DOI: 10.5061/dryad.d7wm37q19
title: Data and R-scripts from: Multiple stressors: negative effects of nest predation on the viability of a threatened gull in different environmental conditions

description: Here, we provide the data and R-scripts used in: Bård-Jørgen Bårdsen and
 Jan Ove Bustnes (2022). Multiple stressors: negative effects of nest
 predation on the viability of a threatened gull in different environmental
 conditions. Journal of Avian Biology.
 https://doi.org/10.1111/jav.02953. Bård-Jørgen Bårdsen and Jan Ove Bustnes
 (2023). Correction to Multiple stressors: negative effects of nest
 predation on the viability of a threatened gull in different environmental
 conditions. Journal of Avian Biology. https://doi.org/10.1111/jav.12915.
 This study assessed the viability of a population of the lesser
 black-backed gull (Larus fuscus fuscus) using data collected from
 2005-2020 from a nature reserve in Northern Norway. The study merged
 results from statistical analyses of empirical data with a Leslie model.
 Here, we provide the underlying data and the R-scripts used to analyse the
 data and run the model. The data set includes information about
 reproduction at several stages (laying, hatching and fledgling), nest
 predation, and individual capture histories (used to estimate apparent
 survival; see Bårdsen and Bustnes 2022). We discovered a misspecification
 error in the matrix model in Bårdsen and Bustnes (2022). This error did
 not change the overall conclusions or the results in the original
 article's empirical analyses. Here, we present an updated version of
 our scripts, i.e., scripts used by Bårdsen and Bustnes (2023). In the
 correction, we also highlight which part of the original article was
 affected by this mistake.
description: Bårdsen and Bustnes (2022),
 including the online Supplementary Material (Appendix
 S1-2), provide a detailed description of the study area and the
 empirical data. In the downloadable software
 ('ToBePublished.zip'), we provide data, metadata, and R-scripts
 for the statistical analyses and the models. Please confer with the
 'README.txt' in 'ToBePublished.zip' for more
 information. We also include the data (without the scripts) from our study
 area as a downloadable dataset ('Data.zip'; see the included
 'README.txt' for details).   
description: <strong>Data</strong> Our study
 area, located within the Horsvær
 Nature Reserve in Northern Norway (65°19′N 11°38′E), is one of
 several key sites within the Norwegian seabird monitoring program (SEAPOP). We view the
 uploaded data as a means to verify the results presented in our article
 (Bårdsen and
 Bustnes 2022). The data available here terminated in 2019
 (reproduction and nest predation) and 2020 (apparent survival). All the
 data is available in 'ToBePublished.zip' (downloadable
 software). Still, we upload the data from our study area as a separate
 file ('Data.zip') for those interested in the data without the
 scripts. You may contact <strong>Jan Ove Bustnes</strong>
 (jan.bustnes@nina.no), responsible for the Horsvær key site if you have any inquiries regarding the data from our study area. If you choose to use the uploaded data, we would appreciate the following: Please acknowledge the persons who contributed to the data collection: Harald Bustnes, Sigfred Jørgensen and Runar Omnø for logistical support; Trond Vidar Johnsen, Morten Helberg, Klaus Maløya Torland, Nils Helge Lorentzen, Kjetil Olsen, Geir Arne Bustnes and Jorg Welcker for field assistance. Please cite Bårdsen and Bustnes (2022 & 2023) as the data source. Please confer with 'README.txt' in the .zip-files for details (metadata). Moreover, we present further information in the article and its online Supplementary Material (Appendix S1-2).  The literature review depends on data collected by others. No one should use these data without referring to the original studies: please confer with the online Supplementary Material (Appendix S5) for details about this data and its primary sources.  <strong>R-scripts</strong> The downloadable software ('ToBePublished.zip') contains the results of the analyses as they emerged in our runs. However, the results may depend on the software version (including the R-packages). Therefore, we have included an overview of the software versions used in 'README.txt' (in 'ToBePublished.zip'). Each R-script saves results in a separate folder (given a name similar to the R-script). This includes session info, such as the version of R and the packages, stored as a text file ('SessionInfo.txt'). The output of the models, which we based on simulations, will differ from run to run (e.g., the assessment of quasi-extinction). Even though the results should not qualitatively differ from ours, the exact numbers may diverge from what we have presented in the published article. Please contact <strong>Bård-Jørgen Bårdsen</strong> (bjb@nina.no) for questions or if you experience any trouble running the scripts. 
description: # Data and R-scripts from: Multiple stressors: negative effects of nest
 predation on the viability of a threatened gull in different environmental
 conditions
 [https://doi.org/10.5061/dryad.d7wm37q19](https://doi.org/10.5061/dryad.d7wm37q19) We provide a 'README.txt' in the zipped files explaining the R-scripts and the data. In addition, all the provided Excel files have a sheet with Metadata explaining the variables.  **Nov 2024:** Here, we present an updated version of the scripts used in Bårdsen and Bustnes ([2022](https://doi.org/10.1111/jav.02953)). Our updated scripts did not affect the statistical analyses of the empirical data; see Bårdsen and Bustnes ([2023](https://doi.org/10.1111/jav.12915)) for a detailed description of how the revised version diverges from the original article.