Figure 1.
Schematic representation of study area.
A representation of the 2,264 km2 study area, divided into a grid of 64 cells of 41 km2 each, and set in the center of a 4,100 km2 landscape, which is outlined in gray.
Figure 2.
Nine detection scenarios by varying σ and p0.
Nine detection scenarios for N = 500 were created by evaluating three values of the spatial scale parameter, (σ = 10, 5, and 1 km), for each of three baseline detection rates, (p0 = 0.20, 0.10, 0.05). As distance from an individual’s activity center increases, detection decreases according to a half-normal function based on the two parameters. Dashed vertical lines indicate 95% home range radii (σ*).
Figure 3.
Three trap configurations: regular, clustered, and sequential.
Three trap configurations were evaluated, shown with J = 128 traps: (a) regular array, (b), clustered, and (c) a temporal sequence in which clustered traps of one arrangement (e.g. triangle) are moved halfway through the sampling period to new grids (e.g. squares). Gray gridlines in (b) and (c) overlay the non-overlapping grid sizes of an estimated female home range. The black outline around the traps depicts the 2,624 km2 study area; the large gray square shows the extent of the 4,100 km2 landscape.
Figure 4.
Trap configuration and number of traps generated eleven designs.
Eleven trap designs were evaluated by varying the regular, clustered, and sequential trap arrangements for J = 128, 96, and 64 traps. Only the regular and sequential arrangements were evaluated for J = 32 traps since the clustered arrangement with one trap per cluster was equivalent to the regular arrangement. Trap spacing did not change when traps were in the clustered and sequential arrangements.
Table 1.
Trap spacing (km) for each combination of trap configuration (regular, clustered, and sequential) and number of traps (J = 128, 96, 64, and 32).
Table 2.
Effective trap spacings for each σ, scaled by dividing trap spacings (4.71, 5.24, 6.40, and 9.60 km) by σ (1, 5, 10 km).
Table 3.
Summary estimates of when true population size N = 500 and J = 128 traps, under each of the three trap arrangements: regular, clustered, and sequential, where mean, standard deviation (SD), range, root mean squared error (RMSE), and mean normalized bias (MNB) are given for each scenario (p x σ x configuration).
Table 4.
Summary estimates of when the true population size N = 500 and J = 128 traps, under each of the three trap arrangements: regular, clustered, and sequential, where mean, standard deviation (SD), range, root mean squared error (RMSE), and mean normalized bias (MNB) are given for each scenario (p x σ x configuration).
Table 5.
For σ = 1 km, summary estimates of in the regular trap configuration when trap spacing increased from 4.71 to 9.60 km (J = 128 to 32 traps) and N = 500.
Table 6.
For σ = 1 km, summary estimates of in the regular trap configuration when trap spacing increased from 4.71 to 9.60 km (J = 128 to 32 traps) and N = 500.
Table 7.
RMSE values of estimators of , as effective trap spacing (i.e., trap spacing/σ) increased under the regular trap configuration and across all baseline detection probabilities (p0 = 0.20, 0.10, 0.05).