Surveys of Santa Cruz Island in April, May and June of 1966 recorded 27 species of butterflies. Records from other surveys add another 6, for a total of 33 species. This is less than half the number that would be found in comparable habitats on the adjacent mainland at the same times of year. Only one endemic subspecies was found, all others being weil documented on the mainland. Several species were present in much greater numbers than usually noted in coastal California, probably due to lack

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... f competition. Other species of ubiquitous or very common occurrence on the mainland were not found at all on the island. This correlates with other offshore islands having vrying degrees of faunal reduction, often depending upon thenisolation from continental land masses. In addition, the native flora and fauna on S.C.I. may be due to the abundance of domestic and feral animals, combined with the introduction of European-type weeds.