For all those adventurous travelers, I just verified with Justyn that I did see a Black-headed Gull today at the Salton Sea SRA headquarters north shore. It was on a strip of sand divided from the beach north of the lagoon inlet with several Bonaparte’s Gulls. It flew about 300 yards out into the sea and swam around. I posted on eBird with screenshot pictures. I probably looked at close to 1000 Bonaparte’s before finding it so patience is a virtue.
Source: SanDiegoRegionBirding Latest Reports