modern conservation. Please spread the word.
The Research Associate will investigate how the skull of extant mammal populations varies according to their environment, with a focus on the interaction between mega-herbivores and vegetation change.
The project aims to understand the relationship between evolved morphological adaptation and phenotypic plasticity in changing local environments. The Research Associate will extrapolate this knowledge to the iconic extinct Australian megafauna, with the aim of establishing how changing conditions of the past might have contributed to the demise of the Australian megafauna.
The candidate will be expected to work within a large group of collaborators at Flinders University and interstate, and supervise postgraduate students. The collaboration environment includes teams of national and international researchers, and will particularly integrate research in Global Ecology Lab led by Corey Bradshaw, and Chris Johnson‘s lab at the University of Tasmania. The candidate will be expected to liaise with academic, administrative and technical staff according to the University’s policies, practices and standards.
Blistering heat, pouring rain, finding volunteers, submitting field-trip forms, forgetting equipment, data sheets blowing away in the wind — a field-based research project is hard at the best of times. Add white sharks into the mix and you start to question whether this project is even possible. These were some of my realisations when I started my Honours year studying shark deterrents.
A specific memory from my first field expedition was setting off on a six-day boat trip with the comfortable sight of land getting smaller and smaller, in an already rough ocean, to find one of the most feared fish in the sea, the white shark. I was intimidated, but also excited.
Over the next few days reality set in and I experienced the true challenges of working in the field. When there were no sharks around, I had to concentrate on the bait line for hours in anticipation of a sudden ambush. When there were sharks around, it was all systems go and there was no room for error — not with a fish of this size. It didn’t matter how tired or seasick I was, the data had to be collected.
When I found out that I had been offered a field-based PhD extending my shark-deterrent research from my Honours, other than being over-the-moon, I knew I had a big few years ahead of me. I immediately began preparing mentally for the challenges that came along with my field-based research. Particularly the long periods of time I knew I would spend away from home and my family.
Most conservation research and its applications tend to happen most frequently at reasonably fine spatial and temporal scales — for example, mesocosm experiments, single-species population viability analyses, recovery plans, patch-level restoration approaches, site-specific biodiversity surveys, et cetera. Yet, at the other end of the scale spectrum, there have been many overviews of biodiversity loss and degradation, accompanied by the development of multinational policy recommendations to encourage more sustainable decision making at lower levels of sovereign governance (e.g., national, subnational).
Yet truly global research in conservation science is fact comparatively rare, as poignantly demonstrated by the debates surrounding the evidence for and measurement of planetary tipping points (Barnosky et al., 2012; Brook et al., 2013; Lenton, 2013). Apart from the planetary scale of human-driven disruption to Earth’s climate system (Lenton, 2011), both scientific evidence and policy levers tend to be applied most often at finer, more tractable research and administrative scales. But as the massive ecological footprint of humanity has grown exponentially over the last century (footprintnetwork.org), robust, truly global-scale evidence of our damage to the biosphere is now starting to emerge (Díaz et al., 2019). Consequently, our responses to these planet-wide phenomena must also become more global in scope.
Conservation scientists are adept at chronicling patterns and trends — from the thousands of vertebrate surveys indicating an average reduction of 68% in the numbers of individuals in populations since the 1970s (WWF, 2020), to global estimates of modern extinction rates (Ceballos and Ehrlich, 2002; Pimm et al., 2014; Ceballos et al., 2015; Ceballos et al., 2017), future models of co-extinction cascades (Strona and Bradshaw, 2018), the negative consequences of invasive species across the planet (Simberloff et al., 2013; Diagne et al., 2020), discussions surrounding the evidence for the collapse of insect populations (Goulson, 2019; Komonen et al., 2019; Sánchez-Bayo and Wyckhuys, 2019; Cardoso et al., 2020; Crossley et al., 2020), the threats to soil biodiversity (Orgiazzi et al., 2016), and the ubiquity of plastic pollution (Beaumont et al., 2019) and other toxic substances (Cribb, 2014), to name only some of the major themes in global conservation.
Several months ago, Daniel Blumstein of UCLA approached me with an offer — fancy leading a Special Section in a new Frontiers journal dedicated to conservation science?
I admit that my gut reaction was a visceral ‘no’, both in terms of the extra time it would require, as well as my autonomous reflex of ‘not another journal, please‘.
I had, for example, spent a good deal of blood, sweat, and tears helping to launch Conservation Letters when I acted as Senior Editor for the first 3.5 years of its existence (I can’t believe that it has been nearly a decade since I left the journal). While certainly an educational and reputational boost, I can’t claim that the experience was always a pleasant one — as has been said many times before, thefastest way to makeenemies is to become an editor.
But then Dan explained what he had in mind for Frontiers in Conservation Science, and the more I spoke with him, the more I started to think that it wasn’t a bad idea after all for me to join.
Climate change implies change in temperature and water, and both factors shape species’ tolerances to thermal stress. In our latest article, we show that lack of drinking water maximises differences in tolerance to high temperatures among populations of Iberian lizard species.
Climate change is a multidimensional phenomenon comprising temporal and spatial shifts in both temperature and precipitation (1). How we perceive climate change depends on whether we measure it as shift in (i) mean conditions (e.g., the mean air temperature or rainfall over a decade within a given territory), (ii) magnitude or frequency of extreme conditions (e.g., the frequency of floods or tornados or the number of days with temperatures or rainfall above or below a given threshold), or (iii) speed at which mean or extreme conditions change in space and/or time.
In aquatic ecosystems, climate change further alters water acidity, oxygen dissolution and melting of ice. However, many people, including some scientists, tend to equate climate change erroneously with increased mean temperatures. Psychologists have made the semantic point that the use of the expressions climate change and global warming as synonyms can give mixed messages to politicians, and society in general, about how serious and complex the climate emergency we are facing really is (2, 3) — see NASA’s simple-worded account on the subject here.
In our latest article (4), we reviewed the ecological literature to determine to what extent ecologists investigating the tolerance of terrestrial animals to high temperatures have looked at thermal effects over water effects. It turns out, they were five times more likely to examine temperature over water.
Frequency of correlations between climate (air temperature versus precipitation) and tolerance to high temperature of terrestrial fauna in 64 papers published in the ecological literature (thickest link = 36, thinnest link = 2) following a systematic literature review in Scopus (4).
This is counterintuitive. Just imagine you have been walking under the sun for several hours on one of those dog days of summer, and you are offered to choose between a sunshade or a bottle of water. I’d bet you’d choose the bottle of water.
This little historical overview by recently completed undergraduate student, Sofie Costin (soon to join our lab!), nicely summarises the history, strengths, and limitations of species distribution modelling in ecology, conservation and restoration. I thought it would be an excellent resource for those who are just entering the world of species distribution models.
Of course, there is a strong association between and given species and its environment1. As such, climate and geographical factors have been often used to explain the distribution of plant and animal species around the world.
Predictive ecological models, otherwise known as ‘niche models’ or ‘species distribution models’ have become a widely used tool for the planning of conservation strategies such as pest management and translocations2-5. In short, species distribution models assess the relationship between environmental conditions and species’ occurrences, and then can estimate the spatial distribution of habitats suited to the study species outside of the sampling area3,6.
While the application of species distribution models can reduce the time and cost associated with conservation research, and conservation managers are relying increasingly on them to inform their conservation strategies4, species distribution models are by no means a one-stop solution to all conservation issues. Read the rest of this entry »
Unicorns, like job security, used to exist (actually, it’s an Elasmotherium)
The term ‘job security’ seems a fanciful idea to budding biologists — you may as well be studying unicorns (and no, narwhal don’t count …)! Now, you’re a fully fledged adult, your thoughts are likely filled with adult questions like ‘where will I live’ and ‘how will I scrape some money together?’. Not knowing where to go next can be very stressful.
A change in profession might help with job security, but if you’ve made it this far in biology, its highly likely that you (like me) have been obsessed with biology since early childhood, and it’s not something you’re willing to give up easily. On top of that, you now have years of research experience and skill development behind you — it would be better if that experience didn’t go to waste. How, then, can we keep funding our biology addiction? I don’t want to sound like a snake-oil salesman here, so let’s be straight-up about this: there are no easy options. But, importantly, there are options — in research, the university sector, and wider afield.
So, down to the serious business. Your options (depending on your personal preferences) are:
1. Research or bust!
In-housepostdoctoral fellowships
Research bodies in Australia, including many universities, the CSIRO and the Australian Museum, offer in-house postdoctoral fellowships for early-career researchers. Applying for one of these postdocs usually involves the candidate developing a research proposal and initiating collaboration with researchers in the institute offering the fellowship. Read the rest of this entry »
For the last 12 years and running, I’ve been generating journal ranks based on the journal-ranking method we published several years ago. Since the Google journal h-indices were just released, here are the new 2019 ranks for: (i) 99 ecology, conservation and multidisciplinary journals, and a subset of (ii) 61 ‘ecology’ journals, (iii) 27 ‘conservation’ journals, (iv) 41 ‘sustainability’ journals (with general and energy-focussed journals included), and (v) 20 ‘marine & freshwater’ journals.
Ecologists often rely on measuring certain elements of a species’ characteristics, behaviour, or morphology to determine if these — what we call ‘traits’ — give them certain capacities to exploit their natural environments. While sometimes a bit arbitrarily defined, the traits that can be measured are many indeed, and sometimes they reveal rather interesting elements of a species’ resilience in the face of environmental change.
As we know, climate change is changing the way species are distributed around the planet, for the main (and highly simplified) reason that the environments in which they’ve evolved and to which they have adapted are changing.
In the simplest case, a warming climate means that there is a higher and higher chance you’ll experience temperatures that really don’t suit you that well (think of a koala or a flying fox baking in a tree when the thermometer reads +45° in the shade). Just like you seeking those nice, air-conditioned spaces on a scorcher of a day, species like to move to where conditions are more acceptable to their particular physiologies and behaviours.
Ecologists use life-history traits to predict which species have the highest probability of moving to new areas in response to climate change. Most studies into this phenomenon have largely ignored that range shifts in fact occur in sequential stages: (1) the species arrives in a new place for the first time, (2) its population increases in size (and extent), and (3) it can continue to persist in the new spot. Read the rest of this entry »
Just a quick post today, my last one for March. Like probably most of you, I’ve been trying to pretend to be as normal as possible despite the COVID-19 surrealism all around me. But even COVID-19 has shifted my research to a small degree.
But I’m not going to talk about the global pandemic right now (I can almost hear the collective sigh of relief). Instead, I’m going to go back to topic and discuss a paper that I’ve just co-authored.
Last year I went to China’s Yunnan Province where I met some fantastic colleagues at the Xishuangbanna Tropical Botanical Garden who were doing some very cool stuff with the variation in plant functional traits across environmental gradients.
Well, those colleagues invited me to participate in one those research projects, and I’m happy to say that the result has just been published in Forests.
Measuring the functional traits of different alpine trees species in the Changbai Mountains of far north-eastern China (no, I didn’t get to go there), the research set out to test how these varied among species and elevation.
Of course, one expects that different trees use different combinations of traits to survive the rigours of mountain life (high variation in temperature, freezing, wind, etc.), but generally speaking, you might expect things like xylem vessel diameter and density to change more or less monotonically (i.e., changing in a consistent manner as elevation rises or falls). This is because trees should adapt their traits to the local conditions as best they can. Read the rest of this entry »
The birth of my daughter, in 2004, thrust upon me a dual task: to be scientifically realistic about all the difficult changes that are here to stay, while staying humanly optimistic about the better things that we still have.
By the time my daughter turned eleven, I had jettisoned my nostalgia for the Earth I was born into in the mid-196os—a planet that, of course, was an ecological shadow of Earth 100 years before, which in turn was an ecological shadow of an earlier Earth. The pragmatist in me had embraced the Anthropocene, in which humans dominate all biophysical processes, and I ended up feeling genuinely good about some of the possible futures in which my daughter’s generation might grow old.
It was a choice to engage in a tough situation. An acknowledgement of rapid and uninvited change. A reaffirmed commitment to everything I have learned, and continue to learn, as an ecologist working with Indigenous people on marine conservation. Fundamental to this perspective is the notion of resilience: the ability of someone or something—a culture, an ecosystem, an economy, a person—to absorb shocks yet still maintain their essence.
As I’ve done for the last six years, I am publishing a retrospective list of the ‘top’ 20 influential papers of 2019 as assessed by experts in F1000 Prime (in no particular order). See previous years’ lists here: 2018, 2017, 2016, 2015, 2014, and 2013.
Skilled ornithologists can tell the age of a bird by the look of its feathers. But many species are advancing the moult of their first adult plumage in response to global warming, and the youngsters look more similar to the adults now than two centuries ago.
The clothes don’t make the (wo)man, but how we dress sends out a lot of information about our tastes, emotional state, or financial situation. In nature, where species have evolved to exploit all kinds of physical and chemical cues, visual communication determines a wealth of feeding and reproductive strategies (1).
Birds are familiar to all of us by the beauty and variety of their plumages (see extreme examples commented by David Attenboroughhere, here and here), which bird fans use to tell juveniles from males, males from females and breeders from migrants. In evolutionary time, birds have gradually moved away from tree-bark browns and tree-leaf greens and, due to functional requirements, modern feathers only span about one third of the colours these animals can perceive (2). They obtain yellows, oranges, and reds from carotenoid-containing food, dark colours from melanin pigment of own synthesis, and the so-called structural colours depend on how light reflects on the barbs of the feathers (2).
Plumage, across its entire range of designs, is a factor crucial to the life history of our feathery friends and, consequently, to evaluate how and how much anthropogenic climate change is impacting them (3).
Plumage and temperature
We know that mammals and birds are modifying their fur and feathers to optimise camouflage against landscapes with more or less snow (4), but less-known are the implications of climate change for feather moulting. Read the rest of this entry »
Each organism has a limit of tolerance to cold and hot temperatures. So, the closer it lives to those limits, the higher the chances of experiencing thermal stress and potentially dying. In our recent paper, we revise gaps in the knowledge of tolerance to high temperatures in cold-blooded animals (ectotherms), a diverse group mostly including…
The Faculty for Mathematics and Natural Sciences of Humboldt-Universität zu Berlin (HU Berlin), Geography Department, has an open position for a tenure-track professorship in Conservation and Development. Starting as soon as possible. This is a Junior Professorship (W1 level, 100%) with a tenure track to a permanent professorship (W2 level, 100%). To verify whether the…
Flooding in the Murray-Darling Basin is creating ideal breeding conditions for many native species that have evolved to take advantage of temporary flood conditions. Led by PhD candidate Rupert Mathwin, our team developed virtual models of the Murray River to reveal a crucial link between natural flooding and the extinction risk of endangered southern bell…
Ecologists often rely on measuring certain elements of a species’ characteristics, behaviour, or morphology to determine if these — what we call ‘traits’ — give them certain capacities to exploit their natural environments. While sometimes a bit arbitrarily defined, the traits that can be measured are many indeed, and sometimes they reveal rather interesting elements of a species’ resilience in the face of environmental change.
An excerpt from 
ConservationBytes.com 
