Singin’ in the heat

9 03 2017
coqui & forest

Common coqui frog male (Eleutherodactylus coqui, snout-to vent length average ~ 3 cm) camouflaged in the fronds of an epiphyte in the El Yunque National Forest (Puerto Rico), along with an image of the enchanted forest of the Sierra de Luquillo where Narins & Meenderink did their study (4) – photos courtesy of Thomas Fletcher. This species can be found from sea level to the top of the highest peak in Puerto Rico (Cerro Punta = 1338 m). Native to mesic ecosystems, common coquis are well adapted to a terrestrial life, e.g., they lack interdigital webbing that support swimming propulsion in many amphibians, and youngsters hatch directly from the egg without transiting a tadpole stage. The IUCN catalogues the species as ‘Least Concern’ though alerts recent declines in high-altitude populations caused by chytrid fungus – lethal to amphibians at a planetary scale (9). Remarkably, the species has been introduced to Florida, Hawaii, the Dominican Republic and the Virgin Islands where it can become a pest due to high fertility rates (several >20 egg clutches/female/year).

Frog songs are species-specific and highly useful for the study of tropical communities, which host the highest amphibian diversities globally. The auditory system of females and the vocal system of males have co-evolved to facilitate reproductive encounters, but global warming might be disrupting the frequency of sound-based encounters in some species..

It is a rainy night, and Don (Gene Kelly) has just left his love, Kathy (Debbie Reynolds), at home, starting one of the most famous musical movie scenes ever: Singin’ in the rain 

Amphibians (see Amphibians for kids by National Geographic) also love to sing in rainy nights when males call for a partner, but now they have to do it in hotter conditions as local climates become warmer. Vocal behaviour is a critical trait in the life history of many frog species because it mediates recognition between individuals, including sexual selection by females (1).

With few exceptions, every species has a different and unique call, so scientists can use call features to identify species, and this trait is particularly useful in the inventory of diverse tropical communities (2). Differences in call frequency, duration and pitch, and in note, number, and repetition pattern, occur from one species to another. And even within species, songs can vary from individual to individual (as much as there are not two people with the same voice), and be tuned according to body size and environmental temperature (3). Read the rest of this entry »





Keeping India’s forests

9 08 2016

I’ve just returned from a short trip to the National Centre for Biological Sciences (NCBS) in Bangalore, Karnataka, one of India’s elite biological research institutes.

Panorama of a forested landscape (Savandurga monolith in the background) just south of Bangalore, Karnataka (photo: CJA Bradshaw)

Panorama of a forested landscape (Savandurga monolith in the background) just south of Bangalore, Karnataka (photo: CJA Bradshaw)

I was invited to give a series of seminars (you can see the titles here), and hopefully establish some new collaborations. My wonderful hosts, Deepa Agashe & Jayashree Ratnam, made sure I was busy meeting nearly everyone I could in ecology and evolution, and I’m happy to say that collaborations have begun. I also think NCBS will be a wonderful conduit for future students coming to Australia.

It was my first time visiting India1, and I admit that I had many preconceptions about the country that were probably unfounded. Don’t get me wrong — many of them were spot on, such as the glorious food (I particularly liked the southern India cuisine of dhosa, iddly & the various fruit-flavoured semolina concoctions), the insanity of urban traffic, the juxtaposition of extreme wealth and extreme poverty, and the politeness of Indian society (Indians have to be some of the politest people on the planet).

But where I probably was most at fault of making incorrect assumptions was regarding the state of India’s natural ecosystems, and in particular its native forests and grasslands. Read the rest of this entry »





Earth’s second lung has emphysema

19 02 2015
© WWF

© WWF

Many consider forests as the ‘lungs’ of the planet – the idea that trees and other plants take up carbon and produce oxygen (the carbon and oxygen cycles). If we are to be fair though, the oceans store about 93% of the Earth’s carbon pool (excluding the lithosphere and fossil fuels) and oceanic phytoplankton produces between 50 and 80% of the oxygen in the atmosphere. For comparison, the terrestrial biosphere – including forests – stores only about 5% of the Earth’s carbon, and produces most of the remainder of atmospheric oxygen.

So there’s no denying that the biggest player in these cycles is the ocean, but that’s not the topic of today’s post. Instead, I’m going to focus on the terrestrial biosphere, and in particular, the carbon storage and flux of forests.

Now it’s pretty well established that tropical forests are major players in the terrestrial carbon cycle, with the most accepted estimates of about 55% the terrestrial carbon stock stored therein. The extensive boreal forest, covering most of the northern half of North America, most of Scandinavia and a huge chunk of Russia, comes in globally at about 33%, and temperate forests store most of the remainder.

That is, until now. Read the rest of this entry »





Incentivise to keep primary forests intact

7 02 2014

The Amazon rainforest. Photo by Rhett A. Butler

I know – ‘incentivise’ is one of those terrible wank words of business speak. But to be heard by the economically driven, one must learn their guttural and insensitive language. I digress …

Today’s post is merely a repost of an interview I did for the new Mongabay.com series ‘Next Big Idea in Forest Conservation‘. I’m honoured to have been selected for an interview along with the likes of Bill Laurance and Stuart Pimm.

Consider this my conservation selfie.

An Interview with Corey Bradshaw

Mongabay.com: What is your background?

Corey Bradshaw: I have a rather eclectic background in conservation ecology. I grew up in the wilds of western Canada, the son of a trapper. My childhood experiences initially gave me a primarily consumptive view of the environment from trapping, fishing and hunting, but I learned that without intact environmental functions, these precious resources quickly degrade or disappear. This ironic appreciation of natural processes would later lead me into academia and the pursuit of reducing the rate of the extinction crisis.

I completed my first degrees in ecology in Montréal and the University of Alberta, followed by a PhD in New Zealand at the University of Otago. After deciding to pursue the rest of my career in the Southern Hemisphere, I completed my postdoctoral fellowship at the University of Tasmania. Multiple field seasons in the subantarctic and Antarctica probably assisted in a giving me a burgeoning desire to change gears, so I left for the tropics of northern Australia to begin a position at Charles Darwin University. Being introduced there to conservation greats like Navjot Sodhi (sadly, now deceased), Barry Brook and David Bowman turned my research interests on their ear. I quickly became enamoured with quantitative conservation ecology, applying my skills in mathematics to the plight of the world’s ecosystems. Nowhere did the problems seem more intractable than in the tropics.

I am now based at the University of Adelaide (since 2008) and have a vibrant research lab where we apply our quantitative skills to everything from conservation ecology, climate change, energy provision, human population trends, ecosystem services, sustainable agriculture, human health, palaeoecology, carbon-based conservation initiatives and restoration techniques.

Mongabay.com: How long have you worked in tropical forest conservation and in what geographies? What is the focus of your work? Read the rest of this entry »





Quantity, but not quality – slow recovery of disturbed tropical forests

8 11 2013

tropical regrowthIt is a sobering statistic that most of the world’s tropical forests are not ‘primary’ – that is, those that have not suffered some alteration or disturbance from humans (previously logged, cleared for agriculture, burned, etc.).

Today I highlight a really cool paper that confirms this, plus adds some juicy (and disturbing – pun intended – detail). The paper by Phil Martin and colleagues just published in Proceedings of the Royal Society B came to my attention through various channels – not least of which was their citation of one of our previous papers ;-), as well as a blog post by Phil himself. I was so impressed with it that I made my first Faculty of 1000 Prime recommendation1 of the paper (which should appear shortly).

As we did in 2011 (to which Phil refers as our “soon-to-be-classic work” – thanks!), Martin and colleagues amassed a stunning number of papers investigating the species composition of disturbed and primary forests from around the tropics. Using meta-analysis, they matched disturbed and undisturbed sites, recording the following statistics: Read the rest of this entry »





The biggest go first

11 12 2012
© James Cameron

© James Cameron

The saying “it isn’t rocket science” is a common cliché in English to state, rather sarcastically, that something isn’t that difficult (with the implication that the person complaining about it, well, shouldn’t). But I really think we should change the saying to “it isn’t ecology”, for ecology is perhaps one of the most complex disciplines in science (whereas rocket science is just ‘complicated’). One of our main goals is to predict how ecosystems will respond to change, yet what we’re trying to simplify when predicting is the interactions of millions of species and individuals, all responding to each other and to their outside environment. It becomes quickly evident that we’re dealing with a system of chaos. Rocket science is following recipes in comparison.

Because of this complexity, ecology is a discipline plagued by a lack of generalities. Few, if any, ecological laws exist. However, we do have an abundance of rules of thumb that mostly apply in most systems. I’ve written about a few of them here on ConservationBytes.com, such as the effect of habitat patch size on species diversity, the importance of predators for maintaining ecosystem stability, and that low genetic diversity doesn’t exactly help your chances of persisting. Another big one is, of course, that in an era of rapid change, big things tend to (but not always – there’s that lovely complexity again) drop off the perch before smaller things do.

The prevailing wisdom is that big species have slower life history rates (reproduction, age at first breeding, growth, etc.), and so cannot replace themselves fast enough when the pace of their environment’s change is too high. Small, rapidly reproducing species, on the other hand, can compensate for higher mortality rates and hold on (better) through the disturbance. Read the rest of this entry »





Improving the Roundtable on Sustainable Palm Oil

23 11 2012

RSPO – don’t be guilty of this

Laurance & Pimm organise another excellent tropical conservation open-letter initiative. This follows our 2010 paper (Improving the performance of the Roundtable on Sustainable Oil Palm for nature conservation) in Conservation Biology.

Scientists Statement on the Roundtable on Sustainable Palm Oil’s Draft Revised Principles and Criteria for Public Consultation – November 2012

As leading scientists with prominent academic and research institutions around the world, we write to encourage the Roundtable on Sustainable Palm Oil (RSPO) to use this review of the RSPO Principles and Criteria as an opportunity to ensure that RSPO-certified sustainable palm oil is grown in a manner that protects tropical forests and the health of our planet. We applaud the RSPO for having strong social and environmental standards, but palm oil cannot be considered sustainable without also having greenhouse gas standards. Nor can it be considered sustainable if it drives species to extinction.

Tropical forests are critical ecosystems that must be conserved. They are home to millions of plant and animal species, are essential for local water-cycling, and store vast amounts of carbon. When they are cleared, biodiversity is lost and the carbon is released into the atmosphere as carbon dioxide, a greenhouse gas that drives climate change.

Moreover, tropical areas with peat soils store even larger amounts of carbon and when water is drained and the soils exposed, carbon is released into the atmosphere for several decades, driving climate changei. In addition, peat exposed to water in drainage canals may decay anaerobically, producing methane – a greenhouse more potent than carbon dioxide.

Palm oil production continues to increase in the tropics, and in some cases that production is directly driving tropical deforestation and the destruction of peatlandsii. Given the large carbon footprint and irreparable biodiversity loss such palm oil production cannot be considered sustainable. Read the rest of this entry »