Border barriers and the natural environment: from Asia to the USA

From the swamps of Africa to the mountains of Southeast Asia and from the US-Mexico border to the steppes of Central Asia, border barriers are emerging in previous nature reserves. They block seasonal migrations of large animals, reduce genetic and species diversity, and threaten the future of millions of species that must move to keep up with a changing climate. Barriers are hazardous when they stretch from east to west over long distances or follow contours on mountain slopes, preventing animals from moving into colder climates. For example, a dam on the border between Poland and Belarus cut through the habitat of local lynxes, reducing their already low genetic diversity.

The three critical borders with the highest numbers of endangered species are those between China and Russia, the United States and Mexico, and India and Myanmar. They are all currently divided by barriers. India has fenced about three-quarters of its border with Bangladesh, stopping the cross-border movement of wild Asian elephants. In Central Asia, border barriers have blocked the ranges and migrations of the steppe goat, wild camel, gazelle, wild ass, bear, snow leopard, tiger, cheetah, deer and Przewalski’s horse. Israel’s wall around the West Bank prevents the seasonal movement of gazelles, foxes, wolves and other animals. The wall on the U.S.-Mexico border bisects the range of 120 mammal species, many of which travel between Mexico’s Western Sierra Madre and the Rocky Mountains.