The distribution and abundance of ants on islands has attracted considerable attention from ecologists and biogeographers, especially since the classic studies by Wilson on the ants of Melanesia and the Pacific islands (Wilson 1961; Wilson and Taylor 1967a,b; see also updates by Morrison 1996, 1997). The species-area curve for Polynesian ants was an important contribution in the development of island biogeography theory (MacArthur and Wilson 1967). Subsequent studies of other island ant faunas, such as those of the Caribbean (Levins et al. 1973; Wilson 1988; Morrison 1998a,b), Japan (Terayama 1982a,b, 1983, 1992), Korea (Choi and Bang 1993; Choi et al. 1993), and island archipelagos in Europe (Baroni Urbani 1971, 1978; Pisarski et al. 1982; Vepsäläínen and Pisarski 1982; Ranta et al. 1983; Boomsma et al. 1987) and North America (Goldstein 1976; Cole 1983a,b), have confirmed the general features of this relationship, although the underlying causative agents and the relative contribution of stochastic and deterministic processes to ant community composition remain points of controversy. The islands in the Sea of Cortés are particularly interesting from a biogeographic standpoint because they vary considerably in size, topography, and isolation. In addition, both oceanic and landbridge islands occur in the gulf, allowing comparisons between faunas that resulted from colonization (assembly) versus relaxation. Nevertheless, the ant assemblages of the gulf islands have received little study. There are a few scattered island records in taxonomic and faunistic papers (Smith 1943; Cole 1968; MacKay et al. 1985). Bernstein (1979) listed 16 ant species from a total of nine Gulf of California islands, but a number of evident misidentifications occur in her list. To the best of our knowledge, no other publications have appeared on the ant communities of these islands. In this chapter, we document the ant species known from islands in the Sea of Cortés and analyze species composition in a selected subset of the better sampled islands. Most of the data come from recent collections made within the last two decades.
Island Specialists: Shared Flora of the Alta and Baja California Pacific Islands