Black Skimmers (Rynchops niger) have been observed on south San Francisco Bay during the nesting season since the late 1970s (Bailey et al. 1992, LeValley and Evens 1982, San Francisco Bay Bird Observatory unpubl. data, Winter and Manolis 1978, Yee et al. 1992), but nesting was never documented. They have nested in southern California since 1972, when five nests were discovered at the Salton Sea (McCaskie et al. 1974). The northernmost previously recorded nesting of the Black Skimmer in California was inland, at the Tulare Lake Basin in Kings County during the summer of 1986 (Erickson et al. 1986).