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Appendix B Concept Plan for the Nature Preserve Rancho San Joaquin Project Background The project site lies in the area of the pristine flood plain of the San Joaquin River, and before this area was diked and drained, it was a mosaic of permanent and temporary ponds, interconnecting sloughs, and extensive marsh land. Lying just east of the foothills of the Innercoast Range, the eastern Tracy area provided the first view of the great Central Valley marshland for travelers as they made their way east over the Old Patterson Pass Road from the Livermore Valley. Today, nearly all of the wetland riparian habitat of the Central Valley has vanished, and only in small remnant areas such as Caswell State Park near Ripon, California, may one glimpse its true former splendor. A second site which lies relatively close to the project area and which has preserved a small segment of riparian wetlands is South County Park at the junction of Airport Way and Division Roads. This park plus the belt of riparian edge which still persists along the nearby San Joaquin River makes the concept of creating a riparian wetland area on the project site a most meaningful one. Besides recreating a small portion of the ecosystem which once dominated this area, it will, if properly designed, help to offset'the ongoing loss of water bird wetland habitat which is the single most important wildlife problem presently facing the Central Valley. It would also help to preserve rapidly dwindling fish and amphibian species such as the Sacramento perch, tule perch, red-legged frog, and California tiger salamander. Habitat Design Listed below are the water bird species for which the habitat of the Rancho San Joaquin Nature Preserve should be designed and the reasons for these choices. 1. Ducks: Mallard Cinnamon Teal, Northern Shoveler,Ruddy Duck Each year more pairs of these species remain in the greater wintering grounds of the Central Valley and breed in scattered pond and slough areas. The Mallard and Cinnamon Teal have become very common summer residents in the greater Tracy area during the past several decades. In the face of continuously dwindling numbers of all waterfowl species, the addition of another breeding site for these ducks would be most significant. Habitat Requirements: All duck species are highly territorial at breeding time. Territories are intraspecific areas which are defended by the drake through the egg laying process. Each pair of each species will defend a feeding pond site where they will feed and breed daily. The nest of all but the Ruddy are located in dense grass or marsh vegetation well away from the shoreline of such pond sites. The Ruddy Duck builds its nest in emergent vegetation over water. The ponds themselves may be relatively small (0.5 acres minimum) since all but the Ruddy Duck can take off directly from the water surface without the necessity of an aquatic runway. Because the Ruddy Duck is among the smallest of our duck species, it does need only a short (50 ft.) water path for take off which can easily be provided by a small pond and a connecting slough or canal. 36