Wildlife Corridors: explained
Frequently asked questions
What is a wildlife corridor?
A wildlife corridor is a connected strip or network of habitat that allows animals, plants, and genetic material to move between larger areas of wild land. Corridors prevent the genetic isolation that occurs when habitats are fragmented by roads, farmland, or urban development. They are a core tool in rewilding, which seeks to restore the connectivity that makes ecosystems self-sustaining. Corridors range in scale from a hedgerow linking two fields to the Yellowstone to Yukon initiative, a 3,200-mile corridor spanning the Rocky Mountains from Wyoming to Alaska.
What are the different types of wildlife corridors?
Wildlife corridors generally fall into three types. Continuous corridors are uninterrupted stretches of natural habitat that let animals move safely across the landscape without breaks. Intermittent corridors, sometimes called stepping-stone corridors, are a series of smaller habitat patches spaced closely enough that wildlife can rest and move between them even without a fully continuous strip of habitat. Infrastructure corridors are human-built structures, wildlife overpasses, underpasses, and culvert crossings, that let animals cross roads, highways, and other barriers safely.
The three main types of wildlife corridor: continuous habitat, intermittent stepping-stone habitat, and human-built infrastructure crossings like overpasses and underpasses.
Why is habitat fragmentation a problem?
When habitats are fragmented, cut up by roads, farms, and cities, wildlife populations become isolated. Isolated populations lose genetic diversity over generations, making them less resilient to disease and climate change. Small isolated populations are also more vulnerable to local extinction from random events like drought or disease outbreaks. Corridors allow individuals to move between populations, maintaining genetic diversity and enabling recolonization after local extinctions.
What is the Yellowstone to Yukon corridor?
The Yellowstone to Yukon Conservation Initiative (Y2Y) is a collaborative project to maintain and restore a connected wild corridor spanning 3,200 miles along the Rocky Mountains from Yellowstone National Park to the Yukon in Canada. The initiative involves over 300 partner organizations working to protect private land, restore degraded habitat, and build wildlife crossings over highways. Grizzly bears, wolves, wolverines, and elk all use the corridor to move between seasonal habitats.
How do wildlife crossings work?
Wildlife crossings, overpasses and underpasses built over or under roads, allow animals to cross safely without being hit by vehicles. They are planted with native vegetation to blend into the landscape and are designed for the specific species in the area. Camera trap studies show that crossings are used by a wide range of species including large mammals, reptiles, and amphibians. Canada's Banff National Park has 44 wildlife crossings and has documented over 150,000 animal crossings since 1996.