ABSTRACT
The wood duck (Aix sponsa) is found throughout eastern North America from southern Canada to the Gulf Coast and in the Pacific Northwest from British Columbia to California. With the approach of cold weather, the wood duck, a migratory species, moves toward the milder climates of the Gulf Coast in the east and the Pacific Coast in the west. Wood ducks differ from other species of waterfowl with regard to roosting behavior by congregating at traditional roosting sites in marshes or swamps. In the midwestern US, the roost population begins to develop in August, attains peak numbers in the latter part of September, and fluctuates downward through the fall. To facilitate counting when light conditions are poor, the observation point selected should silhouette approaching wood ducks against the sky. Two observers may be required to accurately count some large roosts.
