Habitat relationships of breeding birds and winter birds in forested wetlands of West Tennessee

Rapid and substantial losses of wetlands in the lower Mississippi River Valley during the last 200 years have made wise environmental planning increasingly important. Documentation of bird-habitat relationships provides one assessment of human impacts in wetlands. The objectives of this study were to 1) characterize breeding and winter bird communities occurring in west Tennessee forested wetlands, 2) assess bird density, composition, and species richness among watersheds with highly variable degrees of disturbance, and 3) provide habitat models for abundant breeding and winter season birds.

Bird density and species richness in west Tennessee is limited by cumulative impacts of minor projects which reduce forest tract size and alter natural flood regimes. Highest breeding density and species richness occurred in watersheds with the least amount of disturbance. Birds often show a higher mobility during winter than during breeding season. As a result, winter densities and species richness varied among watersheds. Land management that encourages agriculture and water impoundments provided for high densities of blackbirds and waterfowl, which exaggerated density in disturbed watersheds. High winter density and species richness in relatively undisturbed watersheds were attributed to large tract size and relatively normal flood regimes.

Habitat structure is a more consistent predictor of bird density than habitat (tree species) composition. A low percentage of shrub cover was an important structural component of forests with high densities of abundant birds. During winter, small patchy cover appeared to be more beneficial than a continuous shrub layer.