More than 200 species of birds visit the Refuge throughout the year. October, November, March and April are the best months to see large concentrations of waterfowl; shorebird and warbler migrations usually peak around the first week of May; and bald eagles are common in the winter as they gather near the river to feed in open water areas. Deer, squirrel, raccoon, muskrat, turkey, beaver, skunk and opossum are year-round residents.
See thousands of waterfowl feeding in shallow wetlands of the Calhoun Division and on Swan Lake. Bald eagles use this area regularly during winter. Other birds enjoy the grassland habitat near the refuge visitor center. View an abundance of wildlife from the observation decks near the visitor center.
Gilbert Lake is a great place to seek solace and escape the demands of everyday life; bird watching and hiking are allowed and encouraged on the three mile gravel trail in the division. Gilbert Lake is closed each fall to provide sanctuary for migratory birds. Travel the National Scenic Byway (Illinois State Highway 100) to Gilbert Lake, which is adjacent to Pere Marquette State Park in Jersey County, Illinois.