Yolo Bypass Wildlife Area

The Yolo Bypass Wildlife Area is a natural haven for numerous species of birds, bats and other Sacramento Valley wildlife. Most wetland in the wildlife area are managed as seasonal wetlands. They go through an extensive dry period during the spring and summer months. Typically, these ponds are drained on April 1 to stimulate the germination of Swamp Timothy. They may receive a brief summer irrigation and then be flooded in September to provide wetland habitat for migratory waterfowl and shorebirds. Permanent wetlands are flooded year round and tend to be deeper and have more emergent vegetation. These ponds provide important brood water for resident aquatic birds such as mallards, common moorhens and pied-billed grebes. They also provide drinking water for wildlife as well as relief from intense summer heat. This habitat is used extensively for roosting by black-crowned night herons, egrets, and white-faced ibis. Hundreds of thousands of Mexican Free-tailed Bats roost and breed under the Highway 80 overpass adjacent to the Wildlife Area and can be seen leaving their roost at dusk.

Common Residents and Breeding Birds: Black-Necked Stilts, American Avocets, Double-Crested Cormorants, American Coot, Common Gallinule, Pied-billed Grebes, Mute Swans and American White Pelican along with Great and Snowy Egrets and Great Blue and Black-crowned Night Herons and White-faced Ibis. You are likely to find Mallard, Northern Shoveler, Gadwall, and Cinnamon Teal throughout the year. Ring-necked Pheasants and Western Meadpwlarks breed in the grasslands. Virginia and Soras along with numerous Marsh Wrens and blackbirds are abundant and can be heard and often observed in the marshes along the Auto Route. California and Ring-bird Gulls visit regularly. Northern Harrier, American Kestrel, White-Tailed Kites, Red-tailed and Red-shouldered Hawks, Great Horned Owls and Turkey Vultures are some of the raptors that visit the marshes and frequent the riparian willow groves.  Anna’s Hummingbirds nest in the park, as do Kingfishers, Morning Doves, Black Phoebes, Common Yellowthroats, House Finch, Song and Savanah Sparrows, along with Brewer’s and Red-winged Blackbirds and Great-tailed Grackles.

Migrants: Green-Winged Teal, Northern Shoveler, Northern Pintail, Ruddy, and Bufflehead are frequent visitors during the winter months. Greater and Lesser Yellowlegs, Least and Western Sandpipers, Long-billed Dowitchers, Dunlin, Long-billed Curlews, Semipalmated and Black-bellied Plovers, all visit during the Fall Migration and some of these shorebirds stay into November. It is easy to spot a Say’s Phoebe feeding along the marshes edge and White-crowned, Golden-crowned, Lincoln’s Fox and Swamp Sparrows and numerous Western Meadowlarks visit during the fall, winter and early spring months.