Camera trapping and environmental variables
We divided the study area into a grid of 2.7 km x 2.7 km cells (Figure
1) and removed cells with more than ⅔ of their area exceeding 1800 m
altitude and cells more than ½ of their area covered by urban landscape
features. From the remaining cells, we sampled every other cell, when it
was not possible to reach a selected cell, we used an adjacent cell.
Each sampled cell contained a trap station, randomly located within the
cell. We conducted two seasons of monitoring: (1) December
17th, 2018, to March 31st, 2019
(winter) and (2) October 9th, 2019, to January
15th, 2020 (autumn). We installed 64 camera trap
stations during winter, and 76 during autumn, with high spatial overlap
between seasons (Figure 1). Each
trap station had two opposite cameras installed at a height of 40 to 60
cm positioned towards animal paths. We used two camera models per trap
station, a CuddeBack C1 Model 1279 with white flash for high quality
color pictures in night conditions, and a Bushnell Trophy infrared
camera. Camera traps were installed on animal trails along mountain
ridges, mid-slopes, upper valleys, and bottom of slopes to detect
carnivores at various altitudes/habitats. Camera traps were installed
1-2 weeks prior to the start of monitoring to account for additional
anthropogenic disturbance from the camera installation process. At each
camera trap location, we recorded the presence or absences of
anthropogenic disturbance (i.e., logging or settlements) as a binary
variable for species detection and occurrence. We also recordedaltitude (m) via GPS and extracted distance to stream (m),distance to settlement (m), and distance to roads (m) from
the camera trap location using Geographic Information Systems (ArcGIS
10.7, ESRI, Redlands CA). Within a 500-meter buffer around each camera
trap location, we calculated the density of local roads(km/km2), the proportion of forested area and aterrain ruggedness index (TRI)(Riley et al., n.d.) . Full
covariate descriptions and summaries are available in Table 1.