The Black Skimmer (Rynchops niger) feeds strictly in shallow inshore waters, alone or in small groups (Erwin 1977a). Its diet is narrow; in Virginia, silversides (Menidia spp.) and killifishes (Fundulus spp.) make up 90% of its prey (Erwin 1977b). Both its feeding method and efficiency have been reported (Irby 1951, Tomkins 1951, Zusi 1959), but until recently little was known about its nocturnal feeding behavior (Gochfeld and Burger 1994).
Black Skimmers have recently colonized southern California (McCaskie et al. 1974, Palacios and Alfaro 1992) and the Gulf of California (Massey and Palacios 1994). They are now not rare along the Baja California peninsular coast (Palacios and Alfaro 1992, Carmona et al. 1995).