The diverse habitats of the Odessa Complex support 240 species of birds (including 26 species of ducks and geese), 36 species of mammals, 31 species of reptiles and amphibians, and 29 species of fish. This rich assemblage of wildlife in the Complex is an indication of both the quality and quantity of suitable habitats that lie within the confines of Odessa.
Silver maple dominates most forest stands on the Odessa Complex as the result of high mortality on less flood tolerant species after the 1993 flood and other high water events since. Many of the silver maple stands are young and extremely thick. Cottonwood is another flood tolerant species found widespread on the area. There are still stands of pin oak, swamp white oak, bur oak, pecan, and shellbark hickory scattered throughout the area although these species were hit hard by the floods. River birch, ash, willow, sycamore and mulberry make up most of the rest.
Timber stand improvement projects are being carried out in several locations across Odessa to help expand the oak/pecan/hickory component because of their tremendous value to wildlife. Forest areas are important to deer, wild turkey, raccoons, squirrels, numerous songbirds as well as waterfowl and bald eagles.
These areas are dominated by buttonbush (locally called buckbrush), which is a water-tolerant shrub that can form impenetrable thickets. Huge areas of Odessa were once covered in this habitat, but floods and years of high water have greatly reduced its coverage. It requires dry conditions in consecutive years to re-establish over any significant coverage. It is a heavily used habitat of waterfowl and the state endangered copperbelly water snake.
These areas have stands of robust perennial wetland plants such as cattails, bulrush, lotus, arrowhead or bur-reed. This type of wetland covered most of Odessa in the 1940's. Now this habitat is mainly restricted to shallower parts of the refuge although some beds of lotus occasionally cover small areas on the state-managed portion. After drawdowns, some scattered bulrush and arrowhead is seen interspersed with the moist soil annual plants. This habitat is important to bitterns, rails, waterfowl, muskrats and various reptiles and amphibians.
Shallow, Open Water:
Most of the water area of Odessa is made up of this habitat. Its value is mainly for fish and fish eating birds like pelicans, herons, egrets and bald eagles. During drawdowns, much of this area can be transformed into highly productive wildlife habitat by first transitioning to mud flats and then later to moist soil plants.
These areas are usually a transitional stage between shallow open water and moist soil plants, although they are sometimes covered back up by water before plants can germinate and grow. They are important to shorebirds that hunt and eat invertebrates found there.
Moist Soil Areas:
These are areas usually covered by water early in the spring but slowly dry out in late spring or summer. They are characterized by an abundance of annual, seed-producing plants adapted to grow in moist soils. Some common moist soil plants include smartweeds, wild millets, nutsedge, and pigweeds. When re-flooded in the fall, these areas are heavily used by rails early in the season and then more intensively by waterfowl as the season progresses. In the springtime, these same areas have an explosion of invertebrates which feed on the decaying plants from the previous year. For ducks in migration this provides a valuable source of protein which helps to build energy reserves and produce eggs. There are approximately 1,000 acres of this habitat within the Complex in those years when a normal drawdown is possible. The refuge more intensively manages several isolated moist soil units by means of water control structures, stand-alone and tractor-powered pumps, and gravity flow through the system.
Several fields are actively managed for wildlife both in the refuge and at the far south end of the state managed portion. The refuge has a few elevated fields that have been seeded to prairie and others that are annually seeded to winter wheat for use by migrating geese. The state-managed portion has some native grass established in small fields near the Toolesboro access road, and others are seeded to winter wheat and ladino clover for use by deer and turkeys.