Sacramento National Wildlife Refuge Complex - Ecology

Ecology

The water flows in the refuge have to be controlled artificially, and the vegetation has to be managed actively through irrigation and burning, to ensure that the wetlands remain productive, and provide adequate food and resting places for the birds. Between them, the refuges provide a range of habitats: seasonal marshes, uplands, permanent ponds, and riparian areas.

The refuges are provided with facilities for visitors, though these have to be limited to avoid conflict with their primary purpose of conservation. The layout of the wetlands has been planned to allow visitors a good view of the birds while minimising the risk of disturbance to them. There is a visitor's center at the Sacramento NWR, and routes for car tours on the Sacramento and Colusa sites, though visitors are allowed to leave their cars only at selected sites. There are walking trails at both those sites and also at the Sacramento River site. Limited hunting is permitted on some of the sites.

Over 300 species of birds and mammals use the refuges, not all of them migratory. Among those most likely to be seen by visitors (depending on season) are:

• Grebes: Pied-billed Grebe, Eared Grebe
• Pelicans, Cormorants: American White Pelican, Double-crested Cormorant
• Herons etc.: American Bittern, Great Blue Heron, Great Egret, Snowy Egret, Black-crowned Night Heron, White-faced Ibis
• Ducks and geese: Mallard, Pintail, American Wigeon, Cinnamon Teal, Green-winged Teal, Bufflehead, Northern Shoveler, Ring-necked Duck, Wood Duck, Snow Goose, White-fronted Goose, Ross's Goose
• Raptors: Turkey Vulture, Osprey, White-tailed Kite, Northern Harrier, Red-tailed Hawk, American Kestrel, Golden Eagle, Bald Eagle (the eagles are not common, but there is a chance of seeing them).
• Waders and other shorebirds: Ring-necked Pheasant, Virginia Rail, Sora, Common Moorhen, American Coot, Killdeer, Black-necked Stilt, American Avocet, Greater Yellowlegs, Western Sandpiper, Least Sandpiper, Dunlin, Long-billed Dowitcher, Wilson's Snipe
• Gulls etc.: Ring-billed Gull, Herring Gull
• Pigeons and doves: Mourning Dove
• Owls: Great Horned Owl, Barn Owl
• Woodpeckers: Nuttall's Woodpecker, Northern Flicker
• Passerines: Western Kingbird, Yellow-billed Magpie, Tree Swallow, Cliff Swallow, Barn Swallow, Marsh Wren, Ruby-crowned Kinglet, European Starling, American Pipit, Yellow-rumped Warbler, Common Yellowthroat, Savannah Sparrow, Song Sparrow, Lincoln's Sparrow, White-crowned Sparrow, Golden-crowned Sparrow, Dark-eyed Junco, Red-winged Blackbird, Western Meadowlark, Brewer's Blackbird, Brown-headed Cowbird, Bullock's Oriole, House Finch, House Sparrow
• Mammals: Black-tailed Jackrabbit, California Ground Squirrel, Black-tailed Deer.

The Sacramento National Wildlife Refuge Complex boasts a diverse flora, even though large amounts of the historic wetland has been destroyed. Among the diverse wildflowers present is the Yellow Mariposa Lily, Calochortus luteus.