The Empidonox flycatchers (Alder, Willow, Hammonds, Dusky, Yellow-bellied and Grey) are very similar in appearance. In some locations such as California the different ranges are very helpful by eliminating most of them. The minimal white eye ring and the range identified this as the Willow Flycatcher Empidonax traillii
These were photographed at the Shipley Nature Center in Huntington Central Park, Huntington Beach, CA. They are distinguished from the very similar Western Wood Pewee by having shorter wings that just reach the base of the tail. In the Western Wood Pewee the wings reach further down the tail. The range of the Willow Flycatcher includes multiple enclaves along the California Coast.