Spring is an ideal time to visit Grass River Natural Area. Migratory birds make their appearance now and love is in the air. The fascinating ritual of the woodcock's mating dance can often be viewed at twilight. During May, the resident American bald eagles are frequently seen flying back and forth to the nest with food for their young. Grass River Natural Area's diversity of ecosystems provides habitat for more than 60 species of birds.
Mature forests attract a variety of songbirds.
In the deep woods, ovenbirds build ground nests. The upside-down appearance of their nests account for their unusual name. Along clear-cut lands, visitors observe warblers. The preserve's river system provides habitat for favorite waterfowl, including ducks and loons. This allows visitors a good window of opportunity to observe birds and wildlife before trees burst forth in a leafy cover.