WATCHING GOANNAS

This month, naturalist and long-time supporter of WWF-Australia, David Waterhouse, shares insights from his observations of goannas throughout New South Wales. These scavenging predators – scientifically referred to as Varanus – have captured David’s attention on many occasions, particularly with their surprising tree-climbing skills. Driven by his lifelong love for nature and desire to protect and preserve the wildlife and wild places he so fondly writes about, David has included a gift in his Will to WWF-Australia, ensuring his support will continue well into the future.

We hope you enjoy reading David’s personal insights and observations ‘Watching Goannas’ – although we would recommend proceeding with caution if you do see one in the wild!

‘When I was a girl, up on our property near Branxton, some would tell you that their bite was poisonous. My mother said that this was not so, but if one bit you it would leave a sore that would never heal.’ An old lady told me that in Newcastle. She was a child in the 1890s and was speaking about huge lizards called goannas. She also mentioned that the local farmers would usually shoot any they came across, partly because they were egg thieves, but mostly to obtain their oil as a liniment for aching limbs or to rub into saddles to make the leather more supple. I was later to read that they were indeed not poisonous, and the tale of non-healing sores was a myth. However, goanna oil was once bottled and sold for medicine, as well as curing leather. For some years I assumed that ‘goanna’ was an Aboriginal word but later learnt that it was simply a corruption of ‘iguana’, a word taken from South American natives. The famous Komodo dragon of Indonesia is the largest member of the goanna or monitor family. Our east coast goanna (lace monitor) is found all down the east coast and is perhaps the best known, but not the largest, Australian monitor; this being the perentie of the inland deserts.

Most lace monitors are grey in colour, darkening with age to turn almost black. They are by no means rare in many places in bushland, heaths and even partially cleared country. They are scarce close to most cities, but some persist in bushland remnants here and there, even in Newcastle, Sydney and the Gold Coast hinterland. If you come across one while bushwalking, it will scuttle off into thick cover or climb up a tree trunk. In picnic areas goannas may ignore people unless approached. If one is spotted on or near a path and you stand quite still, it may walk away slowly, and you could then discreetly follow it. They are most active in warm weather . Live prey as well as carrion is taken. They are particularly fond of eggs.

If you take the trouble to follow one on the prowl, with its tongue a-flicker, you have a good chance of learning something about their behaviour. Males chase females and two large males occasionally fight each other by wrestling while standing on their hind legs. I have witnessed on several occasions a variety of techniques they use to capture prey. One warm summer’s afternoon on the banks of the Hacking River in the Royal National Park south of Sydney, I spotted a goanna digging on a sandbar in mid-stream. When it stopped clawing back the white sand, it picked out a small, soft-shelled egg and swallowed it. After more digging, it gobbled down about a dozen eggs in all. Obviously, it had been aware that a long-necked turtle had laid its eggs and buried them in what it considered to be a safe spot. On another occasion the continuous raucous screeching of a pair of cockatoos drew my attention to a large goanna determinedly scaling a tree across the river. The ‘cockies’, I soon realised, must have had a nest in the high hollows near the tree’s crown. As the huge reptile was completely unfazed by the screaming and crest raising, one of the ‘cockies’ flew at it and tried to grasp it by the tail. Without stopping its ascent, the goanna immediately began to lash its long tail from side to side so that the bird could not obtain a firm grip, and up and up it climbed until it reached one of the hollows and disappeared inside with ease. After more screaming, the cockatoos finally gave up and flew off downstream. I stayed for some time watching the hollow and developing a crick in the neck. The goanna did not reappear as I had hoped.

In Blackbutt Reserve, Newcastle, I spotted one morning a sacred kingfisher calling loudly and repeatedly dive-bombing a goanna climbing to reach the small bird’s nest hole in a eucalypt. The big lizard was struck again and again by the dagger-like beak, which caused spots of blood to appear on the back of its head. I lost sight of both the bird and the reptile in the treetop and do not know the outcome of the contest. It seems that no matter how small the nesting bird victims may be, they do not hesitate to defend their nests from goannas. In the Capertee Valley, west of Sydney, I once sat and watched a mob of tiny tree martins, even smaller birds than the kingfisher, swirling frantically above multiple hollows in a huge dead tree standing in a paddock. The object of their attention was a distinctively banded goanna which was not grey but sandy in colouration, a colour variety which occurs in some regions rather than a different species. This medium-sized beast entered several hollows, so perhaps the martins had not yet bred – but this did not deter them from buzzing the intruder. The goanna, to satisfy its nutritional needs, maximises its chance by searching for food not just on the ground, but beneath it and high in the trees too. If you see one by chance it is worth watching and quietly following to perhaps learn something of interest. Nature is determined, as highlighted by David’s observations of goannas in this piece. But it needs your help to secure its future. If you, like David, value nature and want to leave a legacy of protection for wildlife and wild places, please consider including a gift in your Will to WWF-Australia, just like David has.