The Pacific Flyway is one of four major North American migration routes for birds, especially waterfowl, and extends from Alaska and Canada to Mexico.
The migrating birds follow ancestral patterns as they move south annually through California to Mexico and beyond.
In California, wetlands provide critical wintering habitat for millions of these birds including geese and ducks. The open water and vegetation in wetlands provide food, rearing areas and cover for waterfowl and shorebirds. In addition to Oregon’s Klamath Basin, major California wetlands along the flyway include San Francisco Bay, Mono Lake, Suisun Marsh, those in the Central Valley and the Salton Sea.
The Central Valley is the most important waterfowl wintering area in the Pacific Flyway, supporting about 60 percent of the total population.
The Sacramento-San Joaquin Delta, the largest estuary on the West Coast, plays an important role as well. It supports hundreds of species of birds that travel along the Pacific Flyway, including millions of traveling ducks and geese on the north-south migration route.
In the Southern California desert, the Salton Sea also provides an important Pacific Flyway stopping point, serving as a jumping off pont for roughly million birds migrating south.