Platypus : The Great Divide
Two raindrops fall side by side, slightly compressed spheres tumbling from the sky. One of these raindrops will arrive in the Southern Ocean just near Goolwa, the other in the Pacific Ocean via Pitwater; half a continent apart.
Like the torn edge of a piece of paper, the Great Dividing Range zig zags a couple of 100km inland from the NSW coastline. Along this line there are no great flowing rivers, this is the start of the catchments, those little drops become trickles, the trickles flowing into small creeks then smaller rivers, until finally into the major rivers of Australia.
Not only does this line represent the Great Divide for water, but also the great dividing line for ecosystems. It is a very fragile boundary.
Living solitary lifestyles, the platypus usually reside a couple of kilometres apart from each other, traveling only around 3km from their burrows mainly foraging for food, they can however, travel further when necessary. With dwindling numbers, and such small travel distances, inbreeding in platypus populations often occurs. The genetic pool size is likely linked to the ease of navigation they have between each other. This is why this Great Dividing line is so important. For platypus to have access to an increased gene pool, they must be able to cross that line on occasion. We should not be putting hurdles in their way.
Navigating and feeding for 12 hours a day, the platypus finds its food by electroreceptors. Swimming and scooping up food and pebbles in its bill with its eyes closed, the platypus relies on those electroreceptors to navigate. The pebbles grind the food, as the platypus doesn’t have teeth.
Dams and physical barriers make it more challenging for platypuses to travel, making it harder to connect with others for breeding. Pumps and machinery act as inhibitors for their navigation, filling their sensitive receptors with white noise, confusing and disrupting their foraging.
Unlike the raindrops that are destined to be half a continent apart, the platypus has a chance, it can traverse the boundary in need. Placing dams on the edge of this fragile boundary makes this journey measurably harder. This will impede their genetic diversity and lead to inbreeding and decreased platypus population.