Why Protecting Wildlife Habitat Isn’t Enough

A protected forest, wetland, or grassland may provide excellent habitat, but wildlife rarely spends its entire life in one place. A mule deer travels between summer and winter ranges. A black bear roams miles in search of food and a mate. An amphibian moves between the forest where it lives and the wetland where it breeds. 

When development divides these landscapes, animals can become cut off from the places they depend on for food, water, shelter, breeding, and seasonal habitat. Even protected areas can become ecological islands if wildlife has no safe way to move between them and the surrounding landscape. 

The ability to move also helps wildlife respond to a changing climate. Fish may seek cooler stretches of a river, while mountain species may move to higher elevations. Connected landscapes give wildlife somewhere to go. 

Even when wildlife can still move through a fragmented landscape — there’s often a greater risk. 

A turtle crossing a road to reach nesting habitat or an elk following a generations-old migration route can suddenly find traffic in its path. More than 1 million wildlife-vehicle collisions occur in the U.S. each year, according to the Federal Highway Administration. 

And the impact goes beyond collisions. Busy roads can become barriers that some animals avoid crossing altogether, effectively cutting them off from habitat on the other side. 

Wildlife crossings and protected corridors can help reconnect these landscapes, making movement safer for wildlife and people. 

Fragmentation doesn’t just divide habitat. It can change the quality of what remains through something scientists call the “edge effect.” 

When a road, development, or cleared area cuts into a forest or other natural landscape, it creates new edges. These areas can experience more sunlight, wind, noise, invasive species, and human activity than habitat farther inside. Those changes often make the remaining habitat less suitable for species that depend on them. 

The smaller and more fragmented a habitat becomes, the more of it can be exposed to these edge effects. So even when acres remain undeveloped, they may not provide wildlife with the same quality of habitat they once did. 

The effects of fragmentation can extend beyond individual animals. When groups of wildlife become separated from one another, entire populations are affected. 

Animals need opportunities to move between populations to find mates and maintain genetic diversity. When those connections disappear, small, isolated populations become more vulnerable to inbreeding, disease, environmental change, and local extinction. 

Keeping habitat connected helps wildlife populations stay healthier and more resilient over time. 

Habitat fragmentation changes how we should think about conservation. The most important property to protect isn’t always the biggest or most pristine. 

At The Conservation Fund, we protect at-risk lands before they’re lost, with a focus on places that make an outsized difference for wildlife. A narrow stretch of forest might be the only connection between two much larger habitats. An undeveloped riverbank could provide an important travel route for bears and other animals. A single property next to a national park could prevent development from creating a gap in an otherwise connected landscape. 

In these places, where we protect land can matter just as much as how much we protect. 

We’re proud to have protected more than 9 million acres of at-risk land — and 94% of it has strengthened habitat connectivity, with more than half focused on habitat for imperiled, endangered, or threatened species.  

Because protecting wildlife isn’t just about giving animals a place to live. It’s about giving them room to move and thrive.