Understanding how seasonal changes in resources and human activity
influence large carnivore space use is critical for effective
conservation, yet such information is scarce for Central African savanna
ecosystems. This study used occupancy modelling with data from camera
traps deployed during the dry and wet seasons in Zakouma National Park
(NP), Chad, to assess seasonal patterns of large carnivore occurrence and
their environmental drivers. Five large carnivore species were detected:
lion, leopard, cheetah, spotted hyaena, and striped hyaena. Prey
availability emerged as the primary driver of carnivore space use in the
dry season. Detections declined markedly in the wet season; occupancy
remained similar across seasons for lions and leopards, whereas other
species exhibited reduced occupancy in the wet season. Our results
indicate that Zakouma NP functions as a critical refuge during the dry
season, when anthropogenic pressure intensifies in community lands due to
the movement of transhumant pastoralists. During the wet season, reduced
human presence in the broader landscape, combined with decreasing prey
availability and flooding that renders parts of Zakouma NP unsuitable,
allows several species to expand their range beyond the park. Within the
Greater Zakouma Ecosystem, these seasonal dynamics highlight the
importance of landscape-level conservation approaches that account for
seasonal shifts in resource availability and human land use to support
large carnivore persistence. ## Description of the data and file structure Data were collected through
a systematic camera-trap survey designed to quantify seasonal variation in
large carnivore occurrence and space use in Zakouma National Park, Chad.
Camera traps were deployed at a network of fixed sampling sites during
both the dry and wet seasons of 2020, using a standardized placement
protocol to ensure comparability across seasons. Each camera station
operated continuously throughout its respective sampling period and
recorded date- and time-stamped detections of terrestrial mammals. The
survey targeted large carnivores, including lions, leopards, cheetahs,
spotted hyaenas, and striped hyaenas, and was structured to generate
detection histories suitable for occupancy modeling. Site-level
environmental and anthropogenic covariates were compiled for each camera
location to characterize seasonal variation in prey availability,
flooding, and human activity. These data were used to evaluate how
seasonal changes in resources and human presence influence carnivore space
use within and beyond the protected area. Download all files in the same
folder before running the R scripts. ### Files and variables #### Excel
files: ##### File: ZNP2020_carnivore_dataset.xlsx **Description:** dataset
including all detections of large carnivores during the survey period.
Variables: station name, Date and Time, Species and Season. ##### File:
ZNP2020_covariatesRAI_use.xlsx **Description:** Site-level covariates that
are included in the analysis. *
Wet2020_RAIprey_log, Wet2020_RAIlarge_log, Wet2020_RAImed_log, Wet2020_RAIsmall_log, Dry2020_RAIprey_log, Dry2020_RAIlarge_log, Dry2020_RAImed_log, Dry2020_RAIsmall_log: log-transformed Relative Abundance Index of wild prey for the wet and dry season. Prey species were separated into large prey of > 250kg: giraffe, buffalo and roan antelope; medium prey between 70 kg and 250kg: waterbuck, greater kudu, hartebeest and tiang; and small prey <70kg: kob, warthog, bushbuck, reedbuck, red fronted gazelle, oribi and common duiker. * Dry2020_RAIlivestock_cap_log: log-transformed Relative Abundance Index of livestock capped livestock at the 99th percentile due to the presence of an extremely high outlier. * MakeModel: made and model of the camera traps Cuddeback Xchange (Cuddeback, Green Bay, Wisconsin, USA), Bushnell CORE, Bushnell Trophy Cam HD Aggressor (Bushnell Outdoor Products, Overland Park, Kansas, USA). * Flash: white flash (W) and dark flash (D) including covert flash (CV) and infra-red flash (IR). * hab_road: True or False, if the camera was deployed along a park road. * hab_water: True or False, if the camera was deployed close to available surface water. * Dist_border_m: distance to park boundary calculated from up-to-date spatial files provided by the park management (African Parks). * Dist_Villa_m: distance to villages calculated from up-to-date spatial files provided by the park management (African Parks). * X5x5_parkroad_m_log: density of park roads calculated from up-to-date spatial files provided by the park management (African Parks). * NDVI_Dry20, NDVI_Wet20: Normalized Difference Vegetation Index calculated using Google Earth Engine with Sentinel-2 satellite images with a 10m resolution, calculating the mean values for each grid square over each survey period. * DryWater_GEEdist_m_log: distance from permanent water in the dry season, identified using Google Earth Engine with Sentinel-2 satellite images with a 10m resolution. * Flood_area: surface area covered in water in the wet season per grid cell, in sqkm, extracted from ground-truthed spatial layer of flooded areas provided by the park management (African Parks). The continuous variables were z-standardized (x − x/σ) to a mean 0 and unit standard deviation. ##### ##### File: ZNP2020_table5d_effort_Dry2020_wide.xlsx ##### File: ZNP2020_table5d_effort_Wet2020_wide.xlsx **Description:** Effort (number of trap nights active) per sampling occasion (5 days) per station for the dry and wet season, also including total days the camera was active over the survey period. ##### ##### File: ZNP2020_table5d_Dry2020_leopard_wide.xlsx ##### File: ZNP2020_table5d_Dry2020_lion_wide.xlsx ##### File: ZNP2020_table5d_Dry2020_spottedhy_wide.xlsx ##### File: ZNP2020_table5d_Dry2020_cheetah_wide.xlsx ##### File: ZNP2020_table5d_Dry2020_stripedhy_wide.xlsx ##### File: ZNP2020_table5d_Wet2020_leopard_wide.xlsx ##### File: ZNP2020_table5d_Wet2020_spottedhy_wide.xlsx ##### File: ZNP2020_table5d_Wet2020_lion_wide.xlsx **Description:** Detection tables for the different carnivore species and different seasons derived from the ZNP2020_carnivore_dataset with sampling occasions of 5 days. 1 = animal detected; 0 = animal not detected; blank = camera not active during the sampling occasion.
#### R scripts: ##### File: compare_det_occ_models.R ##### File:
plot_occupancy_effect.R ##### File: run_ppc_diagnostics.R
**Description:** source scripts that run in the background of the analysis
scripts to compare multiple models (compare_det_occ_models.R), run
diagnostics (run_ppc_diagnostics.R) and plot occupancy effects
(run_ppc_diagnostics.R)
##### File: Occupancy_analysis_spOcc_final_-_after_PR1_share.R #####
**File:** Occupancy_analysis_spOcc_wet_season_final_-_after_PR1_share.R
**Description:** R scripts to run the analysis with spOccupancy for the
dry (Occupancy_analysis_spOcc_final_-after_PR1*.*R) and
wet season
(Occupancy_analysis_spOcc_wet_season_finale_-_after_PR1.R). Download all
files in the same folder before running the scripts.
## Code/software All analyses were run in R version 4.4.2 (2024-10-31
ucrt) -- "Pile of Leaves" with RStudio 2024.12.0+467 "Kousa
Dogwood" Release (cf37a3e5488c937207f992226d255be71f5e3f41,
2024-12-11) for windows.