Shake paws with the devil

One of the nice things about working in evolutionary biology (or any of the related, indistinguishable-for-all-practical-purposes Wild Thing Sciences) is that I was connected to a great number of cool people working on a great number of very cool creatures, in a great number of very cool places. Furthermore, the bureaucrats controlling modern-day Wild Thing Science are safety-paranoid enough that everyone doing "fieldwork" (working in the wild) must bring at least one buddy. That's one of the reasons I always brought volunteers on my trips, and why Wild Thing Scientists are constantly advertising for volunteers. If you're willing to work without getting paid there are many cool opportunities to work with a variety of wild animals worldwide. I know one evolutionary biologist who works solely on theory - all she needs to do her job is a working computer, essentially - but she travels the world going to exotic places and seeing incredible animals simply by tagging along with other biologists. It's actually an enviable system, as the "work" parts of fieldwork, like conducting experiments, collecting and preserving samples, and even just finding whatever animal you've decided you'd like to study, can be incredibly challenging, time-consuming, stressful and expensive. But tagging along on someone else's fieldwork? All the cool parts, none of the stresses!

This brings me to Dave. Dave is a friend of mine, and Scottish, which is why, when he got married, I got to wear a kilt. It was among the more exciting experiences of my life:

Dave (L) and me (R) wearing kilts at Dave's wedding. This was my first (and only) kilt-wearing experience.

Dave (L) and me (R) wearing kilts at Dave's wedding. This was my first (and only) kilt-wearing experience.

Dave is doing his PhD on Tasmanian Devils, one of the coolest mammals around. I took the opportunity to be a volunteer during his fieldwork, and for a week I got to go out every day and see Tasmanian devils in the wild!

Dave is working in the far north-west corner of Tasmania, where the facial tumour disease is still spreading into healthy devil populations. If you haven't heard of the devil facial-tumour disease, and the destruction it has wrought on the world's last Tasmanian devils, check this out.

Dave catches devils by setting traps for them. Each trap is a big PVC pipe blocked at one end, with a door at the entrance and a piece of meat dangling at the back of it. Here's what a trap looks like set, ready and waiting for a hungry devil to come along:

Inside the trap, the meat is dangling by a string at the very back. The string is tied to a pin which is holding the door open. The devil enters the trap, grabs and pulls on the meat, the meat pulls the string, the string pulls the pin, the pin lets go of the door and the door falls, trapping the devil inside.

A view inside a set devil trap, with the meat dangling from a string and ready for a big yank by a devil.

To ensure that the devils spend as little time in the traps as possible, Dave and his volunteers get up before the crack of dawn and drive out to his field site to check the traps. This is what they hope to find:

There's a devil in there! There's a devil in there!

Sometimes the initial excitement about a devil in a tube is unfounded: devils aren't the only predators prowling Tasmanian forests at night, and Dave sometimes has to deal with bycatch. If the bycatch is a tiger quoll, that's just icing on the devil's cake. Tiger quolls are another spectacular Australian marsupial currently going extinct, and getting to see one in the wild is just as much a privilege as seeing a wild devil. However, sometimes Dave catches feral cats, which are harbingers of death to native Australian animals and destruction to the Australian wilderness. Dave takes cats to be euthanized by a local veterinarian.

Dave sometimes catches spectacular tiger quolls, like this one, in traps set for devils.

Sometimes traps are closed with nothing inside. I like to think this is the result of Tasmanian tigers, because they'd be so big that they wouldn't fit completely in the trap, which would prevent the trap door from closing on them. More likely than not, though, it's due to trap malfunction or some other mundane explanation.

If the closed trap proves to contain a devil, now, for better or for worse, you have a devil in a tube. This may seem like a challenge, and devils do have a reputation for being scrappy little balls of teeth and claws, but I learned by watching Dave that as long as you handle them with care and precision they're actually really calm. I watched Dave take measurements from a lot of devils and never once did one try to bite him or scratch him. This is as much to Dave's credit as a professional wildlife biologist as it is to the devil's relative docility: handling wild animals, especially ones with sharp teeth and massive jaw muscles, is not for the uninitiated.

The first step of processing a devil is, of course, to get it out of the tube. To do this, the tube is lifted and tilted, the door opened, and the devil slid gently into a burlap sack:

Due to the weight of the devil and the size of the trap, this requires two people: one of the many tasks for volunteers!

Once the devil is in the burlap sack, it generally stays pretty calm. Dave manipulates the devil-within-the-sack into different positions so that he can inspect it, determine how healthy it is, determine if there's any evidence of the facial tumour disease, and take various measurements:

Here's Dave measuring a devil. It'd be extremely cumbersome to both take and record the measurements while controlling and manipulating a devil-in-a-sack, so data-recording is another important task for volunteers.

Among the parts of the devil Dave inspects are its paws:

Cute little devil paw!

Dave also inspects the female's pouch to see if they're currently nursing:

Tasmanian devil pouches: the pouch on the left belongs to a female without pups, the pouch on the right to a female with pups.

 

Finally, Dave takes a look at the devil's business end: its jaws. Tooth wear is a good way to estimate the age of a devil, as it is to estimate the age of a lot of mammal species. And around the jaws are where any signs of facial tumours will turn up, though the population Dave was working on when I visited had never had any evidence of devils with the facial tumour disease. Here's an inspection of the jaws of a healthy devil:

Dave, and all Tasmanian devil researchers and conservationists, are very concerned about the potential for humans to spread the facial tumour disease between devils. Notice that Dave is wearing disposable latex gloves: those go into the garbage and are replaced in-between each devil. Dave and all the volunteers also use alcohol disinfectant gel in-between each devil just to be safe. A brand new burlap sack is used for each devil. And after the devil is removed from a trap, the trap is thoroughly washed and disinfected before being reset: another job for volunteers!

Finally, it's time for the fun part! After being processed, the devils are released into the woods. The process of getting them free of the sack can be cumbersome, and is an opportunity for pictures to be taken with a devil! Usually, however, the devil takes off like a bat out of hell:

But, there's that rare occasion where the devil pauses for the briefest of moments to say goodbye, and, if you're lucky enough to have a photographer (another volunteer job!) quick on the shutter, it can be captured for all eternity:

Photos by Connie Leon.

Helping Dave work with Tasmanian devils in the wild was an experience of a lifetime. And he's looking for more volunteers!

Death of a trailer

All photos in this post, with the exception of the first one, are by Angus Kennedy.

The recent #fieldworkfail Twitter fad reminded me of something I heard back in January. I was attending a careers workshop at an academic conference and they had a panel of people who conduct job interviews giving advice to us future job seekers. One panellist shared one of her favourite interview questions, which I don't remember verbatim but went something along the lines of "Describe an incident where something went wrong during your fieldwork and how you dealt with it." This is a very fun question because many things go wrong in the field, and the solutions can come from anywhere.  Often times, when something goes wrong in the field, there's no one there to tell you how to fix your problem, and you learn just how resourceful you can be when push comes to shove.

I thought I'd share the biggest catastrophe that happened to me during fieldwork and how we dealt with it, to pre-empt any future interviewers and because Angus got some excellent pictures of the disaster in progress. For the first two years of my fieldwork, we had a little blue trailer that we towed behind our Landcruiser. It was kindly loaned to us by a professor in the Plant Sciences department at ANU. This is the story of how I managed to destroy it. Or, if I'm feeling charitable to myself, how it managed to destroy itself despite my best intentions. 

Our beloved, but ultimately doomed little blue trailer. Photo taken during this other catastrophe.

The Landcruiser is a great fieldwork vehicle for many reasons, but trunk space is not one of them. While in the field I always had up to three volunteers with me, and four people in the Landcruiser leaves little room for storage (and the more people, the more stuff there is that needs to be stored). Our beloved little blue trailer was very useful in transporting all the stuff that comes along with moving a bunch of people through remote areas. Everyone has their own massive backpack filled with personal stuff, their own tent or swag for sleeping, plus we needed to move massive amounts of food and water, a kitchenette with which to prepare meals and eat them, and a propane tank to run the camping stove. Really, the amount of stuff we needed to haul around with us to keep ourselves alive far exceeded the amount of stuff we needed to haul around to do the fieldwork. And that's why we needed that little blue trailer.

At each field site our field camp came tumbling out of the little blue trailer.

The trailer successfully survived my first field season without any major problems. Sure, it needed some repairs when we got back, mostly to the electrical wiring and peripherals, but it survived intact and without any hint of major structural problems. However, my second field season was another story. Before we left, we took the trailer to get a check-up and it turned out the axle bearings needed to be replaced, and so they were. However, a month into our fieldwork the owner of the station we were working at noticed that the grease caps had come off the trailer. The grease caps protect the ends of the axles, preventing stuff from getting onto the bearings inside. Where we do fieldwork the roads are all dirt, and there is a lot of dust. I took the trailer into Alice Springs right away, but it was too late. Dust had gotten into the axles and the bearings had to be replaced AGAIN. They also put new grease caps on. I was assured that grease caps rarely have to be replaced, and that the trailer would now be fine.

In the Outback everything gets covered in red dust. In addition to axle bearings this includes the inside of vehicles (left) and my face (right).

However, not two days later, and after only travelling on paved roads, I notice that the grease caps had once again come off. I thought they must have been put on incorrectly in Alice Springs. We were in Yulara, which luckily has a mechanic's shop despite being not much more than a tourist resort. I got them to put new grease caps on the trailer, asked them put them on "extra tight" and I also asked to buy all the shop's extra grease caps. They looked at me weird when I said I wanted to buy all of their caps, and assured me that grease caps don't just come off and that the trailer would be fine. I bought all their grease caps anyway.

That night driving south I noticed that the grease caps were already starting to come loose. I tried my best to bang them back into place, but by the time we got to Coober Pedy the next day they were gone. At the mechanic's shop in Coober Pedy they cleaned and lubricated the bearings and affixed two more of my grease caps to the axels.

By this time I knew the caps wouldn't stay on. I just wanted to get to Port Augusta, where we could leave the trailer in storage and continue our fieldwork without it. Unfortunately, less than 80km south of Glendambo and only 200km for Port Augusta, the trailer came apart. The trailer's right wheel came completely off the axel and flew off into the bush. My volunteers Angus and Mitch later recovered it, apparently 50m off the road! The axel dug into the Stuart Highway, taking a decent-sized gouge out of the road and shooting up an impressive display of sparks while I tried to slow down and pull over as quickly and safely as possible. When I went back to inspect the trailer the remaining wheel had smoke coming out of the axel, and no grease cap in sight.

The next hour or so was quite demoralising. I had to use the satellite phone to call up my supervisor and the department's fieldwork coordinator to report what had happened. We were essentially stranded. It's illegal to abandon vehicles and equipment by the side of the road in Australia, and punishments are severe (abandoning vehicles in the Outback, usually after covering them in gasoline and lighting them on fire, is something of a shameful tradition in Australia). A call to our insurance provider, the NRMA, confirmed what I suspected: only the Landcruiser was insured, not the trailer, so they weren't coming to get us. The cops came by to check out the situation but weren't about to volunteer to transport our disabled trailer anywhere.

Without any other options, I left Angus and Mitch to watch over the trailer and I drove back to Glendambo. My run of bad luck continued, the only guy in Glendambo with a flatbed truck was out of town for the week. However, I noticed a flatbed parked at the Glendambo roadhouse with a wrecked car as cargo. I went into the petrol station and found the driver: an old, grizzled, significantly bearded guy who looked like he'd been driving outback roads since coming back from serving in the second world war, eating a standard roadhouse meal and watching TV. I tried to ask him if he'd help, but he took one look at me and told me to wait until he was done his dinner. An awkward silence ensued. Finally, after he finished, he explained how much of a hassle it would be to offload his current cargo, drive all that way, and how much behind schedule it would put him. I thought he was going to refuse, but it turned out he was just trying to soften me up for how much he wanted to get paid: $200 cash. Given the circumstances, he could have charged a lot more, and I was happy to hand it over*. The truck driver off-loaded his wrecked car and followed me back down the Stuart Highway to the wrecked trailer. He loaded up the trailer, which looked sad and small lopsided on the huge flatbed, and drove off. By this time it was about 11pm, and we set up camp on the side of the Stuart Highway.

The next morning Angus, the best chef of the three of us, cooked breakfast, which we ate sitting on the highway, getting up for the occasional car or truck zooming past. The Stuart Highway is so straight and flat that there's plenty of warning whenever anyone's approaching, even at 110km/h. 

We packed everything into the Landcruiser, an extremely tight squeeze. If I remember right, we ended up with the propane tank on the floor where the front passenger's feet should go, which did not seem very safe to me. There was absolutely no room in the back, so all three of us had to sit in the front, with Mitch sitting in the middle, crotch-to-gearshift**. We got to Glendambo and were able to throw out enough non-essential stuff to clear space for one person to squeeze into one of the middle seats, though whichever unlucky person sat there was jabbed in the back by lizard-catching rods for the entire ride.

The truck driver said he was going to dispose of our trailer at the Glendambo dump. When we got to our next field site, a sheep station near Lake Everard, and we explained what had happened, the station manager's eyes immediately lit up. All that had happened was one wheel came off? The missing wheel was inside the trailer? The axle was only bent, not broken***? He called up one of his mates to recover the thing from the dump, apparently it was recoverable enough to be useful pottering around the station. I never did hear whether they were able to find it at the dump, or whether it ever became useful again.

This disaster left me with two questions. The first is why did the grease caps keep coming off? While I don't really understand why they kept coming off when I was told repeatedly they very rarely come off, there was evidently some structural abnormality with the trailer that made it easy for the caps to come off. When we took the trailer in for a check-up prior to my second field season, the mechanic pointed out steel plates attached to the wheels. He said he'd never seen anything like them before. He also said they were not properly secured to the wheels and therefore liable to come off unexpectedly, and possibly on the highway, making them quite dangerous. He recommended, and we agreed, to remove them. I now think that these plates were holding the grease caps in place.

Two pictures of the same trailer wheel. The left photo, taken during my first field season, shows the steel plate bolted over the grease cap. The right photo, taken during my second field season, shows that the steel plate has been removed and the grease cap is exposed.

My second question is why did the wheel come off on the highway? It doesn't seem evident to me that the wheel coming off is directly related to the grease cap problem. The wheel came off less than a week after the bearings were replaced in Alice Springs and within that week three separate mechanics had looked at the trailer and deemed it roadworthy. Less than 12 hours before the wheel came off the mechanic in Coober Pedy had cleaned and lubricated the bearings. I genuinely have no idea why the wheel came off. If you have any idea, please let me know.

Campfire with the trailer during happier times.

*Normally expenses during fieldwork get reimbursed, but there was never going to be any sort of receipt or official documentation of this expense. The $200 was my personal penance for the trailer destruction.

**There is actually a seat there, I assume meant for children. 

***Though I didn't look, the axle was likely bent when it dug into the Stuart Highway going 110km/h.

Here are some photos of a very cool lizard

One of Australia's most famous and charismatic animals is the thorny devil (Moloch horridus). It's famous because it looks cool, and because it's not all that easy to find. It's also the only member of the amphibolurine agamids that isn't referred to as a dragon. Although... dragon... devil... I can see a theme here. 

I found my first thorny devil in 2005, when I was an 18-year-old backpacking around Australia. It was crouched down on the Barkly Highway as we were driving between Camooweal and the Northern Territory border. My travel companion - the owner and driver of the car - was getting annoyed at me because I kept yelling for him to stop for animals, and by the time we stopped the animal would be gone (this is a frequent problem when driving at 110 km/hr). I promised him that this time the animal would still be there, and thankfully he stopped. I was so overjoyed I even went to the trouble of taking a picture of it. Here it is:

I am not a photographer. There are better pictures coming.

Not that you can tell from that picture, but the thorny devil is a really weird, unique, beautiful lizard.  Better views of thorny devils can be had by looking at Angus Kennedy's pictures from my 2012 field season. While Angus and Mitch were helping me catch dragons in the Northern Territory and South Australia we came across three thorny devils.

This is the standard thorny devil pose that appears in pretty much all books about Australian reptiles and wildlife. Thurlga Station, South Australia, 2012. Photo by Angus Kennedy.

The thorny devil lives in Australia's more foreboding habitat, the dry, arid interior, where water is a valuable commodity. Its scales are specially designed so that, when any part of the lizard comes in contact with water, that water is funnelled to its mouth through capillary action, the same process that gets water from the roots to the leaves of trees. This was such an incredible discovery that its original description was published in Nature, one of the most important scientific journals. Subsequently, it has been a continuing area of interest for biologists.

A thorny devil at the entrance to an ant's nest. Thurlga Station, South Australia, 2012. Photo by Angus Kennedy.

Other than the water-funnelling thing, there's not much known about thorny devils. A Google Scholar search for their scientific name turns up only thirty two results, many of which are observations of their basic natural history. They're famous for eating ants, and this paper has an adorable picture of one in "characteristic feeding posture" eating ants off the side of a tree. That so little is know about such a famous and charismatic animal is alarming; I can't even find population estimates for them.

Unlike most dragons, the thorny devil ambles slowly. Thurlga Station, South Australia, 2012. Photo by Angus Kennedy.

An additional theme I can see in the limited literature is that thorny devils are slow. In fact, in one of the most hilarious titles to a scientific paper I've ever seen, this article asks "is the devil a sloth?" Although we all know what the authors mean, and scientists are not without a sense of humour (well, most of us, anyway), sloths are, in fact, animals (mammals of the order Pilosa) and thorny devils are definitely not sloths.

Thorny devils have a weird protuberance coming out of the back of their neck. Thurlga Station, South Australia, 2012. Photo by Angus Kennedy.

There's a weird lump coming out the back of the thorny devil's neck. I've heard it said that this is a false head, and that if a thorny devil feels threatened it'll crouch down and stick up its false head for sacrifice to the predator. I can't find any evidence for this in the literature. It is true that, when threatened, the thorny devil will crouch down and arch it back, but this is standard posture for animals that have spiky backs: it presents the predator with their least palatable body part. This behaviour can be seen spike-backed creatures like porcupines, hedgehogs, echidnas, lion fish, armadillo lizards and those horrible spiky caterpillars that curl up in a ball when you touch them. Furthermore, at an extremely informal poll at last year's meeting of Australian herpetologists, I couldn't find anyone who's ever seen a thorny devil without that weird lump. Geckos and skinks, which wiggle their tails to fool predators, are frequently found without tails, and have even evolved a mechanism for automatically detaching their tails and growing new ones. Not that I'm saying the false-head explanation isn't true, but just that I haven't heard of any convincing evidence. If you know of any evidence for the use of the weird lump, I'd be curious to hear it.

Thorny devils are spectacularly coloured and patterned. Thurlga Station, South Australia, 2012. Photo by Angus Kennedy.

Thorny devils are a good example of disruptive colouration. Their colours are the same colours as arid Australia, and they are patterned in such a way that it's hard to make out the shape of the lizard, especially if it's against a complex background. Of course, in these pictures, where we've deliberately placed the lizard against the homogenous backdrop of a dirt road, and it's easy to see.

Thorny devils are the opposite of dolphins: they always look grumpy. Thurlga Station, South Australia, 2012. Photo by Angus Kennedy.

One paper, that I admit is not the most convincing, suggests another adaptation that thorny devils have to their arid home: they may pee on their eggs to keep the eggs moist.

Such a cool lizard! Thurlga Station, South Australia, 2012. Photo by Angus Kennedy.

I thought I'd end with a picture I found online. Thorny devils are quite dramatic looking, especially head-on, but I've never seen them look quite as terrifying as in this artificially-coloured image of a thorny devil skull overlayed onto an image of its head, taken from this website.

The thorny devil at its most terrifying, courtesy of  digimorph.org  .

The thorny devil at its most terrifying, courtesy of digimorph.org.

Vegetation-dwellers, group 2

In his book "Biology and Evolution of Australian Lizards", Allen Greer sorted the lizards I study, the genus Ctenophorus, into different groups based on where they live: those that live in burrows, those that live in rock crevices, and those that live in vegetation. Looking at the phylogenetic relatedness of the Ctenophorus dragons, there are two groups of each: two groups of burrowers, two groups of rock-dwellers, and two groups of vegetation-dwellers. I thought it'd be fun to put up pictures and descriptions of all these groups, since I have a large pile of pictures from my fieldwork. These are my posts so far: Rock-dwellers #1, Rock-dwellers #2,  Burrowers #1, Burrowers #2, and Vegetation-dwellers #1.

This last group of Ctenophorus dragons are known as the military dragons. I don't know why, maybe because their patterns are full of stripes. They are also the largest group of Ctenophorus, with seven species. They're all quite small, weighing around 10 grams or less, and are long-legged sprinters. They don't shelter anywhere in particular, so they use a combination of their speed and any available vegetation to hide from predators. During my PhD, I deliberately went after two species, and we came across a third coincidentally while looking for other dragon species.

The two species in this group that I needed for my PhD were the mallee military dragon (Ctenophorus fordi) and the central military dragon (Ctenophorus isolepis). These two lizards are almost the exact same. They are quick, skittish lizards that are always on the flat ground. They never perch on branches, climb trees, or sit on top of bushes as other dragon lizards often do. They do everything - bask, hunt, mate, etc. - on solid ground. They also have a preferred habitat type, spinifex, and are so closely associated with spinifex that we called them the spinifex dragons. Spinifex is a famous type of grass here in Australia, famous mostly because it is basically a clump of outwards-pointing spears. I vividly remember my volunteers trying to catch mallee military dragons by hand; I had horrible visions of them poking their eyes out on the spinifex as they dove for dragons. The dragons use this to their advantage. If they're scared, they dive into a dense spinifex bush, which is basically an impenetrable fortress of spikes!

The immense spikiness of a spinifex plant. Mulga Park Station, Northern Territory, 2012. Photo by Angus Kennedy.

There were a few key differences between the mallee and central military dragons. First, the mallee military dragon was extremely abundant. We broke all records for single-day lizard catching with this species when, on the very last day of my 2012 field season, we caught 32 mallee military dragons between noon and 5 p.m. That is a lot of dragons! On the other hand, central military dragons are only moderately abundant. It took us two days to catch the same number of central military dragons as we caught mallee military dragons in half a day. This is still much more abundant than any other dragon species. That number of dragons would usually take us 4-6 days to catch, and with the rusty dragon it took three weeks!

Central military dragons are also about double the size of mallee military dragons. Mallee military dragons prefer their spinifex to be under the shade of a canopy of mallee trees, whereas central military dragons like their spinifex exposed, with no trees in sight, like in the picture above.

An additional difference is that central military dragons are sexually dimorphic, meaning that the males and females look different, while mallee military dragons are sexually monomorphic, meaning both sexes look the same. In the case of the central military dragon, this means that the male has a heck of a lot more black on him than the female, and has a more complex pattern. Male and female mallee military dragons look almost identical. There is no sexual dimorphism in this species, except for some extra black markings on the underside of the male.

A male central military dragon (Ctenophorus isolepis). Mulga Park Station, Northern Territory, 2012. Photo by Angus Kennedy.

A female central military dragon (Ctenophorus isolepis). Mulga Park Station, Northern Territory, 2012. Photo by Angus Kennedy.

A male mallee military dragon (Ctenophorus fordi). Gluepot Reserve, South Australia, 2011. Photo by Tobias Hayashi.

A female mallee military dragon (Ctenophorus fordi). Gluepot Reserve, South Australia, 2011. Photo by Tobias Hayashi.

While looking for claypan dragons in southwest Western Australia, we came across a few spotted military dragons (Ctenophorus maculatus). This species is very similar to the other two military dragons, but it doesn't live in spinifex. Instead, they seemed to like areas that were open, but with short woody plants all over the place. They also didn't seem to be nearly as common as the other two, but maybe that was just because we weren't looking.

A female spotted military dragon (Ctenophorus maculatus). near Lake Cronin, Western Australia, 2013. Photo by Angus Kennedy.

Those are the three members of this group of vegetation-dwellers we came across during my fieldwork. Of the other four, only one is widespread and well known. The lozenge-marked dragon (Ctenophorus scutulatus) is the largest member of this group and is found over a large area of Western Australia just north of Perth. The other three species, the long-tailed military dragon (Ctenophorus femoralis), the rufus military dragon (Ctenophorus rubens), and McKenzie's dragon (Ctenophorus mckenziei) are all very poorly known critters. They're all restricted to small areas of remote habitat: the former two halfway up the coast of Western Australia, and the latter on the Nullabor plain. McKenzie's dragon also has the unfortunate distinction of being endangered.

Burrowing Dragons, group 2

In his book "Biology and Evolution of Australian Lizards", Allen Greer sorted the lizards I study, the genus Ctenophorus, into different groups based on where they live: those that live in burrows, those that live in rock crevices, and those that live in vegetation. Looking at the phylogenetic relatedness of the Ctenophorus dragons, there are two groups of each: two groups of burrowers, two groups of rock-dwellers, and two groups of vegetation-dwellers. I thought it'd be fun to put up pictures and descriptions of all these groups, since I have a large pile of pictures from my fieldwork. These are my posts so far: Rock-dwellers #1, Rock-dwellers #2  Burrowers #1Vegetation-dwellers #1.

This second group of burrowers is awesome! Two of the dragons in this group are absolutely spectacular in terms of colour and behaviour, and the other two are mysterious beasts that are little known, rarely seen dwellers of Australia's most unforgiving habitat: salt lakes. They all dig cute little burrows and duck into them if they feel threatened.

They are among my absolute favourite things to chase, which is great because this is the only group that we went chasing all three seasons of fieldwork. We started off chasing painted dragons at the very beginning of my very first field season and we ended my very last field season chasing claypan dragons over two years later.

Painted Dragon (Ctenophorus pictus)

Painted dragons live up to their name. They are gorgeous! The males have brightly coloured heads that are blue, red, orange or yellow, along with a beautifully coloured and intricately patterned backs. The females are also quite intricately patterned, but they are not brightly coloured like the males. This is one of the first species we chased back in September 2011, and we had so many problems! It was a huge challenge just to catch one, and often it took three of us all surrounding the same tree to get a lizard. The trouble we were having had me worried for the rest of my fieldwork. Would we be able to catch enough lizards for my project to work?

We needn't have worried. The problem wasn't that that painted dragons are hard to catch, it was that we sucked at catching painted dragons! By 2012 we'd had a lot of practice, and we were hoovering them up. It turns out painted dragons are among the easiest dragons to catch, owing partially to their habit of sitting conspicuously on the tops of bushes. 

Male painted dragon, Ctenophorus pictus. Turlga Station, South Australia, 2012. Photo by Angus Kennedy.

Female painted dragon, Ctenophorus pictus. Turlga Station, South Australia, 2012. Photo by Angus Kennedy.

Claypan Dragon (Ctenophorus salinarum)

Who knows why they call these things claypan dragons. They don't live in claypans, which are basically dried-up ponds. They live in salt pans, which are basically dried up salt lakes. When it's wet in the Australian scrub, like it was when we were looking for these guys in October 2013, they live on the salt crust around the edges of filled salt lakes. It's a very narrow strip of land, and makes their suitable habitat almost two-dimensional. 

Claypan dragons have a reputation for being hard to find. There are few records of them in the Atlas of Living Australia and almost nothing about them in the published literature. Maybe they have this reputation because people keep looking for them in claypans, because we had no troubles! Before my fieldwork I was worried that we'd have a lot of problems finding these guys. As it turns out, we came across them completely by accident while visiting a tourist spot before even starting our search in earnest! We did have trouble finding lakes where they lived. We visited a lot of lakes where we'd walk all the way around the lake and not find a sign of the dragons. However, when we visited a lake and found one, we'd find another, and then another, etc. They live in impressively high densities where they do live, it just seems that they're picky about which lakes they live around. Someone should use science to figure out why!

Male claypan dragon, Ctenophorus salinarum. Varley, Western Australia, 2013. Photo by Angus Kennedy.

Female claypan dragon, Ctenophorus salinarum. Varley, Western Australia, 2013. Photo by Angus Kennedy.

Lake Disappointment Dragon (Ctenophorus nguyarna)

These critters live in the middle of absolute nowhere. They was discovered by accident in 1996 when a vehicle full of scientists became stuck in the mud on the edge of Lake Disappointment. Lake Disappointment is so named because if you are wandering, lost and dehydrated, in the desert and see Lake Disappointment in the distance, you will think that you're saved. You will be wrong, disappointed, and more likely than not you will shortly be dead. Lake Disappointment is a salt lake and no one's saviour, except perhaps for the Lake Disappointment dragon's. Due to their remoteness we did not go after this dragon during my fieldwork.

Bicycle Dragon (Ctenophorus cristatus)

It's not completely clear that the bicycle lizard belongs in this group. When Greer wrote his book back in the 1980's, he included them in the burrowers, but Melville (2001) places them among the vegetation dwellers. Since the vegetation dwellers don't have a burrow or crevice close by for security, they tend to be long-legged, dainty things that are very good at taking off at high speed. The bicycle dragon certainly fits this bill. They're called bicycle dragons because, when scared, they lift up into a T-rex position, pin their front legs against their chest and rotate their back legs as if they're peddling a bike. This gets them far, fast.

But back to the burrowing. According to the most recent phylogeny (Chen et al., 2012), bicycle dragons are part of this group of burrowers. However, Chen and her colleagues can't be completely sure of this relationship, according to their statistics all they can say is that the bicycle lizard is probably part of this group (thanks to JP for clarifying the meaning of phylogenetic probabilities). Of the four phylogenies published on Ctenophorus over the past fifteen years, none have placed the bicycle dragon in the same place. So the genetics, at the moment, are inconclusive.

What about practically? Do bicycle dragons actually dig burrows? Greer, in his 1989 book "Biology and Evolution of Australian Lizards", says yes. However, others since then have said no, mostly citing personal comments and observations (eg. Meville et al., 2001; Thompson & Withers, 2005). During my fieldwork, we probably caught about forty bicycle lizards, and had another twenty or so escape on us. Not a huge sample size, but not small either. The vast majority took off as I described above. One individual ducked into a burrow. Compare this to the other burrowers we caught: the painted dragon, claypan dragon, and central netted dragon. The painted dragon would duck into a burrow probably around 80% of the time, the rest of the time taking off running or ducking under a bush. The claypan and netted dragons, which live in more exposed habitats than the painted dragon, ducked into burrows close to 100% of the time. So are bicycle dragons burrowers? Maybe they're facultative borrowers, building burrows when it suits them. This is another question that science is a very useful tool for answering.

Male bicycle dragon, Ctenophorus cristatus. Lake Hurlestone Conservation Reserve, Western Australia, 2013. Photo by Angus Kennedy.

Female bicycle dragon, Ctenophorus cristatus. Lake Hurlestone Conservation Reserve, Western Australia, 2013. Photo by Angus Kennedy.

References

Chen, I, Stuart-Fox, D., Hugall, A.F., and Symonds, M.R.E. 2012. Sexual selection and the evolution of complex colour patterns in dragon lizards. Evolution, 66-11:3605-3614.

Greer, A.E. 1989. The biology and evolution of Australian lizards. New South Wales: Surrey Beatty and Sons.

Melville, J, Schulte II, JA, and Larson, A. 2001. A molecular phylogenetic study of ecological diversification in the Australian agamid genus Ctenophorus. Mol Dev Evol., 291:339-353.

Thompson, GG and Withers, PC. 2005. The relationship between size-free body shape and choice of retreat for Western Australian Ctenophorus (Agamidae) dragon lizards. Amphibia-Reptilia, 26:65-72