MY DOG recently survived being bitten by a snake. This left me a great deal poorer, and the dog no wiser, so when a few days ago I saw her pouncing on something long and wriggling I was not happy. I called her off, and (reluctantly) she left her victim: a metre-long goanna.
A year ago we reviewed Simon Watharow's book about living with snakes and other reptiles, and I remembered his comment that a bite from a goanna, in a person, needed careful disinfection, and in a dog, a visit to the vet. So for the next 24 hours I watched the dog carefully for symptoms, but thankfully she seems quite healthy. Also, thankfully, the goanna, which I had given up for dead, made a speedy recovery and disappeared into the bush.
Of course, the animal in question was not really a "goanna", an early settler's attempt at "iguana", but the name has stuck. Correctly, goannas are Monitor Lizards, and they are particularly common in Australia and the islands to the north (but not Tasmania). Some Monitors are very big, and all of them are carnivorous. As author Steve K Wilson says: break your leg on the Indonesian island of Komodo and you are in serious trouble!
Most of us don't know much about lizards. Some of them are small, quick and decorative; some of them look like snakes; some of them are big and even a little scary, like a big goanna with its beady eye on the domestic chooks.
Steve K Wilson's new book Australian Lizards is not a catalogue, like a bird book, but a wonderful journey of discovery through the lives of some of Australia's seven families of lizards. These are the dragons, monitors, skinks, flap-footed lizards, and three families of geckos.
What do they eat? Who eats them? Where do they nest? How do they control their temperatures and their water supplies?
The answer to the last question accounts for their ability to live almost anywhere in arid Australia: they have a waterproof skin, and they lay waterproof eggs, so they don't need to rely on a moist environment to survive. Wilson says that for young Sand Monitors (a fairly common sort of goanna), loss of water from the surface of the eye accounts for sixty five per cent of total water loss. Some species get around this problem by having a transparent lower eye lid, and simply keeping their eyes closed.
And temperature? There's no simple answer, except that many lizards control their temperature according what they are doing at the time. Digesting? Let's warm up a bit. Pregnant snow skinks in Tasmania? Cool it!
Wilson's enthusiasm for lizards is infectious, his writing is clear and entertaining, and the photographs in this beautifully produced book are stunning. Australian Lizards: a natural history (CSIRO Publishing 2012) by Steve K Wilson is available in Cooma from Monaro Books and Music.