Fig 1.
Study region in northern Australia.
The study region is shown in grey. Locations of the independent distributional data sets used for model validation are shown in colour.
Fig 2.
Wild pig habitat suitability model.
Resource quality indices for each habitat variable were modelled in Bayesian networks. Spatial pattern suitability analysis was used to compute resource suitability indices as a weighted function of distance to resource patches (fDr). Habitat suitability was modelled in another Bayesian network. An average habitat suitability index was computed and mapped from six individual expert models. Bar graphs show expert-elicited conditional probabilities and values below graphs show modelled index values ± standard deviation. Probabilities and indices change once evidence about the states of each explanatory variable at a given study area pixel is inserted (i.e. prior probabilities are no longer uniformly distributed).
Fig 3.
Expert-elicited resource suitability in response to distance.
Resource suitability indices (SIr) were computed from elicited response-to-pattern curves (fDr) for each of the four habitat variables in the model: water (A), food (B), heat protection (C) and disturbance protection (D). Curves cross the x-axis at different points because experts defined different home range boundaries.
Table 1.
Model explanatory variables and spatial data proxies.
Table 2.
Validation data sets with ancillary information.
Fig 4.
Sensitivity of habitat suitability to four habitat variables and expert opinion.
Sensitivity to findings was calculated as % variance reduction for each individual expert model and an averaged model (red bar and percentages).
Table 3.
Validation metrics for individual expert and averaged seasonal habitat suitability models.
Fig 5.
Validation plots for individual expert and averaged seasonal habitat suitability models.
Validation was performed against four validation data sets per seasonal scenario (Table 2). The predicted-to-expected (P/E) ratio (y axis) measures the proportion of wild pig presences relative to the proportion of background pixels on a continuous scale of predicted HSI (x axis).
Table 4.
Amount of wild pig habitat in each habitat suitability index class per seasonal scenario.
Fig 6.
Seasonal habitat suitability for wild pig breeding in northern Australia.
Habitat suitability indices were averaged across all expert models and mapped for a wet (March/April–A) and dry (October/November–B) season scenario.
Fig 7.
Share of modelled suitable habitat found in different vegetation types and land use classes for each seasonal scenario.
For each vegetation (panel A) or land use (panel B) category, we show its percent share of highly (HSI ≥ 60) and very highly (HSI ≥ 80) suitable habitat during the dry (top bars) or wet (bottom bars) season, compared to its percent share of the total study region (central bars). Spatial analyses in panel (A) were based on Present Major Vegetation Groups (MVG V.4.1) and analyses in panel (B) on Australian Land Use and Management classes (ALUM V.7).