How Controlled Burns Bring Life to the Pine Island Marshes

The end of prescribed fire season means the marshes are ready to grow back healthier for birds.

In late winter, you might see a plume of smoke rising from Audubon’s Donal C. O’Brien, Jr. Sanctuary at Pine Island, but rest assured that is just part of our annual marsh maintenance program.  

Burns take place in February and March, as wintering waterfowl depart but before the marsh birds make their nests. Within that seasonal window, trained contractors wait for proper wind conditions to ensure the safest burn possible and then set strategic, controlled fires to the marsh grass. 

Controlled burns are important to the conservation of birds and wildlife living at the sanctuary. The process mimics the natural renewal cycle created when lightning strikes set the grass ablaze.  

The fires clear out woody growth—shrubs and small trees—that encroach into the marsh. 

Fire also helps get rid of aggressive plants and cycles nutrients through the wetlands. The combination of more sunlight reaching the bottom of the marsh and new nutrients from the burned plant material helps supercharge the growth of native grasses.  

Before long, new grasses sprout up, providing food and shelter during the nesting season for a host of marsh-dependent birds species, from Seaside Sparrows to secretive species like King Rails and Least Bitterns.  

We're also testing whether fire can be used as a tool to improve habitat for the federally threatened and ultra-secretive Black Rail. Our partners who work in neighboring parts of the North Carolina coast, where Black Rails are more established, improve habitat for this species using prescribed marsh burns—N.C. Wildlife Resources Commissions burned an area for Black Rails in Carteret County earlier this month—and we're hopeful that we can adopt their techniques. 

At Pine Island, we currently burn each area every five years on a rotating cycle, so that only small sections of marsh burn each year. Striking the right balance is important. Too frequent fires can reduce the ability of marshes to rise with the water level over time. Too infrequent and the habitat becomes less diverse. 

By protecting and restoring the marshes of Pine Island and Currituck Sound, we’re helping birds and also keeping the marsh intact for local communities. The wetlands filter water, reduce erosion, and serve as a buffer against extreme weather. 

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