DOI: 10.5061/dryad.9w0vt4bnh
title: Black-legged kittiwake abundance and breeding productivity, OSPAR region II

description: This data set contains information on breeding abundance and breeding
 productivity of black-legged kittiwake (Rissa tridactyla) in OSPAR Region
 II (Greater North Sea). These data have been used to construct a
 demographic indicator of breeding productivity as part of OSPAR Quality
 Status Report 2023, and for reporting under the European Union's
 Marine Strategy Framework Directive.
description: Data on seabird breeding abundance and breeding productivity were
 collected by many (mostly volunteer) observers in countries around the
 Greater North Sea (OSPAR Region II). Data collection was organised by
 national agencies resposible for biodiversity monitoring, and reported to
 the data centre at the International Council for the Exploration of the Seas (ICES, https://www.ices.dk/data/data-portals/Pages/Biodiversity.aspx). Breeding productivity data represent raw observational data, i.e. numbers of nests and numbers of fledged chicks observed for each monitoring plot. Breeding abundance data have been processed into an indicator of relative abundance, as described in: Dierschke, V., Marra, S., Parsons, M., French, G. & Fusi, M. 2023. Marine bird abundance. In <em>The 2023 Quality Status Report for the Northeast Atlantic. </em>(ed. OSPAR). London: OSPAR Commission. Available at: https://oap.ospar.org/en/ospar-assessments/quality-status-reports/qsr-2023/indicator-assessments/marine-bird-abundance/. For this purpose, data on black-legged kittiwakes were extracted.
description: # Black-legged kittiwake abundance and breeding productivity, OSPAR region
 II
 [https://doi.org/10.5061/dryad.9w0vt4bnh](https://doi.org/10.5061/dryad.9w0vt4bnh) This dataset contains the following: * A spreadsheet containing the raw breeding productivity data (Kittiwake breeding productivity region II.xlsx) This spreadsheet includes these columns: \- Country: two\-letter code \- Year: year of study \- Species\_name: scientific name of study species \- Plot\_size: number of nests in study plot\. \-1 indicates no data collection \- Chicks\_fledged: number of chicks fledged in study plot\. NA indicates no data collection \- Chicks\_hatched: number of chicks hatched in study plot\. NA indicates no data collection \- Lat: latitude\, decimal degrees \- Long: longitude\, decimal degrees \- ColonyName: name of study colony \- Region: OSPAR Region \(coded I\-V\) \- SubDivision: subdivision of OSPAR Region\, specifically for birds \(coded 2a\-2f\) * A spreadsheet containing the abundance data, processed as an indicator of relative abundance (Kittiwake abundance region II.xlsx) This spreadsheet includes these columns: \- years: year of study \- BLKI: indicator of relative abundance of breeding black\-legged kittiwake in OSPAR Region II \(arbitrary unit\) * An R script containing all calculations necessary to construct a model-based demographic indicator of breeding productivity (Kittiwake indicator example script.R) ## Description of the data and file structure The R script included uses the data in the two spreadsheets to construct a demographic indicator of breeding productivity for black-legged kittiwakes in the Greater North Sea (OSPAR Region II). ## Sharing/Access information The script and results for all species and regions can also be found here: https://odims.ospar.org/en/submissions/ospar\_marine\_birds\_bree\_results\_2022\_06\_001/ ## Code/Software The R script was constructed in R version 4.2.0 and uses the following packages: readxl version 1.4.0 emmeans version 1.8.0 popbio version 2.7 visreg version 2.7.0