The ongoing refugee crisis, possible further exits from the EU: Europe faces a future with reinforced border security structures. But border fences are the enemy of wildlife, as new findings show.
European migratory decisions following refugees' arrival into the continent may have devastating consequences - not only for humans. Wolves, bears and lynx are only some of the wild animals to be added to the list of victims.
Around 400 kilometers (about 250 miles) of border fences are estimated to have been erected, or are under construction, within the European Union; and more than 2,000 kilometers exist separating it from the non-EU territories, according to a recent study published in PLOS Biology.
The study - the first of its kind in Europe - has shown that construction of these hundreds of kilometers of border security fences represents a major threat to wildlife.
According to researchers, such fences harm wildlife by preventing the animals from accessing key sources of nourishment, even causing death and reducing population size.
In addition to such impacts, border fence construction interferes with European environmental projects such as the Natura 2000 network and the EU Biodiversity Strategy to 2020.
This is not the first time border fences impact wildlife - the border between Mexico and the United States demonstrates that. But the shifting political and demographic landscape in Europe is a new scenario - as such, new mitigation measures would be required to protect wildlife.
Bigger threat for endangered species
Wild animals that come in contact with border fences become victims by entanglement and electrocution - but these deaths only represent the direct and short-term consequences.
Longer-term impacts include obstruction of migration and access to vital sources of food and water, genetic fragmentation of populations and compounded habitat loss, among others.
Along the 670-kilometer border between Croatia and Slovenia are planned 349 kilometers of fencing - approximately 150 kilometers of razor wire fences are said to already be in place, the International Organization for Migration told DW.
These cut out an area within the Dinaric Mountain range, which is home to rare and endangered species including the brown bear, the gray wolf and the Eurasian lynx - three of Europe's five large carnivores.
Despite their low population density and the large space they need to live, these three species have been able to survive during the past years thanks to successful conservation efforts, and to their ability to move between subpopulations. But now, security fences could hinder their future prosperity.
In the case of wolves, the home ranges of five wolf packs living in Slovenia - out of a total of about 10 - are on both sides of the border with neighboring country Croatia. If isolated by fences, wolves in Slovenia may no longer survive.
A step backward for conservation
"The implementation of border fences in recognized natural areas surely means a step backward for European conservation efforts," John D.C. Linnell, leading author of the study, told DW.
According to the researchers, the fence between Croatia and Slovenia is in direct conflict with European projects such as the EU Biodiversity Strategy to 2020, as well as crossing through areas included in the Natura 2000 network.
They point out this fails to fulfill the criteria of the European wildlife conservation framework, particularly the Habitats Directive, which "ensures the conservation of a wide range of rare, threatened or endemic animal and plant species," as described by the European Commission.
However, the commission has not yet found that fences contradict EU environmental legislation. A representative from the European Commission told DW that they are monitoring the issue closely for any problems related to environmental impacts from the border fences.
At this point there has not been such indication, the Commission said. Aside from environmental aspects, the representative pointed out that attempts to build walls or fences between member states have no place in the EU.
Linnell's team also studied the impact of the border fence between Mongolia and China on the Asiatic wild ass, or khulan
Disconcerting North American experience
While most border fences within Europe remain in flux due to the unsure political situation, other borders fences do not exactly shine as a beacon for conservation.
The border along the United States and Mexico, including almost 1,000 kilometers of fencing, has already hindered the movements of all kind of terrestrial animals - from bison to reptiles, and including endangered species.
A study published in 2011 showed that among the species most affected, four were listed by the International Union for Conservation of Nature as endangered or threatened. The international border has caused habitat fragmentation for extremely rare animals, such as the ocelot feline, of which there are only some 100 individuals left in Texas.
Looking into a possible future with Donald Trump as president - a dark one for the environment - the US Fish and Wildlife Service (USFWS) has already estimated that Trump's proposal to extend the border fence could impact 223 of its managed resources, including 111 endangered species and four wildlife refuges.
Even small animals, such as reptiles, have problems crossing some parts of the border fence between the US and Mexico
Bringing wildlife back to wilderness
Despite the negative impact of security fences on wildlife, Linnell points out that nothing is black or white. Border security structures could also prevent the smuggling of wildlife, help keep animals save from illegal hunting, and help delineate a refuge for animals, far from human disturbance. But all this requires further work.
"Now is time to reinforce collaborations and work even harder," Linnell said. Opening some fence sections during migratory seasons and improving the design of border fences so that the risk of entanglement and electrocution are reduced constitute some of the options proposed by the team of researchers.
Linnell hopes that future fence constructions, such as the ones planned to separate the Baltic states from Russia and Belarus, will be subject to careful environmental impact assessments and also consider the needs of wildlife.
But to achieve this, he continued, wildlife conservationists have to strongly engage with governmental actors and start communicating at higher levels. "The work Europe has been doing for decades to increase conservation projects, now has to be reviewed and adapted to a new scenario," Linnell concluded.