BACK TO NATURE - Learning New Things

by Jamie Walker

Evolution seems a long, slow, old process. We think of it as bringing change and development only by imperceptible increments over eons of time. But in some cases, it appears accelerated by necessity often brought about by human impact on the world and wildlife’s ability to learn new things.

This can be the case with behavioural evolution as animals, over relatively short historical periods, have adapted and taken advantage of man-made changes to landscape and habitat.

Some adaptations are not always welcome and may alter the balance of natural relationships. The disproportionate predominance of aggressive Noisy Miners which has occurred in open suburban gardens, with a surfeit of hybrid Grevillea bushes, is an example.

Yet there are many ways and means by which wildlife adjusts beneficially. Collared Sparrowhawks are skilful bush hoppers. Lightweights, their typical hunting mode is to fly low and fast between bushes before flipping over the tops of their cover to strike with surprise on the other side.

Yet a Sparrowhawk which alighted out of the blue, on the open aspect of our front lawn, froze into instant stillness and stared intently at a flowering Callistemon. With the strange, hunch-shouldered walk that raptors adopt, it stalked the Honeyeaters feeding in the shrub.

I never saw the outcome, because I moved to a different window to get a better view. When I arrived there, the hawk and the nectar-feeding birds were gone. No doubt I had missed a moment of drama.

In the flatlands of the Maroochy River valley, I found a roadside area where the reeds had been cut down to ground level. Six Black Kites, which normally hunt using keen sight while soaring, were perched on adjacent fence posts.

As I watched, they dropped down to walk on the cropped surface – fastidiously finding morsels of food on the floor. I surmised that they were eating insects (or perhaps frogs and skinks) that had been exposed or killed by the cutting machinery.

This ability to accommodate change, and to learn, will always enhance Black Kites’ long-term survival chances.

And it didn’t end there. In a similar marshy area on a different occasion, I found the carcase of a large Cane Toad. It was laid on its back and its throat and belly had been eaten : leaving its poisonous upper parts untouched.

I believe this was probably the work of a Torresian Crow – a resourceful, clever-minded bird – and is evidence that all is never lost, and even scourges arising from human misadventure, may yet be overcome by natural forces.