Movement decisions driving metapopulation connectivity respond to social resources in a long-lived ungulate, bighorn sheep (Ovis canadensis)
Data files
Aug 23, 2024 version files 20.68 MB
Abstract
The spatial availability of social resources is speculated to structure animal movement decisions, but the effects of social resources on animal movements are difficult to identify because social resources are rarely measured. Here, we assessed whether varying availability of a key social resource—access to receptive mates—produces predictable changes in movement decisions among bighorn sheep in the US state of Nevada. We compared the probability that males made long-distance ‘foray’ movements, a critical driver of connectivity, across three ecoregions with varying temporal duration of a socially mediated factor, breeding season. We used a hidden Markov model to identify foray events and then quantified the effects of social covariates on the probability of foray using a discrete choice model. We found that males engaged in forays at higher rates when the breeding season was short, suggesting that males were most responsive to the social resource when its existence was short lived. During the breeding season, males altered their response to social covariates, relative to the non-breeding season, though patterns varied, and age was associated with increased foray probability. Our results suggest that animals respond to the temporal availability of social resources when making the long-distance movements that drive connectivity.
This article is part of the theme issue ‘The spatial–social interface: A theoretical and empirical integration’.
README: Movement decisions driving metapopulation connectivity respond to social resources in a long-lived ungulate, bighorn sheep (Ovis canadensis)
https://doi.org/10.5061/dryad.h9w0vt4rs
Description of the data and file structure
BHS_HMM_GPS_cleaned.csv contains cleaned GPS data
BHS_HMM_sheep_covs.csv contains yearly sheep-level data
BHS_HMM_pop_covs.csv contains yearly population-level data
Files and variables
File: BHS_HMM_sheep_covs.csv
Description: yearly sheep-level data
Variables
- sheep: sheep ID
- ecoregion: ecoregion name
- population: population ID
- start_date: start date for yearly data
- age: yearly age (NA = unkown)
File: BHS_HMM_GPS_cleaned.csv
Description: cleaned GPS data
Variables
- ecoregion: ecoregion name
- sheep: sheep ID
- burst: sheep ID burst split by > 36 hrs of missing GPS data
- time: date and time
- x: x coordinate (UTM zone 11N)
- y: y coordinate (UTM zone 11N)
File: BHS_HMM_pop_covs.csv
Description: yearly population-level data
Variables
- population: population ID
- ecoregion: ecoregion name
- start_date: start date for yearly data
- ewes_per_ram: yearly ewe : ram ratio (NA = unknown)
- n_ewes: yearly number of ewes (NA = unknown)
Code/software
Code is available on Github (https://github.com/riccile/BHS_HMM).