DOI: 10.5061/dryad.m0cfxppbk
title: Local sub-population dynamics of a Central European Grey Partridge meta-population support a large-scale conservation approach to halt its ongoing decline

description: Many farmland birds such as the Grey Partridge (Perdix perdix) are
 experiencing sharp declines across Europe, which can lead to fragmentation
 and increasing isolation of local populations. Understanding the
 population dynamics of these local populations is becoming increasingly
 important for effective conservation efforts. In this study, we used data
 from Grey Partridge transect counts with call play-back from 2006 to 2023
 to investigate the population dynamics of a Grey Partridge population in
 central Germany. We employed Generalized Linear Mixed Models to model the
 long-term meta-population trend and assessed synchrony between local
 sub-populations by calculating the cross-correlation and the Loreau
 & de Mazancourt community-wide synchrony. Additionally, we
 assessed stability by comparing the extent of yearly fluctuations between
 sub-populations and the regional meta-population by analysing variances.
 Our analysis revealed that the studied meta-population remained stable
 over the course of the study period, despite ongoing declines observed in
 other regions of Germany. Furthermore, we found that the population
 dynamics of the sub-populations were largely asynchronous, and the extent
 of variance in the sub-populations was significantly greater than in the
 meta-population. The low synchrony between sub-populations indicates a
 prevalence of local factors affecting population dynamics, but further
 research is needed to identify these factors. Our results suggest that
 asynchrony between sub-populations may play a role in stabilizing
 meta-populations at the landscape level. Based on our results, we argue
 that large-scale conservation projects that are able to encompass these
 population dynamics may help ensure the long-term persistence of the Grey
 Partridge.
description: Detailed information on data sampling and processing can be found
 in the corresponding article: Laux, A., Gottschalk, E. Local
 sub-population dynamics of a Central European Grey Partridge
 meta-population support large-scale conservation approach to halt its
 ongoing decline. <em>Wildlife Biology.</em>
 https://doi.org/10.1002/wlb3.01316
description: # Local sub-population dynamics of a Central European Grey Partridge
 meta-population support a large-scale conservation approach to halt its
 ongoing decline
 [https://doi.org/10.5061/dryad.m0cfxppbk](https://doi.org/10.5061/dryad.m0cfxppbk) ## Description of the data and file structure Grey Partridge counts (males) with call playback along transects Date of data collection: 2006/02 - 2023/03 Geographic location of data collection: District of Göttingen, Germany ### Files and variables #### File: Rscript\_Laux\_Gottschalk\_2024\_WildlifeBiology.R **Description:** R-script containing the code used for the analysis in the second revision of the manuscript 'Population dynamics of a Central European Grey Partridge population support large-scale conservation approach'. #### File: data\_transects.csv **Description:** Contains data for all transects used in the analysis: number of calling males, year, area, round, transect, transect length, buffer area, observer, coordinates of the centroid, and distance-weighted auto-covariate. ##### Variables * countID - a unique ID for each count of one transect * transect - numerical transect ID * site - a subsection of the study area used to organise counts * year - year of data sampling - round - sampling occasion in the respective year * N_males - number of calling Grey Partridge males counted along the transect * length - length of the transect in [m] * buf_area_clean - area of the 250m buffer around the transects in [ha], settlements, forests, and standing water bodies have been removed * anon_obs - anonymized observer code * population - sub-population by natural borders that the transect belongs to * Xcoor - X-coordinate of the centroid of each transect * Ycoor - Y-coordinate of the centroid of each transect - ac - distance-weighted auto-covariate for each transect, see methods section for more details #### File: data\_gridcells.csv **Description:** Contains data for the eight gird cells used in the analysis: number of calling males, calling males per 100 ha, buffer area, and growth rate in percent. ##### Variables * cell- unique numerical ID for each grid cell - year - year of the count - N_males - number of calling Grey Partridge males counted in each grid cell - N_per_100ha - number of calling Grey Partridge males per 100 ha buffer area in each grid cell - buf_area_clean - area of the 250m buffer around the transects in [ha], settlements, forests, and standing water bodies have been removed - growth_rate_perc - growth rate in percent for each grid cell and year #### File: growth\_gridcells\_wide.csv **Description:** Contains growth rates per grid cell and year in a wide format. ##### Variables * year - year for which the growth rates are given - cell10 until cell29 - growth rates in percent for each grid cell #### File: Nper100ha\_gridcells\_wide.csv **Description:** Contains the number of calling males per 100 ha (density) per grid cell and year in a wide format. ##### Variables * year - year of data sampling * cell10 until cell29 - number of calling males per 100 ha in each grid cell #### File: data\_natborders.csv **Description:** Contains data for the seven sub-populations delineated by natural borders: number of calling males, calling males per 100 ha, buffer area, and growth rate in percent. ##### Variables * population - unique name of each sub-population * year - year of the count * N_males - number of calling Grey Partridge males counted in each sub-population * N_per_100ha - number of calling Grey Partridge males per 100 ha buffer area in each sub-population * buf_area_clean - area of the 250m buffer around the transects in [ha], settlements, forests, and standing water bodies have been removed * growth_rate_perc - growth rate in percent for each sub-population and year #### File: growth\_natborders\_wide.csv **Description:** Contains growth rates per sub-population (by natural borders) and year in a wide format. ##### Variables * year - year for which the growth rates are given * Diemarden until SeulingenWest - growth rates in percent for each sub-population #### File: Nper100ha\_natborders\_wide.csv **Description:** Contains the number of calling males per 100 ha (density) per sub-population (by natural borders) and year in a wide format. ##### Variables * year - year of data sampling * Diemarden until SeulingenWest - number of calling males per 100 ha in each sub-population #### File: grid\_centroids.csv **Description:** Contains the coordinates for the centroids of each of the eight grid cells. ##### Variables * cell - unique numerical ID for each grid cell * Xcoor - X-coordinate of the centroid of each grid cell * Ycoor - Y-coordinate of the centroid of each grid cell #### File: natborders\_centroids.csv **Description:** Contains the coordinates for the centroids of each of the seven subpopulations. ##### Variables * population - unique name of each sub-population * Xcoor - X-coordinate of the centroid of each sub-population * Ycoor - Y-coordinate of the centroid of each sub-population #### Missing data codes: Missing data is shown as NA. ## Code/software The R-script contains the code used for the analysis in 'Population dynamics of a Central European Grey Partridge population support large-scale conservation approach'. The data files are necessary to run the R code. The R-script was developed using version R 4.4.1 and uses the following packages: * glmmTMB 1.1.9 * DHARMa 0.4.6 * performance 0.11.0 * MuMIn 1.47.5 * Hmisc 5.1-2 * boot 1.3-30 * coxed 0.3.3 * codyn 2.0.5 * data.table 1.15.4 * ape 5.8