Sutter National Wildlife Refuge, the southernmost refuge in the

Sacramento National Wildlife Refuge Complex The Sacramento National Wildlife Refuge Complex is part of the United States system of National Wildlife Refuges (NWR). It is located in northern California, in the valley of the Sacramento River. The Sacramento NWR Complex was created in an att ...

, is located in the Sacramento Valley of

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

, about north of the metropolitan area of

Sacramento ) , image_map = Sacramento County California Incorporated and Unincorporated areas Sacramento Highlighted.svg , mapsize = 250x200px , map_caption = Location within Sacramento ...

. The refuge consists of about , consisting primarily of

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...

impoundments with some

riparian A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks a ...

and

grassland A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...

habitat. About 80 percent of the refuge is located in the Sutter Bypass, a floodwater bypass from the

Sacramento River The Sacramento River ( es, Río Sacramento) is the principal river of Northern California in the United States and is the largest river in California. Rising in the Klamath Mountains, the river flows south for before reaching the Sacramento� ...

that floods at least once a year and may cover portions of the refuge with up to of water. Sutter Refuge typically supports wintering populations of more than 175,000

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form ...

s and 50,000

geese A goose ( : geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera '' Anser'' (the grey geese and white geese) and ''Branta'' (the black geese). Some other birds, mostly related to the she ...

. The mixed riparian forest habitat on the refuge is important for breeding and migrating

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by th ...

birds, and supports a large heron/

egret Egrets ( ) are herons, generally long-legged wading birds, that have white or buff plumage, developing fine plumes (usually milky white) during the breeding season. Egrets are not a biologically distinct group from herons and have the same build ...

rookery A rookery is a colony of breeding animals, generally gregarious birds. Coming from the nesting habits of rooks, the term is used for corvids and the breeding grounds of colony-forming seabirds, marine mammals ( true seals and sea lions), and ...

. The refuge provides habitat for several Federal and State

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

and

threatened species Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of '' critical depen ...

, including

giant garter snake The giant garter snake (''Thamnophis gigas'') is the largest species of garter snake. Relatively rare, it is a semi-aquatic snake with a limited distribution in the wetlands of central California. Description The giant garter snake is the larges ...

, winter-run

Chinook salmon The Chinook salmon (''Oncorhynchus tshawytscha'') is the largest and most valuable species of Pacific salmon in North America, as well as the largest in the genus '' Oncorhynchus''. Its common name is derived from the Chinookan peoples. Other ...

yellow-billed cuckoo The yellow-billed cuckoo (''Coccyzus americanus'') is a cuckoo. Common folk-names for this bird in the southern United States are rain crow and storm crow. These likely refer to the bird's habit of calling on hot days, often presaging rain or th ...

, and

Swainson's hawk Swainson's hawk (''Buteo swainsoni'') is a large bird species in the Accipitriformes order. This species was named after William Swainson, a British naturalist. It is colloquially known as the grasshopper hawk or locust hawk, as it is very fond ...

References

Refuge profileRefuge website
{{authority control National Wildlife Refuges in California Wetlands of California Grasslands of California Protected areas of Sutter County, California Landforms of Sutter County, California