Table 1.

Structural covariates quantified from LiDAR-derived point-cloud data (25 to 50 pulses m⁻²; aggregated at 20-m resolution), capturing three distinct axes of forest structure (horizontal structure, vertical structure, vertical heterogeneity)

Structural axis and metric	Processing method	Spatial extent (m)	Description and justification
Horizontal structure
Gap fraction	CHM	250	Proportion of focal patch containing vegetation below 5 m in height, indicative of gaps in the forest canopy
			Gap avoidance at understory level is documented for ungulates (33) and at canopy level for primates (34). Conversely, orangutans appear to favor areas adjacent to canopy gaps for nesting (35)
Vertical structure
No. of layers	PAD	250	No. of contiguous canopy layers within the vertical column, indicative of connectivity
			Orangutans favor multilayered canopies when selecting nest sites (35)
Canopy height	CHM	250	Mean canopy height as derived from the CHM surface, indicative of forest maturity and level of disturbance
			Mammals actively select forest areas with tall canopies, responding to higher productivity of foraging resources, seasonal refuge from environmental conditions, and structural opportunities for arboreal locomotion and den/nest site selection (34–37)
Plant area index	PAD	500	Plant area index, defined as the one-sided area of vegetation, inclusive of foliage, stems and branches, per unit ground area. Indicative of vegetation density throughout the vertical column
			High vegetation density is favored by apex predators and mesocarnivores to improve hunting efficiency (33, 38). Dense vegetation may also provide important foraging opportunities, thermal cover, and antipredatory refuge for ungulates and secure denning sites for subordinate carnivores (39, 40)
Vertical heterogeneity
Structural diversity index	PAD	500	Composite measure of canopy height, vegetation density, and the distribution of plant matter throughout the vertical column. Calculated as the Shannon Index of the PAD. Indicative of the diversity of subcanopy environments (i.e., niche space) within the plant area distribution profile
			Mesocarnivores select multistrata canopies with an equitable distribution of plant matter throughout the vertical column due to increased microhabitat availability and resource provisioning for prey species (39)
Shape	PAD	500	Morphological measurement of the relative distribution of vegetation within the canopy. Ratio of the canopy height with the maximum PAD and the 99th percentile of canopy height PAD
			Canopy shape could influence primate habitat selection, although there is little evidence to support this from limited applications of this metric to date (34, 35)
Landscape context
Forest cover	CHM	2,000	Proportion of forest cover (forest defined as trees >10 m in height). Indicative of habitat extent and availability
			Linked to mammal occurrence and abundance across the tropics, highlighting the importance of contiguous habitat (41, 42)
Canopy height variability	CHM	2,000	SD of canopy height, describing the variability of the vertical dimension. Indicative of canopy complexity and forest quality
			Primates actively select uniform canopies characterized by low variability as interconnected canopies provide greater lateral connectivity that facilitates arboreal locomotion (34). Conversely, high canopy height variability provides greater structural complexity, which is an important determinant of den site selection by fishers (37)

The covariates were derived from either CHMs or PAD distributions, estimated based on a one-dimensional Beer–Lambert-type model of light propagation through the canopy (43). We calculated landscape context covariates to describe forest extent and quality across broader spatial scales. Covariates were aggregated across spatial extents informed by scale optimization methods to characterize optimal scales of selection for predictors and determine sensitivity to spatial scale (SI Appendix, Table S2).