You’re cruising through the spectacular valley of the Canadian Rockies in Banff and pass below a grassy overpass. Maybe you thought it was just a fancy scenic archway, an old decrepit overpass? Not in the slightest. These structures are a new method of wildlife conservation. They were piloted years ago by biologists - unsure as to whether or not they would actually work - to connect wildlife to larger swaths of land used for grazing, migration and biodiversity that were otherwise corralled by human infrastructure. It turns out these intentional man-made wildlife corridors work quite well.
And why wouldn’t they? Wildlife corridors exist naturally in varied landscapes, connecting animals with new territories otherwise hemmed by geographic obstacles. If a new path opens up, it doesn’t take long for the trail news to spread. Similarly, man-made wildlife corridors are soon discovered by curious creatures looking for a new mate or source of food. In the realm of conservation efforts, the more common and useful wildlife corridors are those established in rural areas throughout the developed and developing world. Here, where farms and human settlements have converted large rangelands and forests into checkerboards, wildlife corridors expand the area available to animals and improve human / animal coexistence.
What are wildlife corridors and why do they exist?
As human settlements across the world continue to develop and population swells, virgin or even conservation land is diminished. Every day on the news we read about new crops (industry farmed palm oil) or infrastructure (roads) that have decimated biodiverse regions around the world. This is hardly an offense of just industry or development; “pastoral” subsistence farmers practice slash and burn agriculture. Without the luxury of ‘fallowing’ their fields, they often encroach into nearby land, often national parks, forests, or other conservation areas, and slash and burn another tract of land for growing their crops. While this may sound like terrible land stewardship, most of these families have no other options to feed their families. The result, from either settlement expansion or intensive agriculture, is scattered and dissected habitat for wildlife.
Without special consideration of the natural movements of wildlife in areas susceptible to the impacts of climate change, development, and ecological pressures, the safety and survival of incredibly important species can be threatened--especially for those that are migratory or few in number. Isolating populations of species from one another can lead to even more significant changes in the ecology of an area. Additionally, and perhaps more importantly, is the concern of declining biodiversity. Individual species need genetic diversity to continue to exist in a healthy state (one of the MANY reasons you shouldn’t marry your cousin), however, the intricate web of biodiversity is both complex and fragile. Species need other species to exist, to thrive. The gazelle needs the grass for nourishment, the lion needs the gazelle for nourishment and the vultures need the lion to kill the gazelle so it can scavenge the remains. And all species need vultures, because by scavenging the remains (very quickly, I might add…) the amount of pathogens spread between species is reduced as the pathogens die in a vulture’s stomach that could otherwise be passed between the lion, the hyena, the jackal, the genet and so on and so on. The circle of life is real and we all need each other.
While it is nearly impossible to reverse the already noticeable impacts of these threats of habitat loss, wildlife corridors are ways to maintain the connection for animals. Corridors serve as a “crosswalk” through/over/under areas that pose a threat to survival, improving the connectivity of fragmented ecosystems. Seen at both small and large scales, they allow wildlife, such as leopards, to roam more freely for food, a mate, or migration without the restrictions.
How do wildlife corridors work?
It should be noted that wildlife corridors are not just a man-made solution, but are also a natural phenomenon you might see in the wild. Considering the difference in man-made wildlife corridors and natural corridors, their functionality can vary.
For man-made wildlife corridors, often a fence is used to avoid risk of danger and guide the animal toward the corridor that bypasses the risky nature of roadways. A study in Alberta, Canada even found that this method has proven to reduce the mortality rates along major highways. Of course, determining where these corridors should go can be one of the bigger challenges. However, researchers have in recent years found better ways to model the connectivity of corridors when planning their placement.
Alternatively, natural corridors are--as you can imagine by its name--naturally occurring. Rather than a hardened, man-made structure like an overpass you might see in Banff, natural corridors provide locations for rest or food for migratory birds, or even provide a mode of passage--such as currents in the ocean, and passages in the ocean that are off-limits to fishing. Many of the wildlife corridors in Africa are a partnership between governments, national parks, reserves and private land-owners. The idea is that land-owners agree to provide some portion of their land as corridors for certain species, and are in turn compensated for the easement (plus as any loss associated with predation of livestock). It is usually a win-win situation for everyone; the wildlife, the land-owner and the government. Increasingly as wildlife photography safaris are becoming more common, the amount of money generated for conservation through this method is a lucrative income stream, providing the land-owner with opportunities to pursue a more sustainable livelihood or to be employed by the tourism industry.
Since these corridors were created and are used without human interaction, it is vital to keep natural corridors alive and healthy. Conserving their function can ensure safe passage for thousands of species across the globe.
Africa: Northern Corridor in Rwanda
The heavily populated, but small-sized country of Rwanda is facing an increasing rate of deforestation, threatening the wildlife and connectivity of ecosystems throughout. Various Rwandan organizations are teaming up to develop a 30-mile long corridor that will connect two national parks that were once naturally connected.
Currently in the works, the Sumatran Wildlife Sanctuary will provide corridors for some of the most threatened species in the area, including the orangutan, tiger, rhino and elephant. Being threatened by the rapidly increasing deforestation due to palm oil production and agriculture, these species can seek refuge through the use of corridors instead of finding themselves stuck in a shrinking natural landscape.
Central/South America: Jaguar Corridor Initiative
Aimed at ensuring safe passage throughout the 6 million square-kilometers of range for jaguars, Panthera has developed a program using corridors. Due to changing landscapes and their natural migratory habits, these jaguars are prone to being killed by people between Northern Mexico and Argentina. In addition to the development of these corridors, Panthera has focused on community and government relations to ensure a sustainable program for all.