Hens may build their nests in the vegetation surrounding a Type III wetland. Most ducklings hatch near Type III wetlands. The vegetation provides cover for nesting while the water serves as a feeding area. Type IV wetlands are usually bigger and hold more water. The most common above-water vegetation is cattail or bulrush.
Vegetation grows in such a way that maze-like pathways to open water are created.
Muskrats inhabit this wetland, as do most waterfowl species and other wetland-dependent birds like the American bittern and black tern . In the case at J. Clark Salyer NWR, this wetland can also provide habitat for gull and tern nesting colonies. Once eggs hatch, hens move their broods to these wetlands for protection from predators. Another common Type IV wetland species is the muskrat. No duck wants to be in the water all the time, constantly swimming.