Cartoon guide to biodiversity loss LXVIII

19 10 2021

Here is the fifth set of biodiversity cartoons for 2021. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


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Video explainer — nasty alien species in Australia

15 09 2021

You know you’ve made it to the big time in Australia when Behind The News does a story on your research. Practically every kid in Australia watches the show at some point during their school years.

Although this was produced last month, I thought I’d post the entire 4-minute video here for your viewing pleasure.

When you popularise your research story for kids, it really gets the message across well.

Thank you, Natasha and BTN for this opportunity.






A domesticated planet

15 06 2021

The abundance of wild animals is regressing speedily as the number of domesticated animals and persons keeps escalating. Such demographic contrast signals that we urgently need to modify our model of subsistence and our interaction with Mother Nature.


If we had to choose between a biodiverse landscape and one hosting a monoculture of pine trees with ruminating cattle, many would take the first option. Biodiversity has an aesthetic value to humans, and also gives us free services like pollination, climate regulation, freshwater depuration or soil formation (1, 2). That is why the mounting rates of biodiversity loss have propelled a multi-angled debate about whether the Earth is experiencing the sixth mass extinction (3, 4) and how biodiversity should be managed to secure our access to ecosystem services (5, 6).

Think individuals, not species

A different way of approaching the biodiversity crisis consists of examining trends in the number of wild animals, with not so much emphasis on the variety of species. Thus, the Living Planet Report 2020, published by the World Wildlife Fund, has compiled thousands of scientific studies about > 21,000 populations of wild vertebrates studied over time (> 4,000 species represented) and concluded that, on average, the number of individuals per population has diminished by 70% since the 1970s (7).

Biomass (birds and mammals) in Planet Earth measured in Giga-tonnes of Carbon (Gt C) (8) for people (red), domesticated animals (blue) and wildlife (green). The pie chart compares those three groups in modern times, and the barplot reports values for mammals from prehistory (~100.000 years ago) to now. Overpopulation of humans and domesticated animals currently outnumbers the biomass of wildlife.

On the other hand, Yinon Bar-On et al. (8) quantified that the biomass of humans and our domesticated mammals currently multiplies the biomass of wild mammals by a factor of 10, and there are 3 kg of humans and poultry for every kg of wild birds (see video featuring this study).

Not only that, during the last 100,000 years through which anatomically modern humans have thrived from a handful of bands of African hunter-gatherers to complex societies living in metropolis, the cattle industry has ended up quadrupling the global biomass of mammals (8).

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Everything you always wanted to know about conservation (but were afraid to ask)

14 05 2021

While some of us still might imagine the conservationist as a fancy explorer discovering new species in a remote corner of the world, or collecting samples while drowning in mud, a growing portion of conservation science nowadays consists of asking people about their ideas and behaviours.

Needless to say, this approach produces a fair share of awkward, if not dangerous, situations. After all, who likes the idea of completing a questionnaire from the fisheries office, asking about compliance with harvest limitations or licence fees? Or, even worse, who fancies being asked about the possession of illegally traded wildlife? 

Many conservationists would really like to have this valuable information, but at the same time it is clear that these questions put people at great discomfort. This leads to biased estimates of important behaviours affecting conservation. This is where specialised questioning techniques can help.

Specialised questioning techniques aim to prevent researchers, or anyone else, to trace back individual answers. Many do so by adding noise with a known distribution to individual answers. Then, when all answers are pooled, this noise is ruled out with statistical approaches. Noise can come from a randomising device (e.g. a die), like in the randomised response technique:

Individual answers can also be masked by asking respondents not to indicate if they engaged in a certain behaviour, but by asking them, out of a list of sensitive and non-sensitive behaviours, to indicate the number in which they engaged. This is the case of the unmatched count technique (a.k.a list experiments):

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Worried about Earth’s future? Well, the outlook is worse than even scientists can grasp

14 01 2021

Daniel Mariuz/AAP

Corey J. A. Bradshaw, Flinders University; Daniel T. Blumstein, University of California, Los Angeles, and Paul Ehrlich, Stanford University

Anyone with even a passing interest in the global environment knows all is not well. But just how bad is the situation? Our new paper shows the outlook for life on Earth is more dire than is generally understood.

The research published today reviews more than 150 studies to produce a stark summary of the state of the natural world. We outline the likely future trends in biodiversity decline, mass extinction, climate disruption and planetary toxification. We clarify the gravity of the human predicament and provide a timely snapshot of the crises that must be addressed now.

The problems, all tied to human consumption and population growth, will almost certainly worsen over coming decades. The damage will be felt for centuries and threatens the survival of all species, including our own.

Our paper was authored by 17 leading scientists, including those from Flinders University, Stanford University and the University of California, Los Angeles. Our message might not be popular, and indeed is frightening. But scientists must be candid and accurate if humanity is to understand the enormity of the challenges we face.

Girl in breathing mask attached ot plant in container

Humanity must come to terms with the future we and future generations face. Shutterstock

Getting to grips with the problem

First, we reviewed the extent to which experts grasp the scale of the threats to the biosphere and its lifeforms, including humanity. Alarmingly, the research shows future environmental conditions will be far more dangerous than experts currently believe. Read the rest of this entry »





Cartoon guide to biodiversity loss LXIII

26 10 2020

The sixth set of biodiversity cartoons for 2020. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


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New journal: Frontiers in Conservation Science

29 09 2020

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, the fastest way to make enemies 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.

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Cartoon guide to biodiversity loss LXII

2 09 2020

The fifth set of biodiversity cartoons for 2020. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


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The only constant is change

27 07 2020

I just wrote a piece for the Flinders University alumnus magazine — Encounter — and I thought I’d share it here.

encounter-2020_Page_01

As an ecologist concerned with how life changes and adapts to the vagaries of climate and pervasive biological shuffling, ‘constant change’ is more than just a mantra — it is, in fact, the mathematical foundation of our entire discipline.

But if change is inevitable, how can we ensure it is in the right direction?

Take climate change for example. Since the Earth first formed it has experienced abrupt climate shifts many times, both to the detriment of most species in existence at any given time, and to the advantage of those species evolving from the ashes.

For more than 3.5 billion years, species have evolved and gone extinct, such that more than 99% of all species that have ever existed are now confined, permanently, to the vaults of the past.

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Cartoon guide to biodiversity loss LXI

31 05 2020

The fourth set of biodiversity cartoons for 2020. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


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Extinction Anxiety

21 05 2020

Earlier this week, the SBS show The Feed did a short segment called ‘Extinction Anxiety’ where I talked with host Alice Matthews about biodiversity extinctions. Given that it has so far only been available in Australia, I made a copy here for others to view.

For more information on the state of global biodiversity, see this previous post.

 

 

CJA Bradshaw





Shifting from prevention to damage control

5 05 2020

timeBack in March this year before much of the world morphed into the weirdness that now dictates all facets of life, I wrote an update for the Is This How You Feel project led by Joe Duggan.

It was an exercise in emotional expression not necessarily grounded in empiricism. But in that particular piece, I had written the following line:

Few scientists in my field are still seriously considering avoidance of environmental collapse; instead, the dominant discourse is centred on damage control.

But is this correct? Is this how most scientists in conservation feel today? In a way, this post serves both as a rationale for my expectation, and as a question for the wider community.

My rationale for that contention is that it is undeniable that biodiversity is going down the toilet faster than even some of the most pessimistic of us could have predicted. We are without doubt within the sixth mass extinction event every experienced on the Earth for at least the last 600 million years.

Yet, there have never been more conservation biologists and practitioners. There have never been more international treaties and accords that expressly aim to protect biodiversity.

To assert that we have failed is unhelpful fatalism, yet it cannot be ignored that biodiversity’s predicament and those charged with turning around its fate are not exactly replete with successes. Read the rest of this entry »





Cartoon guide to biodiversity loss LX

8 04 2020

The third set of biodiversity cartoons for 2020 (plus a video treat). See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


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In pursuit of an ecological resilience in the Anthropocene

3 03 2020

Changing TidesAn excerpt from Alejandro Frid‘s new book, Changing Tides: An Ecologist’s Journey to Make Peace with the Anthropocene (published first in Sierra, with photos courtesy of New Society Publishers)

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.

But what is essence? Read the rest of this entry »





Unlikely the biodiversity crisis will improve any time soon

6 02 2020

hopelessAround a fortnight ago I wrote a hastily penned post about the precarious state of biodiversity — it turned out to be one of the most-read posts in ConservationBytes‘ history (nearly 22,000 views in less than two weeks).

Now, let’s examine whether this dreadful history is likely to get any better any time soon.

Even if extinction rates decline substantially over the next century, I argue that we are committed to an intensifying biodiversity extinction crisis. The aggregate footprint from the growing human population notwithstanding, we can expect decades, if not centuries, of continued extinctions from lag effects alone (extinction debts arising from previous environmental damage engendering extinctions in the future)1.

Global vegetation cover and production are also likely to decline even in the absence of continued habitat clearing — the potential benefit of higher CO2 concentrations for plant photosynthesis is more than offset by lower availability of water in the soil, heat stress, and the frequency of disturbances such as droughts2. Higher frequencies and intensities of disturbance events like catastrophic bushfire will also exacerbate extinction rates3.

However, perhaps the least-appreciated element of potential extinctions arising from climate change is that they are vastly underestimated when only considering a species’ thermal tolerance4. In fact, climate disruption-driven extinction rates could be up to ten times higher than currently predicted4 when extinction cascades are taken into account5. Read the rest of this entry »





The state of global biodiversity — it’s worse than you probably think

24 01 2020

Chefurka biomass slide

I often find myself in a position explaining to non-professionals just how bad the state of global biodiversity really is. It turns out too that even quite a few ecologists seem to lack an appreciation of the sheer magnitude of damage we’ve done to the planet.

The loss of biodiversity that has occurred over the course of our species’ time on Earth is staggering. This loss is now truly planetary in scale and caused by human actions, albeit the severity of which is unequally distributed across the globe1. While Sandra Díaz and company recently summarised the the extent of the biodiversity crisis unfolding1 well in their recent synopsis of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)2 report, I’m going to repeat some of the salient summary statements here, and add a few others. Read the rest of this entry »





Heat tolerance highly variable among populations and species

14 01 2020

Many ecological studies have examined the tolerance of terrestrial wildlife to high and low air temperatures over global scales (e.g., 1, 2, 3). This topic has been boosted in the last two decades by ongoing and predicted impacts of climate change on biodiversity (see summary of 2019 United Nation’s report here and here).

However, it is unfortunate that for most species, studies have measured thermal tolerance from a single location or population. Researchers interested in global patterns of thermal stress collect those measurements from the literature for hundreds to thousands of species [recently compiled in the GlobTherm database] (4), and are therefore often restricted to analysing one value of thermal tolerance per species.

CB_FunctionalEcology_jan2020_Photo

Three of the 15 species of Iberian lacertids sampled in our study of thermal tolerance (9), including the populations of Algerian psammodromus (Psammodromus algirus), Geniez’s wall lizard (Podarcis virescens) and Western green lizard (Lacerta bilineata) sampled in Navacerrada (Madrid), Fuertescusa (Cuenca) and Moncayo (Soria), respectively. Photos by S. Herrando-Pérez

Using this approach, ecologists have concluded that cold tolerance is far more variable than heat tolerance across species from the tropics to the boreal zone (5-8). Consequently, tolerance to heat stress might be a species trait with limited potential to change in response to global warming compared to cold tolerance (5). Read the rest of this entry »





Influential conservation ecology papers of 2019

24 12 2019

Bradshaw-Waves breaking on rocks Macquarie Island
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: 20182017, 20162015, 2014, and 2013.

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Adult disguises

2 12 2019

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.

R Graphics Output

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 Attenborough here, 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 »





Cartoon guide to biodiversity loss LVII

6 11 2019

The sixth set of six biodiversity cartoons for 2019. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


Read the rest of this entry »








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