Data and code from: Avian scavengers modify vigilance across visits to foraging sites
Data files
Jun 10, 2026 version files 100.18 KB
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Carcasses.csv
6.28 KB
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ethology_code_04-06-2026.R
15.30 KB
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README.md
5.23 KB
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Visits.csv
73.38 KB
Abstract
This dataset supports the methods and analyses used to test the differences in behavioral response of avian scavengers at carcasses. The "carcasses" dataset represents each carcass and habitat and other variables associated with each carcass. The "visits" dataset comes from videos from game cameras positioned at the corresponding carcass, each row representing one visit by a scavenger. Several visits may come from a single carcass, and some carcasses are not represented in the visits dataset if cameras did not capture any recordings of scavengers. We assessed variables that were hypothesized to impact the proportion of time spent vigilant by each species at both carcass and visit scales and compared these across species.
Dataset DOI: 10.5061/dryad.v6wwpzh9c
Description of the data and file structure
Game cameras were set on carcasses, and environmental covariates were measured to create the carcasses dataset. Visits from scavengers were recorded from each carcass, and behavioral measurements were summed for each visit using Behavioral Observation Research Interactive Software (BORIS).
Files and variables
File: ethology_code_04-06-2026.R
Description: R script for analysis of datasets. This follows the data analysis section of methods in the associated manuscript, submitted to Ethology.
File: Carcasses.csv
Description: A dataset of carcasses and their covariates. Carcasses were each either found or set out at a unique location in southern Utah, on private sheep summer pastures.
Variables
- Carcass_ID: A unique, consecutively increasing identifying number for each carcass
- Ordinal_day_established: Number of the day (out of 365) that the carcass was first found/set out with cameras recording
- Average_canopy: The averaged canopy closure from each cardinal direction, taken with a densiometer while standing at the carcass. Values represent the number of grid points reflecting canopy, out of 96.
- Distance_to_Pred_cover: The distance (m) from the carcass to the closest obstacle that could hide an approaching predator, represented by a board (0.5 m^2)
- Profile_E: The percentage of a board that was obscured by understory vegetation (between 0 and 0.5 m high), read at the carcass when the board is placed 15 m away from the carcass in a random direction. Readings were categorized into classifications representing 0, 1-20%, 21-40%, etc until full coverage.
- Actual_Slope: The slope taken at a carcass site, in degrees.
- Actual_Elevation: The elevation of a carcass site, in meters.
- Average_veg_height: The height of the tallest vegetation (in cm), including overstory, measured at every meter along a 15 m transect and averaged for each carcass.
- Distance_paved_road: The distance to the closest paved (public, higher-use) road, measured between the GPS point of the carcass and road layer in ArcGIS after completion of fieldwork.
- Distance_all_road: The distance to the closest road, including private and sparsely maintained dirt roads, measured between the GPS point of the carcass and road layer in ArcGIS after completion of fieldwork.
- Initial_weight_kg: The weight of the carcass when first found or set out, either weighed on-site (if below 20 kg) or assumed from existing literature.
File: Visits.csv
Description: Recorded visits by any scavenger to any carcass. Visits were started at first appearance of a scavenger and ended when the scavenger either left the area (ie a visible takeoff) or was not at the carcass for 15 minutes, at which point the last sighting of the scavenger was used to end the observation.
Variables
- ID: A unique, consecutively increasing identifying number for a visit.
- Visit_per_carcass: The visit number for a particular carcass, across species.
- Visit_per_species: The visit number for a particular species at a carcass, regardless of potential repeated visits by individuals.
- Carcass: The unique number assigned to the carcass, that relates to the carcass dataset.
- Date: The date of scavenger visit.
- Species: The species of scavenger.
- Time_arrive: The first appearance of that scavenger in frame, from the game camera.
- Wind: The visually estimated amount of wind from video, on the beauford scale.
- Cloud_cover: The visually estimated percentage of cloud cover.
- Temp: The temperature in degrees Celsius, as recorded by the game camera (measured in F and converted).
- Eaten_arrival: The percent of the carcass that was eaten at the start of the visit, visually estimated from the recording.
- Number_of_individuals_at_arrival: The number of other individuals with concurrent visits when the focal individual appears.
- Time_leave: The time that the scavenger leaves frame and ends the visit, as displayed on the camera.
- Eaten_leaving: The percentage of a carcass that has been eaten at the end of the visit.
- Number_of_individuals_at_leaving: The number of other individuals with concurrent visits, when the focal individual departs.
- Feeding_time: The number of seconds spent feeding during a visit.
- Vigilance_time: The number of seconds spent being vigilant during a visit.
- Other_time: The number of seconds within frame spent on other behaviors, such as aggression or moving around a carcass during a visit.
- Out_of_frame_or_unsure: The number of seconds spent out of frame or too far away/obscured to confidently determine behavior.
- Number_of_displacements: The total number of displacements of other individuals caused by an individual.
Code/software
R (version 4.2.1)
RStudio (recommended)
Packages are loaded within the code, but versions are specified below:
car version 3.1.3
ggeffects version 2.3.1
ggplot2 version 4.0.0
glmmTMB version 1.1.12
lubridate version 1.9.4
qpcR version 1.4.2
tidyverse version 2.0.0
viridis version 0.6.5