Northern Harrier
Northern Harrier

Colorado
Recognized as an Audubon Important Bird Area, the 13,455-acre Browns Park National Wildlife Refuge is home to more than 200 bird species, and hosts upwards of 20,000 waterbirds in the spring and fall. Established by Congress to provide sanctuary for migratory birds and threatened and endangered species, Browns Park Refuge provides the only significant wetland, riparian, and grassland habitat for miles around.

The Invaders
The aggressive perennial pepperweed has invaded about 1,100 acres of the refuge's wetland, riparian, and grassland habitats. Perennial pepperweed forms a thick blanket over the ground that shuts out sunlight, which reduces native species' ability to survive. It spreads mainly by underground roots at a rate of several feet per year. Pepperweed infestations degrade and eliminate the plant diversity that many birds and wildlife depend upon for food, cover, and nesting. 

Threat to Birds
The Northern Harrier, a ground nesting raptor, faces population declines throughout the Intermountain West, largely due to the loss of wet meadow grassland habitat. Northern Harriers depend on lush wet meadow grasslands for nesting. Perennial pepperweed can wipe out this habitat in a few years, thus reducing plant diversity and available nesting habitat for the Northern Harrier and many other ground nesting birds.