Four-lane highways may be a necessity to our modern society, but they can be a death trap for millions of animals that try to cross them. Around the world, wildlife need to roam for breeding, foraging, and to carry out their traditional migrations–but they are often blocked by ranches, farms, roads, and other human-made obstacles. While national parks and preserves offer some protection to wildlife, even the magnificent Serengeti and Yellowstone parks are too small to sustain healthy populations over generations. But now comes new hope for wildlife through an approach called “connectivity conservation.” Some of the world’s most beloved species–lions, bears, antelope and elephants–can be preserved by linking the world’s wildlife refuges with tunnels, overpasses, and protected land corridors. From North America’s Yellowstone to Yukon Conservation initiative to Southern Africa’s elephant highways stretching across five nations, see how animals are on the move again.