NAIROBI – For the elephants that are returning to southern Angola, after herds were devastated during the country’s civil wars, the battle is far from over. Old land mines, sown during the decades of conflict that ended in 2002, are threatening the lives and limbs not only of people, but also of the growing elephant populations that are crossing into Angola from northern Botswana on ancient migration routes that continue into Zambia. Mines are a particularly stark example of how humans interfere with migratory journeys that have linked breeding and feeding sites across the globe for millennia.
Up to 10,000 animal species are thought to migrate. Yet, increasingly, air, water, and land routes are being destroyed by barriers, ranging from roads, fences, dams, and power lines to unsustainable hunting or fishing practices, habitat degradation, pollution, and climate change.
One example is the critically endangered Irrawaddy dolphin, found in the Bay of Bengal and Southeast Asia. Barriers to its migration range from entrapment in fishing nets to conditions caused by gold mining and dam building.
Likewise, someone strolling through Norway’s Fennoscandia region in the 1900’s would have marveled at the abundance of Lesser White-fronted Geese, which then numbered in the thousands. Today, only 20-30 breeding pairs remain – the result, according to the World Wildlife Fund, of the drainage of wetlands in countries such as Greece, and of hunting along the bird’s migration routes.