A wildlife corridor, also called a habitat corridor or green corridor, is an 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 into smaller pieces, limiting where animals can move. Habitat fragmentation from human activities harms the variety of plant and animal life, and wildlife corridors help lessen this damage. By allowing animals to move between areas, corridors prevent issues like inbreeding and low genetic diversity that can happen when animals are trapped in small, isolated groups. Corridors also help plants by allowing animals to spread pollen and seeds between separated areas. In addition, corridors can help animals survive changes in climate by connecting areas with different temperatures. However, corridors near human areas may lead to more conflicts between people and wildlife, which need to be managed carefully.

Purpose

Habitat corridors are a helpful tool for protecting wildlife in places where natural habitats have been damaged or lost. When land is broken into pieces, animal groups may become small or separated from larger groups. Habitat corridors can be created by local people, scientists, Indigenous groups, planners, and others who care about the environment. As the climate changes, corridors also help animals move between cooler and warmer areas, allowing them to find better living conditions as their usual homes change. Corridors should be large enough to support healthy animal groups, remove obstacles that stop animals from moving, and connect different groups of animals.

Corridors help fix and keep stable the groups of animals that are separated by helping them do important things for nature:

• Moving to new areas: Animals can travel to find food or other resources if their usual home runs out of supplies.
• Migration: Animals that move seasonally can travel more safely without being blocked by human-made structures.
• Mating: Animals can find partners in nearby areas, which helps keep their genes strong and diverse.

Wildlife corridors have many meanings. They can be any space that allows animals to move, plants to grow, and genes to mix between groups. Other meanings include a long stretch of connected land, a path animals use to travel between different homes, areas where plants grow and spread, places where animals move because of events like fires or floods, and spaces where endangered animals can grow their numbers by joining with other groups.

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

Types of corridors

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

Habitat corridors can also be classified by their continuity. Continuous corridors are unbroken strips of habitat, while "stepping stone" corridors consist of small, separate areas of suitable habitat.

Wildlife corridors may include aquatic habitats, or riparian zones. Areas along rivers can serve as wildlife corridors, helping animals move between land and water. Removing barriers in rivers can restore connectivity in aquatic habitats, increasing the size of habitats available for species.

Corridors may include crossings such as underpasses or overpasses. These structures allow animals to cross human-made structures, like highways or canals, which helps reduce deaths from vehicle collisions. Some animals prefer the cover of underpasses, while others prefer the open space of overpasses.

Wildlife overpasses and underpasses allow different species to move, as species have preferences for certain types of crossings. For example, in Banff National Park, black bears and mountain lions often use underpasses, which offer a dark, protected path to cross the Trans-Canada Highway. Grizzly bears and large animals, like elk, often use overpasses. Large animals and carnivores also frequently use underpasses, while smaller animals were less common in underpasses between 2008 and 2018. Studies in Banff show that wildlife may take time to become comfortable using overpasses and underpasses, but they often learn to use them.

Wildlife corridors can be formed in different ways, such as as a long, unbroken stretch of habitat or as a series of smaller habitat areas. In conservation, the SLOSS dilemma (choosing between one large area of habitat or several small areas) has been debated for many years. Large, connected areas like national parks have often been the focus of conservation efforts. However, many studies show that connecting smaller habitat areas, especially when linked to a large area, can support more species than either a single large area or separate small areas.

In a wildlife corridor, connecting several small habitat areas, called "stepping stones," can help reduce biodiversity loss and habitat fragmentation. Connecting smaller habitat areas also supports climate adaptation and genetic diversity. In forests, linking high-quality "stepping stone" habitats can reduce fragmentation. To find suitable small areas for a 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 key for biodiversity.

Wildlife corridors can also be created in urban areas, such as cities and towns. Urban areas often overlap with regions of high biodiversity, and urban development can affect biodiversity in many ways, such as changing animal behavior, reducing the number of species, and altering genetic diversity. While urban areas often have less biodiversity, they may still have many types of plants. Corridors, whether long, unbroken stretches of habitat or "stepping stones," can help improve biodiversity in urban areas.

Wildlife corridor usage

Most species can be divided into two groups: animals that use corridors briefly and animals that live in corridors for many years.

Animals that use corridors briefly stay in them for a short time, such as a few hours. They use corridors for activities like seasonal migration, young animals moving to new areas, or traveling between parts of a large territory. Large plant-eating animals, medium to large meat-eating animals, and species that move long distances during certain times of the year are examples of these animals.

Animals that live in corridors for many years may spend their entire lives in linear habitats, such as narrow strips of land or vegetation. In these cases, the corridor must provide 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 to collect animal hair. These techniques help track how animals move and how genes are shared between populations. Testing DNA can also show how animals move and mate, helping scientists understand how corridors affect migration and genetic diversity over time.

Monitoring how animals use corridors can also involve tools that are easy for people to use, such as apps for recording bird sightings. For example, apps like eBird and i-Tree can help track bird populations. Cameras that take pictures of animals in the wild are another way to monitor how wildlife uses corridors.

Corridor planning

Wildlife corridors work best when they are planned with care, taking into account how animals live, such as how they move during different seasons, how they avoid dangers, how they spread out to find new areas, and what kind of homes they need.

Designing corridors that have some randomness or unevenness and are placed at right angles to nearby habitat areas can help increase the variety of plants and animals. However, this design might create edge effects, where the quality of habitat near the edges of an area is often worse than in the middle parts of the habitat.

Fencing should be considered when planning wildlife corridors. It can help protect animals by working with overpasses and underpasses along roads, which reduces the number of animals that die from hitting vehicles. Because it is not always possible to build fencing along an entire road, it is important to place fencing in areas where animals are most likely to be killed by vehicles. When planning fencing, people debate whether it is better to use many short fences or a few long ones. Many short fences may not be as effective because animals can more easily move around them, increasing the risk of harm.

Wildlife corridors can be created with the help of many different groups, including the public, local communities, water management organizations, recreation departments, non-profit groups, government agencies, and landowners. To successfully create corridors, these groups must agree on a common goal and vision. Clear rules and laws about how the corridor will be managed, programs that encourage businesses to support the corridor, and research that identifies the best places for corridors (such as areas with high-quality habitats or near other corridors) are important for connecting habitats effectively.

Indigenous knowledge

When people build more things in natural areas, it affects both humans and animals. To help restore these areas over time, local communities, including Indigenous groups, must support these efforts.

Sometimes, large projects to help nature recover do not include the ideas of many different groups. Instead, some plans use ideas from settlers about how landscapes work, rather than using Indigenous knowledge about the natural world. This can cause differences in how people understand where animals live, what types of animals are there, and how their habits change with the seasons. Indigenous ideas about movement show that being able to make choices about where to go helps build strong relationships between people and the land. These relationships, called "expansive Indigenous modes of relationship," can help improve future plans for protecting large areas of land and connecting them. For example, the Yellowstone to Yukon Conservation Initiative is described as a new way of thinking, but Indigenous groups like the Flathead Nation have already been managing large areas of land for many years, helping animals like bison move freely. Some people worry that the language used to describe connecting land areas focuses more on settler ideas, which is a concern raised by the Land Back movement.

Taking care of land and water can help Indigenous groups who rely on animals for traditions like fishing and hunting. Many Indigenous groups manage wildlife, but they often have limited money to care for large areas of habitat. In Canada, in 2025, Parks Canada and the province of British Columbia announced $8 million to help create wildlife corridors and support Indigenous groups in managing these areas. Also in Canada, a Mi'kmaw organization in Nova Scotia received $491,000 from Parks Canada’s program to help protect 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 happens because of damaged wildlife habitats and competition for resources. This conflict can result in animals being killed on roads, animals eating crops, animals attacking livestock, or humans being hurt or killed. In India, many corridors that connect large areas of habitat also overlap with human settlements, such as rural villages. People in these areas respond to the conflict in various ways, such as by poisoning animals, trapping them, or harming them. These actions can reduce progress in protecting wildlife.

To reduce human-wildlife conflict, different 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 effort.

Another way to reduce conflict is by offering incentives to improve attitudes toward wildlife corridors. One example is direct payments for ecosystem services (PES), which gives money to landowners and farmers to encourage practices that lower human-wildlife conflict.

Other methods to reduce conflict include communal guarding systems. In parts of Africa and Asia, farmers work together in groups to watch for animals, such as elephants. When they spot an animal, they make noise to encourage it to leave the area. This approach helps reduce damage to crops.

Examples

The network of wildlife overpasses and underpasses in Banff National Park in Alberta, Canada, was started in the 1980s to reduce wildlife collisions along the Trans-Canada Highway. The network includes six overpasses and 38 underpasses. Created by Parks Canada, the project covers more than 180 kilometers along the Trans-Canada Highway and has reduced wildlife collisions by 80%. The overpasses and underpasses have been used more than 200,000 times by many species, including red foxes, hoary marmots, snakes, and boreal toads. Road deaths for large carnivores are 50 to 100% less than before the project, and the road death rate for ungulates like elk is nearly zero. The overpasses have trees and native grasses, with fences on both sides to help animals avoid the highway.

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

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

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

In a corridor ecology experiment in South Carolina, United States, five areas of land were studied for butterfly movement and plant reproduction. The areas included a central area, four habitat patches around it, 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 were placed in the central area, and female holly plants in the connected patch had 70% higher seed production compared to those in disconnected patches. Seed dispersal through bird droppings was the most common method of seed spread in the connected area.

In the United States, the Florida Wildlife Corridor Act was passed in June 2021, protecting a network of nearly 18 million acres of connected ecosystems. Starting from the Alabama border, through the Florida panhandle to the Florida Keys, the corridor includes state parks, national forests, wildlife management areas, agricultural land, and ranches.

The Darlington Ecological Corridor in Montreal, Canada, is an example of an urban ecological corridor. It connects Mount Royal, a park in the city center, to a railway corridor through the Côte-des-Neiges-Notre-Dame-de-Grâce borough. The corridor began in 2014 as a project led by Université de Montréal researchers, the borough, and groups like Éco-Pivot, which supports urban greening. The corridor was initially created to help foxes on Mount Royal but later expanded to include other interests. It includes community food gardens, roadside pollinator gardens, and natural stormwater management through rain gardens. The project aims to restore biodiversity in Montreal and improve food security.

The Mont Boullé Ecological Corridor in Jean Drapeau Park on Île-Ste-Hélène in Montreal, Canada, is another urban ecological corridor. In 2023, the park started a project to create a dense forest on the island, planting over 27,000 plants, including small plants, shrubs, and trees. The project includes removing invasive species, building walkways to protect new vegetation, improving rainwater filtration by creating a 334 square-meter plant-filled valley, restoring historic stoneworks and trails, adding human infrastructure like water fountains, and protecting nearby archaeological sites.

• Paséo Pantera (also known as the Mesoamerican Biological Corridor or Paséo del Jaguar), ended in 2018 due to funding issues
• European Green Belt
• Yukon to Yellowstone Conservation Initiative in the Americas
• National Ecological Network, a network of corridors and habitats for wildlife in the Netherlands
• Kanha-Pench corridor along NH 44 in India
• Terai Arc Landscapes in the Lower Himalayan Region
• Banff National Park network of wildlife corridors in Canada