More than 1.2 million people sought asylum in European countries last year, and in response to one of the largest human migrations the EU has ever seen, hundreds of miles of border fences have been constructed since 2015 to keep refugees out.
Soon, Europe will contain more border walls than it did during the Cold War. Since the fall of the Berlin Wall, European countries have spent approximately $570 million on 750 miles of fencing—cement, electric, chain-link, and barbed wire—both inside and outside the trade bloc. When refugee numbers saw their highest levels in 2015, instead of offering sanctuary, several countries hastily built "temporary" walls to "safeguard" their national borders. Many pointed out that feelings of xenophobia were also at work in the United Kingdom's "Brexit" referendum, in which voters ultimately opted to leave the EU on Thursday.
Refugees aren't the only ones shut out by these fences. Over the last decade, EU nations have failed to consider the dire consequences that anti-immigration fences present to native wildlife, a new study published this week in PLOS Biology argues. Not only do Europe's border fences trap and kill vulnerable species, they also cut off seasonal transboundary migration routes, and can even restrict population gene flow.
"We hypothesise that 9/11 was the main driver, when the risk of terrorism and drug dealers coming in meant that governments were closing their borders to reduce the risk while conservationists were driving for a more open system to allow wildlife to cross," the study's co-author, Matt Hayward, told the BBC.
Interestingly, the end of the Cold War marked a fortuitous time for conservation biology in Europe. New international laws and agencies, like the Convention on International Trade in Endangered Species, helped to foster in a new age of cooperation and open-access. And as tensions across Europe continued to thaw, researchers were able to collaborate on projects aimed at protecting migratory species that roamed across national borders.
"In part due to the harmonisation of legislation across borders and restored connectivity, Europe has witnessed a tremendous recovery of its large carnivore and herbivore populations in recent decades," the study notes.
But now, many biologists are concerned that recent anti-immigration measures could stall, or even undo, the monumental strides that conservationists have achieved over the past several decades. According to the study's observations, between 15,534 and 18,641 miles of new border fences pose a threat to wildlife in Eastern Europe and Central Asia.
A large percentage of these fences might even be illegal, as they appear to have been built in opposition to rules set forth by the United Nations Educational, Scientific and Cultural Organization and the EU's own Habitats Directive, the study adds.
In Slovenia, the 2015 construction of a razor-wire security fence along its Croatia border disrupted the habitat of brown bear (Ursus arctos), gray wolf (Canis lupus), and Eurasian lynx (Lynx lynx) populations in the Northern Dinaric Mountains. Brown bear already suffer from habitat fragmentation and hunting in Slovenia, and half of the country's resident gray wolf packs have home ranges across the border in Croatia. Lynx numbers, which are notoriously small, are especially vulnerable to inbreeding if individuals aren't able to move between subpopulations.
However, the authors acknowledge that—if done right—border walls don't have to be detrimental to wildlife. Both Mongolian gazelle (Procapra gutturosa) and Asiatic wild ass (Equus hemionus) actually profit from the pastoral refuge and poaching protection provided by fences as the Mongolian-Chinese border.
"If you look at lion populations around Africa, the best way to conserve them is to have them behind fences in large-scale national parks," Hayward said. "So conservation fencing by itself is not a bad thing; it's where we don't consider the impacts or carry out environmental assessments with these border fences—that's where the damage is done."
Moving forward, the study stresses that European governments should fully, and transparently, evaluate the potential harm that border walls could present to native species. Additionally, high-tech monitoring tools and wildlife-friendly fencing materials can also help to mitigate some of the negative impacts.
But most of all, the authors hope that in the face of geopolitical strife, conservationists will recognize the benefits of international partnerships, and strengthen their alliances across borders for the sake of animals that have none.