I’m inclined to think this is a dark-eyed junco singing. At least that’s what I’d think if I heard that where I live, and I think DEJUs should also live where you made this recording. But it’s possible there’s some other species I don’t know that sounds similar.
I guess? I don’t know the vocalizations of those various bigger shorebirds well enough to be confident based on what I can hear in the video, and I’m not seeing enough detail to be sure. But if they were biggish, brownish shorebirds in the San Diego area, then yeah, Long-billed Curlew is a likely suspect.
Other possibilities would be Whimbrel or Marbled Godwit. But I think these sound more like the Long-billed Curlew vocalizations I was just listening to in my Sibley app than either of the other two species.
Thank you for the excuse to birdwatch. Always worthwhile! :-)
