Absence of top predator changes landscape
A fence built to keep out wild dogs has dramatically changed a huge swathe of the Australian landscape.
According to a study published in early July by the Journal of The Royal Society Interface, the iconic outback structure seems to have altered an entire ecosystem.
Subsequently reported in Science magazine, the story is centred on what have become two different landscapes either side of a fence in Australia’s Strzelecki Desert in the south.
On one side there are 10-meter-high sand dunes with patches of dense woody shrubs, and just a few km away on the other side the dunes are shorter and flatter – surrounded by sparse vegetation.
The reason for the difference, according to the study? Dingoes.
The researchers compared the landscape on both sides of the century-old 5000 km wire mesh fence, designed to keep Australia’s wild dogs from private land and livestock. And the results are astounding.
Drone-captured images of the dunes and vegetation cover on either side of the fence were compared to historical aerial photographs taken between 1948 and 1999. And the result is about 60 more woody shrubs per hectare on the side of the fence with no dingoes. The dunes on the non-dingo side are also about 66 cm higher.
The likely explanation, the team says, is that without a top predator like the dingo, smaller hunters such as foxes and cats have flourished, decimating prey species like hopping mice and rabbits.
With fewer animals left to eat the plant seeds, the shrub cover has increased. The shrubs hold down sand and cause winds to skim over their tops, causing dunes to grow taller and carving the landscape differently on the two sides of the fence.
Natural Images 2018