Data from: Influence of reproductive status on occupancy of salvage-logged boreal forest by moose (Alces americanus)
Data files
Apr 24, 2025 version files 15.23 KB
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Detection_Predictor_Variable.csv
3.11 KB
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MooseOccupancy_MultiState.csv
1.45 KB
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MooseOccupancy_SingleState.csv
1.45 KB
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Occupancy_Predictor_Variables.csv
6.56 KB
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README.md
2.66 KB
Abstract
Wildlife-habitat relationships reflect the behavioural choices made by species in response to perceived risks and rewards. Ungulates must often choose between habitats that provide forage and those offering concealment from predators, yet natural and anthropogenic disturbances create risky landscapes where tradeoffs may be difficult to navigate. Ungulate responses to forest disturbance may vary by sex and reproductive state, given that reproductive females with calves often prioritize predator avoidance. We investigated state-dependent habitat use by reproductive and solitary moose (Alces americanus) in response to salvage logging after a widespread infestation by spruce beetle (Dendroctonus rufipennis) in the boreal forest of Yukon, Canada. We used camera traps and multi-state occupancy models to examine moose occurrence in unsalvaged and salvage-logged forests at different regenerative stages (0–10 years and 11–25 years post-logging) and levels of tree retention after logging. We compared results to single-state occupancy models that did not account for reproductive status. As predicted, single-state models showed high use of stands with low canopy cover and maximum tree removal (i.e., clear-cuts). This suggested that moose capitalized on shrubby forage available in logged stands, regardless of regenerative stage. However, this result was overly simplistic. Multi-state occupancy models revealed that forest age was the most important factor for female moose with calves, in contrast to solitary moose. Females with calves tended to avoid newly logged areas and preferred regenerating and unsalvaged forests with hiding cover, although estimates of effect size had low precision. Climate change is contributing to the rising frequency and severity of bark beetle outbreaks, and post-infestation salvage logging has been implicated in the decline of moose populations in western Canada. Our results support the need to maintain diverse, mixed-age forest landscapes to meet the food and cover requirements of moose in different demographic classes.
Dataset DOI: 10.5061/dryad.bk3j9kdpn
Description of the data and file structure
Data collection methods are described in detail in the following publication: Thomas, J.P., M.L. Reid, R.M.R. Barclay, and T.S. Jung. 2025. Influence of reproductive status on occupancy of salvage-logged boreal forest by moose (Alces americanus). Ecology and Evolution: 15:e71302. https://doi.org/10.1002/ece3.71302
Files and variables
Files:
MooseOccupancy_SingleState.csv
MooseOccupancy_MultiState.csv
Occupancy_Predictor_Variables.csv
Detection_Predictor_Variable.csv
Description:
Data is contained in 4 csv files:
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MooseOccupancy_SingleState: Each numbered column represents a 15-day survey period. 0 = no moose detected during survey period; 1 = moose detected during survey period (any sex or reproductive status); NA = no survey data.
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MooseOccupancy_MultiState: Each numbered column represents a 15-day survey period. 0 = no female moose detected; 1 = female moose detected; 2 = female moose with calf detected; NA = no survey data.
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Occupancy_Predictor_Variables: Variables hypothesized to influence site occupancy by moose. Predictor variables and their measurement units are described below (additional details about data collection are provided in Thomas et al. 2025).
stand_type: Low-retention logged (20–249 trees/ha), high-retention logged (250–820 trees/ha), un-salvaged
stand_age: Early-seral (0-10 years) and mid-seral (11-25 years)
canopy: Canopy cover (%) of stand calculated with a spherical crown densiometer
deciduous_stems: Number of deciduous stems (stems/10m2), including shrubs and trees <2 m tall
lateral_cover: Percent visual cover (%), measured with a 2 m tall cover pole
CWD: Total number of downed trees with diameter >4cm along three 40m transects
water_distance: Distance (km) to nearest wetland, lake, or river
linear_density: Linear disturbance density (km/km2) within 500 m of camera
forest_cover: Unsalvaged forest cover (%) within a 500 m radius of camera
bears: Camera detection rate (detections/day) of grizzly bears and black bears
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Detection_Predictor_Variable: Survey month (hypothesized to influence probability of moose detection, given occupancy). Each numbered column represents a 15-day survey period.
"NA" indicates missing values.
Code/software
Spreadsheet data is formatted for use with occupancy modeling software such as program PRESENCE or the accompanying R package, Rpresence.
