Here we report on several lines of evidence that lead us to suspect the anthropological extinction of the woodrat Neotoma bunkeri Burt from Isla Coronados, Mexico. This species is represented by only six adult specimens housed at the Museum of Systematic Biology, UCLA, and appeared to be unique in that it had attained a very large body size relative to other insular or mainland woodrats. Our analysis suggests that depletion of food resources and/or the presence offeral cats have led to the decline. Similar combinations of habitat destruction and predator introduction on other small islands in the Gulf of California are probably endangering many extant insular populations, and may ultimately lead to the extinction of an array of unique flora and fauna.