{"id":1655,"date":"2025-07-17T23:35:20","date_gmt":"2025-07-17T23:35:20","guid":{"rendered":"https:\/\/www.newsbeep.com\/au\/1655\/"},"modified":"2025-07-17T23:35:20","modified_gmt":"2025-07-17T23:35:20","slug":"27-year-study-of-feral-free-reserve-in-sa-offers-insight-into-pre-colonial-times","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/au\/1655\/","title":{"rendered":"27-year study of feral-free reserve in SA offers insight into pre-colonial times"},"content":{"rendered":"

Conservationists have offered surprising insights into what small mammal colonies may have looked like before Europeans arrived in Australia.<\/p>\n

A study that began more than 27 years ago in a reserve in outback South Australia found the impact from invasive species far outweighed that of native predators.<\/p>\n

Previous studies estimated the impact from introduced predators was “two or three times” that of their native counterparts, but recently published findings<\/a> suggest it could be up to 33 times.<\/p>\n

\"A<\/p>\n

Plains mice are a threatened species. (Supplied: Arid Recovery)<\/p>\n

Co-founder and principal researcher at the Arid Recovery Reserve Katherine Moseby said small mammals within the invasive-free, 123-square-kilometre reserve had been free to thrive since it was created at Olympic Dam in 1996.<\/p>\n

Located 560 kilometres north of Adelaide on the traditional lands of the Kokatha people near Roxby Downs, the site is adjacent to an operational mine owned by BHP.<\/p>\n

The reserve was created by scientists in the short window that followed the dramatic impact the calicivirus<\/a> had on SA’s rabbit population.<\/p>\n

\"A<\/p>\n

Katherine Moseby says it took decades for some species to respond to the feral-free environment. (ABC News: Gary-Jon Lysaght)<\/p>\n

In the nearly three decades that followed Dr Moseby and her team observed significant population booms among mammals such as bilbies, bettongs and native mice following rain events on both sides of the reserve’s fence.<\/p>\n

Species on the feral-free side were able to thrive and move freely, but those outside the reserve were quickly suppressed by foxes and cats and had their habitats negatively impacted by rabbits.<\/p>\n

“Animals build up after rains and then they spread out and repopulate areas where they sort of go extinct during drought,” Dr Moseby said.<\/p>\n

“So having cats and foxes there is suppressing those booms and preventing those animals from really recolonising over broad areas.”<\/p>\n

\"A<\/p>\n

The reserve was created in 1996. (Supplied: Arid Recovery)<\/p>\n

Expanding territory<\/p>\n

The team found some small mammals on the reserve were able to expand into new habitats.<\/p>\n

Plains mice, which generally favour clay interdunal swales, were recorded on dunes within the reserve.<\/p>\n

\"A<\/p>\n

Feral cats are blamed for two thirds of mammal extinctions since European settlement. (Supplied: Arid Recovery)<\/p>\n

Hopping mice also expanded into the swale areas.<\/p>\n

“We saw this expansion of niches of the different species,” Dr Moseby said.<\/p>\n

“It really gave us an understanding of what things might have looked like before European settlement.”\"A<\/p>\n

Bilbies inhabited three quarters of Australia before European settlement. (Supplied: Department of Natural Resources)<\/p>\n

Invasive Species Council engagement director Imogen Ebsworth said the results of the study provided helped to inform approaches to wildlife restoration.<\/p>\n

“We’ve often been having to hypothesise about how much of our landscapes particular little critters occupied,” she said.<\/p>\n

“What this study shows is, if you take out the feral predators, where we thought that some creatures were confined to very small amounts of ecosystem and habitat preferences, they probably actually had a much bigger range.”<\/p>\n

\"A<\/p>\n

Imogen Ebsworth says the study fills an information gap. (Supplied)<\/p>\n

Another unexpected observation was the order in which species increased.<\/p>\n

The numbers of smaller mice started increasing first and house mouse populations more than doubled in the first two years.<\/p>\n

Further into the study the population of some smaller species began to decrease in line with an increase of larger mice such as the spinifex hopping mouse and the plains mouse.<\/p>\n

Competitive interactions between species also increased in most cases, with hopping mice exerting the greatest competitive effects on themselves and other rodents.<\/p>\n

\"A<\/p>\n

A quoll with the Arid Recovery team. (Supplied: Arid Recovery)<\/p>\n

Need for control<\/p>\n

The eradication of invasive species is unlikely to be achieved and some control methods, including baiting, can have unintended consequences on native animals, according to Dr Moseby.<\/p>\n

She said the study reinforced the importance of pest control.<\/p>\n

\"A<\/p>\n

Animals such as bettongs thrived in the remote reserve. (Supplied: Samantha Kirby\/Arid Recovery)<\/p>\n

“When we tend to think of conserving threatened species, we just look at the habitat they’re currently in and we think we need to conserve that,” she said.<\/p>\n

“But understanding that if we didn’t have cats and foxes there, or if we can control them effectively, they’re going to spread out into other habitats.<\/p>\n

“It’s important to be protecting a wider variety of habitats so that animals can expand into those once we get cats and foxes under control.”\"A<\/p>\n

A juvenile reptile in the reserve. (ABC North and West SA: Khama Gilchrist)<\/p>\n

Ms Ebsworth said it was a challenge worth taking on.<\/p>\n

“Cats have been directly responsible for over 20 extinctions<\/a> in Australia since colonisation,” she said.<\/p>\n

“Feral and domestic cats are killing around two billion native wildlife every year.<\/p>\n

“If we take on the challenge of managing feral cats and foxes, we can actually have a wildlife revival in this country that goes beyond sanctuaries.”<\/p>\n","protected":false},"excerpt":{"rendered":"Conservationists have offered surprising insights into what small mammal colonies may have looked like before Europeans arrived in…\n","protected":false},"author":2,"featured_media":1656,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[2409,2399,2402,64,63,2408,75,2406,2405,2407,2404,2401,2400,2403,128],"class_list":["post-1655","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-2409","tag-arid-recovery","tag-arid-recovery-reserve","tag-au","tag-australia","tag-endangered-native-species","tag-environment","tag-feral-cats","tag-feral-foxes","tag-feral-rabbits","tag-invasive-species-impact","tag-kokatha","tag-native-species","tag-sa-reserve","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/1655","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=1655"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/1655\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/1656"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=1655"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=1655"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=1655"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}