A project to study the feasibility of eradicating feral pigs (Sus scrofa) from a 2,250-ha exclosure was initiated June 1989 by The Nature Conservancy through cooperative agreements with the University of California and the California Department of Fish and Game. The cost and effectiveness of 3 methods were evaluated: (1) trapping, (2) hunting without dogs, and (3) hunting with dogs. As of October 1990, we had removed a total of 1,421 pigs from the pasture at a cost of $87,000. No pigs were known to remain. Trapping appeared to be the most efficient method at high to moderate densities but a small percentage of pigs was trap-shy. We recommend a multi-method, seasonal approach to feral pig eradication on Santa Cruz Island. We also evaluated an aerial census method for monitoring pig density. A pre-eradication aerial census produced an estimate (90% confidence limits) of 907 ? 284 pigs (39.4 ? 12.3 pigs/km2}. A post-trapping phase aerial census yielded an estimate of 158 ? 90 pigs (7 .0 ? 4 pigs/km2). Based on population reconstruction derived from age estimation of removed pigs, the actual pig numbers at the time of each census were 1,379 (60.9pigs/km2} and 174 (7.7 pigs/km2}, respectively. The aerial estimates thus deviated from the population reconstruction estimates by 34% and 9% at the high and low densities, respectively.
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