Re-introduction of native mammals helps restore arid landscapes

September 22, 2017, University of New South Wales
Re-introduction of native mammals helps restore arid landscapes
A burrowing bettong. Credit: Thomas J. Hunt

Small native mammals eat more plant seeds than had been realised, and their loss to predators such as foxes and feral cats has likely caused significant changes to vegetation in outback Australia.

Small native mammals including bettongs are much bigger consumers of than had been realised, and their loss due to predation by foxes and has likely caused significant changes to vegetation in outback Australia, UNSW Sydney research shows.

"Our findings overturn the long-standing view that ants are the most important species when it comes to eating and removing seeds in the Australian desert," says study senior author and UNSW scientist Associate Professor Mike Letnic.

"We are only now beginning to appreciate the vital ecological role once fulfilled in the Australian landscape. This new knowledge reinforces the importance of rewilding projects.

"Re-establishing populations of locally extinct mammals is not just good for those species; it is good for the environment and can help restore arid lands."

The study is published in the journal Functional Ecology. It was conducted in central Australia at two desert sites where small native mammals have been re-introduced into predator-free exclosures – the Arid Recovery Reserve in South Australia and the Scotia Wildlife Sanctuary in south-western NSW.

"We carried out a cafeteria experiment, where we set out trays of native shrub seeds that only mammals or ants could access," says study first author and UNSW Science PhD candidate Charlotte Mills.

"We compared seed removal rates in rewilded areas with those outside the predator-proof fences, where few native mammals live. Up to eight times more seed was taken from the trays in the rewilded areas."

Photographs and other evidence such as footprints and droppings confirmed that mammals were active around the trays. Surveys also revealed there were fewer woody shrub seedlings in rewilded areas compared with areas outside the exclosures.

"These results show that mammals are important predators of seeds and their re-introduction has helped restore the landscape and helped prevent the encroachment of woody shrubs," says Associate Professor Letnic.

The dramatic increase in the spread of unpalatable woody shrubs in recent decades is regarded as a major problem by farmers and conservationists, despite the plants being natives.

Many rewilding projects globally have focussed on the re-introduction of charismatic large animals, such as wolves and bears. But the Australian research shows that reintroducing the missing small animals which breed in large numbers can have a high impact and help restore ecosystems.

This will be a key aim of the Wild Deserts project to reintroduce native mammals to Sturt National Park in north western NSW, launched by the NSW Environment Minister Gabrielle Upton in September.

Wild Deserts is a partnership between The NSW Office of Environment and Heritage, UNSW and Ecological Horizon, in collaboration with Taronga Conservation Society Australia.

Explore further: Detective work across dingo fence reveals new factor in woody shrub invasion

More information: Charlotte H. Mills et al. Rewilded mammal assemblages reveal the missing ecological functions of granivores, Functional Ecology (2017). DOI: 10.1111/1365-2435.12950

Related Stories

Teaching threatened species to be wary of predators

July 5, 2017

A study of burrowing bettongs in the Australian desert has shown for the first time that exposing threatened native animals to small numbers of predators in the wild teaches them how to avoid their enemies.

Addressing feral cats' diet may help protect native species

February 2, 2015

Because reducing the impacts of feral cats—domestic cats that have returned to the wild—is a priority for conservation efforts across the globe, a research team recently reviewed the animals' diet across Australia and ...

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.