Figure 1.
The Ndoki-Likoula Conservation Landscape.
A - Geographic location, B - Main vegetation types, and C - Land-use types and human access features.
Table 1.
Socio-economic and management features of the Ndoki-Likouala Conservation Landscape.
Table 2.
Hypotheses and predictions tested for spatial distribution of ape nest and elephant dung counts.
Table 3.
Elephant dung density (Dung piles/km2) and individual elephant density (Inds/km2) with 95% confidence intervals (95% CI) and percent coefficient of variation (%CV) for each survey stratum and for the landscape.
Table 4.
Great ape nest density (Nests/km2) and individual density (Inds/km2), 95% confidence intervals (95% CI) and percent coefficient of variation (%CV) for each survey stratum and for the landscape.
Figure 2.
Elephant and ape density by habitat type.
A – Elephant density, B – Great ape density; Clearing = natural forest clearings (bais and yangas) and light gaps, Swamp = swamp forest, Closed/Open TF = Closed-canopy or Open-canopy terra firma forest, Mono. = monodominant Gilbertiodendron forest.
Figure 3.
Estimated conditional dependence of sign densities on landscape covariates.
Estimated conditional dependence of Elephant dung density (left column), Gorilla nest density (middle column), and Chimpanzee nest density (right column) on distance to the NNNP boundary (first row), distance to roads (second row), distance to settlements (third row), logging history (fourth row), distance to bais (fifth row), and density of yangas (sixth row). Estimates (solid lines) and confidence intervals (dashed lines), with a rug plot indicating the covariate values of observations (short vertical bars along each x-axis), are shown are shown. Y-axis scale can vary between species for a particular covariate.
Table 5.
Results of the Generalized Additive Model analysis.
Figure 4.
Predicted density surfaces from final composite models.
A - Elephant dung density (Distance to bais, density of yangas, distance to roads, distance to NNNP boundary, stratum, Y coordinate), B - Gorilla nest density (Distance to NNNP boundary, stratum, X coordinate), and C - Chimpanzee nest density (Distance to NNNP boundary, distance to roads, stratum, Y coordinate). Density surfaces displayed in ArcGIS 9.2 (ESRI, Redlands, USA) using a Natural Breaks (Jenks) classification set to 10 classes.
Table 6.
Elephant design- and model-based abundance estimates (N and N′, respectively) with 95% confidence intervals (95% CI and 95% CI′) and percent coefficient of variation (%CV and %CV′) for each survey stratum and for the landscape.
Table 7.
Great ape design- and model-based abundance estimates (N and N′, respectively) with 95% confidence intervals (95% CI and 95% CI′) and percent coefficient of variation (%CV and %CV′) for each survey stratum and for the landscape.
Figure 5.
Landscape survey strata and transect placement.
NNNP = Nouabalé-Ndoki National Park, LTCR = Lac Télé Community Reserve, FMU = Forestry Management Unit.
Table 8.
Covariates used for Generalized Additive Modelling analysis.