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the Delta during mid-winter. Most breed in northern California and winter in the southern half of the state and the west coast of Mexico. The seasonal wetlands produced in winter in the Great Valley support 25% of North America's waterfowl populations, and over 60% of those waterfowl found in the Pacific Flyway (Heitmeyer et. al. 1989). Although Tracy Lakes do not provide water depths (after flooding) that are suitable for feeding waterfowl, they do provide important loafing habitat. Diving species such as canvasback (Aythya valisineria), ring-necked ducks (A. collaris), and scaup (Aythya sp.) are regularly found on both lakes. During the short period of shallow inundation (mid-December through mid-January), puddle ducks can forage on seeds and tubers from emergent water plants. The majority of the lake becomes unusable to dabblers once water elevations reach 14+msl. The lake bottom varies in height from 7.5 to 10+ feet msl. Appendix B lists those migrant species that have been observed on the ranch. Sandhill Cranes. There has been some speculation that greater sandhill crane (Gros canadensis tabida) regularly utilize the Buckeye Ranch and although observers have recorded the species from the ranch, nearly all observations are of birds flying overhead. Sandhill cranes do readily utilize the irrigated pastures and open farmland around Buckeye Ranch for three reasons: cranes are species of open country; they require open vistas for detection of predators; and they find the tubers, seeds, and animal life that make up their diet on the wintering grounds. Two major winter roosts of sandhill cranes can be found within 6 miles of Buckeye Ranch. The furthest, is on Bract Tract where they roost on flooded farmlands and the Woodbridge Ecological Reserve. Winter Christmas counts regularly document between 8,000 and 15,000 birds utilizing the tract (Engilis unpubl. data). The second, and much closer roost Buckeye Ranch Resource Plan (November, 1993) 56