Into the Victorian Mallee
I had an invitation to head out to the far northwest of Victoria, Australia on a scientific expedition led by Shannon Braun to study aspects of reptile life in the Mallee. It’s not the kind of thing I would want to miss out on, but I had brought back a souvenir from Borneo. A tropical ulcer on the calf of one leg must have contacted a blister on my other leg. It spread overnight and became the size of a playing card, so I had to miss the first few days of the expedition.
But the next opportunity came a few days later and ecologist David De Angelis offered me a ride to the study site. This was out in the Mallee country of Victoria’s far north west, in a harsh environment dominated by tough trees, shrubs, salty soil and spiny grass. Needless to say it is fantastic reptile habitat and is home to a large variety of species. Shannon’s project is still ongoing and once published we will show some of the results here. But the project was just one of many reasons to go to the Mallee country.
So, I guess it’s a good idea to explain Mallee before we go any further. Simply put, the harsh sandy and stony soils in the less wet parts of Australia are often dominated by a special group of Eucalypt (gum) trees, known as Mallee trees. These are highly adapted to such an environment. The trunk is below the ground and is sort of like a giant tuber known as a lignotuber. It stores energy and moisture, only the branches show above the surface. Fires can blaze through and burn the branches, but the lignotuber below the ground is unhurt and begins to send up new branches right away. A whole habitat is formed by Mallee trees and bears the same name.
The campsite itself is right on the river bank, a few kilometers from the Mallee. River red gums are massive eucalypt trees that grow right along the Murray River and provide so much habitat for so many animals. Flaking bark shelters geckoes, hollows are homes for birds, reptiles and tree frogs while the ground underneath and the fallen branches provide dwellings for many ground dwelling species. So a look around at night with spotlights revealed a number of them.
The first animal to capture my attention was this tessellated gecko. Like most geckos, this one feels like velvet to the touch. It wanders about on the ground or on fallen branches under the river red gums and feeds on small insects.
The next, and the most common and widespread of all geckos in Victoria is the marbled gecko. A small species it is found as far south as the Mornington Peninsula and inner Melbourne, but is more common along the rivers in the red gums. At night they emerge to hunt insects and spiders on the tree trunks.
If a gecko isn’t careful it may stumble into one of these. Known as huntsman spiders in Australia, there are many unrelated yet similar looking species and none of them are dangerous to humans. This species is one of the larger ones, nearly the size of a human hand. They sit head-down on the tree trunks and feel for nearby movement, lunging suddenly to capture prey. They do not build a web, but shelter from predatory wasps and birds under loose bark by day.
Also under the redgums was this handsome eastern Banjo Frog (Limnodynastes dumerilii) which burrows into the soft soil by day and emerges at night to feed when it is warm and humid, or after rain. The call is a short, explosive “bonk” much like the plucking of a banjo string. A chorus of these frogs is an amazing sound.
|Ants are also common. This is a Polyrachis of sorts. Normally I wouldn’t post about them, but this one is particularly interesting because it has an impostor…|
|This is not an ant, but a species of spider that specifically imitates the Polyrachis ant above. It is the same size, has the same colours and imitates the way they move. Seriously! I have an article <click here> that goes into more detail about this exact thing in North Queensland.|
But the Mallee was needing to be explored. It is a reptile’s paradise, as reptiles are more efficient with energy and usually require less water than many other animals it is perfect habitat for them. Basically the terrain is old, undulating dunes with swales (small valleys) in between. On top and on the sides of these dunes a nasty grass, spinifex dominates. It is like someone carelessly dropped a bunch of hypodermic syringes the size of knitting needles in a pile. Small reptiles love it, they build burrows under it and live among the spines, largely safe from predators.
The most obvious of the reptiles is the tiny Mallee dragon (Ctenophorous fordii) which shuttles about from clump to clump of spinifex grass, snatching up insects as it goes.
But after dark is the best time to find many of the Mallee reptiles.
While filming a desert skink for an upcoming video, Ryan, one of the team called out that he had spotted a snake. It was the newly described strap snouted brown snake (Pseudonaja aspidorhyncha) which was previously known as the Mallee form of the western brown snake. Still very deadly to humans, it sat perfectly and we kept our distance, but managed some great photos.
Sitting on branches near ground level were many stone geckos (Diplodactylus vittatus) which, like most geckos feed on small insects that may wander past.
Living in burrows in the sand, or commandeering the burrows of smaller animals is the beaded gecko (Lucasium damaeum) which blends in well with the sand.
Every now and again we spotted the normally elusive southern spiny tailed gecko. A slow moving species of the Mallee they rely on two things to evade detection. First is great camouflage, but if that fails they can ooze a honey-like fluid from the tail which causes great irritation to the eyes of attackers. The most striking thing about this gecko is the blue lining of the mouth.