… The vast majority of Tricolored Blackbirds spend their whole lives in California. A handful breed in Oregon, Washington, Nevada, and Baja California, and at least 20 of the birds were spotted last year in Idaho. Most, however, nest in the San Joaquin Valley, and many are known to breed a second time in the early summer months—often 50 to 100 miles north in the wetlands and willows of the Sacramento Valley. It’s here, too, that the birds feed on rice in the fall. They often browse the paddies alongside other blackbirds—including the very similar Red-winged Blackbird—that farmers can legally cull as pests. This has inevitably led to losses of Tricolors over the years.      Although the species’ native nesting habitat has been almost entirely removed from California, they’ve adapted with varying success to shifting land use. Where vineyards and orchards have replaced grassland and marsh, the blackbirds have mostly disappeared.

Related article: 

• California State Parks – News release: California State Parks Begins General Planning Process for Great Valley Grasslands State Park