| Twelve linear models for estimating feral pig population density were generated from data on feral pig sign and densities collected in 5 habitat types in Hawaii. Densities were back-calculated from population reconstructions with data collected from pigs eradicated within fenced units. Indices to feral pig populations included frequency of pig digging, scats, tracks, plant feeding, beds, and rubs. Three age classes of sign were recorded. Sampling intensity ranged from 50 to 310 plots/km^2 in the 5 areas. Significant models for fresh digging exhibited considerable variability in the densities predicted, probably dependent on substrate available for digging. Densities predicted from fresh scat models were consistent in 2 areas, but models failed to predict densities in the other 3 areas. The model for all fresh sign encompassed variability in all habitats sampled and gave the most precise predictions across habitats. None of the models was useful at population densities of |
