Mudflats

Mudflats 512 x 218

Most of the mudflat habitats are outside the main levees of Duck River and Busseltown Dewatering areas, and are influenced by TVA’s Kentucky Lake operation schedule. Under the current water control schedule the drawdown of Kentucky Lake from summer pool (359 MSL) toward winter pool starts around July 5 and steadily drops to winter pool (354 MSL) by December 1. By mid to late August the level typically drops approximately two feet. At this level water is completely off the willow-buttonbush zone, allowing woody plants and herbaceous perennials an opportunity to “breath” and seedlings to germinate. 

 

Annual plants, such as yellow nutsedge, germinate in areas where the sunlight is sufficient. Shorebirds and early migrating blue-winged teal readily utilize the newly exposed mudflats that are free of dense woody vegetation. The water level continues to drop throughout the fall, exposing vast areas of mudflats. Normally, during the fall the only habitat available to shorebirds on the refuge are the flats associated with Kentucky Lake. Annual grasses and sedges carpet these flats providing browse for geese and some species of ducks. This habitat is critical for early migrating geese that start arriving in late September because it is typically the only habitat available at this time of the year, since crop harvest has not yet been initiated. Throughout the fall and winter tens of thousands of green-winged teal, wigeon, and gadwall forage on these flats. 

 

During winter and early spring flood events many of the mallards, black ducks, and wood ducks will vacate the managed habitats in the bottoms to utilize the newly flooded moist-soil, willow-buttonbush, and bottomland hardwood habitats along the shoreline of the reservoir. Over 55% of the duck use and 48% of the goose use on the refuge is found to occur in the reservoir as opposed to the more intensively managed impoundments. 

 

The water schedule reverses on April 1 and the reservoir is allowed to quickly rise to summer pool by May 1. The willow-buttonbush zone is again flooded providing excellent wood duck brood habitat, as well as habitat for many other species of birds, reptiles, amphibians, and mammals. This habitat is also essential for spawning and fry survival for many species of fish.