Birding Adventures in the Australian Outback

For 16 days this July, I had an adventure in the Australian outback. It had a road trip. It had camp cooking. It had sand dunes and scrubland and bush walks and hot springs and country towns and dragons and a marathon, and it had birds – lots and lots of birds.

An everlasting daisy.

Cloud formations over Big Red (Nappanerica), the largest sand dune in the Simpson Desert.

To be specific, I was lucky enough to be included on a remote field trip to survey birds in inland Australia for Dr Richard Fuller’s Spatial Ecology research group. I accompanied Master Birders Claire Runge and Nick Leseberg for two weeks of surveying along the Birdsville track, starting in Adelaide, South Australia and ending up in Birdsville, Queensland. I was primarily the expedition’s chef and scribe, but by the end of our trip I believe I had earned the rank of Novice Birder, seeing a total of 67 “lifers” (birds I’d never seen before) and starting a bird list of my own.

Brown Falcon (Falco berigora) taking flight.

A group of Zebra Finches (Taeniopygia guttata) chilling and preening at a highway petrol station.

By combining the results from their long-term surveys with remotely sensed data on weather and climatic conditions, the Fuller lab aims to determine how the distribution of birds in Australia’s remote regions is altered by climatic change. The surveys conducted along the Birdsville and Strzelecki tracks will also help us figure out exactly what birds are out there and where they go as the seasons change.

A Letter-winged Kite (Elanus scriptus) at dusk, preparing for a night of raptorish activity. Letter-winged Kites are uncommon and nomadic, and sighting numbers are further decreased by their nocturnal life history.

The Gibberbird (Ashbyia lovensis), a type of Australian chat only found on the gibber plains.

As we made our way across the country, we saw some amazing things. Some nights were spent camped out on gibber plains, without a single shrub in sight – a situation that was far more comfortable than you might imagine. In the mornings we found Gibberbirds, smooth-snouted earless dragons, and lots of old hand tools made by indigenous people long ago. We also found a nesting Inland Dotterel, faithfully sitting on her eggs until we unwittingly almost walked over her, when she leapt up and played the bird with the broken wing until we’d moved away.

Smooth-snouted Earless Dragon (Tympanocryptis intima) making itself look big. Most of the insects and reptiles out on the gibber plains are well camouflaged.

Nesting Inland Dotterel (Charadrius australis), sitting steadfastly on her four, well-camouflaged eggs.

Other nights we camped at Artesian hot springs, lush with vegetation and bird life. Here we got to hang out with Pied Stilts, White-breasted Woodswallows, Black-fronted Dotterels, Whistling Kites, along with hundreds of Galahs who shacked up for the night above our tents.

Morning at an artesian hot spring.

A Pied Stilt (Himantopus leucocephalus) fishing in an artesian hot spring.

It wasn’t just the fauna that amazed me – the adaptations of the plant life to such a harsh environment blew my mind. We surveyed at salt plains that looked like a scene from the bottom of the sea, or a kind of terrestrial coral reef. We trekked amongst the saltbush, including the chenopods with their spectacularly aggressive seed pods (seriously. Those things hurt!), Acacia and Eucalypt woodlands and Spinifex grasslands. We also found some furry trees along a riverbed, which turned out to be Acacias with minni ritchi, a type of reddish-brown bark that continuously peels back from the stem.

Samphire (Tecticornia sp.), a salty succulent that comes in all different colours and shades and looks kinda like a sea anemone.

With its leaves and flowers in different shades of green, with its huge succulent seed pods – I have no idea what this plant was, but it was beautiful.

An Acacia with minni ritchi (a type of bark that continuously peels back from the trunk and branches, giving the tree a furry appearance).

Despite the beauty of the places we were travelling through, there were some chilling reminders of some of the problems the ecosystem out there faces. The number of rabbits we saw was absolutely astounding – sometimes it was all I could do not to roll an ankle in the massive tunnel networks they’d created throughout some areas of the landscape. We also saw a disturbingly high number of prints from feral dogs, cats and foxes, all of which pose a massive predation threat to the small birds, reptiles and mammals that live there (especially ground-nesting birds like Lapwings and Dotterels). In addition, the degradation of the land by cattle and sheep was extremely obvious at many of the sites we surveyed.

Fox prints in the sand. Foxes are an invasive animal in Australia, and along with feral cats and dogs they pose a major threat to small mammals, reptiles and birds.

The skull of a small mammal, half buried in the ferrous oxide-rich dirt.

All of these things made me appreciate how fragile the balance of the ecosystem is. The research the Fuller lab is carrying out is not only important in determining how climate change will affect species distributions, but it also will help us determine where rare species like the Chestnut-breasted Whiteface and the Letter-winged Kite occur, and therefore which areas we should focus on conserving. We live in a beautiful world, with an amazing amount of biodiversity even within our harshest environments. It would be a shame to lose that biodiversity due to lack of knowledge and understanding.

Dusk and tracks (from Nick!) on Big Red.

This trip was a fantastic experience for me, and one that I know many people will never get to have. I am extremely grateful to the Fuller lab for including me on this research trip, and to Nick and Claire for making it so much fun. Thank you for the adventure!

Nick, Claire and I in front of our trusty 4WD at Wild Dog Hill in Whyalla Conservation Park. Image credit: Claire Runge.

A Wedge-tailed Eagle (Aguila audax) circling in the sunset at Stoke’s Hill.

All images by Rebecca Wheatley unless otherwise credited.

The Grand Slam: how hard should you hit?

The trade-off between performance and accuracy is a problem faced by a lot of different animals in a variety of situations. For example, consider a squirrel running along a bare branch to get from one tree to another; the faster it runs, the less time it spends exposed to predators. However, as the squirrel runs faster, it also increases its chances of mis-stepping and falling to its potential doom. So, to get the best of both worlds, the squirrel needs to optimise its running speed depending on its chance of slipping (the width of the branch) and the cost of falling off (the height from the ground).

Squirrels know what’s going down (or do they)? Image source: Wikimedia commons.

These sort of performance/accuracy trade-offs are also commonplace in the human world. How fast should you smash out a text message to your supervisor asking him (politely) to email back your latest draft before the number of typos makes the whole thing unintelligible?  In particular, these trade-offs are of a great deal of interest in elite sports. An awesome example of a sport where this trade-off is of utmost importance is in singles tennis. 

Serving hard: Heather Watson, Roger Federer and David Ferrer. Image source: Wikimedia commons.

In tennis, it’s pretty well accepted that if you serve really hard, it’s more difficult for your opponent to return the ball. But the harder you serve, the more likely it is that you’ll miss the service area and fault. So, players will usually belt it out on their first serve, but if they miss the first serve they’ll hedge their bets and serve softer the second time round to make sure they don’t double fault.

A/Prof Robbie Wilson, Dr Chris Brown and I have been testing this idea about performance trade-offs and optimal strategies using data from the men’s singles in the 2013 Australian Open. We’ve found this observation to be generally true: the probability of winning the point increases as the serve speed approaches its maximum, but the probability of faulting increases as well (for most players – some players are really consistent at getting it in regardless of how fast they serve). This was reflected in the frequency of high serve speeds in the first and second serves.

Jérémy Chardy, Andy Murray and Janko Tipsarevic. Image source: Wikimedia commons.

We’ve also constructed an optimality model which predicts the optimal serve speed taking into account the probability of faulting and the cost of a fault. An optimality model is, in essence, a mathematical model where you input the risks and rewards of a specific situation for a given individual, and it will tell you the optimal response for that individual if it wants to both minimise the risks and maximise the rewards. Optimality modelling is useful because it allows us to calculate the optimal response of specific individuals to any situation. We are looking at whether their opponent’s world ranking (ability to return a fast serve) and the point they’re going for or defending against (normal, game, set or match) affects their serve speed in relation to their optimum, but more on those results later.

Rafael Nadal, Caroline Wozniacki and Jérémy Chardy. Image source: Wikimedia commons.

We hope that our research can teach us more about how animals optimise their behaviour and physical efforts to improve their chances of successfully performing a given task. Depending on what we find, we might even be able to offer specific recommendations to tennis players wanting to improve their service game – who knows what the future might hold!

Andrew Hunter, a PhD student in our lab, is looking at performance/accuracy trade-offs in soccer. Will the results be similar between an individual and a team sport? We don’t know yet, but it will be interesting to find out.

Novak Djokovic, Agnieszka Radwańska and Venus Williams. Image source: Wikimedia commons.

The boldest gecko: personality in a reptile

Animal behaviour is a big field - and it's constantly expanding as research reveals gaps in our understanding of why animals do the things they do. One topic in animal behaviour that holds a great deal of interest for me is that of animal personality. This is a relatively new concept and, frankly, it's a little bit controversial. The word "personality" conjures up a variety of mental images, most of which pertain to one animal in particular: us. It goes without saying that people have different personalities; we experience it every day. But do other animals have personalities as well?

Great tit (Parus major), beadlet sea anemone (Actinia equina) and pumpkinseed sunfish (Lepomis gibbosus); three species that display animal personality, from very different groups. Image source: Wikimedia commons.

In animal behaviour, the term "personality" is defined as consistent differences in behaviour displayed by individuals. An example of a personality trait is how an individual responds to a threatening situation, termed boldness or shyness. Bold individuals are undaunted by threatening situations and will approach the stimulus, while shy individuals will stay away or hide. There are heaps of different personality traits that have been studied, including boldness, exploratory behaviour and aggression, amongst many others. Individuals' "personalities" are thought to range along a proactive-reactive continuum, where proactive individuals are aggressive and bold while reactive individuals are more passive and shy (sound familiar? It's not unlike a simplified version of the extroverted/introverted behaviour displayed by people). There is growing evidence that "personality" is present within many groups of animals. Despite this, we don't really know much about what determines an animal's place along the proactive-reactive continuum or why this variation exists.

My study species: the Asian house gecko (Hemidactylus frenatus). Image credit: Wikimedia Commons (1 & 3) and Rebecca Wheatley (2).

During my honours project, I investigated "personality" in male Asian house geckos (Hemidactylus frenatus). I measured the anti-predator behaviour (a proxy for boldness) of 100 geckos by filming each gecko for one hour and then by calculating the proportion of time it spent inside the shelter in its terraruim. Each gecko was measured under three different treatments:

1. "empty terrarium": where nothing (aside from the shelter) was added to the terrarium, to give me a measure of each gecko’s normal amount of anti-predator behaviour
2. "terrarium with novel object": where I added a novel object to the terrarium, to see what happened to their anti-predator behaviour when something new was added to the environment
3. "terrarium with threatening stimulus": where I added a threatening stimulus, to see how their anti-predator behaviour changed when something scary was added to their environment

I found that different individuals reacted to the treatments in different ways, but the overall trend looked like this:

We can see that when a novel object was added to the environment, the geckos' anti-predator behaviour generally decreased when compared to their standard level of anti-predator behaviour. This might be because they wanted to check out the new object to make sure it wasn't food or some other valuable resource. However, when I added a threatening stimulus, their anti-predator behaviour jumped back up again to around the same as its standard level. So it seems that the threatening stimulus effectively cancelled out the novel object effect.

How do we know if these behaviours constitute as "personality"? Well, I found that while different individuals displayed consistent anti-predator behaviour within treatments, they also responded to the treatments in different ways. Some displayed more anti-predator behaviour when the environment was altered (were "shyer"), while others displayed less (were "bolder"). Therefore, from our definition, we can see that their anti-predator behaviour is a personality trait: they display consistent differences in behaviour that are context-specific.

Checking on my gecko housing set-up. Image credit: Amanda Niehaus.

But why do individuals have different personalities? Previous research has found that a few things can be associated with an animals' boldness or shyness. A large body mass is often associated with a bold personality, which is probably because heavier individuals are usually larger and more likely to win in a fight (so they have a good reason to be bold). Similarly, individuals with a hard bite force, a strong claw pinch or any other performance trait which would give them an advantage in a contest are usually bolder as well. The possession of traits that might make it easier for them to escape from a predator in a pinch, like fast running speed, have also been associated with boldness. In addition, resting (or "standard" for reptiles) metabolic rate has been linked to animal personality; it's thought that bolder, more aggressive individuals need a higher metabolic rate to keep up with their energetic demands.

I investigated how some of these traits interact to effect boldness in my geckos. I measured each gecko's mass, standard metabolic rate, maximum running speed and maximum bite force and analysed their interactive effects on anti-predator behaviour. Contrary to what I expected (and to what the literature would lead us to predict), I found that none of these traits affected anti-predator behaviour. This could be due to a few different things: one possibility is that boldness and shyness in Asian house geckos has a hormonal basis. It could also be that "personality" in geckos develops based on experiences rather than any specific physiological or performance trait. To discover the answer to this question, further research into the interactive effects of such traits on personality needs to be done.

One of my geckos in his metabolic chamber. I did all my metabolic tests during the day (when they are least active, being nocturnal animals) so I could get an accurate estimate of their resting (standard) metabolic rate. Image credit: Amanda Niehaus.

Anyway, why does it all matter – why does "personality" even exist? The fact is there are costs and benefits to being both proactive and reactive. Proactive individuals are bolder and more aggressive, so they are usually better at holding territories and getting laid – but they're also a lot more conspicuous to predators, so they tend to "live hard, die young". Reactive individuals, on the other hand, might not have the best real estate or as many mates at any given time, but their shy behaviour means they usually live longer. So, if we imagine an ecosystem where predation is low, it's better to be proactive and reap the benefits without the risk of being eaten. But if the ecosystem changes (for example, a bunch of predators move into the neighbourhood) and all the proactive guys die off – who is left? This is the most popular theory as to why different personalities exist; so that if conditions change quickly, some individuals survive and the population continues.

Although extremely interesting, these personality experiments were only one small aspect of my honours project, which aimed to answer questions about fighting ability (resource-holding potential) and fighting strategies. More on that later!

Bit of a teaser for the rest of my project. Image credit: Amanda Niehaus.