A wildlife corridor, also called a habitat corridor or green corridor, is a special area that links groups of animals that have been separated by human activities such as building roads, expanding farms, growing cities, clearing land, and other developments. These corridors help reduce the problems caused by habitat fragmentation, which happens when natural areas are divided and animals cannot move freely. This fragmentation is often caused by fast-growing cities and transportation systems. Habitat fragmentation from human activities harms biodiversity, and wildlife corridors help lessen these negative effects. By allowing animals to move between areas, corridors prevent issues like inbreeding and low genetic diversity that happen when animals are trapped in small, isolated groups. Corridors also help plants by allowing animals to spread pollen and seeds between separated areas of habitat. In addition, corridors can help animals survive climate change by connecting areas with different temperatures, such as warmer and cooler regions. However, when human settlements are near corridors, they can sometimes lead to more conflicts between people and wildlife, which needs careful management.

Purpose

Habitat corridors are a helpful strategy in places where natural habitats have been damaged, which can harm the variety of living things. When land is broken into pieces, animal groups may become unstable or separated from larger groups. Habitat corridors can be created by local communities, citizen groups, scientists, Indigenous people, land managers, urban planners, and others who care about the environment. As the climate changes, corridors can also help animals move between cooler and warmer areas, allowing them to adapt as their living spaces change. Corridors should be large enough to support small but important groups of animals, remove obstacles that stop animals from moving, and connect different groups of animals.

Corridors help bring together and keep stable groups of animals that are separated by helping with important processes for living things:

• Moving to new areas: Animals can travel to find new places to live if their main home lacks food or other resources.
• Seasonal movement: Animals that move from one place to another during certain times of the year can do so more safely and easily without being blocked by human-made barriers.
• Mating with others: Animals can find mates in nearby areas, which helps increase the variety of genes in their population.

Wildlife corridors have many meanings. They can be any space that allows animals to move, share genes, and reproduce. Other meanings include a long, connected stretch of habitat; a path that animals with large ranges can use to travel between different areas; a place where plants can grow and spread; and a space where animals can move because of changes in their environment, such as fires, floods, or climate change. These corridors also help animals that are at risk by allowing their numbers to grow from other areas.

Wildlife corridors improve habitat connectivity, which means how well plants and animals can move between different parts of their environment.

Types of corridors

Habitat corridors can be grouped based on their width, with wider corridors usually supporting more wildlife movement. However, how well a corridor works also depends on its design and how it is built.

Habitat corridors can also be grouped based on whether they are continuous or not. Continuous corridors are long, unbroken areas of habitat, while "stepping stone" corridors are made up of small, separate pieces of habitat that are spaced apart.

Wildlife corridors can include aquatic habitats, such as areas along rivers. These river zones help animals move between land and water. Removing barriers in rivers, like dams, can help restore connections in water habitats, which increases the size of areas where species can live.

Corridors can also include structures like underpasses and overpasses. These crossings allow animals to move safely over or under human-made structures, such as highways or canals, which helps reduce the number of animals killed by vehicles. Some animals, like black bears and mountain lions, prefer underpasses because they are darker and offer more cover. Other animals, like grizzly bears and elk, often use overpasses. Over time, many animals learn to use these crossings regularly.

Wildlife overpasses and underpasses help different species move because animals have different preferences for crossing structures. For example, in Banff National Park, black bears and mountain lions often use underpasses, while grizzly bears and elk prefer overpasses. Large animals and carnivores tend to use underpasses regularly, while smaller animals, like some types of deer, used underpasses less between 2008 and 2018. Studies in Banff show that animals may take a few years to get used to using these crossings, but they often start using them regularly.

Wildlife corridors can be created in different ways, such as as long, unbroken areas of habitat or as a series of smaller habitat patches. In conservation science, the SLOSS dilemma (whether to protect one large area of habitat or several smaller areas) has been debated for many years. Large, connected areas like national parks have often been the focus of conservation efforts. However, research shows that connecting smaller habitat areas, especially when linked to larger areas, can sometimes support more species than protecting only one large area.

In a wildlife corridor, connecting several small habitat areas, called "stepping stones," can help reduce the loss of species and the breaking up of habitats. Connecting smaller habitat areas can also help animals adapt to climate changes and maintain genetic diversity. In forests, connecting high-quality "stepping stone" habitats can reduce the effects of habitat fragmentation. To find good areas for a wildlife corridor, it is important to consider how far they are from protected areas, existing corridors in the area, which areas have many species, and which habitats are important for biodiversity.

Wildlife corridors can also be created in urban areas, such as cities and towns. Urban areas often have high levels of biodiversity, but urbanization can affect biodiversity in many ways, such as changing animal behavior, reducing the number of species, and lowering genetic diversity. While urban areas often have less biodiversity, they can still have many types of plants. Corridors, whether they are long, connected areas of habitat or small patches, can help improve biodiversity in cities.

Wildlife corridor usage

Most species can be grouped into two categories: passage users and corridor dwellers.

Passage users spend short amounts of time in corridors, often crossing them in a few hours. They use corridors for activities like seasonal migration, moving to new areas as young animals, or traveling between parts of a large area they call home. Examples of passage users include large herbivores, medium to large carnivores, and animals that migrate long distances.

Corridor dwellers, however, live in corridors for many years. Species like plants, reptiles, amphibians, birds, insects, and small mammals may spend their whole lives in these narrow habitats. In these cases, the corridor must have enough food, water, and shelter to support these species.

Scientists study how wildlife uses corridors by using methods like marking animals and catching them again later, or using traps that collect animal hair. These methods help track how animals move and how genes are shared between them.

Scientists also use genetic testing to study how animals move and mate. By looking at how genes are passed between animals in a group, scientists can learn more about how corridors help with migration and keeping genetic diversity alive over time.

Monitoring how animals use corridors can also be done with tools that are easy for people to use. For example, to track bird populations, tools like eBird and i-Tree can be helpful.

Additionally, scientists can study animal use of corridors by looking at pictures taken by camera traps.

Corridor planning

Wildlife corridors work best when they are planned with care, taking into account how animals live. This includes thinking about when animals move during the year, how they avoid dangers, how they spread out to find new areas, and what kind of homes they need.

Corridors can help more animals live in an area if they have some randomness or unevenness in their design and are placed so they cross habitat areas at an angle. However, this design can sometimes create problems near the edges of habitats, where the quality of the habitat is often lower than in the middle parts of the habitat.

Fencing is an important part of designing wildlife corridors. It can be used with structures like overpasses and underpasses along roads to help protect animals from being hit by cars. Since it is not always possible to build fencing along an entire road, it is better to place fencing in areas where many animals are killed on the road. When planning fences, people debate whether it is better to build many short fences or a few long ones. Many short fences might not work as well because animals can move around them more easily, which increases the chance they will be harmed.

Wildlife corridors can be created with the help of many different groups, such as the public, local communities, water management groups, recreation departments, environmental organizations, government agencies, and landowners. To make sure wildlife corridors are built successfully, these groups need to agree on a common goal and plan. Clear rules about how the corridor should be used, programs that encourage businesses to support the corridor, and research that shows where corridors are most needed (like areas with good habitats or near other corridors) are all important for helping animals move between habitats.

Indigenous knowledge

The growth of human activities into natural areas affects both people and animals. Restoring habitats over time needs help from local communities, including Indigenous groups, who live near these areas.

Sometimes, ecological restoration projects do not include the ideas of many different groups. Instead, knowledge from Indigenous people about nature is often replaced with ideas from settlers when planning wildlife corridors and large-scale conservation efforts. This can lead to differences in how people understand where animals live, what types of animals are present, and how their habits change with the seasons. Indigenous views on movement believe that the ability to make choices about where to go helps create strong connections between people and nature. These connections, called "expansive Indigenous modes of relationship," can help improve future conservation efforts. For example, the Yellowstone to Yukon Conservation Initiative is described as a new way of thinking about conservation, even though Indigenous groups, like the Flathead Nation, have long practiced similar methods, such as managing bison across large areas. Some people worry that the language used about connecting wildlife areas comes from settlers, not Indigenous communities, which is a concern for the Land Back movement.

Managing land and water areas can help Indigenous groups who rely on wildlife for cultural practices like fishing and hunting. Many Indigenous groups care for wildlife, but they often have limited money to manage large areas of land. In Canada, in 2025, Parks Canada and the province of British Columbia announced $8 million in funding for wildlife corridors and Indigenous stewardship. Also in Canada, a Mi'kmaw organization in Nova Scotia received $491,000 from Parks Canada's National Program for Ecological Corridors to help manage wildlife corridors on the land.

Human-wildlife conflict

Corridors can overlap with areas where people live, leading to conflicts between wildlife and humans. Human-wildlife conflict, which happens when wildlife homes are damaged and people and animals compete for resources, can result in animals dying on roads, animals eating crops, animals attacking livestock, and injuries or deaths to humans. In India, for example, many corridors that connect large areas of wildlife habitat also overlap with human settlements, including rural villages. People in these areas respond to the conflict in different ways, such as by poisoning animals, trapping them, or harming them. These actions can harm efforts to protect wildlife.

To reduce human-wildlife conflict, several strategies have been used. In India, for example, people have tried fencing areas, moving animals to new locations, and sterilizing wildlife. These methods are often costly and require a lot of physical work.

Encouraging better attitudes toward wildlife corridors is another way to reduce conflict. This includes offering direct payments for ecosystem services (PES), which gives money to landowners, farmers, and others to adopt practices that lower human-wildlife conflict.

Other methods to reduce conflict include organized community efforts. In parts of Africa and Asia, farmers work together in teams to watch for animals, such as elephants, and alert each other when they are nearby. When they see an animal, they make noise to encourage it to leave the area. This organized method can help reduce damage to crops.

Examples

In the 1980s, Banff National Park in Alberta, Canada, started building a network of wildlife overpasses and underpasses to reduce collisions between animals and vehicles on the Trans-Canada Highway. This network includes six overpasses and 38 underpasses. Parks Canada created the project, which covers more than 180 kilometers along the highway. The project has reduced wildlife collisions by 80%. Observations show that over 200,000 animals, including red foxes, hoary marmots, snakes, and boreal toads, use the overpasses and underpasses. Road deaths among large carnivores are 50-100% lower than before the project, and road deaths for animals like elk are nearly zero. The overpasses have trees and native grasses, and fences on both sides help guide animals away from the highway.

In 2001, a wolf corridor was restored through a golf course in Jasper National Park, Alberta. This corridor is frequently used by wolves.

Along the Delhi-Mumbai Expressway near the Ranthambore Tiger Reserve, a 3.5-kilometer wildlife overpass network was built, with each section about 500 meters long. The project, created by the National Highway Authority of India (NHAI), also includes a 1.2-kilometer underpass. As of 2026, the project was partially completed.

In Southern California, researchers studied 15 underpasses and drainage culverts to see how often animals used them as corridors. These structures were effective for carnivores, mule deer, small mammals, and reptiles, even though they were not designed for animals. Scientists found that factors like nearby habitat, underpass size, and human activity influenced how often animals used the structures.

In South Carolina, a study monitored five areas of land to observe butterfly movement and plant reproduction. The areas included a central habitat, four surrounding habitat patches, and a wildlife corridor connecting the central area to one patch. Butterflies placed in the central area were two to four times more likely to move to the connected patch than to disconnected patches. Male holly plants placed in the central area had female holly plants in the connected patch produce 70% more seeds than those in disconnected patches. Seed dispersal by birds was the most significant increase in the connected area.

In the United States, the Florida Wildlife Corridor Act was passed in June 2021. This law protects nearly 18 million acres of connected ecosystems, stretching from Alabama’s border through Florida’s panhandle to the Florida Keys. The corridor includes state parks, national forests, wildlife areas, farmland, and ranches.

The Darlington Ecological Corridor in Montreal, Canada, is an urban ecological corridor. It connects Mount Royal, a city park, to a railway corridor through the Côte-des-Neiges-Notre-Dame-de-Grâce borough. The project began in 2014, led by Université de Montréal researchers, the borough, and groups like Éco-Pivot, which supports urban greening. Originally designed to help foxes on Mount Royal, the corridor expanded to include community gardens, pollinator gardens, and rain gardens to manage stormwater. The project aims to restore biodiversity and improve food security in Montreal.

The Mont Boullé Ecological Corridor in Jean Drapeau Park on Île-Ste-Hélène, Montreal, is another urban example. In 2023, the park started a project to create a dense forest with over 27,000 plants, including shrubs and trees. The project removes invasive species, builds walkways to protect new plants, creates a 334-square-meter valley to improve water infiltration, restores historic trails and stoneworks, adds water fountains, and protects nearby archaeological sites.

Examples of other ecological corridors include:
– Paséo Pantera (also called the Mesoamerican Biological Corridor or Paséo del Jaguar), which ended in 2018 due to funding issues.
– The European Green Belt.
– The Yukon to Yellowstone Conservation Initiative in the Americas.
– The National Ecological Network in the Netherlands, which connects wildlife habitats.
– The Kanha-Pench corridor along NH 44 in India.
– The Terai Arc Landscapes in the Lower Himalayan Region.
– The Banff National Park network of wildlife corridors in Canada.