DOI: 10.5061/dryad.41ns1rnsg
title: Multimodal data helps in identifying spatio-temporal patterns and habitat associations of <em>Aquila chrysaetos</em> (Golden Eagle) in Finland

description: Understanding the spatial distribution of individuals is essential for
 effective species conservation. We investigated the spatio-temporal
 distribution of  Aquila chrysaetos  (golden eagle) in
 Finland using nest surveys, citizen science observations, and
 environmental data from 1982 to 2021. We extended a popular N-mixture
 model to estimate population abundance while accounting for the number of
 recently hatched nestlings, the spatial distribution, and correcting for
 biases in the observation process, all integrated into a two-stage
 Bayesian hierarchical model. Results of our model aligned with the
 previously known north-oriented distribution of A. chrysaetos in Finland,
 supporting its applicability to A. chrysaetos and other species with
 similar ecological requirements and life-history traits. Furthermore, we
 observed the highest densities of successful nests near open landscapes,
 such as marshes and peat bogs, whereas dense forests, port areas, and
 areas of high human population density had a strong negative effect. While
 the temporal trend of nest abundance has remained constant over the years,
 the overall population abundance showed an increasing trend until 2007,
 after which it stabilized. Finally, we detected a higher amount of A.
 chrysaetos movements in southern and southwestern Finland than elsewhere
 in Finland, opening up new possible areas for conservation targets.
description: # Multimodal data helps in identifying spatio-temporal patterns and
 habitat associations of *Aquila chrysaetos* (Golden Eagle) in Finland
 Dataset DOI: [10.5061/dryad.41ns1rnsg](10.5061/dryad.41ns1rnsg) ##
 Description of the data and file structure This repository contains all
 data, code, and results for the two-stage simulation process described in
 our study. Each stage is organized into a separate folder with
 standardized file formats to ensure reproducibility and clarity. ### Files
 and variables All datasets are structured as matrices, where **rows
 represent spatial sites** and **columns represent time steps** (years).
 The dataset consists of Stage_I_II.zip folder. #### Stage I - Nest
 counting model * CountNest.Rdata: Matrix containing the number of nests
 observed in survey data at each site *i* and time *t*. * Data_1.RData:
 Matrix of environmental covariates extracted from the CORINE Land Cover
 map at each site *i*. * FMI_Cov.RData: Average temperature data from the
 Finnish Meteorological Institute for each site *i* and time *t*. *
 Stage_I_Code.R: R script to: * Apply the alr (additive log-ratio)
 transformation to environmental covariates * Structure the data * Run MCMC
 sampling using the **NIMBLE** package * Stage_I_MCMC_results.Rdata: An R
 list object containing: * My samples: posterior samples from the MCMC *
 Code 2: the NIMBLE model specification #### Stage II - Population level
 modelling * Cov_Data.Rdata: Contains the Hex. G object, used for
 constructing maps and hexagonal grid structures for Finland.  *
 FMI_Cov.RData: Average temperature during the breeding season at each site
 *i* and time *t* (reused from Stage I). *
 Obs.Data_YearCount_1980-2022.RData: Aggregated citizen science bird
 observations per site *i* and time *t*, spanning 1980–2022. *
 Pop_Data.RData. Aggregated human population data from Statistics Finland
 and the location of observation towers, for each site *i*. *
 Prob_Nest_ArlQ.Rdata: Posterior distribution of nest counts derived from
 Stage I modeling. * Stage_II_Code.R: R script to: * Structure the data *
 Build the adjacency matrix for the CAR model * Run MCMC sampling using the
 **NIMBLE** package * Stage_II_MCMC_results.Rdata: An R list object
 containing: * My samples: posterior samples from the MCMC * Code 3: the
 NIMBLE model specification ## Code/software To run the code, you will
 need: \- R (version ≥ 4.0.0) \- The following R package (install as
 needed):  nimble ## Access information Other publicly accessible locations
 of the data: * National Land Survey of Finland * Statistics Finland *
 Finnish Meteorological Institute Data was derived from the following
 sources: * The Finnish Biodiversity Information Facility (FinBIF)