Originally part of the flood zone of the Sacramento and Cosumnes rivers prior to the creation of levees, this IBA also protects patches of remnant valley riparian woodland dominated by Valley Oak, as well as several vernal pools. Designated only in 1994, Stone Lakes NWR protects nearly 20,000 acres of grassland, cropland and freshwater wetland habitat straddling I-5 just south of Sacramento (T. Harvey, in litt.). The refuge area represents a mosaic of public (state and federal) and private land, about a third of which is under cultivation. The Sacramento Regional County Sanitation District Bufferlands (The Bufferlands) extend 2,650 acres of habitat north toward metropolitan Sacramento, and Delta Meadows River Park (State of California) extends the habitat south into the Sacramento Delta, essentially contiguous with the vast Cosumnes River Preserve. Delta Meadows features a remnant Tidal Freshwater Swamp along the Sacramento River, which, though small, provided a model for The Nature Conservancy's efforts to restore a portion of the Cosumnes River Preserve (JT). Stone Lakes and the Cosumnes form a V around the southern border of the Sacramento-Elk Grove metropolitan area, and provide a critical buffer between the urban footprints of Sacramento and Stockton. Furthermore, Stone Lakes contributes strongly to the undeveloped land between the Sacramento Delta and the Sierra foothills via the Cosumnes River.
This IBA is known to support large numbers of waterfowl (at least 6000 per day in winter at Stone Lakes, generally 10,000+ at Bufferlands) and both migratory and wintering shorebirds (2000+ each Dunlin and Black-bellied Plover winter at Bufferlands, fide C. Conard). The Bufferlands have seen peaks of Canvasback of the 15-20,000 individuals, and Ring-necked Duck exceeding 2000 birds (C. Conard, via email). During surveys in 1998, Stone Lakes was found to support the largest breeding colony of Double-crested Cormorants (180 pr.) in the Central Valley (Shuford 1998a). A handful of Swainson's Hawks and Burrowing Owls breed here, and heron rookeries hosts around 300 birds at Stone Lakes and 75 pairs at Bufferlands (Great Egret, Great Blue Heron). It is likely that continued investigation of the area and the restoration of the native habitats (especially riparian vegetation) will reveal additional sensitive species utilizing the site. Important non-bird species documented from the area include Valley Elderberry Longhorn Beetle and Giant Garter Snake, both endemic to the Central Valley.
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Aside from the Bufferlands and the patchwork 4000 acres of Stone Lakes NWR, much of the habitat in this area is under severe threat, and it is not known whether the qualities of this IBA can withstand these pressures (fide B. Treiterer, pers. comm.). The main conservation issue in the region involves the conversion of "bird-friendly" grassland, pastureland, and cropland to comparatively sterile vineyards, which have already claimed thousands of acres of wildlife habitat in the area around Stone Lakes (and elsewhere in California). Exotic species, including Pepperweed and Water Hyacinth, continue to threaten grassland and marshy areas of the refuge. Finally, pesticide use remains at high levels in the area, and may be impacting bird reproduction. Fortunately, an active staff at Stone Lakes is working with local landowners to acquire their unwanted parcels and to establish conservation easements on surrounding lands. For the past ten years, Bufferlands has supported a major riparian/wetlands restoration ("Upper Beach Lake"), and similar work at Stone Lakes continues, in both cases with the help of numerous volunteers from the community.
Originally part of the flood zone of the Sacramento and Cosumnes rivers prior to the creation of levees, this IBA also protects patches of remnant valley riparian woodland dominated by Valley Oak, as well as several vernal pools. Stone Lakes NWR currently protects about 4000 acres (of a 20,000 project area) of grassland, cropland and freshwater wetland habitat. In addition, Delta Meadows features a remnant ?Tidal Freshwater Swamp? along the Sacramento River.
"Water-Open Water-Other" refers to "vernal pool"