Wildlife scientists fall on both sides of the fence when it comes to erected barriers to limit conflicts between animals and humans.
While on the one side, fences and barriers can be a great tool to limit human-wildlife conflicts or keep animals from dangerous road crossings, they can also hinder natural migration routes and mobility.
“Large-scale fencing can disrupt migration pathways and reduce access to key areas within drylands, such as seasonal foraging areas,” said Sarah Durant of the Zoological Society of London in a release. Durant is the lead author of a new study published in the Journal of Applied Ecology. “This can lead to severe reductions in migratory wildlife populations and may prompt wider impacts on non-migratory species.”
The researchers said that proper policies should be put into place to evaluate if and when fences should be used based on factors including wildlife movement and distribution, predictions of climate change and the costs and benefits to locals.
Some national parks in Africa are using fences as a way to protect animals from poaching and other problems, such as the 120-kilometer fence that authorities have installed around Rwanda’s Akagera National Park.
But the authors of the study found that there isn’t much evidence showing that fences are actually effective, especially in dryland ecosystems.
“Fencing can initially appear to be an easy conservation solution,” said James Deutsch from the Wildlife Conservation Society and a coauthor of the paper in a release. “Yet, unless fencing strategies have local community support and financing for maintenance, there is a danger that they may generate more problems than they solve.”
Researchers in Canada found in March that bad fences may do more damage than good for some species. They found that holes allowed reptiles to get into highway areas, but that they could sometimes lock them into a kind of deathtrap when they couldn’t find another hole from which to escape.
The authors of the new paper recommend using the United Nations’ Conventions on Migratory Species (CMS) — an intergovernmental treaty that aims to protect land, ocean and avian species — as well as the UN’s international agreement on combating desertification to develop future policy and guidelines for dryland fencing.
The CMS’ Scientific Council responded by proposing the formation of a working group to deal with fencing problems.
“CMS is concerned about the impact of human-wildlife conflict on both wildlife and on vulnerable livelihoods of marginalized people, and would like to better understand the impacts of fencing, or alternative methods, if used to mitigate such conflicts,” said study coauthor Roseline Beudels-Jamar from the CMS Scientific Council.
|Joshua Rapp Learn is a science writer at The Wildlife Society.