Over the last few decades, there has been a generally widespread increase in North American gull populations (e.g., see Conover et al. 1979, Am. Birds regional reports). Although this trend principally involves the commoner species, a number of extralimital species (i.e., “rarities”) also have been documented. However, the apparent increase in reported rarities exceeds that of the commoner species. This apparent increase is at least partly due to an increase in the number and expertise of field observers (see Fussell et al. 1982). A significant proportion (majority?) of these “rarities” are immature birds, notable in being difficult to identify (Fussell et al. 1982, Grant 1982, Farrand 1983). Recent identification articles (e.g. Gosselin and David 1975, Lehman 1980, Lauro and Spencer 1980) as well as the newer “sophisticated” field guides (e.g. Farrand 1983, Scott 1983) have greatly contributed to heightened observer awareness, resulting in increased discoveries of “rarities.” Thus, it should not be surprising to find that previously unrecorded species “suddenly” occur with regularity in small numbers. However, apparently sudden changes in status and distribution of a given species should be viewed with caution and, for each case, supported by a particular explanation should be provided.