Fascinating new research shows that introduced animals, often seen as “invasive” species that damage native plants, isn’t true.

This research, published in Science, one of the world’s foremost publications, found that both native and introduced species of plant-eating megafauna (weighing over 45kg) have similar impacts on native plants.

The research supports a change towards how we think of these animals, and any negative public sentiment generated simply due to an animal being introduced is wrong. This echoes similar calls that the Australian Deer Association has been making regarding the maturing of the conversation regarding wild deer in Australia.

Earth’s terrestrial ecosystem has been shaped by megafauna over the last 35-55 million years, including present-day Australian plant and animal species, which evolved on a continent dominated by earth-trampling beasts. Such megafauna included hoofed horse-like kangaroos, tree-thrashing marsupial tapirs, and two-tonne diprotodons that resembled wombats and were migratory.

As humans spread out from Africa, much of the world’s megafauna went extinct, including in Australia. Consequently, the Australian ecosystem underwent a radical change. Previously, this megafauna would have consumed large volumes of fibrous, low-nutrient plants. With their extinction, fires may have intensified, and once-widespread rainforests shifted to fire-prone eucalypt forests.

The research set out to evaluate the effects of megafauna on plant abundance and diversity.

It found no evidence that introduced megafauna have different impacts on native plants than native megafauna. Nor that the effects of introduced megafauna in biologically distinct places such as Australia are different from their effects in their native ranges.

Instead, ecological explanations rather than whether an animal was native or introduced explained the effects of native and introduced megafauna.

This suggests that studying introduced megafauna simply as wildlife rather than as an ecological problem will help us respond to native or introduced megafauna coming into conflict with conservation goals.

While the impacts of introduced animals, such as eating plants or trampled vegetation, are often met with alarm, Australia’s extinct megafauna would also have trampled sensitive plants and eaten huge volumes of vegetation. A prime example is the world’s largest marsupial, the Diprotodon Optatum, which, while migrating across Australia in herds and weighing over two tonnes, would eat an estimated 100-150kg of vegetation a day.

This is further evidence that supports the concept that perhaps, introduced megafauna such as wild deer, fill an ecological niche created after the extinction of Australia’s megafauna.