Following an interview, I aim to accompany Vaguely Accurate podcast guests into the field or lab to experience their research methodologies and techniques firsthand. I will share these experiences through blog articles such as this one, which will complement each podcast. I may not be able to do this for every guest given geographic constraints or health and safety limitations; however, I will try my best.
After interviewing Ashleigh Wolfe (PhD Candidate, Urban Reptile Ecology), I certainly felt more at ease about sharing land with the native venomous reptiles of Australia. Like many, I was under the presumption that all of Australia’s wildlife was “out to get me.” However, Ashleigh quickly put me at ease by explaining that there is in fact logic to the actions of lethal snakes – even the more “grumpy” ones like the tiger snake – and that the nonlethal reptiles are fairly placid. In a further attempt to educate myself about these misunderstood reptiles, I accepted Ashleigh’s invitation to join her and her supervisor, Dr. Bill Bateman (Behavioural Ecologist, Curtin University) in the field the following day.
The next day, I arrived at Bibra Lake full of enthusiasm (and a little trepidation). Bibra Lake is a wildlife and wetland reserve located south of the Perth metropolitan area. The lake was rife with various algae and the perimeter was swarming with various species of native flora.
Our goals for the day included:
- Using Very High Frequency (VHF) to track down the locations of two female dugites (Pseudonaja affinis) that had streamline trackers attached
- Downloading the GPS information from these trackers
- Observing the environment for bobtail lizards and collecting physiological and geographical data of any bobtails located
- Visiting each site of a “snake repellent” experiment and downloading the camera data.
Stuck Between A Rock And A VHF
The first thing Ashleigh set out to do was to track two female dugites. These are the most common and abundant snakes found in urbanised Western Australia. Capable of reaching more than 2m in length and averaging 1.5m in length, these venomous reptiles are pretty intimidating! To track them, we used a VHF transmitter and receiver. The transmitter had previously been placed on the snake’s body. Each transmitter emits a high frequency signal that is picked up by the receiver, which indicates the strength of the signal. The stronger the signal, the closer the instrument is to the transmitter. It quickly becomes a very sophisticated game of hide and seek. Once a snake’s location is identified to within 30cm, the GPS data is downloaded via a Bluetooth signal. This GPS device stores geographic coordinates at regular intervals so that movement can be monitored.
We quickly found the location of the first dugite. According to Ashleigh, this particular snake is almost always found under a large tomb-like slab of rock; however, previous GPS data indicate that the snake moves about a large radius to hunt. Upon approach, the tail of this stunning reptile was protruding from the rock. This was the first time I had seen a wild, venomous snake up-close and the size of it startled me. I saw about 10cm of thin-looking tail and was thus under the assumption that it would not be much longer than 40cm. I was very wrong. According to Dr Bateman, this particular snake is approximately 1.6m long.
Before moving onto our second game of ‘hide and seek’, we discovered a bobtail in a state of crypsis among the overgrown grass. I was impressed with Ashleigh and Dr Bateman’s abilities in locating these animals. These medium sized reptiles are hard to see due to the patterns on their scales and, therefore, according to Bill, you are better off using your ears to locate them.
Bobtailsare iconic for their blue tongues and, therefore, are also aptly known as blue-tongue lizards. It is also fascinating to know that the tail holds the fat reserves, which are a strong indicator of the health of a bobtail lizard. A healthy specimen will be eating and storing fats regularly, however, an unhealthy specimen, such as a diseased bobtail, is likely to avoid eating or may have diarrhoea. This results in a thin tail due to low fat stores. One theory that Ashleigh is also testing is an unproved method to tell male and female bobtails apart by counting the scales along the length of their tail. Less than seven scales represents a female. The underlying concept behind this theory is that male bobtails possess a hemipenis – a bi-lobed reproductive organ, representing two attached penises held within the tail. For this reason, it is presumed that the male tail is longer than the female.
Ashleigh picked the bobtail up without hesitation and began to complete a form that contained physiological and geographic data of many other wild bobtails. The number of these creatures Ashleigh had held – and the fact that they are not venomous but their bites “just hurt a lot” – explains why she was so confident handling them. She offered me a chance to hold the reptile so that other measurements could be acquired. This was when I learned a potentially very helpful tip that I will now share. ‘If you are bitten by a bobtail lizard and it refuses to let go, tickle its tail. This will encourage the animal to remove its jaws in an attempt to have a second bite, at which point, you should promptly remove your hand.
After recording the required data, Ashleigh pulled out a pair of tweezers and removed two large ticks from the animal’s ears. Unsurprisingly, this can be uncomfortable for bobtails. The reason that the ticks can be commonly found in bobtails’ ears is due to the protection it offers for them. Rather disgustingly, I obtained a beautiful souvenir from this interaction, identified by my partner when I got home. A tick had fastened itself onto my shoulder.
We failed to find the second dugite as it had removed the VHF tracker from its body. We are unsure how it managed to achieve this, however, Ashleigh and Dr Bateman now aim to recapture and replace the tracker upon its body.
Not What It Says On The Tin
The final objective was to visit each of the eight sites located throughout the reserve. These sites are used to study the effectiveness of “snake repellent.” The methodology for this study is fairly simple: five branded snake repellents and three controls are used to encase a lure (hot bathing plate) at each site. Facing each lure are two motion cameras, configured to trigger if anything approaches. The controls include scented and unscented substances. I am unable to say much more about this study other than the fact that bandicoots seem to love the new smells and many repellents seem to have questionable results. For a final experiment, Ashleigh will host ‘arena trials’ at her University, Curtin. In these trials, snakes will be placed in the open, where they will have to choose a burrow for protection. One borrow is will have repellent and a second will not have repellent.
I loved getting to see what is involved within ecological field research. Interacting with the environment and animals was an amazing experience and I have learned so much. I would like to thank Ashleigh and Dr Bateman for allowing me to join them and I wish them both the best for their future research endeavours.