In The Conversation, October 2011

And just in case you haven't been following our latest and greatest soccer research, here's a piece we wrote for The Conversation - including a review of the biggest dive in history!

Radio Interview: Cheating in Soccer

Last week, Robbie was interviewed on 612 ABC Brisbane radio. Here's the link!
http://blogs.abc.net.au/queensland/2011/10/diving-and-the-art-of-deception-dr-robbie-wilson.html

Tackling the Problem of Diving in Football

Some consider it an art form, others cheating. Whatever your thoughts, diving by soccer players is one of the most controversial and despised actions in sport. Diving represents a deliberate attempt to deceive the referee, with players falling – even rolling around - to suggest they’ve been illegally fouled. Diving has long been a source of embarrassment for the world’s most popular sport, yet even football’s governing body (FIFA) has had little success at stamping out this behaviour.

University of Queensland PhD student Gwendolyn David, along with her supervisor Dr Robbie Wilson and other UQ colleagues have taken a fresh look at diving behaviour in an attempt to identify the mechanisms that can be used to control it.

image

In a study published this week in the prestigious open-access journal, PLOS One [http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0026017] these researchers explored the behaviour of soccer players and referees in the context of animal signalling theory.
“Theory predicts that deceptive behaviour should occur only when the prospective benefits outweigh the costs and when the risk of detection is low,” says Ms David. “So we expected that deception would be driven by the potential payoffs and would be limited by punishment.”

David undertook a play-by-play examination of 60 matches across six high-profile professional leagues to see when and where players faked fouls, and when they were likely to get away with it (or not). She found that – as predicted - diving occurred most often when the potential payoff was greater: namely, in the offensive side of the field and when the two teams had tied scores.

But the most exciting result came from looking between the leagues. “We found that players dived more often in leagues where referees were more likely to reward dives with a free-kick or penalty,” says Dr Wilson.

This means that when referees don’t detect or punish diving then dives are more common. “The most effective means of controlling deception, whether it’s a footballer or an animal, is via punishment. But, of the more than 2800 falls we observed and the 169 dives, we never once saw a diving player punished,” says David.

“Our results clearly show that reducing deception in sports like soccer is largely up to the referee and governing bodies. Players will try to deceive referees when the benefits are high, but better detection and administration of punishment may help reduce its prevalence” says Dr Wilson.

“Some progressive professional leagues, such as the Australian A-League and American MLS, have already started handing down punishments for players found guilty of diving. This is the best way to decrease the incentive for diving,” said Dr Robbie Wilson.

For more information on the study or for interviews, please contact Dr Robbie Wilson (Senior Researcher) at +61 458204962 or r.wilson@uq.edu.au. For other information on this research group’s work see the lab soccer website: www.soccerscience.net.

Honest Signalling in Koalas

Dr Bill Ellis is a postdoctoral researcher in the lab, who spends much of his time in the field tracking and studying koalas (and other cool animals).

In a recent project, Bill and colleagues (from Australia and the University of Vienna) learned that male koalas - which make loud, grunting bellows - have a particular vocal anatomy that means their call can give others a non-visual indication of the caller's body size.

This is the first time that a permanently-descended larynx has been found in a marsupial.

Pretty cool.

Though Robbie and the rest of us in the lab weren't part of this research, we're proud of Bill's awesome work, and thought you might like to read about it! You can find out more about the project here, on the Koala Ecology Group website or more about animal signalling here.

Animal Signalling

We're giving signals whether we know it or not. All the time - and without saying a word - we show others that we're bored or interested or infatuated or annoyed ... And this ability certainly isn't unique to humans.

Signalling is pretty much everywhere in the animal kingdom.

We know that some organisms use displays or calls or body structures to attract mates ... or ward off intruders ... or show how wonderfully strong and appealing they are. (Hmmm ... can you think of any examples?)

But what scientists are starting to figure out is that not all these signals are - shall we say - honest. Sometimes appearances aren't the same as reality. And there are times when it pays to show what you might be, rather than what you actually are. We're studying dishonesty in signalling in a number of different research systems, including crabs (who signal strength via their claws) and soccer players (who signal fouls via dives).

photo by Skye Cameron

You can read more about our signalling work here:
Cheating pays off for females but not males
How humans differ from crabs

Or here:
Walter G, Van Uietregt V, & Wilson RS. 2011. Social control of unreliable signals of strength in males but not females of the crayfish Cherax destructor. Journal of Experimental Biology. 214: 3294-3299.

Wilson RS & Angilletta MJ. In press. Dishonest signals of strength. In Ed. D. J. Irschick, M. Briffa, and J. Podos. Animal Signalling: a Functional Perspective. Ralph Wiley Press.

Wilson RS, Condon CH, David G, FitzGibbon SI, Niehaus AC & Pratt K. 2010. Females prefer athletes, males fear the disadvantaged: different signals used in female choice and male competition have varied consequences. Proceedings of the Royal Society of London Series B 277: 1923-1928. 
 
Wilson RS, James RS, Bywater C & Seebacher F. 2009. Costs and benefits of increased weapon size differ between sexes of the slender crayfish, Cherax dispar. Journal of Experimental Biology 212:853-858.

Bywater C, Angilletta MJ and Wilson RS. 2008. Weapon size is a reliable predictor of weapon strength and social dominance in females of the slender crayfish. Functional Ecology. 22:311-316.

Seebacher F & Wilson RS. 2007. Individual recognition in crayfish (Cherax dispar): the roles of strength and experience in deciding aggressive encounters. Biology Letters 3:471-474. 
 
Wilson RS, Angilletta MJ, James RS, Navas C & Seebacher F. 2007. Dishonest signals of strength in male slender crayfish (Cherax dispar) during agonistic interactions. The American Naturalist. 170:284-291

Cheating Pays Off for Females But Not Males

In the social circles of crustaceans, the claw means everything. Larger claws can be used to signal dominance, staving off unnecessary battles between poorly-matched opponents. However, if two similarly-sized individuals fight it out - it's usually the one with the stronger claw that wins.

Fighting fiddler crabs - photo by Skye Cameron

Unlike humans, where opponents can assess strength visually (e.g. bicep size), crustacean muscle is contained within a hard exoskeleton. This means that crustaceans can't determine each others' strength without testing it in combat, and it opens the possibility for cheating. Cheating could benefit individuals by gaining them dominance without having to fight; meaning access to better quality food, enhanced mating opportunities, and safer shelters - all without risk of bodily harm in combat or the high metabolic costs associated with maintaining strong claw muscles.

And cheating may be as easy as growing a large, wimpy claw.

By and large, animals are thought to signal their value (i.e. strength, power, dominance) honestly. But Dr. Robbie Wilson of the University of Queensland has found that many crustacean species actually cheat - producing large but weak claws that fool potential competitors.

These are exciting findings, because they show that cheating is likely to evolve under particular circumstances.

As part of his honours research in Dr. Wilson's lab, Gregory Walter found that female crayfish, Cherax destructor, are more likely to benefit from cheating compared with males. In his experiments, he measured claw sizes, body sizes, and claw force for each crayfish, and then observed which crayfish won in competitive, same-sex bouts - and, importantly, whether dominance was gained by signalling or battling.

Cherax destructor - photo by Gregory Walter

"We found that having large, wimpy claws was prevalent among both males and females," explains Dr. Wilson. "But only females gained dominance by cheating."

It turns out that male C. destructor tended to fight more often than females, so dominance among males was acquired via claw strength - an unfakeable trait. On the other hand, dominance among female C. destructor was most often determined via signalling alone, leaving claw strength untested and rewarding females with large, but weak, claws.

"In fact, females were pretty bad at judging each others' potential strength [based on claw size]," Dr. Wilson continues. "Giving sub-standard females the chance to be dominant."

This work has just been published as:
Walter G, Van Uietregt V, & Wilson RS. 2011. Social control of unreliable signals of strength in males but not females of the crayfish Cherax destructor. Journal of Experimental Biology. 214: 3294-3299.

You can read more about Dr. Wilson's research on honest signalling here. 
Written by Dr. Amanda Niehaus

Sabbatical is Not Just One Big Holiday ...

Robbie's currently on sabbatical - or long study leave. But what is it? And what exactly is Robbie meant to be accomplishing on all these trips to the US and Europe and Sydney and Groote Eylandt?

Well, according to Wikipedia a sabbatical is:

'a ceasing [of] work, or hiatus.' 

But it also says - hidden a paragraph or two later - that in modern times a sabbatical is:

'any extended absence in the career of someone in order to achieve something.'

Uh oh. So there are expectations.

At UQ, a sabbatical is granted every 3 to 5 years - and gives academics 6 months off from administrative and teaching duties. There is an expectation that the academic will use this time wisely - to collaborate with researchers overseas, or undertake extended field trips, or write a book, or punch out half a dozen publications or so. Basically, it's time to catch up on all those things that an academic is supposed to be doing (in between teaching and supervising and sitting on committees).

The academic-on-sabbatical doesn't actually have to leave home - but getting out of town does make it easier to leave office stresses behind and focus.

On his sabbatical, Robbie will attend two overseas conferences; collaborate with researchers in Sydney and France and Phoenix; finish up those 20 or so papers that currently hang in various states of completion/submission/revision; begin writing a book on maximising soccer performance; make two jaunts field trips to Groote Eylandt; and various other duties that will enhance his career and make his life easier when he returns to full-on duties in February.

So there you have it: what a sabbatical is, where you can still get one, and what you might like to do while you're on it. Not bad, hey?

Studying Mosquitofish from the South of France is Not as Glamorous as It Sounds, Part 3

The fish have been collected, the experimental plans organised, and now ... it's time to watch and swim and measure fish.

 

Robbie and Frank split up the work associated with their experiment - Robbie observed the females' behaviour and Frank measured metabolic rates.  

Here's the behavioural set-up:

And the metabolic set-up:

 

Frank swam fish in a little glass jar to ramp up their metabolic rates, so he and Robbie could calculate the metabolic scope.

That's all we can say for now, as the data haven't been analysed and the paper has yet to be written. But we wanted to give you some insight into what an eco-physiological experiment entails. It may not be as glamorous as it sounds, but the excitement of discovery and exploring new ideas is what keeps scientists going. The development of an experiment like this one was a lot of fun!

Studying Mosquitofish from the South of France is Not as Glamourous As It Sounds, Part 2

We now return to our story of mosquitofish from murky waters in southern France ... gallantly collected and brought back to the lab, where they were used to address a very important question:

How expensive is pregnancy?

Now, having been pregnant once before, I was willing to share my own experiences with expense in pregnancy: the financial costs associated with becoming addicted to eBay; the social costs of inexplicable moodiness; the energetic costs of lumbering to and from the bathroom; the mental costs manifested in an inability to concentrate/find keys/remember things.

But, apparently fish are different.

Mosquitofish, in fact, are live-bearers that can produce 20 to 70 young in a pregnancy - young that altogether can weigh up to 30-40% of the female's own body weight.

This extra mass and the energy required to produce all these baby fish can substantially increase a female's metabolism - even when she's resting. A higher resting (or basal) metabolism would be expected to limit a female's metabolic scope.

What's metabolic scope? It's the difference between resting and maximum metabolic rates - or the amount by which the body can increase metabolism to deal with high levels of physical activity or stresses. Because maximum metabolic rates are limited by the body's capacity to uptake oxygen and eliminate cell waste, they don't change much. So we expect the metabolic scope of a pregnant mosquitofish to diminish as her resting metabolic rate increases.

But.

That's not all.

Temperature also increases the resting metabolic rate of fish: higher temperatures mean higher resting metabolic rates.

So that's what Robbie and Frank and their French collaborators were keen to look at - how temperature affects the metabolic scope of pregnant mosquitofish.

(to be continued ...)

Studying Mosquitofish from the South of France is Not as Glamourous As It Sounds, Part 1

Recently, Robbie was invited to collaborate with scientists at France's prolific CNRS (Centre National de la Resherche Scientifique). These researchers included Head of the CNRS's Ariege unit, Prof Jean Clobert; and Marie Curie Fellow, Dr Camille Bonneaud. Robbie joined his long-time Australian collaborator and friend - A/Prof Frank Seebacher - in the idyllic location of Moulis* to study the behaviour, physiology, and performance of the invasive mosquitofish (Gambusia holbrooki) relative to their state of pregnancy.

*Let me assure you, that for all the un-glamourousness of the fish- and data-collection, the research station was spectacularly situated.

Imagine working in a well-funded research program in a quaint French village, in a building that adjoins a rushing brook amidst the green-capped mountains of the Pyrenees.
Mag. nif. ique.

But, alas, mosquitofish don't like pristine, bubbling streams. They prefer dank, stagnant places. So when Robbie and Frank took a drive toward the Mediterranean coast, it was looking for swamps. And though there are no pictures to document the collection of the fish, it allegedly involved:

1) wading through reeking swamp mud
2) numerous biting insects
3) a decomposing, floating, probable-mammal the size of a beaver
4) a swift change of clothes before returning to the hire car

And a pink net.

Some hearty beef stew and a few beers upon returning home didn't hurt, either.

Then it was off to the lab to set up the experiments ... (to be continued) ...

Biodiversity Research with Anindilyakwa Rangers

Our team has headed back up to Groote Eylandt (and I'm still here ... sigh ... ), so I thought I might take this opportunity to talk more about our collaboration with the Anindilyakwa people of the island. We have much to learn from each other - but more than that, collaboration between scientists and Indigenous peoples can be a rewarding and effective means of conserving the environment.

Aboriginal Australians have a powerful cultural connection to their environment. It sustains them, physically and spiritually. Conservation of biodiversity is innate, and information about the environment - the organisms that inhabit it, the seasonality of events - have been passed down via narratives and stories for thousands of years. Though this knowledge is more qualitative than quantitative, it represents a long-term picture of the environment that few, if any, scientific studies would provide.

Besides, the ability of Aboriginal trackers and rangers to navigate the bush is incomparable - which facilitates conservation-based studies of wildlife, including the northern quoll. On our trips to Groote Eylandt, our team trains the Indigenous Rangers in scientific methods of capturing, tagging, and 'processing' animals. We talk through research ideas, hypotheses, protocols, and analyses with them. And we absorb their beautiful culture.

We'll be sharing more about our current trip shortly, including photos of some very non-quoll-related fish, and a story about why Billy is currently sitting poolside at the resort, rather than working. (Ahem)

How to Catch and Process a Quoll*

*and no ... we're not making sausages out of them ...

So how do you catch a feisty little marsupial, that's nocturnal and ground-dwelling and generally doesn't like to be caught?
Ecologists typically use baited traps, but of a sort that aren't likely to harm the captured animal - like this Elliott Trap, which has a door that springs shut when the animal steps inside.

Just before dark, our intrepid quoll-catchers set out the traps (with goodies inside) and then return to camp to give the quolls a chance to find - and take - the bait.

When a quoll's been captured, we take it back to the lab to 'process' it. Which sounds really suss but actually just means that we measure them and add tracking and identification devices to them. This is so we can obtain information about the health and size of the quolls, and keep track of particular individuals over time.

After we've taken all the important measurements, it's time to 'mark' the animals. In this study, we mark with ear tags, pit tags (like microchips), and collars - which may seem like overkill, but actually allows us to collect different kinds of data.

Ear tags are like earrings that have a specific number on them, unique to the animal. This means that if we catch this quoll again, we can easily and quickly determine its identity. Ear tags, toe tags, and leg or flipper bands (depending on the animal of focus) are commonly-used by ecologists for this purpose.

Pit tags are the second line of identification ... they're inserted under the skin, and hold all the relevant information about the animal - just like the microchip that you can get for your dog or cat. The coolest thing about pit tags? You read them with a scanner.

(as in, "clean up on aisle 3 ... ")

And collars - they're for the purpose of tracking the animal, using either radio frequencies or GPS (depending on the type of collar). By tracking individuals, ecologists can learn more about how the animals interact with each other, how large their range is, and how much they move around. If you want to know more, we talked about tracking koalas here and here.

After all this, the quoll is released back into the wild ... where it is no longer the anonymous little carnivore it once was.

So now you know how to catch and process a quoll. (Or, for that matter, any animal of ecological interest). Please use your wisdom for good, not evil.

Thanks Gavin, Sean, Robbie, Billy and Bill for the great photos!

Run Gecko Run (Don't Ever Look Back)

How do scientists study running performance? Well, with humans we'd take subjects out onto a track and measure how fast they could sprint between two points.

With geckoes?

It's pretty much the same. Except we have
to design a track that encourages the gecko to move as quickly as it can in a straight line. (Because geckoes aren't as good at taking verbal directions as humans are ... )

Skye's current experiment is based around this running track. She puts a gecko into the near end (as shown in the top photo) and then chases it down the track with a foam paddle. Don't worry, the gecko's fine - the paddle is just to prevent it from stopping or turning around or anything that might disrupt measurements.

As the gecko runs down the track (away from us, in this picture), it passes the 4 light sensors that help Skye to accurately record the gecko's speed. Skye repeats the run 3 times more, so that she can get the gecko's fastest performance (best of 12 time splits - 3 trials x 4 sensors).

After measuring running performance, Skye takes the weight of the gecko to account for its body size in her calculations. This is because larger geckoes will be able to run faster independently of temperature.

Then, the gecko returns to its home in the lab.

Each gecko completes 8 running trials at temperatures between 15 and 38 degrees Celcius. Some populations won't ever have seen some of these temperature extremes in the wild (and others will have). 

Skye is predicting that where a gecko comes from will affect how it performs at these different temperatures. For example, at low temperatures geckoes from tropical North Queensland should perform more poorly than geckoes from Brisbane - because, in nature, Brisbane geckoes experience low temperatures every year (and tropical geckoes don't). 

Skye's still working hard measuring gecko running speeds ... so we can't tell you any results yet. But watch this space!

Why Temperature Matters to Geckoes

At the moment, Skye's doing a really cool experiment looking at how Asian house geckoes from different environments handle changes in temperature.

Why is this important? Well,
climates are changing. And scientists want to know how species will handle climate change - will they go extinct? will they do even better?

To answer these questions, we have to know more about how species perform across their natural range. Because animals that are already living close to their thermal limits might be at greater risk if things heat up, or even cool down. And because some animals have a greater capacity to rapidly adjust to temperature change (or acclimate) than others. And because most of the animals on the planet are what we call ectotherms, which (unlike humans) can't warm themselves up internally: their digestion, brainpower, muscle activity - everything - is dependent on the temperature in their environment.

So what's Skye doing? She's collected Asian house geckoes from across their latitudinal range in Australia - from Brisbane all the way up to Cape York. (ahem - more traveling??). Geckoes from all these different populations have grown up in quite different environments - but in general, temperatures get hotter and less variable as you head north from Brisbane.

Which leads us to some fundamental questions in thermal ecology: do animals in these different environments become 'experts' at performing under just those conditions? Or can they perform over a wide range of temperatures - just not very well? Is the pattern changeable (suggesting acclimation) or unchangeable (suggesting adaptation)?

Skye is testing these questions by looking at the running performance of geckoes from different populations  - across a range of temperatures. If you've ever watched a gecko on your window at night, you'll see why running is so important to them - it's how they catch prey, but also how they escape from predators and is a key factor in determining dominance of individuals.

So looking at running performance is a great way to assess how temperature affects the geckoes' ability to survive and make babies.

This is just a teaser, really. Letting you know why *some* people spend hours tending to and running geckoes in all sorts of temperatures. In the next post, I'll talk a bit more about the specifics of Skye's study - including her amazing experimental set-up!