Big Lake includes the 11,000-acre Big Lake National Wildlife Refuge (U.S. Fish & Wildlife Service) and the adjacent 12,320-acre Big Lake Wildlife Management Area (Arkansas Game & Fish Commission). Big Lake is the largest Mississippi River drainage area in northeast Arkansas, and supports an extensive bottomland-hardwood forest habitat, lowland oak forest, as well as both permanent and ephemeral lakes and ponds. The area is an island of natural habitat in an agricultural and urban landscape. It is used extensively by breeding birds, including many species of concern, wintering waterfowl, and migrating songbirds.
Waterfowl were observed during winter from 1999-2003 with >100,000 being observed by U.S. Fish & Wildlife Service airboat surveys of Big Lake NWR conducted greater than or equal to two times/winter. Site regularly supports significant densities of one or more of the bird species considered by Audubon as vulnerable in Arkansas (explain below): Big Lake provides a stopover for migrating birds along the Mississippi flyway, as well as provides breeding habitat for many species of concern, including Yellow-crowned and Black-crowned Night-Herons, Northern Bobwhite, King Rails, Red-headed Woodpeckers, Acadian Flycatchers, Wood Thrush, Loggerhead Shrikes, American Redstarts, Prothonotary Warblers, and Baltimore Orioles. Breeding bird surveys of the area are required to determien the density and reproductive success of these species. Site regulary supports 10,000 waterfowl (excluding snow geese) or more: Censuses conducted on the National Wildlife Refuge portion of the Big Lake IBA show that over 100,000 waterfowl use the area for wintering each year. Approximately 80% of birds observed are Mallards. Site includes one or more outstanding examples of the following special bird habitats: Big Lake IBA contains cypress-water tupelo swamp, bottomland hardwood forest, and some lowland oak forest. This site is important for Arkansas birds due to its location and habitat quality. As previously stated, Big Lake provides a stopover for migrating birds along the Mississippi flyway, and is a unique natural area in the midst of agricultural fields. Many species of concern breed in the Big Lake IBA.
The most serious threats to avian habitat at Big Lake are siltation and agricultural run-off from the farmlands to the north. The Corps of Engineers controls the drainage channels, thus the staff of the NWR and WMA are unable to alter water management practices. Excessive flooding in late spring has elminated much of the natural understory vegetation, including cane. It is likely that this site may have once supported substantial populations of Bachman's and Swainson's Warblers before habitat conversion. At this time, the Swainson's Warbler is probably not present or is rare, but surveys are needed to confirm the status of this and other passerine species. Habitat conversion at Big Lake would be enhanced by reducing the amount of flood water entering the area. However, the importance of this area as a run-off easement for the surrounding farmlands makes reduction of water input difficult. Communication and collaboration with The Corps and local farmers is needed.