Northern Prairie Wildlife Research Center
The six national wildlife refuges of the Sacramento National Wildlife Refuge Complex lie like a small oasis in a sea of agriculture in the Sacramento Valley. The valley is bordered east and west by the Sierra Nevada and the Coast Mountain Ranges.
The refuges - Sacramento, Delevan, Colusa, Sutter, and Butte Sink - cover some 24,000 acres of grassland, marshes, ponds, and seasonal wetlands. They are located 50 to 90 miles north of Sacramento, California. The Butte Sink NWR is an important sanctuary and is closed to the public.
The sixth refuge - Sacramento River NWR - is currently being acquired. Riparian and wetland habitats will be located intermittently along the Sacramento River from the city of Red Bluff south to Colusa.
These refuges represent a small portion of the vast grasslands, seasonal marshes, and permanent ponds that once existed in the Sacramento Valley. Millions of migratory waterfowl and other water birds wintered here with deer, elk, pronghorn, and grizzly bear.
Today, most of the wetlands are gone, having been drained and reclaimed for agriculture. Levees were constructed to confine rivers for flood control and irrigation. Gone too, are the pronghorn, elk, and grizzly bear; however, some of the most spectacular concentrations of waterfowl on the continent can still be seen. These are among the most intensively managed wildlife refuges in the nation.
Havens for Wintering Waterfowl
Many of the ducks wintering in the Sacramento Valley are produced in Alaska and the prairie pothole region of North America. Most of the geese migrate from Alaska and the Canadian arctic. Ducks begin arriving during August and are joined by geese in September and October. Numbers may exceed two million by December after the wetland areas of the Klamath Basin and other areas to the north become frozen.
Pintails, mallards, wigeon, northern shoveler, snow, Ross's, and white-fronted geese are most commonly seen during these months, but the careful observer can find many others. Waterfowl numbers gradually decline in February and March when they return to their northern breeding grounds.
Habitat Diversity Attracts Birds and Other Wildlife
Although managed mainly for migratory waterfowl, the refuges are also attractive to other wildlife. The marshes, with readily available fish, frogs, and invertebrates are attractive to grebes, white pelicans, egrets, herons, and bitterns. Shorebirds probe the mud for seeds, snails, and worms. Raptors find an abundance of waterfowl, rodents or small birds on which to feed. Woodpeckers, warblers, and other songbirds feed and nest in the cottonwoods and willows bordering the waterways and creeks. Deer and jackrabbits graze in the grasslands and on edges of wetlands.
Scientific names are included with the mammal, reptile, amphibian and fish species since their common names may vary with locality.
Mammals ___ Opposum (Didelphis marsupialis) c ___ Vagrant Shrew (Sorex vagrans) r ___ California Myotis (Myotis californicus) u ___ Red Bat (Lasiurus borealis) u ___ Hoary Bat (Lasiurus cinereus) u ___ Pallid Bat (Antrozous pallidus) u ___ Mexican Free-tailed Bat (Tadarida brasiliensis mexicana) u ___ Big Free-tailed Bat (Tadarida molossa) u ___ Desert Cottontail (Sylvilagus audobonii) r ___ Black-tailed Jackrabbit (Lepus californicus) c ___ Beechy Ground Squirrel (Callospermophilus beecheyi) c ___ Botta Pocket Gopher (Thomomys bottae) u ___ Western Harvest Mouse (Reithrodontamys megalotis) u ___ Deer Mouse (Peromyscus maniculatus) u ___ California Vole (Microtus californicus) u ___ Muskrat (Ondatra zibethicus) c ___ Black Rat (Rattus rattus) c ___ Norway Rat (Rattus norvegicus) c ___ House Mouse (Mus musculus) c ___ Coyote (Canis latrans) u ___ Red Fox (Vulpes fulva) u ___ Gray Fox (Urocyon cinereoargenteus) r ___ Ringtail (Bassariscus astutus) r ___ Raccoon (Procyon lotor) c ___ Mink (Mustela vison) r ___ Western Spotted Skunk (Spilogale putorius) r ___ Striped Skunk (Mephitis mephitis) c ___ River Otter (Lutra canadensis) r ___ Black-tailed Deer (Odocolieus hemionus columbianus) c ___ Beaver (Castor canadensis) c
Refuge Manager Sacramento National Wildlife Refuge 752 County Road 99 West Willows, California 95988 Telephone: 916/934-2801
No person shall, on the basis of race, color, sex, age, national origin, religion, physical or mental restrictions, be excluded from participation in, denied the benefits of, or be otherwise subjected to discrimination in any program or activity of the Department of the Interior.