Data from: From steps to home ranges: How habitat disturbance influences the movement drivers of an arboreal primate
Data files
Apr 16, 2026 version files 1.62 MB
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pigra_broad_scale_data.csv
8.14 KB
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pigra_intermediate_scale_data.csv
31.17 KB
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pigra_small_scale_data.csv
1.57 MB
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README.md
10.06 KB
Abstract
The persistence of animal populations in anthropogenic landscapes often depends on adjusting their foraging and movement strategies to environmental changes that involve energetic trade-offs. However, it remains unclear how ecological resilience translates into movement flexibility and which factors influence animal movement in modified environments.
Howler monkeys (Alouatta spp.) are known to cope with significant anthropogenic pressure across their range. We examined how a gradient of habitat disturbance alters the intrinsic traits of black howler monkeys (A. pigra) and extrinsic habitat characteristics, and how these factors, in turn, drive their movement.
We monitored six groups of black howler monkeys in southeastern Mexico for one year, collecting data on activity, diet, movement, neighboring-group presence, food availability, and microclimate. We developed intrinsic and extrinsic models to identify the main drivers of movement across three spatiotemporal scales.
Our results revealed scale-dependent responses to disturbance. At the smallest scale (5-min steps), movement probability increased with folivory levels and proximity to neighboring groups but was significantly constrained by high temperatures. At the intermediate scale (daily paths), resource sparseness led to longer daily travel distances, while social crowding in isolated fragments increased path circuity, reducing travel efficiency. Finally, at the broadest scale (use of space), groups in highly disturbed sites exhibited up to 99% seasonal home range overlap, indicating spatial saturation and a lack of buffering capacity against environmental stochasticity.
Our analyses show that while black howler monkeys exhibit behavioral flexibility, their capacity to cope with anthropogenic disturbance is limited by environmental and spatial constraints. As human activities continue to alter ecosystems, animals must adjust their strategies to navigate changing habitats and shifting resource availability; however, when environmental limits exceed an organism's inherent flexibility, populations may face an increased risk of local extinction.
Dataset DOI: 10.5061/dryad.zw3r228nn
Description of the data and file structure
From June 2023 to May 2024, we monitored six black howler groups under all weather conditions. During the first five months, two field teams, each with three observers, monitored one group four days a week, rotating among the six groups weekly. Starting from November 2023, only a single team continued the observations. We randomized the sequence of group observations to control for temporal autocorrelation. Observation days started at 5:30 AM and ended at 5:00 PM, when the black howlers usually settled into their sleeping trees. We followed the Principles for the Ethical Treatment of Non-Human Primates established by the American Society of Primatologists.
Movement and intrinsic characteristics
Since black howlers conduct their daily activities as a cohesive group, we selected one adult individual each day as the focal animal. All groups contained 4-5 adults plus their young (2-4); therefore, we randomly rotated the focal individual among the adult members within each group to ensure even sampling throughout the study period. All study groups were habituated to the researchers’ presence before data collection. We identified all study individuals based on genital morphology, facial characteristics, and location of temporary botfly infections. In each observation team, one observer conducted instantaneous focal sampling every five minutes throughout the day, recording the focal individual’s activity (resting, feeding, traveling, or other), diet (fruits, leaves, flowers, or other), and location using a handheld GPS device (Garmin 65S) with an accuracy of ± 2 m. To prevent GPS error accumulation, we used the same coordinates when the individual stayed in the same tree for multiple sampling intervals.
Extrinsic characteristics
We considered neighboring group calling, spatiotemporal food availability, ambient temperature, and forest-patch size as extrinsic characteristics. For neighbor group calling, we recorded whether a neighboring group was calling during each focal sampling and estimated its distance from the focal group as follows: encounter (<50 m and detected visually), medium (50–200 m and detected aurally with moderate intensity), and far (>200 m via distant vocalizations).
For the temporal food availability, we followed the Gentry protocol for botanical surveys (Gentry, 1982), placing ten 50 m x 2 m linear vegetation transects in each home range, spaced at least 50 m apart. We marked all trees within transects with a diameter at breast height (DBH) ≥10 cm (Arroyo-Rodríguez & Mandujano, 2006). At the end of each observation week at a given site, we walked along the transects estimating the phenology of the marked trees using the Fournier percentage-based scale (0= 0%, 1= 1-25%, 2= 26-50%, 3= 51-75%, 4= 76-100%) to estimate the presence of leaves, fruits, and flowers (Fournier, 1974). Additionally, when a focal individual fed on a tree during focal sampling, we marked it for subsequent identification. We identified all transects and food trees to the species level, whenever possible. For ambient temperature, we recorded values every 5 min using a wireless datalogger (Kestrel Drop D3) 1 m above the ground directly below the focal individual. For forest fragment size, we used high-resolution satellite imagery provided by the ESRI World Imagery basemap in ArcGIS Pro 3.4.0. We digitized the forest patches and calculated their sizes as the total area of closed-canopy cover, clearly differentiated from the surrounding anthropogenic matrix (e.g., pasture, oil plantation, etc.).
Files and variables
File: pigra_broad_scale_data.csv
Description:
Variables
- ID: Unique entry identifier.
- Disturbance: Disturbance level (low, medium, high).
- Group_ID: Group identifier.
- Season_ID: Season during which data was collected.
- Week_ID: Sequential observation week number.
- Week_Home_range: Home range size during the sampling week (hectares).
- Resting: Proportion of time spent resting during the sampling week.
- Feed: Proportion of time spent feeding during the sampling week.
- Travel: Proportion of time spent traveling during the sampling week.
- Folivory: Proportion of feeding time spent feeding on leaves during the sampling week.
- Frugivory: Proportion of feeding time spent feeding on fruits during the sampling week.
- Group_calling: Proportion of time the group produced loud calls during the sampling week.
- NeighborIndex: Proportion of time non-focal groups were heard at all estimated distance ranges during the sampling week.
- Food_separation: Pairwise distances between feeding locations during the sampling week (meters).
- FAI: Total food availability index during the sampling week.
- Fragment_size: Size of the forest fragment (hectares).
- Season_Home_range: Home range size during the sampling season (hectares).
- Season_Foraging_effort: Calculated index by dividing the time individuals spent feeding and traveling by the time they spent resting during the sampling season.
- Season_Group_calling: Proportion of time the group produced loud calls during the sampling season.
- Season_NeighborIndex: Proportion of time non-focal groups were heard at all estimated distance ranges during the sampling season.
- Season_Food_separation: Pairwise distances between feeding locations during the sampling season (meters).
- NA values and empty cells: Not available
File: pigra_intermediate_scale_data.csv
Description:
Variables
- ID: Unique entry identifier.
- Disturbance: Disturbance level (low, medium, high).
- Group_ID: Group identifier.
- Season_ID: Season during which data was collected.
- Week_ID: Sequential observation week number.
- Follow_ID: Sequential behavioral sampling day number.
- total_distance: Total distance traveled during the sampling day (meters).
- euclidean_distance: Distance between the start and end locations registered each sampling day as an indicator of daily displacement (meters).
- circuity_index: Index calculated by dividing total_distance by euclidean_distance. A Circuity Index of 1.0 represents straight-line travel, while a value >1.0 indicates less efficient travel.
- Resting: Proportion of time spent resting during the sampling day.
- Feed: Proportion of time spent feeding during the sampling day.
- Travel: Proportion of time spent traveling during the sampling day.
- Folivory: Proportion of feeding time spent feeding on leaves during the sampling day.
- Frugivory: Proportion of feeding time spent feeding on fruits during the sampling day.
- Group_calling: Proportion of time the group produced loud calls during the sampling day.
- Temperature: Mean ambient temperature during the sampling day (°C).
- NeighborEncounter: Proportion of time non-focal groups were heard at 50 m or less and detected visually during the sampling day.
- NeighborMedium: Proportion of time non-focal groups were heard at 50–200 m and detected aurally with moderate intensity during the sampling day.
- NeighborFar: Proportion of time non-focal groups were heard at >200 m via distant vocalizations during the sampling day.
- Food_sites: Number of unique trees the focal individual fed from during the sampling day (n).
- Food_separation: Pairwise distances between feeding locations during the sampling day (meters).
- NA values: Not available
File: pigra_small_scale_data.csv
Description:
Variables
- ID: Unique entry identifier.
- Disturbance: Disturbance level (low, medium, high).
- Group_ID: Group identifier.
- Week_ID: Sequential observation week number.
- Follow_ID: Sequential behavioral sampling day number.
- Individual_ID: Unique individual identifier.
- Timestamp: Record of the time and date of a single instant sampling (dd/mm/yyyy hh:mm).
- movement: Binary response variable. 5-minute interval coded as movement (1) if step length >0 m and non-movement = 0.
- step_length: Euclidean distance between consecutive pairs of coordinates registered every five minutes (meters).
- turning_angle: Relative turning angle between pairs of Active Steps (step_length != 0; degrees)
- Resting: Binary response variable. Coded as (1) if the individual was resting during instant sampling and (0) otherwise.
- Travel: Binary response variable. Coded as (1) if the individual was traveling during instant sampling and (0) otherwise.
- Feed: Binary response variable. Coded as (1) if the individual was feeding during instant sampling and (0) otherwise.
- Folivory: Binary response variable. Coded as (1) if the individual was feeding on leaves during instant sampling and (0) otherwise.
- Frugivory: Binary response variable. Coded as (1) if the individual was feeding on fruits during instant sampling and (0) otherwise.
- Group_calling: Binary response variable. Coded as (1) if the group was producing a loud call during the sampling interval, and (0) otherwise.
- Temperature: Ambient temperature during instant sampling (°C).
- NeighborEncounter: Binary response variable. Coded as (1) if non-focal groups were heard at 50 m or less and detected visually during the sampling interval, and (0) otherwise.
- NeighborMedium: Binary response variable. Coded as (1) if non-focal groups were heard at 50–200 m and detected aurally with moderate intensity during the sampling interval, and (0) otherwise.
- NeighborFar: Binary response variable. Coded as (1) if non-focal groups were heard at >200 m via distant vocalizations during the sampling interval, and (0) otherwise.
- NA values: No turning angle provided due to lack of movement.
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