The Short-billed Dowitcher Limnodromus griseus and Long-billed Dowitcher Limnodromus scolopaceus share the a similar geographical range and are so similar in appearance that they are often just referred to a Dowitchers. They are best distinguished by their call. The Short-billed Dowitchers have a "tu-tu-tu" call while the Long-billed Dowitcher has a "keek-keek" then trills. These were photographed on the mud flats of the San Joaquin Wildlife Sanctuary, Irvine, CA. Based on the call I have called these Short-billed Dowitchers.
In January a visit to San Joaquin showed Dowitcher with perceptibly longer bills which I suspect are Long-tailed Dowitchers (0201, 0517, 0411)
A motion picture of the flock shown (0432) is available in on the movie page. One doesn't realize how noise polluted our skies are, especially next to the John Wayne Airport, until we try to record bird sounds. I have deleted the airplane noises and left in the few rare bird songs. Then in the latter part of the movie I have dubbed in the Short-billed Dowitcher calls from the iPhone iBird Explorer Western app.