ECOLOGICAL ASSOCIATIONS OF FEEDING SITES OF FERAL PIGS IN THE QUEENSLAND WET TROPICS

Data from 152 plots (0.8 ha) and 659 small quadrats (0.04 ha) were use d to assess rooting activity by feral pigs in forest communities in no rth Queensland. Study sites spanned the rainforest-sclerophyll-forest gradient along the western margin of the wet tropics region. Detailed floristic, physiognomic and edaphic data were recorded for each plot a nd used to develop a predictive model of pig activity in these habitat s. The most striking result was that rooting activity varied markedly among different forest types. Wet sclerophyll forests consistently had the greatest area disturbed, followed by mesic and dry sclerophyll fo rests. Both rainforest and rainforest-invaded sclerophyll forests had relatively low activity levels. There were some differences in rooting activity among different geographic regions, but few effects of local topography, soil type or proximity to water. A mathematical model was developed to predict the ecological associations of pig rooting activ ity, using generalised linear modeling. Pig rooting was associated wit h certain attributes of wet sclerophyll forests and with slopes and ri dge tops, but the model had limited effectiveness, with fitted values explaining 16% of the actual variation in rooting activity. This may h ave resulted because microhabitat preferences of pigs varied among dif ferent forest types and seasons. We suggest that pigs could be consumi ng fungal fruit-bodies in sclerophyll forests, and if so they may comp ete for food with some native, mycophagous mammals.