Some additional notes for myself about Australia, with no claim whatever to originality. This time, I focus on biology:
Australia is very old and very remote. It is also, as I remarked yesterday, relatively low-lying. To sum up, it’s the oldest continent, and the flattest, and, overall, the driest. Most of it is either semi-arid or altogether desert (e.g., the Outback), but there are alpine regions, too, and some of it (including the area where I’m currently writing) is tropical rainforest. It’s an entire continent to itself, after all, so it’s quite diverse.
If I read the statistic correctly, there are an estimated 250,000 species of fungi — fungi! — in Australia, of which only 5% have been described.
But, in itself, Australia represents diversity. It’s very different from the rest of the world. Because of its isolation, for instance, many of the species of flora and fauna here are endemic to the continent — more than 45% of the birds, 84% of the mammals, roughly 85% of the flowering plants, and 89% of the in-shore, temperate-zone fish. Australia has 755 different species of reptiles, more than any other country, including some of the most venomous snakes in existence. (I can already hear some of you squealing with delight at the very thought of it!) Moroever, as you can easily imagine, the Great Barrier Reef, the largest coral reef on Earth, which runs right along coastal Queensland where I’m sitting, is remarkably rich in its variety of life. Which includes great white sharks, sea-going crocodiles, and an abundance of jellyfish. So many that there are more warning signs out and about than there are people in the water. The beaches (around here, anyway) are pristine, gorgeous, and surprisingly — or, maybe, not so surprisingly — deserted.
Along with Antarctica, for which the explanation is pretty obvious, Australia is the only continent without native felines or cats. However, feral cats probably arrived in the seventeenth century, provided by Dutch shipwrecks. Later, in the eighteenth century, European settlers brought them deliberately, considering the beastly little hunting machines cute (as, in fact, I myself do). They have likely been responsible for the massive decline or even extinction of a significant number of native species.
But so have humans been. The first arrival of humans to Australia, about 60,ooo years ago, was evidently catastrophic for many plant and especially animal species, and the European settlement, following upon the Dutch discovery of what they called “New Holland” in 1606, also had a profound effect.
Australian forests are mostly evergreen and, in them, the eucalyptus tree is notable and fairly dominant. I grew up with eucalyptus trees all around me in southern California and always thought of them (when I was a boy) as just typical local trees, but they’re recent arrivals there, having been introduced to California by Australian miners in the 1850s during the “Gold Rush.”
But, of course, Australian biology is most associated in the minds of many with its unique animals.
Marsupials, for example, who give birth to relatively undeveloped young who often reside for a certain amount of time in a pouch located on their mothers’ abdomen, are native only to Australasia and the Americas. (Think, in the Americas, of opossums.) And nearly 70% of the 334 currently extant marsupial species occur on mainland Australia or very nearby, in Tasmania and New Guinea (not far from where I currently type) and on nearby islands. Australian marsupials include wombats and wallabies and, of course, koalas and kangaroos.
Not to be overlooked, though, is that glorious egg-laying mammal the duck-billed platypus, which is native to eastern Australia. Then, too, there is the native Australian dog known as the dingo — which, although called “native,” is probably a relative newcomer to the continent. It may have been brought as a domesticated dog about 3500-5500 years ago and then gone feral.
Finally, among birds, there are such Australian natives as the emu and the kookaburra.
A unique place, this.
Posted from Port Douglas, Queensland, Australia