Fieldwork, Groote Eylandt, NT

Leaving Darwin, the propellers outside hummed loudly (reassuringly). We pressed our noses to the windows, looked out on the wild top coast of Australia. The fires lit by thousands of years of tradition. And then, we were there. Over the mines, into the red dirt.

the GEMCO manganese mine

On the deck with Jennifer and her niece; with Chopper; with MacBook Pro

We drove east to Umbakumba then headed into the bush on sandy tracks. We set up tents on top of a berm, feeling {relatively} safe from water-borne crocs and collected firewood from the beach. We watched a heavy moon pull itself up into the sky.

Picnic Beach, Groote Eylandt | Jaime and Eddie set out, bait, and mark quoll traps

Under Jaime's guidance, we set out traps for quolls, hoping to catch at least a few to obtain measurements and hair samples.

We caught 4. Plus a few bandicoots. It was good enough for Jaime to get her samples, and good enough for me - these were the first wild quolls I'd seen.

It was only a week ago we got back from Groote Eylandt. What a special place. Wild, and raw, and special. An island of contrasts, between a traditional culture and a modern mining industry. An island with a lot of crocodiles.

It was my first trip up, and Nelle came along. We met the Rangers and friends and family and Gavin and Kerry and the rest of the team and Alex-from-Stanford. We drank tea on the deck at the Ranger station, and packed up everything {but petrol} for a quoll-catching venture to the east side of the island. {Former labmate} Billy was appointed Ranger Coordinator. We learned our first Anindilyakwan words. We entertained Nelle, and learned the value of ABC for Kids downloads {and PhD students}.

A quoll curled up in its very own, custom-made pillowcase | fishing for dinner

We were almost as successful catching fish ... the ocean here teems with them {apparently} but we didn't have much luck. Three fish only made it into our bellies.

That's ok. We had plenty of patience ... and potatoes. 

- written byAmanda Niehaus

Crabs will fake it to avoid a fight

Crabs will fake it to avoid a fight, research finds Dr Robbie Wilson, Head of the Performance Lab at UQ, where this study was conducted, said the research identified more than just some crabby behaviour. “This study is important because it reveals the general principles behind how liars and cheats are controlled and encouraged in nature.“Whether it's a soccer player diving to fool a referee or a crab trying to intimidate a rival with weak claws, our lab has shown that individuals cheat more when their deception is likely to go undetected,” Dr Wilson said.

Ms Candice Bywater who is finishing her PhD on fiddler crabs, said that she found that more males bluff their way through fights when they are less likely to get caught.

“When there are lots of crabs living in one area, there is lots of competition for resources like females and food. High competition means there is a greater chance of males having to fight each other to win resources compared to when there are not many crabs about. Those crabs might not have to fight at all,” Ms Bywater said.

“Crabs that have strong claws will generally win fights. Producing large and strong claws is important to their survival.

“Where crabs are likely to have to fight a lot, the crabs are producing large, strong, reliable claws. We found that when there are not many other male crabs in a population (low competition), males produce large but relatively weak claws (unreliable), as they don't have to fight as often and ultimately because can get away with it."

In nature, signals may be behavioural, as in growling or posturing, but are often structural, including the antlers of a deer, and the enlarged fore-claw of many crustaceans.

A male that overstates his quality could improve his ability to gain food or mates, but surprisingly, most signals are honest reflections of a male's prowess.

Written by UQ Media

Adaptation + Acclimation

Most animals live in environments that vary on some scale - temperatures change daily and seasonally; salinities change with rainstorms; even water levels change with the tides. Organisms must be able to respond behaviourally and physiologically to these changes in their environment, to maintain high levels of performance that keep them alive and reproducing.

In my lab, we study how changes in temperature influence animal performance. We focus on temperature because it varies naturally over days and months, and now with global climate change, over years as well. Human developments also affect temperature at a local scale - creating urban 'heat-islands' that get - and stay - hotter than surrounding areas. Understanding how animals respond to temperature is key to their conservation.

What is acclimation?

Acclimation is a general term for the physiological changes that occur in organisms in response to changes in the environment. Fundamentally, it's assumed that these changes allow performance to be enhanced - or at least maintained - in the new environment. Acclimation can be measured at many different levels, from whole-animal performance down to biochemical reactivity rates; and looking at multiple levels within a study allows us to get a complete picture of how animals deal with environmental change within their lifetimes.

What is adaptation?

Adaptation refers to genetic changes that occur across generations or among populations, in response to long-term changes in climatic conditions like temperature.

Why are adaptation and acclimation important?

Global climates are changing, and conservation of species depends on understanding how they will respond to these changes both in the short- and long-term. Our research examines the behavioural and physiological changes that animals make when temperatures change, the heritability of acclimation abilities among generations, and the difference in thermal tolerances and physiology among spatially-variant populations of the same species.

Our aims in this field

We want to understand

• how performance relates to temperature
• how behaviour and physiology are modified in new or changed environments
• whether these modifications are heritable
• how populations differ in the ability to adjust to new temperatures

Games + Strategies

What are games?

Two Tone Fiddler Crab - Andrew Mitchell

In the the fields of ecology and evolution, games refer to strategic decisions made by individuals or strategic adaptations made by genomes (respectively) to maximise survival and/or reproductive output. Usually, games refer to some sort of conflict, physical or otherwise.

In nature, organisms may:

• compete with others to gain resources or mates;
• evade predators; 
• capture prey; 

and the formula for optimal success in life may differ between males and females, or even between parents and their offspring. All of these conflicts can be thought of as games or strategies, modeled using mathematical algorithms, and tested in natural systems to better understand how organisms use behaviour and physiology to get the most out of life.

Understanding deception

In my research group, we focus on the behaviour and physiology associated with deception. You might imagine that individuals could enhance their survival or reproduction by pretending to be better performers than they actually are - but in reality, deception is surprisingly rare in nature. We believe this is because deceptive individuals that get caught are punished severely, either physically or socially, resulting in a dramatic reduction in reproductive and/or lifespan potential.

Most of our work focuses on the physical performance among crustaceans, which are among the few animals to routinely use deception; crustaceans may use their enlarged claws to battle for dominance (and access to mates or resources), and our work has shown that claw size - which is used as a signal of strength - is not always an accurate indicator of actual strength. Though crustaceans with large-but-strong claws are likely to dominate, some individuals produce large-but-wimpy claws and seem to get away with it. How does this happen? Does the pattern of deception vary among populations, sexes, and species?

Why is this important?

Using our crustacean model, we are testing theoretical questions about the environmental and social factors that promote or limit deception in nature. Because we're testing general models, our work can be applied not only to crustaceans, but to all animals, including humans.

Photo: Anthony O'Toole

In fact, we're building on our research on crayfish and fiddler crabs to examine deception in human sport; specifically, diving in soccer. Our work is also relevant to other fields like economics, political science, and psychology.

Our aims in this field

Our work on deception will enable us to:

• better understand the use of deception in animal communciation
• advise sports authorities in ways to reduce deception in games
• enhance game theoretic models

How to fight dirty

If you're a crayfish, your best bet is probably to grow an intimidatingly-large claw ...but pack the muscle (i.e. punch) into the other claw.

Many animals - like crayfish - signal their fighting prowess by displaying specialized limbs, musculature, or weaponry to others. In signaling, bigger is often better; but in a fight, rivals could gain advantage by concealing their real strength in less conspicuous limbs.

Cryptic asymmetry occurs when differences in limb strength are unrelated to differences in limb size, and was previously considered only in primates; however, we found asymmetric strength in males of the slender crayfish, which use their claws in display and combat. 

Photo: Anthony O'Toole

In a paper just published in Biology Letters, Robbie and collaborator Mike Angilletta suggest that asymmetric strength could be used to confuse rivals and influence the outcome of fights.

(look over here... look over here... ) WHAM.

Big News at the Moment - Feb 2012

1. Robbie got his 69th publication, and for some reason thought that was funny.

2. Candice returned from the US, jet-lagged and culture-shocked. We've missed her.

3. Billy's still ... somewhere?

4. Jaime's officially started her PhD, and taken up the last desk in the Fun Zone.

5. Another of Candice's PhD papers just got accepted for publication! This one's:
Bywater, C & Wilson RS. 2012. Is honesty the best policy? Testing signal reliability in fiddler crabs when receiver-dependent costs are high. Functional Ecology (in press Feb 2012)

6.  Robbie decided it was time to get married. To me.

And that's February, 2012!

The Scent of a Predator (Well, Kind of)

The following article is adapted from a talk presented by Jaime Heiniger at SICB 2012, along with coauthors Billy Van Uitregt and Robbie Wilson. The original talk was called: "Fine tuning anti-predator responses: are the costs of inducible predator defences proportional to the magnitude of the responses?"

***

For amphibians, it's a mad, mad world. And - importantly - an unpredictable one. Natal pools might contain predators, or not; competitors, or not; food, or not; and conditions can change every day. As a result of all this unpredictability, many amphibians can alter their appearance and behaviour in ways that increase their likelihood of survival. But these defensive strategies usually come at a cost - slower growth, higher metabolic requirements, and smaller size at maturation are just a few common outcomes.

toadlets in the lab

To maximise the benefits and minimise the costs associated with predator defense, it's predicted that the magnitude of the defensive response should reflect the magnitude of the threat. Thus, more threat = more phenotypic change; and less threat = less phenotypic change. This is known as the threat-sensitive predator avoidance hypothesis (TSPAH), and although it's known that prey can fine-tune their responses to the degree of predation risk, it's unclear if the magnitude of threat-sensitive defensive responses relate to their associated costs.

{Jaime} tested this idea by examining the effects of increases in perceived predation risk on the expression of defences and their associated costs in larvae of the toad, Bufo marinus. She reared tadpoles in varying concentrations of predation cue* and quantified their growth, morphology and development, as well as metamorphic size, locomotor performance and oxygen consumption.

*for those curious, predation cue is actually water from around deceased tadpoles. Tadpoles are sensitive to the smell of their dead mates. (Aren't we all?)

taddies in the lab

{Jaime} found that tadpoles responded to increases in perceived predation risk by gradually decreasing their activity.

As a consequence of their more-sedentary lifestyle, individuals metamorphosed later, smaller and with reduced endurance. Toads that emerged from the different treatments didn't vary in maximum jumping distance but those from 'high predation' treatments metamorphosed with longer relative hind limbs - meaning they could jump farther for their body size.

jaime's metamorph habitats

 These are interesting results, because they show that
a) toads produce defenses that are proportional to the perceived threat
b) defensive behaviour is costly
c) the costs are in proportion to the amount of defense
d) but phenotypes produced in response to predation threat may aid the individual.

Cool stuff, Jaime!

Why Be Fake? Because Honesty is Too Expensive ...

In earlier posts, we've talked about the life of a crab ... and about the predisposition for some crabs to fake how strong they are. At SICB in January, Candice presented a talk detailing why exactly it pays to be weak.

image by Dan Hancox

Here's my recap on Candice's talk ...
Crustaceans are violent types, posturing and fighting for territories, mating partners, and resources. Because claws are such excellent weapons, fights are often decided by the individuals merely checking each others' claws out. Bigger claws = dominance. This ameliorates the risks associated with claw-battle, while still deciding dominance.

But Candice has found that the size of the claw is not always indicative of its strength - namely, some individuals are fakers. You see, claw muscles - which are used to clamp and tear in a fight situation - are hidden inside the chitinous claw. So a big-clawed crustacean might just lack big muscles underneath, meaning it's more likely to lose if the interaction escalates into a fight.

So why wouldn't a crustacean just grow the muscle? This is what Candice wondered. She noticed that crabs with re-generated claws tended to have wimpy claws, relative to their claw size. So, she measured the energy needed to maintain claw muscles in fiddler crabs with strong, original claws as well as crabs with weak, regenerated claws.

 

Candice believes that dishonesty in fiddler crabs is related to metabolic costs - namely, how much energy is required to keep that muscle active. Crabs with strong, original claws spent ~22% of their metabolic energy budget on their claw muscle - pretty close to the amount of metabolic energy humans use to support our large glucose-hungry brains.

In contrast, crabs with weak, re-generated claws used only ~12% of their daily energy on claw muscle.

That constitutes a massive energetic savings for fakers, unless they get caught ...

CB in DC

At this precise moment, Candice is working at the Natural History Museum in Washington, D.C. - measuring crustacean claws as part of a study for her PhD.

Or, she might be sleeping. (I can never get those time-differences right ... )

At any rate, this is her lovely little brownstone ...

She's even famous now, in a "The Lost Symbol" kind of way, toiling away in the crustacean collections in Pod 5* at the Museum Support Centre (MSC), a high-security warehouse in the sketchy part of town.

*The same section of the warehouse featured in Dan Brown's book ... in case you haven't read it yet.
 

And how does Candice spend her days in DC? She's on the bus at 7:30, heading to the Natural History Museum in downtown DC, where she catches the shuttle to the warehouse facility where the crustacean collections are housed.

In to her little lab in the wet collections rooms by 8:30, she starts taking photos of crab claws and measuring the sizes of the shell and legs - for different specimens and different species. It sounds like quick work, but given she has to take 3 measurements of each crab leg (and each crab has 8 measurable legs), she may just be there ... all year.

Not really. But I'm sure that's how she feels sometimes. 10-15 minutes per crab x a warehouse full of crabs = significant porters needed at the end of the day.

Candice measures claws on her own, but has lunch with the other 10-15 researchers who work at the warehouse measuring, cataloging and sorting other types of invertebrates. They all chat and sometimes have science talks, so it's been a great way to meet everyone else.

Then it's back home again, to forget about claws for 12 hours or so.

And why is she doing all this? Candice is looking for tradeoffs between claw size and other morphology among different crustacean species - compensatory mechanisms (like we just learned about with geckoes). We'll talk more about the science after she gets back.

(all the pictures in this post were provided by Candice. Thanks!)

Trade-offs in Gecko Design

Sounds glam, right? Gecko design?

At the 2012 SICB in Charleston, Skye presented research that shows how traits that improve bite force in geckos have negative impacts on the gecko's sprint speed. Meaning that males who are better fighters might also be less adept at escaping predators ...

Costly design indeed.

Let's learn more by having a look at Skye's abstract, with {comments in brackets from me}.

Trade-offs and compensatory traits: bite force and sprint speed pose conflicting demands on the design of male geckos (Hemidactylus frenatus)

by Skye Cameron, Melissa Wynn and Robbie Wilson

The evolution of exaggerated ornaments and armaments is driven by the benefits accrued to reproductive success and by the costs imposed on viability. {This means that} when traits are required to perform multiple functions that are important to both reproduction and viability, trade-offs can result in a compromised phenotype.

{Imagine, for example, a species of bird in which females are more likely to mate with males that have larger tails; but males with larger tails are more likely to be captured by predators. Both reproductive potential and survival are important to the male - so evolutionarily, the bird may end up compromising on tail length to make sure he both reproduces and survives.}

image

{Intuitively, we expect that exaggerated male traits (like super-long tails) would decrease locomotor capacity, resulting in lower survival rates due to predation.} Despite only mixed empirical support for such locomotor costs, recent studies suggest these costs may be masked as a result of the evolution of compensatory mechanisms that offset any detrimental effects.

{What are compensatory mechanisms? Imagine if that bird with the long tail-feathers developed longer wings, that enhanced its flying abilities. It might offset some of the survival costs of the long tail.}

In this study, {Skye} provides a comprehensive assessment of the importance of potential locomotor costs that are associated with improved male-male competitive ability by simultaneously testing for locomotor trade-offs and compensatory mechanisms. For males of the Asian house gecko (Hemidactylus frenatus), both fighting capacity and escape performance are likely to place conflicting demands on an individual’s phenotype.

image

Males that are highly territorial and aggressive are more likely to require greater investment in jaw size/strength in order to compete with rival males; {Skye} found that males with larger heads had stronger bites and showed greater prey-capture and fighting capacity. This performance trade-off was amplified for male geckoes with larger heads when {they were} sprinting up inclines.

image

{So, what does this mean? Geckoes with large heads are better at fighting and better at capturing prey, but may be worse at evading predators themselves. A compensatory mechanism would be something - like longer legs - that would enhance their ability to avoid predation.} {However, Skye} found little evidence for compensatory mechanisms that off-set the functional trade-off between bite force and sprint speed.

Ongoing work in this area includes testing the survival of male geckoes with different sized heads in controlled-but-natural conditions.

Bigger *is* Better: Phallus size and male physical performance across temperatures

The second presentation we'll discuss is Robbie's. Robbie's talk - though sadly fraught with technological difficulties - conveyed to the audience the answer to that age-old question:

does a bigger phallus actually mean the male is better?

I won't give away the ending just yet, (or maybe I will ... ) - in mosquitofish, anyway - the answer seems to be yes.

Bigger is Better in all environments: temperature-induced variation in phallus size is a reliable indicator of male physical performance and gamete quality

Males of many organisms possess elaborated structures that are used to engage in fights with other males and/or to attract females during courtship. The size and elaboration of these secondary sexual traits can be affected by the environment via its influence on the condition of an individual male. This link between male condition and the elaboration of male sexual signals is one of the most important mechanisms maintaining the reliability of these traits as signals of male quality.

male elk use extravagant antlers to battle for females

The role temperature plays in mediating the condition of individual males and the size and elaboration of their sexually selected traits is currently unknown. Males of the eastern mosquitofish (Gambusia holbrooki) possess a modified anal-fin phallus (gonopodium) that is used as both a signal of dominance and a stabbing weapon during male-male competitive bouts {as well as to fertilise females}.

image

{Robbie} examined the effect of temperature on the size of this putative sexual signal (phallus size) by chronically exposing males to either 20° or 30°C for four weeks. {He} also tested the influence of these thermal environments on various measures of male quality; including male territorial performance, swim speed and gamete function.

Males chronically exposed to 30°C possessed longer phalluses, greater ejaculate sizes, larger testes and faster sperm swimming speeds than those exposed to 20°C. This is the first study to show that environmental variation in phallus size can be a reliable indicator of male physical performance and gamete quality.

{And what does this mean, and why does it matter? Well, it means that mosquitofish may have higher reproductive outputs in warmer environments, and might do even better than they currently do when climates warm further. In Australia, mosquitofish are invasive and by out-competing and eating eggs and young of natives, they are aiding the decline of native fish populations.}

Not good. Who knew that global warming would increase phallus sizes ...

Death After Sex in the Australian Bush

Charleston wasn't just about pizza and beer, though with any scientific conference that's always a part of it ...

First up, we'll hear about Jaime's poster. Jaime did a 1st class honours degree in the lab, studying the way Rhinella marinus (cane toad) tadpoles respond to the presence of predators in their environment. But that's not what she was presenting here ... Jaime also recently was accepted into the PhD program at UQ to study quolls on Groote Eylandt, and she was keen to get the word out there about her new study system.

Now.

More about quolls and sex and the bush, as conveyed by Jaime and her co-authors on the poster, Robbie and Billy {with clarifications from me along the way}

image by Candice Bywater

Death after Sex in the Australian Bush: determinants of survival and reproduction in males of the world’s largest semelparous* mammal {*meaning they die after breeding!}

The northern quoll (Dasyurus hallucatus) is a medium-sized (approx. 1 kg) predatory marsupial previously common across the entire top-end of Australia. This species is the largest known semelparous mammal in the world, which means mating is highly synchronous, males live for only one year, and males undergo total die-offs soon after the mating season.

Such population-wide male die-offs are presumably due to the physiological stress of procuring copulations and the intense fighting among males. A small proportion of females will survive to produce a second litter, but there are no documented cases of survival to a third breeding season. The young are born after a short gestation period and then carried in a rudimentary pouch for approximately 60-70 days.

Females will then leave young in dens while they forage, returning to suckle until young are independent at 4 – 5 months. Both sexes are solitary throughout the year with a home range averaging 35 ha for females and approximately 100 ha for males during the breeding season but varies greatly between individuals.

During {Jaime's} study, {she} will be investigating the morphological and performance determinants of both survival to reproductive-age and fecundity among males of this species on Groote Eylandt, an Indigenous-managed island off the coast of the Northern Territory. Northern quolls are still highly abundant on this island and this population offers a unique opportunity to understand the evolution of this extreme mating system and the role physical performance plays in the reproductive success of males.

We can't wait to hear more!

A Little Bit About Our Research on Performance

The basis of our lab's research is performance - performance of animals, including humans, in the context of their biotic or abiotic environments. We're interested in trade-offs between traits such as speed and endurance; the ways that changes in temperature or oxygen levels or life stages affect performance; and - in the case of sport - we're interested in optimising performance levels.

Currently, we're looking at projects such as:



1. Skill, balance, and athleticism in soccer performance (humans)

See the following posts for more detail:
Research and Innovation in Soccer (on our soccer website)
Measuring Individual Performance in a Team Context (on our soccer website)
The Importance of Effective Receiving and Passing (on our soccer website)
Assessment of Receiving and Passing Skills (on our soccer website)

 

 2. Weapon strength in signalling animals (crustaceans, lizards)

See the following publications for more details:

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. View abstract here.

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. View abstract here. 

Seebacher F & Wilson RS. 2006. Fighting fit: Thermal plasticity of metabolic function and fighting success in the crayfish Cherax destructor. Functional Ecology 20: 1045-1053. View abstract here. 

crustaceans fighting to establish dominance

3. Tradeoffs in locomotor performance (fish, crustaceans, amphibians, insects, humans)

See the following publications for more details:

Angilletta MJ, Wilson RS, Niehaus AC & Ribiero P. 2008. The fast and the fractalous: tradeoffs between running speed and manoeuvrability in leaf-cutter ants. Functional Ecology 22:78-83. View abstract here.

James RS & Wilson RS. 2008. Explosive jumping: Morphological and physiological specialisations for extreme jumping in Australian rocket frogs. Physiological and Biochemical Zoology 81:176-185. View abstract here.

Wilson RS & James RS. 2004. Constraints on muscular performance: trade-offs between power output and fatigue-resistance in skeletal muscle. Proceedings of the Royal Society of London B 271: S222-S225.

Van Damme R, Wilson RS, Van Hooydonck B, & Aerts P. 2002. Performance constraints in decathletes. Nature 415:755-756. View abstract here.

  

do a male threadfin rainbowfish's streamers affect his swimming?

4. The myriad ways that the abiotic environment (i.e. temperature, pH, UV radiation, oxygen levels, etc) or the biotic environment (i.e. competitors, predators, etc) influences performance (frogs, fish, crustaceans, lizards)
See the following posts for more detail:
Run Gecko Run
Measuring Toad Jumps
Studying Mosquitofish in the South of France

And the following selected publications:
Wilson RS, Lefrancois C, Domenici P & Johnston IA. 2010. Environmental influences on unsteady swimming behaviour: consequences for predator-prey and mating encounters in teleosts In Fish Locomotion: An eco-ethological perspective (Eds Domenici, P & Kapoor, BG). Science Publishers, NH, USA. 

Barth B & Wilson RS. 2010. Life in Acid: interactive effects of pH and natural organic acids on growth, development and locomotor performance of larval striped marsh frogs (Limnodynastes peronii). Journal of Experimental Biology 213: 1293-1300. View full text here.

Condon CHL & Wilson RS. 2006. Effect of thermal acclimation on female resistance to forced matings in the eastern mosquito fish. Animal Behaviour 72: 585-593. View abstract here.

Wilson RS. 2005. Temperature influences swimming and sneaky-mating performance of male mosquitofish Gambusia holbrooki. Animal Behaviour 70:1387-1394. 

Billy measures jumping performance in a toad metamorph

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?