Arctic gull recorded in Southern Calif.

A small white gull with an ordinary name had bird watchers flocking to the Salton Sea for what they call a "mega-rarity."

The Salton Sea, a 35-mile-long lake stretching across the Imperial and Riverside county line, is a popular stop for birds heading south, and Guy McCaskie, co-author of "Birds of Salton Sea," believed he spotted a Ross' gull there a week ago.

The appearance of the arctic bird nearly 100 miles east of San Diego would be the first reported in California and would place it hundreds of miles farther south than it had ever been seen.

The gull, which normally breeds in Siberia or Greenland, rarely appears south of Alaska, and is only spotted in even the northern part of the lower 48 states every few years.