Among those savage beasts I would number my fellow human beings as occupying a special place.

The crimes and delinquencies of our nasty and aggressive human species are manifold.

They range from wholesale alteration of the planet, the cruel enslavement of their own (and many other innocent) species and probably the eventual rendering of much of the planet uninhabitable.

The fertile rolling hills and wide coastal plain here on the west coast of South Australia are a far cry from the noisy and polluted concrete landscape that is our state capital to the east, but it is still a man-made aberration.

The land around Tumby Bay may look like a bucolic rural scene but it was created by the dispersion of a previous gentle and unassuming people by occupiers from across the seas; invaders who clear felled its vegetation and contained tracts of land within thousands of kilometres of wire fencing.

Where once kangaroos and other wildlife roamed freely there are now enclosed paddocks of mono-crops and hard-hoofed, erosion-creating sheep and cattle interlaced by skeins of bitumen, electric cables and pipelines carrying chemically treated water.

To see the world in its natural state one has to travel to the very remote outback or the rapidly diminishing wilds of places like Papua New Guinea.

Once upon a time the planet was covered by a mosaic of complex ecosystems that functioned in their own right.

Every living and breathing organism had a part to play in a symbiotic system that over the aeons had shaped themselves to perfectly fit into their physical environment.

In each of these ecosystems humans had their place and their part to play in their health and continuance. But human presence was no more important than the tiniest insect or the most humble algae.

Today, the number of unique ecosystems in this mosaic have been considerably reduced. Most, if not all, of these systems have been irreversibly changed or destroyed at the hands of human beings.

There are very few places in the world now where human beings still form essential parts of local ecosystems. Some of those places are in Papua New Guinea. None of them are in Australia.

The only intact ecosystems in Australia occur in remote wilderness areas where human beings have never set foot or been an important part of the landscape.

And yet, these tiny ecosystems are still in danger as humans work assiduously to heat up and alter the climate systems they need to survive.

One day, perhaps in the not too distant future, the planet will arrive at a single, catastrophically degraded ecosystem.

What that might look like is too horrific to contemplate because it will be the point when humanity and many other species cease to exist.

What then can we make of the function of human beings? Are we the destroyer of ecosystems and the planet as we know it?

Is this what Mother Nature intended us to be, its destroyer?

Did she nurture us through time to become the most intelligent organism ever to exist on the planet so we would ultimately destroy it?

Or are we an experiment that is in the final throes of total failure? Are we simply the product of a tragic mistake? Has evolution failed?

So does Mother Nature now plan to get rid of us as quickly as possible? Are we a plague that is uncontrollable and running rampant? Is there a correction and new balance required in which we have no part?

Sometimes, when I see another squashed baby magpie at the side of the road or a splattered and bloody mess that was once a sleepy lizard, woken from his winter slumber and looking for his lifelong mate in the wrong place, these thoughts occur to me and I get angry.

We are truly unpleasant creatures. In terms of a species we are the coronavirus of the animal kingdom.