DOI: 10.5061/dryad.6djh9w19m
title: Differential responses to weather and land-cover conditions explain spatial variation in winter abundance trends in a migratory bird of conservation concern

description: Effective conservation strategies for animal populations require knowledge
 of relationships between population dynamics and their environmental
 drivers. However, these processes often vary within animal populations,
 requiring site-specific conservation planning. Given limited financial
 resources, identifying groups of sites with similar population dynamics
 can help practitioners efficiently implement conservation programs to
 larger areas. We evaluated spatial patterns and environmental drivers of
 wintering site trends in a migratory bird of conservation concern, the
 Greenland white-fronted goose (Anser albifrons flavirostris). We used
 latent class analysis to identify trend patterns in 35 years of abundance
 data among 59 geographically discrete Greenland white-fronted goose
 wintering sites. We developed a state-space abundance model in a Bayesian
 framework to quantify the effects of weather and land-cover conditions
 experienced throughout spring migration, summer breeding, autumn
 migration, and wintering periods on variation in wintering site abundance.
 We identified two main patterns in Greenland white-fronted goose abundance
 trends: northeastern wintering sites declined on average by 2% per year,
 while southwestern wintering sites declined on average by 14% per year.
 Differential responses to weather and habitat conditions likely explained
 variation among groups, as geese at southwestern wintering sites were more
 negatively affected by harsh weather conditions (e.g., low temperatures
 and high precipitation on breeding areas) and poor habitat conditions
 (i.e., low-quality grasslands and croplands) on wintering areas. Future
 conservation efforts to improve the suitability and nutritional quality of
 agricultural areas, especially cereal croplands in autumn and early winter
 and grasslands in late winter and early spring, could potentially improve
 local habitat conditions, especially in the southwestern wintering sites
 where abundance declines were steepest. Synthesis and applications: We
 demonstrate the potential to delineate animal populations based on spatial
 patterns in population dynamics using long-term abundance monitoring data,
 which are commonly the only available data for conservation practitioners.
 By grouping sites based on spatial patterns in local abundance trends, we
 can further test hypotheses about how these groups are differentially
 affected by changing environmental conditions. This information is
 important for informing efficient conservation planning over large areas
 when financial resources are limited.
description: # Differential responses to weather and habitat conditions explain spatial
 variation in winter abundance trends in a migratory bird of conservation
 concern. This repository contains the data and code used in the following
 publication: Schindler, A. R., A. D. Fox, C. K. Wikle, B. M. Ballard, A.
 J. Walsh, S. B. A. Kelly, M. D. Weegman. (2024). *Journal of Applied
 Ecology*, 00,
 1-12. [https://doi.org/10.1111/1365-2664.14804](https://doi.org/10.1111/1365-2664.14804).  Data DOI: [https://doi.org/10.5061/dryad.6djh9w19m](https://doi.org/10.5061/dryad.6djh9w19m)\ Code DOI: [https://doi.org/10.5281/zenodo.13126638](https://doi.org/10.5281/zenodo.13126638) All analyses were completed using R. See manuscript for details. Please contact the corresponding author with questions about this data package or to seek potential collaborations using these data. --- ### Description Model code and associated data files to quantify geographic patterns of abundance trends among Greenland white-fronted geese (*Anser albifrons flavirostris*) wintering sites and examine how weather and land-cover changes explain variation in wintering site abundance. --- ### Authors Alexander R. Schindler Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada Anthony D. Fox Department of Ecoscience, Aarhus University, Aarhus, Denmark Christopher K. Wikle Department of Statistics, University of Missouri, Columbia, MO, USA Bart M. Ballard Caesar Kleberg Wildlife Research Institute, Texas A&M University-Kingsville, Kingsville, TX, USA Alyn J. Walsh National Parks and Wildlife Service, Dublin, Ireland Seán B. A. Kelly National Parks and Wildlife Service, Dublin, Ireland Mitch D. Weegman Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada --- ### Code files * `01_estimating_site_trends.R`: code for estimating abundance trends of individual Greenland white-fronted goose wintering sites * `02_determining_number_of_groups.R` : code for exploratory analysis to determine number of groups to use in the latent class analysis * `03_LCA.R`: code for the latent class analysis to group wintering sites into groups based on abundance trends and location (i.e., latitude and longitude) * `04_fix_label_switching` : code to fix label-switching in LCA model results * `05_ss_env.R`: code for estimating the effects of environmental variables on annual trends in abundance ### Data files * `count_data.csv`: Greenland white-fronted goose wintering site count data * `roost_site_coordinates.csv`: (scaled) coordinates of roosting locations for all Greenland white-fronted goose wintering sites * `pland_data.csv`: percent land cover data for all Greenland white-fronted goose wintering sites * `weather_data.csv`: weather data * `winter_GDD_data.csv` : cumulative growing degree days (GDD) for all Greenland white-fronted goose wintering sites ### Data file column names (see manuscript for further details) * `site_name`: name of each Greenland white-fronted goose wintering site * `site_id`: numerical identifier for each Greenland white-fronted goose wintering site * `year`: year in the study (1984-2018) * `year_id`: numerical identifier for each year in the study (i.e., 1-35 corresponds to 1984-2018) * `count`: number of Greenland white-fronted geese counted * `lat_scale`: (scaled) latitude of the corresponding wintering flock * `lon_scale`: (scaled) longitude of the corresponding wintering flock * `composite_year` : 5-year composite range of the corresponding land cover data * `grass`: % grassland cover within a 15km radius of the corresponding wintering flock * `cereal`: % cereal crop cover within a 15km radius of the corresponding wintering flock * `peat_bog`: % peat bog cover within a 15km radius of the corresponding wintering flock * `scaled_grass`: (scaled) % grassland cover within a 15km radius of the corresponding wintering flock * `scaled_cereal`: (scaled) % cereal crop cover within a 15km radius of the corresponding wintering flock * `scaled_peat_bog`: (scaled) % peat bog cover within a 15km radius of the corresponding wintering flock * `spring_storm_days`: number of days with a severe storm during spring migration * `spring_precip`: cumulative precipitation (in mm) during spring staging * `pre_breed_freeze`: number of days below freezing during the pre-breeding period * `post_breed_precip`: cumulative precipitation (in mm) during the post breeding period * `autumn_storm_days`: number of days with a severe storm during autumn migration * `autumn_freeze`: number of days below freezing during autumn staging * `scaled_spring_storm_days`: (scaled) number of days with a severe storm during spring migration * `scaled_spring_precip`: (scaled) cumulative precipitation during spring staging * `scaled_pre_breed_freeze`: (scaled) number of days below freezing during the pre-breeding period * `scaled_post_breed_precip`: (scaled) cumulative precipitation during the post breeding period * `scaled_autumn_storm_days`: (scaled) number of days with a severe storm during autumn migration * `scaled_autumn_freeze`: (scaled) number of days below freezing during autumn staging * `winter_GDD` : cumulative growing degree days (GDD) on wintering areas from 01 January to day of goose departure from wintering areas * `scaled_winter_GDD` : (scaled) cumulative growing degree days (GDD) on wintering areas from 01 January to day of goose departure from wintering areas