The huge impact on wildlife of the humble fence

Study’s author says some species are ‘winners’ and others are ‘losers’ in fenced world, writes Rory Sulivan

A metal fence under construction on the border between Germany and Poland on 24 September, 2020. (EPA)

Fences have a large and often overlooked impact on the world’s ecosystems, a new study has suggested.

In a paper published by the journal BioScience, a global team of researchers argue that fences can greatly affect certain species and should therefore be the subject of further research to help to mitigate against “one of humankind's most pervasive alterations of our planet”.

"To put it simply, in a fenced world, there are winners and there are losers," the study’s authors write.

The desert bighorn sheep is cited by the researchers as a potential “loser” if a planned US-Mexico border fence is erected, as populations of the species will become isolated, leading to a “dangerously” restricted gene pool.  

The authors also say that their research yielded up some surprises, such as the finding that a conservation fence in Australia had “unintended negative consequences” on native reptile populations living near it, including eastern long-necked turtles.

“The fence disrupted turtle movement patterns, isolated populations, and led to high mortality rates,” the authors write.

The academics also found that pre-existing fence research largely focuses on target species - meaning those for whom the structures are erected. Of the 446 studies they analysed, only 24 per cent of them included research on both target and non-target species.

The authors hope to see further focus on "fence design and placement and fence construction and removal” to tackle the problems caused by the barriers.