Relocation of animals could drive some species towards extinction – study

The relocation of animals to make way for land development rarely succeeds and could be driving some species towards extinction, according to a new study.

An international team of scientists found that “mitigation translocations” – where animals were moved from the path of building projects – were “increasing rapidly” and far outnumbered instances of science-led relocations of animals to help recover populations.

While millions of dollars are spent on mitigating developments’ impact upon animals, the study found little evidence that these projects worked. Such projects could, in some cases, be placing species at even greater risk.

According to the report, mitigation actions “all too often fail to follow accepted scientific best practices and are poorly documented, providing few opportunities to apply lessons learned and to improve the conservation efficacy of similar projects in the future.”

Simon Clulow of the University of Newcastle, one of the report’s co-authors, said: “While animals are spared a socially unacceptable death of being crushed under a bulldozer, they then perish out of sight.

“We are approving developments upon mitigation strategies that are flawed. If this isn’t managed well, it contributes to species decline and ultimately risks extinctions.

“This should be a call to arms for the conservation community. It’s a real elephant in the room that needs to be addressed.”

The report highlights a lack of data around the number of animals moved and their prospects once they are relocated. The documented examples suggest current practices are not working.

In Australia, more than $14m has been spent in the past 15 years to translocate just one species – the green and golden bell frog, a species that had to make way for the construction of the Sydney Olympic village. This compares to the estimated $3.3m provided for science-based conservation of all other amphibians during this period.

Clulow said the relocations, often undertaken by contractors with non-specialist skills, affected all kinds of wildlife, spanning mammals, reptiles and birds. He said a range of mistakes had been made, including putting animals into the wrong habitat or failing to think through the consequences of the relocation.

“Most habitat is at its ecological carrying capacity, so there’s no room for new animals,” he said. “Then there are animals such as the swamp skink, which is an aggressive and territorial species and has been moved due to developments.

“You either put it into unoccupied habitat, which expands its range and has unintended consequences, or you put it in the habitat of other skinks, which has a horrible outcome for the newcomers.

“The regulatory intent is to avoid harm, but in reality we are not sparing these animals death at all. In some cases it actually causes harm.”

The report calls for better monitoring and reporting of relocations and a shift to the science-based methods used by conservationists undertaking species recovery programs.

“I’d really like to see the application of best practice scientific principles to these translocations,” Clulow said. “They need to do the groundwork. They have evaded academic scrutiny and aren’t monitored. It needs to be scrutinised to the same level as the conservation community.”

The study, featuring the work of scientists from the US, UK, New Zealand and Australia, was published in Frontiers in Ecology and the Environment.