Estimating sizes of wild pig populations in the North and Central Coast regions of California

摘要: We developed a mark-sighting approach with automatic camera systems and assessed the size density of wild pig (Sus scrofa) populations in North Central Coast regions California 1994 1995. Eighty 149 pigs were captured tagged at 4 6 study sites 1995, respectively. Of those animals, 202 (88%) subsequently sighted among over 3,000 photographs obtained from 54 stations. Sighting rates for both nontagged similar between years averaged 2.8 ± 0.5 0.4 pigs/camera-station night, all during 5.7 0.8 night. Mark-sighting data analyzed program NOREMARK provided estimates population size, narrow 95% confidence intervals (95% CI) most research suggested we sufficient sightings reliable populations. It also proved possible to identify determining minimum sizes, CI encompassed sizes 8 10 sites. An important factor influencing reliability was proportion animals resighted. At one site where few sighted, CIs large did not encompass estimate. Mean densities ranged 0.7 3.8 pigs/ km 2 , comparable previous on studied. Densities increased potentially related higher rainfall forage availability Also, lower areas relatively high hunting pressure, suggesting that sport may be effective reducing numbers some areas.