Watershed: a more efficient sampling unit for mountain camera traps

Area of Science:

• Ecology
• Wildlife Conservation
• Spatial Sampling

Background:

• Traditional camera trap (CT) surveys use 2D grids, often ignoring mountainous terrain's impact on species distribution.
• Complex mountainous terrain, with diverse elevations and habitats, requires specialized sampling strategies for accurate wildlife monitoring.

Purpose of the Study:

• To compare the effectiveness of watershed-based sampling with grid and elevation gradient patterns for wildlife camera trapping in mountain forests.
• To assess how habitat factors and topography influence CT survey outcomes in complex mountainous environments.

Main Methods:

• Contrasted capture rate (CR), species richness, and relative abundance index (RAI) across watershed, grid, and elevation gradient sampling patterns.
• Analyzed habitat factor correlations and heterogeneities using Analysis of Similarities (ANOSIM).
• Conducted surveys in southwest China's mountain forests under comparable sampling intensities.

Main Results:

• Watershed sampling yielded higher CR, species richness, and habitat heterogeneity.
• Elevation gradient sampling provided more stable species and RAI compared to the grid pattern.
• Topographic factors indirectly influence CT results through vegetation distribution in small-scale mountains.

Conclusions:

• Watershed sampling aligns well with mountainous elevation differences and complex topography, enhancing wildlife diversity capture.
• Watershed-based spatial sampling designs are recommended for mountainous areas, considering elevation gradients and topography for accurate species distribution studies.